Decarbonizing with water

[frag]

I want to do just that to see if it could get rid of a light but anoying roughness at idle that nothing else seems to be able to cure.

1) I'm not afraid of water lock cause I know how to meter the water in the throttle body a little at a time thru a small vac hose, just like I did when I used Sea Foam.

2) What I'm afraid of is killing the cat. Anyone know about this. How will the cat react to steam going thru it ?

3) Last question: how much water should I use for it to have a real cleaning effect ?

Thanks in advance.

[mtsmiths]

I want to do just that to see if it could get rid of a light but anoying roughness at idle that nothing else seems to be able to cure.

1) I'm not afraid of water lock cause I know how to meter the water in the throttle body a little at a time thru a small vac hose, just like I did when I used Sea Foam.

2) What I'm afraid of is killing the cat. Anyone know about this. How will the cat react to steam going thru it ?

3) Last question: how much water should I use for it to have a real cleaning effect ?

Thanks in advance.

 

Jeeze frag, the last car I did this to was a flathead Ford, so who knows? OTOH, if a little steam could kill a cat every HG whine on this board would have been followed by a thousand dollar catalytic converter howl!

 

I can't imagine, but that's pure speculation, so you best wait until someone who knows whereof he speaks responds.

 

I just didn't want you to feel lonely with no responses.

[nipper]

Nothing to worry about, what kills the cat is raw gas, not carbon and water, which the car normally expells anyway.

i havent done this since 1980, but it is still a tried and trued method. Thats why blown HG 's have one really clean cylinder (on any car but subaru's).

One thing, point the car AWAY from the neighbors, and make sure you are upwind from the car. this makes a hell of a lot of smoke. Use a spray bottle. Do it untill the exhaust is puffy white. Dont let the car stall.

 

 

nipper

[frag]

Nothing to worry about, what kills the cat is raw gas, not carbon and water, which the car normally expells anyway.

i havent done this since 1980, but it is still a tried and trued method. Thats why blown HG 's have one really clean cylinder (on any car but subaru's).

One thing, point the car AWAY from the neighbors, and make sure you are upwind from the car. this makes a hell of a lot of smoke. Use a spray bottle. Do it untill the exhaust is puffy white. Dont let the car stall.

nipper

 

I intended to use the same small vac hose (connected to the throttle body just upstream of the throttle plate) I used when i tried Sea Foam. The vac pull is very light at idle and becomes stronger as you open the throttle.

Where would you spray the water?

Makes me wonder: is it normal for even a very light vaccum to be present there at idle or should there be none at all when the throttle plate is closed???

[nipper]

I intended to use the same small vac hose (connected to the throttle body just upstream of the throttle plate) I used when i tried Sea Foam. The vac pull is very light at idle and becomes stronger as you open the throttle.

Where would you spray the water?

Makes me wonder: is it normal for even a very light vaccum to be present there at idle or should there be none at all when the throttle plate is closed???

 

 

sigh....

 

Ok basics, the wider the throttle is open, the less vaccum there is. Close the throttle its at the highest (accelration is close to 0 in hg deccelration 28 in hg).

http://www.imperialclub.com/Repair/Fuel/VacuumGauge/index.htm

http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_resourcecenter_encyclopedia_gauges.asp

 

There are many places to pull a vacume, and depending upon what it does, it can be choked, reverse or not even go to the engine directly.

 

I would use a spray bottle and spray it down the thraot of the snorkle of the air box, AFTER the air filter.

 

nipper

[hankosolder2]

I would use a spray bottle and spray it down the thraot of the snorkle of the air box, AFTER the air filter.

 

nipper

 

I think that is a VERY bad idea on a car with a hot-wire MAF sensor, and poses a significant risk of damaging the expensive MAF sensor.

 

Frankly, I also question the need to decarbonize a modern engine...the tighter regulation of fuel/air mixture in a port injected car compared to old carburated cars means that there tends to be few carbon deposits. I haven't found much of anything in the various engines I have stripped down over the years.

 

Nathan

[nipper]

I would use a spray bottle and spray it down the thraot of the snorkle of the air box, AFTER the air filter.

 

nipper

 

I think that is a VERY bad idea on a car with a hot-wire MAF sensor, and poses a significant risk of damaging the expensive MAF sensor.

 

Frankly, I also question the need to decarbonize a modern engine...the tighter regulation of fuel/air mixture in a port injected car compared to old carburated cars means that there tends to be few carbon deposits. I haven't found much of anything in the various engines I have stripped down over the years.

 

Nathan

 

 

Nathan,

Your not going to hurt it since the sensor can deal with 100% RH. Using a spray bottle is essentially the same thing. Notice i said SPRAY BOTTLE and not ppour it down the throat of the hose.

I agree about the carbon thing, but engines to get carbon inside the heads. my 97 obw autopsy i saw alot of carbon on the head but very little on the pistons.

 

nipper

[WoodsWagon]

sigh....

 

Ok basics, the wider the throttle is open, the less vaccum there is. Close the throttle its at the highest (accelration is close to 0 in hg deccelration 28 in hg).

 

Except for ported vacuum, which comes off of the TB right by the plate. Ported vacuum was a big thing in the carb and vacuum advance disty days.

[Virrdog]

I intended to use the same small vac hose (connected to the throttle body just upstream of the throttle plate) I used when i tried Sea Foam. The vac pull is very light at idle and becomes stronger as you open the throttle.

This is what I did, no need to regulate it there, the smallish hose is enough. Make sure you suck down enough water. Too little water does just about nothing. When I did it, after enough water went through the car started belching carbon out the exhaust... a couple of days later there was a large ellipsoid shape of dead grass on the other side of the chain link fence.

[cookie]

just don't let the water freeze Frag. Today I had to clean my windshield twice here in San Mateo because the water froze as soon as I sprayed it on. I imagine it's a bit cooler where you are. Good thing you have Labatts antifreeze.

[frag]

sigh....

 

Ok basics, the wider the throttle is open, the less vaccum there is. Close the throttle its at the highest (accelration is close to 0 in hg deccelration 28 in hg).

 

nipper

 

Thanks for the basics, Nipper , but i was talking about ported vac, just (like I wrote...) upstream of the throttle plate. I still would like to know how come there is vaccum (very little but some) there at idle (when the throttle plate is closed). I thought that all the air was going thru the IAC valve at idle and none around the closed throttle plate. If so, it would mean that air is sucked passed the throttle plate when closed and that could be the reason for my slightly rough idle.

So I ask again, is it normal to find a little vac upstream of the throttle plate at idle?

And since i'm asking questions, is ther anyone out there that cured a rough idle by decarbonizing with water?

[frag]

 

Frankly, I also question the need to decarbonize a modern engine...the tighter regulation of fuel/air mixture in a port injected car compared to old carburated cars means that there tends to be few carbon deposits. I haven't found much of anything in the various engines I have stripped down over the years.

 

Nathan

 

Maybe I was misled, but I read over an over on this board that the boxer engine was prone to carbonizing. That's why I thought that after more than 150 k miles, this might be responsible for the idle roughness.

[frag]

just don't let the water freeze Frag. Today I had to clean my windshield twice here in San Mateo because the water froze as soon as I sprayed it on. I imagine it's a bit cooler where you are. Good thing you have Labatts antifreeze.

 

It's 16° C. here today (warm front) but the temp will be much lower tomorrow.

I'm going to the country tomorrow and it will be -15° C during the night there.

Red wine keeps one warmer than beer though.

Have a good week end Cookie.

[cookie]

You too frag. By the way it is common on some engines that when they wear more air gets by the throttle body. most throttles leak a little, but not so much the IAC can't compensate. Sometimes they have bushings that wear out and make the mixture hard to control. Not sure about your model, I'm sure somebody here will tell us if that's an issue.

I sure have heard of lots of folks sying thier Subie had carboned up (much more than other modern cars I know of) and I reckon it can't hurt to decarbonize.

I have also heard of lots of folks having idle problems from cracked lines or IACs that need cleaning.

The only problem I've had lately with the Forester is noise in the rear I thought might be a tire but maybe a bearing. I had it put on a lift and it is a tiny tire seperation so I got lucky.

Good luck on your trip mate!

[fnlyfnd]

Why don't you just use seafoam again??

 

Would a damaged (by water, etc..) MAF throw a CEL??

[Distance Commuter]

... So I ask again, is it normal to find a little vac upstream of the throttle plate at idle?...

 

I would think so. The IAC would basically "leak" some controlled vacuum around the throttle body + plate, pulling air from the same source the throttle plate gets it. So if you measure vacuum on the airbox side of the throttle plate you'd pick up whatever vacuum is there, permitted by the IAC. Not as much vacuum as there is on the engine side of the throttle plate, but probably roughly the same amount as if the plate was cracked open a hair to permit idle without an IAC.

[Commuter]

Maybe I was misled, but I read over an over on this board that the boxer engine was prone to carbonizing. That's why I thought that after more than 150 k miles, this might be responsible for the idle roughness.

frag - I know that the late 90's 2.5l engine is somewhat prone to this. I've dealt with it a couple of times (and again right now) in my 97 OB. I've heard that the fuel maps are on the rich side. Emily of CCR once posted that these engines look like a carburated engine from the 70's when they tear them down, there is that much build up in them.

 

With your 2.2l engine, I'm not so sure. It would depend on the fuel maps I guess, amoungst other things. The engines are very similar though. I can't say I've noticed much about 2.2l issues posted here. It's one of those things though that could be misdiagnosed easily as a poor idle can be caused by many things.

 

I seem to have some of this going on again with my car. My idle is fine though. Where I've always noticed it is when I feather the gas starting off. Eg, revs between 600 and 1000 rpm; easing into a parking spot, that sort of thing. I got my hands on some Marvel Mystery Oil and it seems to be helping, but there is still some hesitation there. Where did you get the Seafoam from, as I wanted to try that stuff?

 

Commuter

[jon38iowa]

frag - I know that the late 90's 2.5l engine is somewhat prone to this. I've dealt with it a couple of times (and again right now) in my 97 OB. I've heard that the fuel maps are on the rich side. Emily of CCR once posted that these engines look like a carburated engine from the 70's when they tear them down, there is that much build up in them.

 

With your 2.2l engine, I'm not so sure. It would depend on the fuel maps I guess, amoungst other things. The engines are very similar though. I can't say I've noticed much about 2.2l issues posted here. It's one of those things though that could be misdiagnosed easily as a poor idle can be caused by many things.

 

I seem to have some of this going on again with my car. My idle is fine though. Where I've always noticed it is when I feather the gas starting off. Eg, revs between 600 and 1000 rpm; easing into a parking spot, that sort of thing. I got my hands on some Marvel Mystery Oil and it seems to be helping, but there is still some hesitation there. Where did you get the Seafoam from, as I wanted to try that stuff?

 

Commuter

 

You can buy Seafoam at many Automotive retailers: Napa, Auto Zone, Advance Auto, and numerous others. Google Seafoam, and on their corporate site you will find a Listing of stores that sell it.

[frag]

I bought SeamFoam at Carquest in Montreal.

I've got black sooth in the tail pipe, so I think my engine is running rich and might have carbon in the cylinders head.

Evevrything else is Ok: O2 sensor, temp sensor, plugs, wires, fliters, IAC has been cleaned, no detectable vac leaks, etc.

Moreover the engine runs perfectly except at idle.

That's why I want to try decabornizing with water. Seafoam helped but did not cure the problem completely.

I'll keep you posted on the results.

[mtsmiths]

Remember frag ... ICE water, better yet, grab the Stoli outta the freezer!

[cookie]

Folks have talked about some of the 2.2s having slightly sticking valves as well. Some MMoil might help that if that's the case.

[skizix]

Thinking about trying this, but a little sketched out.

 

So, assuming spray bottle...do you do this at idle only, or do you tweak the throttle whilst you spray? If too little spray is not enough, how do you tell when it's enough water? How about too much? Nipper, you say, "do not let the car stall(!)". What happens if it stalls? Bad? Or you're just saying that if it stalls...too much water may have been WAY too much, and hydro-locked the chambers? Better to tweak the throttle to make sure no stall, or better to **not** add enough water at idle to make it stall?

 

I ask because: I've been dealing with hesitation, and jerky accelleration and decelleration. Checked everything and replaced a few sensors/parts (with definite improvements, etc. -- for sure had other probs, now resolved), and am left with few options. Recently did a tank with BG44K, and saw improvement. Jerky accel is all but gone (but not completely), and evil hez is noticeably less frequent. Car is running well, but still hesiation -- occasionally, but obvious -- especially when starting from a stop on an uphill. As if the BG worked, but not completely.

 

Thinking carbon buildup in chambers is a definite possibility for my intermittent, incurable, and "undectable" (OBD-II, etc.-wise) issues.

 

BTW, never had any issues like this with my '90 leg, 2.2l, despite a chronically sooty exhaust pipe (and no other real probs to 235k miles).

 

So, more BG? (napa guy says 2x in a row, BG44K is **baaad** -- wha?), water blast, or seafoam? Is serial BG44K really bad (...said it would "blow my rings")? Is there possible damage with seafoam? And...putting the garden hose down my intake would obviously explode my engine, but if done with respect (and how does one find the balance b/t effective and safe?), can water-blast do damage?

 

So you know: I bought this '02 OBW with 99k miles, and have had to replace the neutral switch (5MT) and the IAC, to get it running smoothly. Neither caused a relevant CEL, and so the car could've been running rich for a while without correction from the ECU -- either or both of those defects could've conceivably caused increased carbon deposits, IME. Ya think? Or...?

[nipper]

try seafoam first

 

nipper

[skizix]

try seafoam first

 

nipper

 

Ok, thank you. You seem to be the voice of much reason/experience, so I'll bite.

 

So then...which seafoam method? In the tank, or in the intake? Any other tips that might not be enumerated on the bottle? Anything to be concerned about?

 

(Yeah, I know..search. But search on this site seemed limited. Anyone who can tell me how to do an "AND" search here on two or more terms has my gratitude. Seems two search words inevitably precipitates an "OR" search, more often than not yeilding piles of irrelevant stuff, severely clouding one's view.)

[Virrdog]

There is very little to worry about, you will not hydrolock your engine. You'd have to use a garden hose down your throttle body to do that. Putting the seafoam in different places does different things. Putting it in your gas tank will help with any moisture and help clean out things like your injectors. Running it through your intake manifold will help clean out the carbon deposits inside your combustion chamber.

 

Run a hose from the fitting on top of your throttle body (if you have one?) and stick the other side into the bottle when you have the engine revved up. You can get a helper or get a hose long enough to run back into the car. Get the car to about 3k rpms and insert the tube and try to maintain that engine speed, you'll need to use the throttle quite a bit. Once you get through half the bottle or so shut off the engine. Wait a minute or two and start it back up. It will smoke and might bog a little, but keep it running and go drive it hard. Then you're ready for the next car. Or you can put the rest of the bottle in the gas tank.

 

This is how I have done it many, many times. Haven't blown anything up, yet... I think.