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Old 06-22-2009, 11:44 AM   #1
Scooby Specialist
Member#: 106470
Join Date: Feb 2006
Chapter/Region: NWIC
Location: Kent WA
2004 GT-1 ICSCC #9

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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