Why it's NOT smart to block your _PCV_ (edited) gas path

[Hank Roberts]

Edited 8/12, noting we've all been chasing a red herring for a while; the original info should have been that a blocked _PCV_ in these engines leads to ring problems.

 

See around the third page of the thread for that correction. So, everything before the post from CCRINC is based on the wrong info I got from a phone call. They meant PCV, not EGR, blockage leads to oil ring failure in their experience.

 

--> Now I'm gonna beg CCR to write down for me, and proofread, all the directions that they told my mechanic over the telephone, so I can try to make sure he really understands their directions, and checks off each step by step as he follows them, when he puts the rebuilt parts in. <------

 

Edited 8/7, adding the bracketed words in the title. I found that pinions about this question are strongly held, as you'll see reading on here. It quite surprised me.

 

-------- original post below-----

 

Back in March, I bought my old friend's Subaru GL wagon.

His shade-tree mechanic had told him for a year or more not to worry about the Check Engine light being on, that he couldn't figure out the problem but it passed the California smog check (with the light briefly off, just after resetting the computer) so no worries.

 

I bought it.

 

I found that the mechanic had crimped the tubing leading exhaust gases to the EGR so it was flat -- no gas moving at all. Replacing the tubing didn't fix the code. Replacing the EGR valve didn't fix the code. Replacing the EGR valve _solenoid_ didn't fix the code.

 

Taking the engine apart enough to clean packed hard carbon out of the ports leading from the exhaust side to the EGR valve, and from the EGR valve to the combustion side, fixed the code.

 

The EGR exists to reduce the total amount of oxygen in the INTAKE air while the engine is up to running temperature. It leads some combused gases back from the exhaust to the intake. Without it, the engine runs with the wrong fuel/air ratio once it's warmed up.

 

There's more, though.

 

Without the EGR system working, I learned today from a competent professional engine rebuilder who's seen this in several Subaru engines -- there's too much pressure on the exhaust side, as well as the wrong combustion mix.

 

That, over a few years, not only plugs up the ports with carbon, it eventually sticks the oil rings in their grooves and the engine starts consuming more oil.

 

A mechanic who doesn't know this -- most don't, including the three I know of who've worked on this car -- won't think the EGR is a problem when it's disabled.

 

And the third mechanic, sure the oil loss had to be a gasket somewhere since the engine looked so good, replaced the head gaskets (confirming that yes, indeed, the cylinders are smooth, the engine looks very low miles).

 

Replacing the head gaskets involves planing the heads down to make sure they are perfectly flat, before reassembly.

 

Planing the heads reduces the volume of the combustion chamber.

 

Lower volume --> higher compression, just slightly.

 

Higher compression --> the oil starts blowing out past the already bad rings, fatally.

 

My engine was using half a quart in 300 miles (of 20W-50) before I gave up and went to the rebuilder.

 

There, after answering a few questions about how this might have happened, I learned the above.

 

Old vehicles invent new failure modes. This took several years of having the EGR system disabled, before the engine was on the edge of failure -- then having the compression increased, which made the failure happen all of a sudden.

 

Be warned. Don't plug up that EGR system. Check for carbon blocking the ports if your solenoid and valve and tubing look clean or have been replaced.

 

Know it can happen, and has happened to a number of other people besides me who've had their damaged engines looked at by a rebuilder who recognized the pattern.

[stephenw22]

I've been looking over my subarus lately, and doing a lot of thinking about the egr system, and there's one part that I don't understand.

 

The egr valve is on the passenger side of the intake. Does the exhaust gas go into the passenger side of the intake, or is there a passage that somehow distibutes it evenly between the cylinders?

 

I was thinking the other day that unless you're able to take the exhaust gas and evenly split it between cylinders, an egr system would actually cause large imbalances in cylinder temperatures. If it went into the passenger side cylinders, they'd always be richer and the drivers' side cylinders would be leaner.

 

Maybe it's more of a problem in warmer climates, but having a bad egr system doesn't seem to affect engines up here. Over 5 years, I put 100k miles on my turbo wagon with a malfunctioning egr system. The only thing that could kill that car was mice that chewed through a ton of my wiring.

 

I'm definitely NOT an expert, but that's my experience up here with my cars.

[Tin Soldier]

I have a bad EGR code on my loyale. I have a new valve and tried a new solenoid. Sometimes when it's raining the light goes out. How much did you have to tear down to clean it out? I should probably do this to mine. I notice and difference in the winter.

[Hank Roberts]

> how much ... tear down ...?

Mechanics did it (one did half the job, the other did the whole job); I have bad carpal tunnel, failed surgery, and cannot hold onto tools, so maybe someone else can answer how much work it is, and what the exact configuration is. My car is SPFI, no idea about others.

[85Sub4WD]

FINALLY, I am not alone in my desire to have a good EGR system!!

 

I have never had my EGR system get dirty enough one the cylinder block side to need cleaning, but to get the EGR tube off properly involves removing the intake manifold, after that you should be able to ram a copper wire down the hole in the head to break carbon loose on the walls (be weary of the valve below), and the passageways to the EGR valve itself are VERY easy to clean with the manifold off.

I would leave the throttle body on myself (one less gasket to replace).

 

make sure you purge your coolant system well

[Adam N.D.J.]

Actually EGR doesn't have anything to do with fuel/air mix. That is why they only open during cruise over a certain RPM when engine loads are at their most and steadiest, your carb still pulls in the same amount of air and fuel (or fuel injection maintains 14.7 stoich). The only purpose of the EGR (Exhaust gas recirculator) is to lower the combustion temperatures, and there for lower the NOx. Oxides of nitrogen, cause smog, low altitude ozone layers (bad for humans to breath), and nitric acid (acid rain). As far as the EGR "bleeding" off exhaust pressure, this is also a myth, the maount of EGR flow that is directed into the intake is minimal to the amount that flowing through a stock exhaust. Every race and high performance car that I have built has had the EGR system either disabled, removed, or not even installed.

In cap, the EGR is an emissions device, disabling it will have the same effects as removing the ASV valve. As far as the curing of the code, I've had some things, as simple as changing a spark plug wire, to as hard as basically rewireing half the car cure codes before. And mechanics, they can soak you for a lot, I know, many a day I run into people that if I was that way, could soak the heck out of em for almost anything. (Why yet sir, your 99 ford has a bad set of points in it. But your in luck, we happen to have a set in stock, and can sell em to ya for a mere $95.99)

[Hank Roberts]

Say more, please. I don't quite follow how you figure the amount of oxygen.

 

Looking it up, quickly, what I find seems to agree with what the engine rebuilders told me (note, these are not the mechanics who didn't have a clue about the problem; these folks rebuild Subaru engines, and have described what they see coming back).

 

Certainly a race engine runs hotter -- and wears faster. The problem they described to me is people blocking their EGR system and making their Subarus in normal driving run hotter and damage the oil rings.

 

How many miles do you get out of your high performance racing engine? Anywhere near 100,000 miles before the rings need to be replaced?

=========

 

Here's a few searches that agree with what you say about engine heating, but seem to add up the oxygen and fuel and non-combustible gas amounts like the engine rebuilders explained it to me. Do you have a different reading of this than I do?

-------

 

Some searches:

 

... part of the fuel / air mix is replaced by exhaust gases, less fuel is needed. Because the exhaust [is] mostly non-combustible gas, such as CO2, the engine runs properly at the leaner fuel / air mixture without failing to combust.

-- ttp://www.autozine.org/technical_school/engine/vvt_4.htm

 

... shooting exhaust into the mix ... enables a leaner mix without the (otherwise) corresponding high heat, making for better mileage and lower emissions with no downside.... EGR can drop the internal cylinder temp by over 2000 degrees.

-- http://www.type2.com/library/exhaust/emissio.htm

 

A pretty technical discussion only available from Google's cache, this is a long one, cite to the Google cache follows it, picking this up in mid-debate (lively one, worth reading in full):

 

From: jgd (John De Armond)

X-Source: The Hotrod Mailing list

Date: Mar 1993....

>: >Reference: Heywood, "Internal Combustion Engine Fundamentals", p. 837-8,

>: >including graph showing approximately 10% improvement in fuel economy

>: >for 20% EGR (for a certain engine and speed/load point).

>: ^^^^^^^^^^^^^^^^

>Bob Valentine wrote:

>: Exactly. At some point, there will be a gain. But at what

>: percentage of the time does the engine run at that point...

 

It should be pointed out that the chart in question shows large gains

for fast burn chamber designs. On the same chart is a line for slow

burn chambers that shows much less improvements and then only at

low (5-10%) EGR injection. This graph shows why EGR has such a bad

rap. Older designs were CRAP. The EGR valve slammed open at part

throttle and dumped a large but fixed amount of EG in. One could

typically FEEL the EGR kick in on a 70s and early 80s car. There is

now a large education task at hand to reverse the perceptions of the

last couple of decades. ...

 

--http://66.102.7.104/search?q=cache:wKvyd0e3jSwJ:yarchive.net/car/air_induction.html+EGR+fuel+air+mix

 

(LOTS more there; heavy hitters from a decade ago in the newsgroups, I recognize their names from other technical arguments, in the age of dragons when flaming was a high art (grin).

 

Note the above are NOT specific to Subarus -- just an attempt to find published explanations of how EGR works and what might happen when it's not working.

 

--------

Posted in the spirit I learned long ago

-- "The best way to get good information on the Internet is

to post what you know, and await correction."

 

More welcome; references especially welcome, I love looking up the footnotes.

[Hank Roberts]

Adam, I found more that helps me understand what you posted, I think.

 

Subaru describes the system as using a stoichiometric air-fuel mix at all times, as you say. When the car's not going full-throttle, the system delivers less fuel to the engine, so also delivers less "air" -- to fill up the cylinder, the difference is filled up with already-burned exhaust gases. I see mention of anywhere from 10% to 25% of the cylinder volume is from the EGR, on various kinds of engines.

 

Subaru:

 

"... the EGR (exhaust gas recirculation) valve. This function involves mixing exhaust gas and reducing the volume of air, with the aim of enhancing fuel efficiency and thereby restricting the volume of gasoline when cruising at a constant speed.

 

"Ideally the air-gasoline mixture that is delivered to the cylinder will maintain a stoichiometric air fuel ratio and be constant. For this reason, when fuel is restricted the volume of air must also be reduced.

 

"Since the cylinder has a 500 cc capacity, on occasions when it is unnecessary to have large output such as during cruising, a balance between cylinder capacity and necessary volume of air is achieved by mixing exhaust gas with air."

-- http://www.subaru.com.hk/pdf/SNS0201.pdf -© FUJI HEAVY INDUSTRIES Ltd., 2002

 

I also found a lot more discussion of carbon blocking up engine passages -- more of a problem in newer vehicles with a separate EGR port to each cylinder:

 

-----

"EGR systems are ancient yet remain largely misunderstood. Matters have been made even worse by a radical evolution in EGR systems. ...

 

"... Lack of maintenance causes one or more of the individual cylinder tubes to become clogged with carbon and soot from the recirculated exhaust gas. As tubes become clogged two things happen. The cylinders with clogged tubes get no EGR and cylinders with non-clogged tubes get too much EGR.

 

" ... equipment and chemicals to keep EGR passages clean. EGR cleaning, using equipment, should be performed at intervals of not more than thirty thousand miles. Without periodic cleaning, concrete-like carbon deposits close-off EGR passages. If this is allowed to happen the cost to remove the carbon can exceed your “investment-in-prevention” by a factor of ten."

 

http://www.garage-pak.com/pat-goss-washington-post/2003-wp-investment-in-prevention.cfm

 

And there's lots of discussion about how unburned carbon builds up in the engine;

unburned carbon can be hot enough to ignite fuel in the absence of a spark, causing "dieseling" where the engine keeps running with the ignition off -- I know that one, from old cars with purely mechanical fuel pumps!

 

The diesel engine discussions, in particular, have a lot of info about how unburned carbon will damage the oil and the oil rings.

 

So -- I may not understand this yet, it's complicated. But I see why the engine rebuilder says they see disabled EGR causing carbon buildup, and eventual engine damage.

 

I found a _lot_ of info about unburned carbon particles causing oil and oil ring damage; it seems to be routine for diesel engines, and the mechanism seems the same when a gasoline engine builds up a lot of carbon particles.

 

 

Adam, when you build a high performance racing engine with no EGR or a disabled EGR -- do you also have a different fuel system than the ordinary Subaru driver would?

 

I see quite a bit about programming custom engine computers saying that on a stock engine design, the EGR is assumed to be functioning and the problems described happen if it's not.

 

Here's one from a Jeep builder of custom electronic fuel injection:

 

" ... One more comment about spark timing. When EGR is engaged, the combustion process is slowed down. So factory spark timing curves are advanced 3-6 degrees at part throttle operation (beyond what they could normally be without EGR) to regain some efficiency due to the slower combustion. Also, on non-computer controlled vehicles with carburetors, the carbs are jetted lean (10% less fuel) at part throttle since the system was designed for the EGR valve to be operational during all part throttle operation.

 

"If the EGR valve fails to open, the mixture will be lean since you will now have more air in the combustion chamber. Now, combine this lean mixture with timing that is advanced too far for a non-EGR situation, and you have a combination that will produce engine damaging detonation. Drive the vehicle like this with detonation for very long and you can kiss the engine goodbye.

 

"This scenario affects programming an EFI system in the following ways. When I program a spark table for an engine, I start by looking at the factory curves for the centrifugal and vacuum advance. But I have to keep in mind that these curves are setup for EGR operation at part throttle. So I have to take out 3-6 degrees of timing at all part throttle load conditions. ..."

-- http://www.customefis.com/emissions.html

 

So I'm curious, for the high performance and racing engines without EGRs

 

-- how many miles does one of your engines go between rebuilds?

 

-- Do they run much at moderate highway speeds (where the EGR would operate) vs. at top speed (where EGR doesn't operate anyhow - and I assume the design of the carbeurator or fuel injection and engine computer already take that into account)?

 

From all that stuff I've poked through, it now makes good sense to me -- an engine being run at top speed doesn't use its EGR system anyhow, the EGR shuts off at full throttle, and the fuel/air system assumes that to be the case. So for racing, there's no issue blocking or disabling an EGR, because you're running mostly full throttle all the time. Is that right?

[Humble Nuto 53]

surging? hmmmmm

http://www.autoshop101.com/forms/h61.pdf

 

too much EGR, interesting.

i havent had the classic sube-surge issues on any subes ive owned.

but

i have noticed an increase in detonation since i removed all that plumbing

on the carbed ea82.

[NorthWet]

I wanted to post yesterday after first seeing this thread, but had to work instead of play...

 

Adam is mostly right, and thank you for shining some light on this. The EGR is not there to effect air/fuel ratios or do anything to oxygen or to exhaust backpressure (another totally misunderstood engine concept). The EGR allows combustion products to dilute the intake charge, causing a reduction in the intensity of the combustion process with the intent of reducing PEAK combustion temperatures and pressures. To understand this, think about running 100% oxygen and how strong the combustion process would be, and then think if we only had a tenth as much oxygen as is normally present how weak the combustion would be.

 

Oxides of nitrogen require an extreme amount of energy to form, as do any compounds of nitrogen (think nitroglycerin, nitromethane, ammonium nitrate, etc). This energy level occurs in an engine only during peak combustion temperatures (and pressures), and lowering that peak temp causes fewer NOx molecules to be created. To a certain extent, NOx production is the sign of thermally efficient combustion.

 

EGRs generally are only used at partial throttle, as they muck up drivability at idle, and reduce peak power at full throttle. Recirculation amounts are around 10% of intake charge.

 

So, the electronic engine management uses feedback to keep A/F ratios at a certain level (actually richer than stoichiometric, to provide feedstock for the catalytic converters), and the EGR is not involved. And the ECU has no way of telling if the EGR system is functioning or not: AFAIK, the only ECU input from to the EGR system is whether or not there is a specified resistance value where it thinks the electrical control is for the vacuum control that moves the metering valve. In other words it is 2 steps removed from the EGR flow with no way of monitoring it and can be spoofed by inserting a 20 cent resistor in place of the solenoid.

 

And, by the way, the ECU is pretty primitive in the 80's vehicles, with little processing power to do much beyond keeping up with A/F feedback, and injection and ignition duties in the later models. The CPU chip in the Turbo/MPFI ECUs are basically the same as in an Apple II...

 

So, EGR is a pollution control, good for the environment, not really a concern for the driver/owner as long as it is functioning correctly, and not much of a mystery. And, BTW, several of the Subaru EA82s variants do not even use EGR; they rely on a properly functioning reduction catalyst, I guess.

 

Also, all that talk about compression and rings and oil seemed just way off. Increased compression could cause additional gasses to get past the compression rings and be "blowby", but it won't suck more oil past the oil control rings. And given the heckish conditions of pressure at peak combustion, a little extra static compression is meaningless.

 

And don't even get me started on this whole "exhaust backpressure" thing...

[calebz]

Hank.

 

 

I have to wonder how it can be such a terrible thing to have no EGR when Subaru built a number of their EA82s without them. I currently own 2 EA82s with no EGR ports on the heads.

[Hank Roberts]

Why would you expect a problem, when an engine's not designed for an EGR and doesn't have one?

 

Your engines built without an EGR are in vehicles that don't have an ECU or fuel system that's set up to change the amount of fuel, assuming the presence of an EGR, right?

 

So,, because nothing's being adjusted to reduce the amount of fuel used while the engine is cruising, your combustion mix won't be going too lean at any point. No problem.

 

Or if you're using them in race cars, no problem -- the fuel system isn't reducing the amount of fuel delivered when run at top speed, so the EGR is assumed shut off anyhow and won't be missed while in that condition.

[NorthWet]

...

Your engines built without an EGR are in vehicles that don't have an ECU or fuel system that's set up to change the amount of fuel, assuming the presence of an EGR, right?...

Different years of the same application either have EGR or don't. The examples that I have seen (and I expect is Calebz's case) are the most electronically controlled examples, the Turbo MPFIs.

 

EGR does not require electronic electronic managment, no more than a carburetor does. EGR just "is". Without electronic management, they jsut setup the carburetor to compensate.

 

EGR exist for one purpose and one purpose only: To reduce peak combustion temperatures that promote formation of oxides of nitrogen.

[Hank Roberts]

..Isn't that the same as the descriptions I've been finding? It seems like everyone's saying the same thing, or parts of the same story -- but seems kind of like those wise men and the elephant, each person's chunk is part of the description.

 

Summing what everyone's saying and everything I've read, seems to come to this:

 

Design without an EGR -- the cylinders always fill (say 500 cc) with a fuel-air mix.

The fuel-air mix is always the same ratio of fuel to oxygen, stoichiometric; at cruise this burns a little more gas than needed to keep rolling along, but it has to fill the cylinders with that same mixture, so there's no alternative -- only way to avoid going too lean and too hot.

 

Design with an EGR -- the cylinders always fill with the same volume, say 500 cc, but in cruising, it uses say 450 cc of the standard fuel-air mix, and 50cc of exhaust gas. The fuel-air mix is still the same ratio of ffuel to oxygen. So it's not too lean or too hot.

 

Design for an EGR but don't provide it -- the cylinders always fill with 500 cc of fuel-air mix; in cruise, the carb or fuel injection is (either by vacuum or electronic control) sending a little less fuel, and there's no makeup, no EGR gas, the difference is made up with extra intake air -- so there's too much oxygen, too lean a mix, and too hot combustion.

 

Design for an EGR and it's malfunctioning or plugged -- same problem, too lean and too hot in cruise.

 

Design like the Jeep guy with modified engine controls -- the cylinders always fill, say with 500 cc of fuel/air mixture, no EGR gas used, but he changes the timing to avoid burning too hot, and maybe changes the amount of fuel at cruise without running lean and hot by timing differently.

 

It seems everyone's saying the same thing about how EGR _works_. It lets the engine run with less fuel at cruise without also running too lean and too hot, and it shuts off when the throttle's open and using all the fuel it can handle on each combustion cycle.

 

Right? Racers run fast, they don't cruise, so EGR wouldn't matter anyhow, and they rebuild more often than daily drivers want to.

 

Maybe there's uncertainty about how it _doesn't_ work when it's meant to and fails?

 

How about consequences?

 

Is there an argument about whether running too lean and too hot at cruise (for ordinary drivers) _does_ increase the amount of unburned fuel particles, and/or that carbon does pack up the ports, and can damage the oil rings eventually?

 

Obviously I've got too much time on my hands, while I'm waiting for the transmission and engine to come in. They go on the truck Monday. Once they're in, I'll be OUT.

[WJM]

Total BS.

 

EGRS (S for system) is ONLY there to recycle exhaust gases for reburning so that tail pipe emissions are 'better.'

 

Any given EA82 is designed the same and its was a hit or miss if an EA82 car came wth an EGRS or not.

 

My shop instructor at school said it was a "performance enhancing device"....total BS. I found out the hard and smart way (both at the same time, go figure!) way that reburning exhaust gases is BAD.

 

why would you want yout intake charge to got from sub 120* F to over 1000*F?????????????????????????????????????? Thats stupid.

 

ERGS only exist to lower certin tail pipe emissions and lower performance.

[NorthWet]

The EGR gasses enter the intake of a carb'd engine after the mixture is set. It is merely a dilution of the mixture that the carb provides. The EGR in an EFI is after the system decides what amount of fuel to inject. Again, it is merely a dilution of the charge. Removing EGR gasses does not significantly affect the A/F ratio, just how far apart the reactant molecules are away from each other, and how much energy-absorbing "inert" material exists inbetween.

 

A mixture that is lean (excess oxygen) does not burn hotter. In fact, it will burn cooler than a slightly richer than stoich mixture. We perceive it as "hotter" because it burns slower, so it does not reach peak pressures at an efficient time to produce power, so we have to increase the throttle opening to compensate, and the mixture is more likely to still be burning during the exhaust stroke, again sapping power and rejecting more energy as heat to the water jacket and into the exhaust sytem.

 

No significant amount of carbon particulates should be reaching the oil control rings, and they are constantly being washed with filtered oil. Gummed up oil control rings would be caused by degraded oil and/or very worn compression rings allowing hot gases to cook the oil in the oil control rings.

[NorthWet]

Total BS.

 

EGRS (S for system) is ONLY there to recycle exhaust gases for reburning so that tail pipe emissions are 'better.'...

... why would you want yout intake charge to got from sub 120* F to over 1000*F?????????????????????????????????????? Thats stupid...

Will, the amount of exhaust gas that passes throught the EGR is insignificant from the point of view of "reburning". And with an oxidation catalyst there is absolutely no point in doing any "reburning".

 

The EGR gasses are nowheres near 1000degF when they are brought into the intake manifold. That would mean that the EGR tube should be glowing cherry red or better, would risk melting both the tube and the intake fittings, and would cause ignition of the intake charge in a carb or SPFI system. It would also mean that the EGR passages wouldn't coke up.

 

NOx emissions are very hard to control, and the EGR was the original go-to technology to handle this. With the advent, and advancement, of reduction catalyst technology, EGR is not necessarily needed. As tougher emissions standards get implemented, that old go-to of EGR might bridge the technology gap. So you might see some that have EGR and some that don't.

[WJM]

either way EGRS are junk and I will not have a car that has one that functions.

[Hank Roberts]

I started this to research what the Subaru engine rebuilder told me on the phone from their own experience.

 

Google does turn up some people saying an EGR can be disconnected or left plugged up-- those links almost always lead back to threads posted at usmb.net!

 

The rest of the links I found searching Google pretty consistently support what the Subaru engine rebuilder said happens, for a lot of different kinds of engines and model years.

 

I'll keep looking; what I've found so far, I've posted so you all can look at the original sources.

 

I'm not arguing with your opinions (as long as you're not my mechanic!) -- I'm looking for references and discussion about how engines work, and facts about how they wear out over time from people who get their hands dirty and see a lot of them over the years, to form an opinion. And my opinion, if I ever get that far, is going to change as I find facts to inform it.

[Qman]

The EGR does not control, make or cause carbon!

 

The carbon problem is the result of oil burning. Bad rings and valve seals and the lack of oil changes cause your carbon problem. A poorly tuned engine will also contribute to this same problem. I run my engines without EGR's any time I can. Both of my EA series engines are built with larger cams, bigger carbs and altered exhausts. They are used for daily, race, and fun-time.

 

That will dismiss the thought of race applications only not causing issues. I drive my vehicles fast, slow and everywhere in between. Off-road, off-camber and over the top have caused zero issues. I have 10K on my little Brat, about 5K on my big Brat. I have about 5k on my XT6 as well.

 

BTW, let's add some more controversy to this. None of them have catalytic converters either. Just because a guy in a shop claims to be a mechanic does not make him one. I claim to have mechanical experience. I don't claim to be a mechanic. I have worked for dealerships and in retail and private shops including my own. Check around, I seem to build some pretty good rigs.

[WJM]

No you dont! All your 'rigs' are crap Qman!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

:-p

[Meeky Moose]

well, all i can say (not getting too technical) is that my personal experience with them has always been, rip them off, fab a plate, and block it off.

 

and every time i do it, the car magically runs stronger and smoother.

ohh and my temp gauge always ride at the same place it did beforehand 1/4 on the guage.

i've never had an issue with excessive carbon or oil burning.. got about 15k on this engine with the egr blocked, no issues yet..

[ccrinc]

OK, OK, OK!!!!!

 

Geez, what a brouhaha!

 

I admit...I am the one who told Hank that a blocked EGR might be part of reason that he's using a really big chunk of oil.

 

I meant...PCV. Sorry, I was caught during a really busy Friday at the end of a long, hectic week.

 

PCV, EGR, ASV, LSD (which can have more than one meaning), VVT, DOHC SOHC. Doesn't anybody spell anything out anymore?

 

EGR may be "older" school technology, but it does work to reduce emissions. A bad PCV can cause oil rings to seize in the pistons. If you have a SPFI engine, the retrofit kit from the dealer is a good idea.

 

Or, the engine's just worn out...period.

 

Sorry, gentlemen. As Rick (aka Yoda) would say, "I'm talking out my ______".

Chalk it up to a long week.

 

Emily

http://www.ccrengines.com

[edrach]

Emily, you of all people don't have to apologize to anyone. However, you certainly kept a small group of us from getting bored this weekend! I hope all is well with you and yours. ---ed---

OK, OK, OK!!!!!

 

Geez, what a brouhaha!

 

I admit...I am the one who told Hank that a blocked EGR might be part of reason that he's using a really big chunk of oil.

 

I meant...PCV. Sorry, I was caught during a really busy Friday at the end of a long, hectic week.

 

PCV, EGR, ASV, LSD (which can have more than one meaning), VVT, DOHC SOHC. Doesn't anybody spell anything out anymore?

 

EGR may be "older" school technology, but it does work to reduce emissions. A bad PCV can cause oil rings to seize in the pistons. If you have a SPFI engine, the retrofit kit from the dealer is a good idea.

 

Or, the engine's just worn out...period.

 

Sorry, gentlemen. As Rick (aka Yoda) would say, "I'm talking out my ______".

Chalk it up to a long week.

 

Emily

http://www.ccrengines.com

[edrach]

OK, OK, OK!!!!!

 

http://www.ccrengines.com

 

Emily, to keep another long debate going, is there any way to tell the interference status of the EJ22 engine from the outside (serial number, visible mechanical differences, etc.)? This debate has been going on longer than the EGR debate this weekend. See http://www.ultimatesubaru.org/forum/showthread.php?t=40824. If probably wouldn't hurt to start a new thread on that topic since I shouldn't be hi-jacking this thread.