Cylinder 2 misfire questions

[xt2005bonbon]

You said in your OP that you did a ghetto leakdown. So you know how to do one then right?

 

 

As for the valve clearance check, you need to remove

 

-the battery (it's in the way)

 

-coil packs

 

-valve cover (a few 10mm bolts)

-then grab your filler gauge and measure the space between the cam lobes and the buckets. You will have to slowly rotate the engine (via the crank pulley with a breaker bar) so the cam lobes point away from the bucket. There must be a walkthrough on the web for our engine. You technically do not need to check the passenger side at this time.

 

 

Keep in mind that you will have to have some rtv and possibly a new valve cover gasket for re-installation. Although you may be able to reuse your old one..

 

 

see this old pic I posted with the specs (to the right of the table)

[samuel082799]

You said in your OP that you did a ghetto leakdown. So you know how to do one then right?

 

 

As for the valve clearance check, you need to remove

 

-the battery (it's in the way)

 

-coil packs

 

-valve cover (a few 10mm bolts)

-then grab your filler gauge and measure the space between the cam lobes and the buckets. You will have to slowly rotate the engine (via the crank pulley with a breaker bar) so the cam lobes point away from the bucket. There must be a walkthrough on the web for our engine. You technically do not need to check the passenger side at this time.

 

 

Keep in mind that you will have to have some rtv and possibly a new valve cover gasket for re-installation. Although you may be able to reuse your old one..

 

 

see this old pic I posted with the specs (to the right of the table)

 

So I didn't feel like pulling the valve cover off yet since I dont have any gaskets, and I'm trying to drive to work tomorrow since it is raining ( I only live a couple of blocks away from work). I did a wet compression test while I had the plugs out. I added about a teaspoon of oil into the cylinder and put the compression tester back on. It yeilded the same low compression as the dry test. From my understanding if by adding the oil and the compression increased than the issue could be pinpointed as rings or ringland failure because the oil creates a temporary seal increasing compression. So I think these results may mean that my issue may be valve related. What style buckets does our engines have is it the solid buckets or shimmed buckets?

[samuel082799]

Ok, so weird update. Yesterday I had to take my car out of town, I wouldn't have if I had the choice but I had to. What happened was I drove 40 miles to a military base where I filled up with MTX gas I think it was called (comparable or better to the quality of chevron). on the way up it was misfiring at idle only, the last time I felt it noticeably misfire at idle was waiting at the front gates of the base. once I filled up the car stated running better and better the more I drove, I went through the full tank approximately 320 miles and when I got home it wasn't misfiring anymore. that's all fine and dandy but it doesn't solve the issue of the low compression. so this morning I decided to do another compression test before I pulled the valve cover. This time I was going to do a hot and cold test so I got the care to operating temp and did my compression test and the hot test came back as 85. now I was sad because I was like "must be the rings" and waited for it to get cold and did the test again and it came back as 90. I don't exactly know what this means but my guess is that the quality fuel coupled with the extended driving cleaned off carbon deposits on the valves which were making it tight. the only thing I changed since the 50 compression test was the gas. Where do I go from here, do I just keep putting good fuel in it and see if it fixes itself or do I pull the valve cover and check the valves and change the buckets? or could it be another problem? please help me I am soooo confused at this point.

[xt2005bonbon]

well that may probably mean that the rings are fine and that you have tight valve clearance. As I previously stated,the compression may worsen as the car warms up, that is if the valves have tight clearance and the rings seal well. At least that's my understanding. So if I were you, I would now check the valve clearance next. And if your clearances are fine then, borescope time and/or teardown..

[Max Capacity]

Go buy a can of Fuel system cleaner, I think its B14 or something like that from Walmart. I do one can a year.

 

https://www.google.com/search?ei=NVHkXcrJLcLH5gKJiYHQCQ&q=berryman+fuel+system+cleaners&oq=berryman+fuel+system+cleaners&gs_l=psy-ab.12...9926.19355..21408...0.2..1.252.1297.5j4j2......0....1..gws-wiz.......0i71j0i13j0i13i30.l99KZLUMdzc&ved=0ahUKEwiKuKnB0ZXmAhXCo1kKHYlEAJoQ4dUDCAs

[samuel082799]

well that may probably mean that the rings are fine and that you have tight valve clearance. As I previously stated,the compression may worsen as the car warms up, that is if the valves have tight clearance and the rings seal well. At least that's my understanding. So if I were you, I would now check the valve clearance next. And if your clearances are fine then, borescope time and/or teardown..

 

I'm kinda worried that if I pull the cover and adjust the valves that they will be loose if whatever is causing this loosens up more. I went back on base today and got some more MCX gas. I have a can of seafoam the kind you spray in, would it be a good idea to do that before I check the valves? I feel like that would be better at targeting carbon build up on the valves.

[Max Capacity]

If good gas made a difference, I'd pour some fuel system cleaner in the gas tank...

[xt2005bonbon]

I'm kinda worried that if I pull the cover and adjust the valves that they will be loose if whatever is causing this loosens up more.

 

 

I think you are confused on how it works (don't worry, I was too ). The proper clearance between the bucket and the cam lobe allows the valve to fully close and provide a good seal on the head (thereby providing good compression in the cylinder). A tight clearance does the contrary: the valve cannot fully close, resulting in a poor seal, which in turns decreases compression resulting in misfiring.

So a looser clearance would also provide good compression. However, I presume the downside would be delay in valve opening/closing including not opening enough for good intake/exhaust flow.

 

 

 

This picture may help?

http://speed.academy/wp-content/uploads/2015/02/Subaru-WRX-turbo-camshaft-upgrade-044.jpg

 

 

 

 

And doing that cleaning may help.

Edited December 2, 2019 by xt2005bonbon

[samuel082799]

 

see this old pic I posted with the specs (to the right of the table)

 

So I got done with school this semester and finally got around to checking the valves. What I found was the intake valves were all perfect, measuring in at .20. the exhaust on cylinder 2 measured between .25 and .28, the .28 was a little to tight but it did go in. The other exhaust valve measured .33. for cylinder 4 the exhaust measured .35 and .28. so the exhausts are a little bit out of spec, but idk if that is enough to cause the misfiring I have been experiencing. Also a recent development, sometimes on my way to school the dipstick will shoot out and spit oil all over my engine, which is making me think my rings are the problem. So should I pull those shims and get the right size and hope it fixes the problem or do I just chalk it up to the rings being the problem and moving on with my life?

[Max Capacity]

Blowing the dipstick out is a concern.

 

Is your PCV plugged up ?

 

I'm not sure that exhaust valve being tight would allow enough exhaust gas to get past the valve guide to effect the dipstick ?

 

Oh, can you rent a bor-a-scope and look inside #2 ?

[samuel082799]

Blowing the dipstick out is a concern.

 

Is your PCV plugged up ?

 

I'm not sure that exhaust valve being tight would allow enough exhaust gas to get past the valve guide to effect the dipstick ?

 

Oh, can you rent a bor-a-scope and look inside #2 ?

 

I have a brand new Crawford air oil separator, so there is no pcv valve anymore, it should be pretty free flowing, but I'm going to pull the lines and blow through them and make sure nothing is clogged. I will see if I can get a bite scope rented.

[StkmltS]

Sounds like you're making good progress and I really hope you figure out your misfire, especially because it sounds like youre car might be a close relative to mine. I don't have a ton of extra time to contribute very much advise but I'll keep checking back to see your progress.

 

Explore every option before deciding to tear into your motor, because your problem might not be that deep. Read through my rebuild thread and you'll why I say that.

[Berge56]

sorry been a while and it looks like you've done a fair amount of diagnostic work. The first thing that sticks out to me is your compression test not being within 8-10% for all 4 cylinders. Anything below 120psi is signs of a rebuild being needed.

 

Based on that fact that you are pressurizing your block and blowing your dip stick out to me means you have really bad rings or more likely a broken ring land. Since you've stated the car has been misfiring a lot, my guess is broken ring land. This is not a valve adjustment and if it is valves, you probably dropped a valve guide and or again more likely burnt a valve.

 

Pull the engine and start the rebuild process bud before you grenade bearings, take out your turbo or even worse cause catastrophic damage to the heads from something letting go.

 

You can expect head rebuild and resurface to run 600-800 bucks with stock parts.

 

I've done this plenty of times for friends to know what costs are associated as well as the work involved. Good luck!

[xt2005bonbon]

Your clearances are not that bad. I don't think they're causing the misfiring problem. And yeah your dipstick shooting out probably means your rings are bad.

 

How is your oil consumption again?

[samuel082799]

sorry been a while and it looks like you've done a fair amount of diagnostic work. The first thing that sticks out to me is your compression test not being within 8-10% for all 4 cylinders. Anything below 120psi is signs of a rebuild being needed.

 

Based on that fact that you are pressurizing your block and blowing your dip stick out to me means you have really bad rings or more likely a broken ring land. Since you've stated the car has been misfiring a lot, my guess is broken ring land. This is not a valve adjustment and if it is valves, you probably dropped a valve guide and or again more likely burnt a valve.

 

Pull the engine and start the rebuild process bud before you grenade bearings, take out your turbo or even worse cause catastrophic damage to the heads from something letting go.

 

You can expect head rebuild and resurface to run 600-800 bucks with stock parts.

 

I've done this plenty of times for friends to know what costs are associated as well as the work involved. Good luck!

 

That is what I was thinking, and i have already started getting my engine parts together, the only parts I want to reuse from the engine are the heads, bit I could care less about the short block because it is all going to be new. I was going to get work done on the heads regardless, but I am hoping that the car will last me through the rainy season since it is my only car. I ride my motorcycle pretty much exclusively now, unless it is raining or really cold. I live in San Diego so we don't get much rain, but it's that time of the year. After the rain passes I will put a new engine in it. If I drive it nicely, only when I have too, do you think it will last me a couple of months without doing any catistrofic damage to the heads? I was also going to replace the turbo this week do to alot of oil in my intake system, do you think I should hold of on that, I don't really see how a bad ringland could blow my turbo unless a piece of piston maraculusly slipped past the valve. My main concern is keeping the heads usable, maybe puting 1000 miles on it at most till the rebuild. I caught this problem supper early, so I feel like it may have enough life left in it to get me through. Any advice is appreciated, I think I'm just going to leave the valves because I dont think it is out of tolerance enough for that to be my issue. Are there any other test I can do to more directly target the piston or ring as the issue?

[samuel082799]

Your clearances are not that bad. I don't think they're causing the misfiring problem. And yeah your dipstick shooting out probably means your rings are bad.

 

How is your oil consumption again?

 

I do my oil changed every 2700 miles and not including the initial oil in, it goes through 5 quarts in that amount of miles

[xt2005bonbon]

well then, I think that is it (ringland). same for me if it makes you feel any better.

[Berge56]

It's so common it sucks.

[samuel082799]

I'm pretty sure most of the oil consumption is coming from the turbo because the intercooler and throttle body coupler have alot of oil in them, not just a little, like puddles.

[xt2005bonbon]

mmh. check your pcv valve then. See if it rattles.

[samuel082799]

I checked all of the lines on the AOS all I found was that one was slightly kinked but I don't think it was enough that it wouldn't flow air but I re routed it anyway so it wasn't kinked. I also took a pick of the throttle body coupler to show you what I am talking about as far as oil goes.

[StkmltS]

Yikes that's a lot of oil.

Even without an AOS I've never seen anything close to that in my intake innards.

 

Did you check your PCV yet?

 

Would oil in the combustion chamber cause a misfire, or predetonation (knock)?

[xt2005bonbon]

I'd think more knock than misfire.

[samuel082799]

Yikes that's a lot of oil.

Even without an AOS I've never seen anything close to that in my intake innards.

 

Did you check your PCV yet?

 

Would oil in the combustion chamber cause a misfire, or predetonation (knock)?

 

I don't have a pcv anymore, the AOS deletes that. I do get knock according to my data logs which I suspect is from the oil loweringy octane.

[Max Capacity]

From that photo, I'd say turbo oil seals.