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Old 06-22-2009, 10:44 AM   #1
generalee69
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Default Do these symptoms sound right?

I had a rather dismal race weekend, but that is to be expected every now and again. I just wanted to post up here to get some more opinions before I dive into the problem.

I posted in here because I am hoping some of the normal track whores & racers will pass by it.

A little background: My car is a road race prepped 04 STi. Down at PIR (Portland International Raceway) a couple of weeks ago, towards the end of our race (20 minutes into a 30 min race) the car just felt down on power at once it reached 6000rpm. Boost psi, oil psi, water temp, oil temp, and AFR's all were normal. It almost felt like it wanted to misfire if I would have just kept my foot in it and tried to force it much past 6500rpm... I just short shifted the rest of the race to finish.

This weekend we were up in Mission. Same thing right out of the box. Car just wouldn't pull up past 6000rpm. I also noticed A LOT of oil blow by from the valve cover breather lines (we're talking about 10 to 12 ounces in 20 minutes). The PCV catch can looked normal (minimal amount of oil and some condensation). Also, after one of the sessions I came in and the inlet hose off of the breather catch can had blown off the can (so there was some pressure built up in the can).

At this point I was trying to figure out what would cause a pressure build up in the top of head... I thought maybe the filtering media in the can was too restrictive, so I completely removed the filter for a session. No change in the amount of oil after the next session, but the line stayed attached to the can at least. I also popped a CEL during this session.

I swapped plugs after that session to a one step colder NGK Iridium IX. The plugs I pulled out looked good. No signs of detonation but not oily either. By the judgement of several races located around my pit, we all agreed they plugs looked "good". In a bad move though I forgot/ran out of time to reset the CEL.

With the new plugs in, the car pulled past 6000rpm again, no stutter. BUT it still just didn't feel like it had any power. Boost psi, oil pressure, water temp, oil temp, and AFR's still look good/normal.

Between our last practice and our race I only had 15 minutes. So I checked the oil and the catch can levels. The oil was low by about the amount that was in the catch can (again 10 to 12 ounces). I still didn't have time to reset the ECU either.

About 3 or 4 laps into the race I finalllllly notice that the Boost psi is not normal anymore. Max of about .08mPa. OK turbo is toast. They red flagged the race and had us shut off our engines while they were cleaning up an RX-7 that just broke a concrete barrier in half (and moved it 10 feet). When they let us start back up, the blown turbo oil seal was confirmed by the MASSIVE amount of smoke that came out of the tail pipe of my car. I think I completely covered 1/4 of the track in smoke Still finished 8th out of 22.. being down 80 to 100 hp I didn't think that was all that bad !

All the other gauge readings looked good/normal.

So to summarize:
- Had problems with engine power for probably 50-60min of track time
- Gauges looked normal
- A lot of "blow by" into the valve cover breather catch cans
- Turbo finally gives up (low boost psi and big smoke during startup).

Here is my check list to do:
- compression and leak down to verify nothing bad with the motor
- change/flush engine oil
- have the CEL code(s) read
- pull the turbo off

What other opinions are out there? What else to check?

1)Does the oil puking into the catch can sound normal for a turbo that is about to die? -- Turbo is feed from oil in the head correct? returns to the head also..??
2)Does the engine stutter/low pulling power match with the bad turbo oil seal diagnosis?
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Old 06-22-2009, 11:02 AM   #2
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I think that between inspecting the turbo and doing a compression/leakdown test you will find your answer. It sounds like either a cracked ringland or a damaged turbo seal.
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Old 06-22-2009, 11:07 AM   #3
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Are people cracking ring lands on forged pistons? I broke a ring land last summer on the stock pistons and just had the engine rebuilt with Mahle forged pistons.

I'm not trying to argue with you, just playing devils advocate... Wouldn't a broken ringland lead to blow by through the PCV system? Not through the valve cover breather?

That's what still doesn't add up to me... why was the valve cover pushing so much oil.
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Old 06-22-2009, 11:17 AM   #4
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Quote:
Originally Posted by generalee69 View Post
Are people cracking ring lands on forged pistons? I broke a ring land last summer on the stock pistons and just had the engine rebuilt with Mahle forged pistons.

I'm not trying to argue with you, just playing devils advocate... Wouldn't a broken ringland lead to blow by through the PCV system? Not through the valve cover breather?

That's what still doesn't add up to me... why was the valve cover pushing so much oil.
Ah, didn't realize you had forged pistons. It's still possible to damage a ringland with detonation but it seems more likely that it's a turbo issue. I'd start there. Although I'm not sure why you would be blowing oil out the valve cover breather in that situation. Hopefully someone else will offer an opinion about that.
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Old 06-22-2009, 11:31 AM   #5
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Hopefully someone will have an answer why the turbo going bad would cause that (maybe wishful thinking, but after the weekend I've had I need a little good luck).

If the car had been detonating at say 6000 or 6500 RPM, and I started to short shift at 5800-6000 (therefore avoiding the detonation point)... do you think the plugs would have shown signs of detonation still? Or would the short shifting have allowed the plugs to "clean themselves up"?

The real bummer about the weekend, is that it rained right before the Sunday race... It would have been my chance to shine against the 600hp stock cars that couldn't get any traction and kept fogging up their windshields. Instead an Integra took the overall race win... and I got to stand in the grandstands to watch. I don't think I have been that despondent,dejected, pissed off, whatever you want to call it in a long time. One of the worst feelings ever is standing in pre-grid when they give the 1 to go whistle, and realize you aren't sitting in your car like you are supposed to be.
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Old 06-22-2009, 12:27 PM   #6
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Time to add a spare turbro to the list of parts.
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Old 06-22-2009, 12:38 PM   #7
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Quote:
Originally Posted by WAYGONE1 View Post
Time to add a spare turbro to the list of parts.
I've had an FP green sitting on my workbench for the past few months, half heartedly looking for an excuse to put it in .. but not having the justification to spend the money on all the supporting modifications. That time/justification has arrived. I want to make sure nothing else is wrong with the motor before I spend the time/money to ramp up the HP though.
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Old 06-22-2009, 12:47 PM   #8
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Is it possible that the oil from the valve cover breather lines has nothing at all to do with the turbo, and is just from pulling sustained high G's?

-Mike
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Old 06-22-2009, 12:56 PM   #9
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Possibly... but the cans are located in the stock battery location and the hoses are 1/2" ID. So the hose off the "t" pipe on the intercooler runs across the engine bay and then into the can... pretty long routing for the oil to get there by sustained cornering g's. To the point where I would think the oil pump would suck air before I could fill the valvetrain area with enough oil to reach all the way to the can.

Also, isn't there baffling in the valve cover to prevent that?

The oil is routed to the turbo via the passenger side head correct? Does it return to the head also, then drain into the pan?
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Old 06-24-2009, 10:35 PM   #10
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The plastic water bottle on the left is from the valve cover breather. As you can the bottle is basically full (1 pint) after 20ish minutes on the track.

The glass jar on the right is from the PCV catch can after 90+ minutes of track time.

I still need to get the car down to the shop to run the compression and leak down tests... but I would think that if a piston ring land was crack the PCV can would be full of oil too?? Or is that just wishful thinking?

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Old 06-25-2009, 07:55 AM   #11
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How long are the lines from the heads to the Catch can? How big is the line? I run my lines all the way up to the firewall to stop the oil pushing out of the heads under cornering forces. If you don't have some rise in the line you'll push out large amounts of oil.

-Duncan
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Old 06-25-2009, 08:11 AM   #12
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Something is overpressurizing the block and pushing the oil out the valvecovers. Unfortunately, my money is on the ringlands. They will let the chambers get oiled up and cause a smoky startup....but the plugs will also show signs of it when pulled. When you go to do your compression/leakdown test, see if your plugs still look as clean as the other set you pulled out.

Good luck with it anyway.....hope it's something minimal.

Jay
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Old 06-25-2009, 09:47 AM   #13
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Quote:
Originally Posted by dunk View Post
How long are the lines from the heads to the Catch can? How big is the line? I run my lines all the way up to the firewall to stop the oil pushing out of the heads under cornering forces. If you don't have some rise in the line you'll push out large amounts of oil.

-Duncan

The cans are located in the OEM battery location. I used the stock metal line in front of the intercooler and patched right after it. So the lines come out of the valve cover vertically, go through the OE metal black line, and then wrap all the way over to the battery location. 1/2" ID hose the whole way.

Here's a couple of pictures of the setup





Quote:
Originally Posted by Storm View Post
Something is overpressurizing the block and pushing the oil out the valvecovers. Unfortunately, my money is on the ringlands. They will let the chambers get oiled up and cause a smoky startup....but the plugs will also show signs of it when pulled. When you go to do your compression/leakdown test, see if your plugs still look as clean as the other set you pulled out.

Good luck with it anyway.....hope it's something minimal.

Jay

I broke a ringland last fall down at Reno-Fernley Raceway. And it would smoke on startup, but not nearly this bad. It would also do the smoke stack out of the oil filler tube. I guess I should check that tonight also.

What is the path from the crankcase to the valve cover that would allow this much oil to blow into one of the cans, but not the other? I can see if a(or multiple) ringland(s) were broken how it would pressurize the crank case... but I just can't visualize how that would pressurize the valve cover/cam area without getting a bunch of blow by past the PCV also.
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Old 06-25-2009, 10:47 AM   #14
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How many times have you run at PIR?

When I had a valve cover breather setup like yours I would fill a catch can in one 20 minute session at PIR. However at Pacific Raceways it would only be full at the end of the day. PIR side loads the car for much longer giving the oil time to build up in the head.

A drain back catch can system is the way to go for the head breathers.

As for the smoke at startup? Compression and leakdown to confirm the engine health. Pull the downpipe and check for turbo shaft play
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Old 06-25-2009, 10:50 AM   #15
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Quote:
What is the path from the crankcase to the valve cover that would allow this much oil to blow into one of the cans, but not the other?
On the track where this was happening, which head would have been on the outside of most of the corners? Do you still have the cross engine breather installed? The one that goes between the heads and to the block which is in addition to the normal PCV system?
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Old 06-25-2009, 10:53 AM   #16
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Quote:
Originally Posted by mick_the_ginge View Post
How many times have you run at PIR?

When I had a valve cover breather setup like yours I would fill a catch can in one 20 minute session at PIR. However at Pacific Raceways it would only be full at the end of the day. PIR side loads the car for much longer giving the oil time to build up in the head.

A drain back catch can system is the way to go for the head breathers.

As for the smoke at startup? Compression and leakdown to confirm the engine health. Pull the downpipe and check for turbo shaft play
This was after Mission. Avg speed of about 60mph... very slow, tight course. There are a couple of corners that have side loads for fairly extended periods, but the speeds are lower.
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Old 06-25-2009, 10:55 AM   #17
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Quote:
Originally Posted by MasterKwan View Post
On the track where this was happening, which head would have been on the outside of most of the corners? Do you still have the cross engine breather installed? The one that goes between the heads and to the block which is in addition to the normal PCV system?
The hard metal line under the intake manifold I assume you are talking about? It connects the 2nd valve cover breather lines together. Yes it is still there.

Mission has mostly left hand corners... oil pushing right side head.
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Old 06-25-2009, 10:56 AM   #18
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Oh, ok, you have totally broken something then
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Old 06-25-2009, 10:58 AM   #19
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Quote:
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Oh, ok, you have totally broken something then
si

I know it is all speculation until I start running tests, just want to attempt to narrow down the possibilities.

I still don't understand theoretically how a broken ringland could cause oil to push out through the valve cover... but not through the PCV?
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Old 06-25-2009, 04:30 PM   #20
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I say it might be a valve seal.

Explains why you might have had that smokey start up as well. Oil leaking into the exhaust manifold and once you started it up out came the smoke.
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Old 06-25-2009, 05:19 PM   #21
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I just think oil is collecting in that head and normal engine pumping from the pistons is pushing it out through the vent line. High G's in a corner is like tilting the engine over. It prevents gravity from letting the oil drain back into the pan. I'll bet your valve cover fills with oil in those corners.
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Old 06-26-2009, 11:32 AM   #22
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Originally Posted by MasterKwan View Post
I just think oil is collecting in that head and normal engine pumping from the pistons is pushing it out through the vent line. High G's in a corner is like tilting the engine over. It prevents gravity from letting the oil drain back into the pan. I'll bet your valve cover fills with oil in those corners.
I agree. Which is why you should always run a little more oil for road race and an accusump IMO
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Old 06-26-2009, 12:51 PM   #23
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Quote:
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I agree. Which is why you should always run a little more oil for road race and an accusump IMO
+1, and run the biggest breather lines you can. I run 3/4 for the crank and 1/2 for the heads.

-Duncan
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Old 06-26-2009, 01:35 PM   #24
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+1, and run the biggest breather lines you can. I run 3/4 for the crank and 1/2 for the heads.

-Duncan
Yeah i've just got 1/2" on both lines.

I usually run 5qts instead of the 4.8... but I have also heard bad things about running too much oil. So I didn't want to push that line.

I'm getting the car to my buddies shop this afternoon to run tests. I'll report back after that.

Thanks again for all help, I appreciate it.
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Old 07-01-2009, 03:05 PM   #25
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Just a quick update. Scheduling conflicts have prevented me getting the car to my buddy's shop. It should happen by the end of the week.

Here are a couple of theories that I think are possible:

1) The crank case is pressurized by having a restriction on the PCV breather line (maybe the foam in the catch can is too restrictive). This would not allow oil from the turbo to drain back into the pan. So the oil backed up into the head, and had no where else to go but the catch can. I think if this were the issue, the PCV catch can would have been catching a lot of blow by. BUT it could cause the turbo seal to be blown if it was deluged with oil.

2) There is a restriction in the oil line going to the turbo (coming off the head at the banjo bolt). Since oil couldn't get to the turbo, it failed. The oil line that feeds the turbo also feeds the right side AVCS. So theoretically it makes sense that if there was a restriction, then the AVCS wasn't functioning properly (hints the stutter at high RPM -- the cam wasn't advancing). The infamous "screen" in the bajo bolt HAS been removed.

3) The oil passage in the head is cracked. Oil pressure is filling the valve cover/cam area, but not feeding the turbo and AVCS with oil pressure.

What I don't know is the how the oil is routed through the head until it gets to the "T" at the banjo bolt. Or if it is possible for that line to be restricted and force oil into the cam/valve cover area.

What say you?
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