96 2.5l OBW head gasket project

[mnwolftrack]

you might be interested in the following video animation on youtube:

 

 

It goes through the complete view of an engine and all it's parts, then shows how everything works. There are a bunch of results on youtube if you search "internal combustion engine." This should be the one I am thinking of, but I am on dialup internet and it would take 2 hours to get through this particular one to verify it's the one I"m thinking of. It starts out with a spinning block, then the crank, pistons, rods, etc... come flying in, then other parts start coming in. Eventually, the engine is completely assembled and it shows the animation of the fuel entry and everything.

 

Unless i'm misunderstanding you, rotating the crank 360 degrees and reinstalling the timing belt isn't going to affect anything. The crank will be exactly where it was before you rotated it.

 

This may also help:

 

http://en.wikipedia.org/wiki/Otto_cycle#The_Otto_cycle

 

There are 4 strokes to the 4 stroke engine: suck, squeeze, bang, blow.

 

1. piston at TDC, intake valve opens, piston travels all the way down and sucks air in.

2. intake valve closes, piston moves all the way back up, squeezes air (compression).

3. piston is back at TDC, spark plug fires, bang, piston moves all the way down in the power stroke with all valves closed.

4. piston moves back up, exhaust valve opens, and blows the now combusted fuel/air mixture out the exhaust.

[sublute]

OK, The piston sucks fuel in -stroke one, then the piston compresses- stroke two, then the plug fires and the power stroke three, the piston returns to TDC again to blow out exhaust-stroke four (no spark).

 

If the computer tells it to spark at exhaust stroke and not at compression stroke, it is out of sync 360 degrees, right?

 

Anyhow, the reluctor on the crank has 6 tabs, I can't see how many trigger magnets the drivers side intake cam has and I'm not going to take it off to see.... I just took the T-belt off and will rotate the crank 360 degrees.

 

I'll let you know what happens.

 

If I'm wrong, I'll at least know how to change the T-belt in my sleep now....

[idosubaru]

i'm totally lost here - what happened with these items i asked about:

 

spark at each cylinder.

fuel at each cylinder

compression test.

 

need this information to see where the problem is originating. struggling through TDC and the last two pages of information i doubt will solve your problem. on the older series engines it doesn't matter the orientation of the crank, somehow the ECU adjusts or can sense it so to speak. you can install a timing belt...engine runs perfect, then remove the timing belt, rotate crank 360 like yo'ure suggesting and reinstall and it will still run perfect. wouldn't surprise me if the EJ stuff is the same way. hope i'm wrong, but if not we really need that info above to keep from guessing.

[johnceggleston]

it's a 4 stroke engine but the piston only has 2 strokes. the cam determines wheather it's exhaust or compression. i think you should do it the way wolftrack and the book says, forget the arrows. go with the correct marks.

 

your belt may have been correct, but until you are sure it is senseless to look for other problems.

 

on a side note, on a 2.2L, if the crank is in the correct position, and the bekt marks are correct, and the belt marks are correct on the cam pulleys, it's good. no questions. it makes no matter how many times the crank may have been rotated, or the cams for that matter. the only difference on a DOHC is the relative position of the second cam pulley to the first.

[tomson1355]

The crank doesn't know the difference between a compression stroke and an exhaust stroke, or between a power stroke and an intake stroke. It's just going up and down while the valves determine the types of strokes. Hold all the cams in place and rotate the crank 360, and it's still doing the same thing.

 

Which is what everybody else has said.

 

What does the engine sound like when you turn it over? Does it sound normal? Or is it really fast, indicating bad timing and low compression? Or is it really slow, indicating bad timing and late valves? If the timing is out enough to keep it from starting, you should hear it in the sound of the engine when you turn it over. If you don't have compression, you'll be able to feel it turning the crank over by hand.

[mnwolftrack]

What I was trying to clarify in my previous posts is it doesn't matter how many times you turn the crank 360 degrees or which direction you turn it. The crank will still be right where it was and nothing will have changed. Taking the belt off leaving the cams in place, and rotating the crank 360, and putting the belt on won't make any difference. The pistons will all be where they were and so will the reluctor. The crank doesn't have a clue or care. It's a 1-to-1 ratio with itself. The only way to get the crank shaft off is to not have the reluctor slash at noon. In other words, rotating the crank 360 degrees and putting everything back together will not solve your problem.

 

The engine block and heads themselves do not know or care where in the combustion cycle it is. It's up to the computer to determine which of the 4 strokes it's on, and where the cams are in relation to the crank. The computer determines when to fire the plugs based on the cam/crank indicators and sensors. On older cars, it's the distributor that takes care of this. It IS possible to put a distributor in 180 backwards or 360 degrees off and get backfiring through the intake because the plugs are firing on the wrong stroke, however, this isn't possible on the subi unless the crank and cams are totally misaligned with respect to each other. As long as your timing marks are aligned and you put the belt on, that's it. It's aligned. There's nothing you need to do to figure out which stroke the engine is on. All the sensors, magnets, etc... are fixed and can't be installed incorrectly.

 

I don't even know how you could change when the computer is supposed to fire the plugs at a different stroke on this car, short of butchering the reluctor ring and spinning it into a position not normally possible on the crank,or cam position indicators, or butchering the location of the sensors and moving them somewhere else.

 

As grossgary said, messing with TDC and focusing on the belt won't solve your problem if the belt is aligned properly. I was hoping my last two pages of information was at least somewhat helpful to determine if the belt was at least installed correctly, considering it is an easy mistake. My last two pages of "help" probably aren't very helpful because I'm trying to understand how the belt was aligned and to try and clarify that rotating the crank 360 won't do anything.

[idosubaru]

sublute - please answer these questions no matter how many pages it gets pushed back:

 

spark at each cylinder.

fuel at each cylinder

compression test.

[sublute]

OK, thanks for all the responses.

 

I understand now that the cam sensor determines the type of stroke.

 

I did take off the t-belt and put it back on. I at least know that it is right and I realize it can be done in 2 hours. I am also understanding much more about this engine. Thanks everyone for your patience while I think out loud in trying to figure this out and for good answers and advice.

 

In answer to the three questions,

 

I do know there is fuel getting to the cylinders. The plugs were all wet when I took them out yesterday. I dried them out and blew out the cylinders.

 

I know spark is getting to two cylinders. 1 and 3. I will check the other two and do a compression check today.

 

The car sounds normal when I crank it, but I don't have any experience with the New Gen Subaru's.

 

On a side note, I would like to say that this is the most civil site I've been to. I have not seen a single flame or A-hole type behavior anywhere on the USMB. I am a luthier specializing in lutes and early music instruments and this site is more civil than the lute listserv! Another newsgroup I moniter is rec.audio.tubes and it is a mess with a really high A-hole factor.

 

Thanks... OK, enough of the warm fuzzies and time for the coffee to kick in and roll up my sleeves and do spark and compression tests...

[mnwolftrack]

On a side note, I would like to say that this is the most civil site I've been to.

 

now that you mention it, I 100% agree with you. I belong to many, many Internet Forums (this is the only subi forum I belong to), and this forum's members are highly considerate and polite to other members, even the newbies (and I'm still a newbie).

 

Back on topic, after 2 pages of some confusion on my part, it sounds like you've got the belt on correctly and are using the proper alignment marks. With that out of the way, you can focus on the big three; spark, fuel, and air. For a while there, I thought you had the crank aligned to the wrong mark.

 

Lots and lots of things can keep the car from firing, but lots of things can also just make it run poorly but still run. Seeing as the car ran beforehand, it's got to be something simple.

 

Regarding spark, do you have another car you can look at and at least hook up a spark plug to a spark plug wire and visually inspect how the spark looks? It doesn't even have to be the same car. The reason I mention this is because I was trying to diagnose a Camry that sputtered out on us while driving home on the freeway, and it refused to start again. I checked all this kind of stuff, the belt, compression, spark, fuel, and nothing indicated a problem. At about the 4th time I looked at the distributor cap and rotor, I realized there was a faint crack under the rotor and even fainter burn mark around it. I put a new cap and rotor on to the tune of $15, and let me tell you, the spark was MUCH brighter than what I thought was good spark before. The old rotor's crack was allowing some of the power of the spark to dissipate within the distributor, and not all of it was reaching the plugs. There was enough spark getting to the plugs that I saw "spark," but it was no where near what it should have been. The car fired right up with the new cap and rotor. One of the downsides of the newer technology on these subi's is.... no $15 cap and rotor.

 

With any luck, your car's issue is going to be something very simple. Trying to find the cause is not always fun, but it at least provides a good learning experience. You'll now be able to look at any 2.5L and be able to do a timing belt with your eyes closed. Heck, having to pull a 2.5L out because I drove the rear main seal in too far gave me a good experience and I widdled my engine pulling time down to 1 hour 50 minutes. I griped and groaned about my mistake, but I at least learned some things from it.

 

Regarding how the car sounds when you try to crank it, have you ever cranked the engine with the spark plugs removed such as when doing a compression test? You may have noticed the engine was turning over much faster and smoother because there was no compression because all the air was leaking out the spark plug holes. If the cams/crank were misaligned, valves bent, pistons had holes, or there were cracks in the cylinder walls, air would be able to get out and compression would not form. The more cylinders affected, the easier this is to notice. Just trying to manually rotate an engine with a wrench on the crank bolt will let your arm feel the difference in ease between turning over an engine with spark plugs installed vs. not installed.

[sublute]

Good idea about checking the spark on my Loyale. I'm not used to these fancy platinum spark pluge and that would provide a good reference. I can also just get the reference from an old platinum plug I pulled from the car.

 

It is unfortunately raining hard today...

 

I did have questions about how hard or easy it was to crank the engine. I could feel the compression on strokes as I rotated the crank to align the belt/cam/crank. That warmed me up for the t-belt job.... I will now quantify this with the compression test. I just have to get some office work done and hopefully have time to do this before I pick my 3 yr. old daughter from pre-school.

 

I used a small crow bar to jam into the slot in the flex plate slot via the inspection window to undo and torque the cranshaft accessories pulley. I didn't read about anybody doing this. See any harm in doing it this way?

[mnwolftrack]

No harm at all. It's standard practice on any vehicle to wedge something against the flywheel to unbolt or re-torque the crank pulley. On many vehicles I've worked on, this is next to impossible though, so I've had to come up with creative solutions to get the crank from spinning while trying to undo the bolt.

 

With regards to the 2.5's, I just stuck a round bar (small crow bar) in the inspection hole and did the same thing you did. It was actually easy to do this on the subaru. You are NOT supposed to use a combination of wrenches on the crank bolt and cam bolts (on any vehicle) to use opposing forces against each other to tighten or loosen things, but you probably already knew that. It places a lot of stress on the timing belt or timing chain depending on the vehicle. Cam's usually have "special service tools" or other easy methods to keep them from spinning, but the crank is usually a bit harder especially if you can't get to the flywheel.

[sublute]

OK, I checked the compression on cyl 1-2-3, Sorry I just couldn't seem to angle #4 to get the plug out tonight... Mojo's not there...

 

1-175

2-165

3-173

4-???

 

I forgot to hold the throttle open when doing these... I also didn't disconnect the fuel pump

 

spark seems kinda wierd? it seems to be firing too often and maybe weak.

 

All the plugs 1-3 were wet. I checked with an old dry plug, too. same result.

 

One #2 cyl. the plug flashed significantly brighter. I'm going to compare with the Loyale right now.

 

Do I suspect the coil? Sensors?

[mnwolftrack]

compression looks good. Even if #4 were low or zero, the engine would still run.

 

Regarding the coil pack, didn't you say at one point in this 11+ page of posts that you thought the coil was getting weak? Or am I remembering things wrong?

[idosubaru]

compression seems okay.

seems like you're getting fuel, have you pulled a line to verify?

it's time to double check this spark. is there any chance you swapped wires onto the wrong output of the coil while doing this work? that would artificially change your ignition timing. i would also wonder about the ignition coil, swap in another and see what happens, should be able to find a used one for not much $$.

[sublute]

Hello, I will take your advice and start another thread... I was on a one track state of mind to get this done.

 

I had briefly ruled the coil out after checking that it had been replaced 35k miles ago, however I did pull the coil and measure it last night.

I got 1.0 ohm across the primary and a flash of 19K across the secondarys 1-2 and 3-4 It is a Diamond unit. That seems within tolerances. My DMM is off by several tenths in the lowest range, so that 1 ohm is closer to the .7 ohm spec. The flash of the 19K has to do with the way the DMM reads pushing through the coil???

 

I'm still suspicious about the spark, too.

 

I ran the fuel line into a container and yes, plenty of fuel. plugs are wet when I pull them. Could the injectors be stuck and dumping fuel?

 

Do I start checking sensors?

 

Anyhow, I'll start that new thread, now.