IanM

Hey guys,
My 951 has contracted a bit of a problem, and I would much appreciate some input on the issue. The motor is a rebuilt 2.5L w/ about 25K miles on it, runs very strong, lots of mods including a T04E 50 trim Garrett hybrid w/ #8 hotside and an MAF.

Lately, I've been having a problem with oil (blue) smoke. When I first start the car, no smoke, runs fine. However, after about 5-10 minutes of either idling or driving (ie. once it reaches operating temperature) I get quite a bit of blue smoke out the tailpipe. After a few minutes of driving the smoke clears and never comes back. However, if I then stop the car and let it idle for awhile, smoke will come back again, and it will keep smoking at idle or very light cruise until I start running it through the gears again. So, it seems the problem only occurs in a vacuum situation, when the engine is at full operating temp.

I inspected the plugs, and all are fine except #4, which is somewhat wet and has carbon buildup on it. Compression test shows all cylinders to have high compression, w/ #4 actually being about 10psi higher than the others. BTW, I have an AEM wideband, and the a/f ratios are perfect. After reading some posts on Rennlist, I'm wondering if the #4 valve stem seals may have popped off the guides. Or, is it possible the problem could be related to the turbo seals (this is a Huntley Stage2 turbo built by Majestic, and has run flawlessly for the past 3 years) and/or a plugged crankcase breather system?

Thanks guys...

daniel951

didn't huntley racing say to run oil restrictors in their turbos? just a thought but since it was rebuilt by majestic i have no idea.

David Floyd

Valve stem seal is what I was thinking, since occurs under vacuum.

You could do a leakdown test to check overall engine condition.

cas951

When my turbo went out I had the exact symptom. My car ran perfectly fine untill 5-10 minutes later or Eng temp reaches operting temp than it would smoke. It turns out I had a bad turbo seals as I had a 1/2 inch free play on the turbine shaft. I would suspect that the seals on the turbo is leaking slightly but the leak is not bad enough to show while you are driving. I think the reason it shows after you shut it off is , The turbo still spins freely for several minutes after shut off and the leak will build up while it is spinning and the oil is not being burned. When you start up the car there is enough oil buildup that it's noticeable when the car reaches operating temp.

The # 4 cylinder showing 10 PSI higher than the other 3 cylinder seems to indicates that your valve stem seals are leaking oil which is lubricating the piston rings which gives you higher compression readings. Try doing a compression test while it's cold and see if there is any difference.

IanM

Thanks guys. No, Huntley did not recommend a restrictor, at least not to me. It's been running fine for 3 years with no restrictor. To clarify - the turbo wasn't rebuilt by Majestic, it was built by Majestic. I believe Derek had all his turbos built by them.

fast951

Do a search on all bad turbos, see what they have in common!

rage2

Seems like everyone's having the exact same symptoms lately (including me). I had my turbo done by TEC, and no restrictor. Turbo's coming off next week, going to have Alamo redo the seals locally and rebalance it. This time, restrictor is going in just in case.

Zero10

Interesting, I have the same problem!

If I idle for perlonged periods of time, i.e. in heavy traffic, every time I get it over 2000rpm it smokes BADLY. I go through about 16-20L of oil per week. However, it only burns oil on #4. If I drive it really hard, the smoke will go away after a couple runs to 5500RPM, and won't return until I take it easy for a while. I was s***ing bricks thinking it was the rings on #4, but it seems like you have the same problem as me!

Again, my compression was 151 on the first 3, and 165 on #4. I presume this is due to the excess oil in that cylinder. In my case, it was on a fresh rebuild though. It was a stock K26/6, with no measurable shaft play in any direction, although there seems to be a bit of oil in the intake now.

Be sure to post with what you find!

rage2

Good to see I'm not the only one polluting and annoying the hell out of other Calgarians lol.

hosrom_951

Dude,
16-20 Liters of oil per week is just over doing it, you rebuilt the engine and all............but that is just too much (way too much).

How did you pin point it was #4??

Zero10

I looked at the plug. It's just BURIED in soot and carbon and crap.

Yep, pissing calgarians off left, right and center

I ran at secret street on friday, and I was told that you could see exactly where I ran from my smoke trail. When I passed the finish line, the smoke was still hanging there from when I started... It's sick.

I can't afford to keep dumping oil in like this, but I'm certain it's not rings, so I'm looking for all other explanations. I might rebuild the turbo just to be certain...

Anyhoo, the oil usage has come down a little bit... It used to be 20-22L, now it's about 16-18L per week. Not perfect, the guys at the local parts store think I'm doing oil changes 2-3 times a week. The most amazing thing, is even with all this oil burning, my oil is just black after only a couple hundred miles...

rage2

Oh, that was you in the 951. I was in the white turbo civic with the beat up body trying to find traction .

Zero10

Hmm, drawing a blank on the civic. I recall a couple other cars there, but for some reason the civic isn't coming to mind. That skyline was busy destroying my vision, so perhaps I missed it. All those bright flourescent colors...

We were all trying to find traction that night. I got mine pretty sideways a couple times. I've never tracked a car with LSD before. I'm not used to the lack of control when you hit the gas too hard, but I really like the extra traction, so I'll live. That big puddle on the infield almost took my car from me. I hit it at about 105-110, and it went right over the windshield, so I was driving out my driver's side window, trying to hit my wipers while making the hard left, and I came in too hot, almost went off the outside into the wall, it got kind of crazy. I see why people don't like racing in the rain!
I went through almost a full 4L jug that night, and I only had 4 or 5 runs.

rage2

What kinda times were you running? When my car was just chipped, I was running 14.0's at 99mph at race city. You haven't seen running in the rain till you run the full roadcourse in full wet conditions. The front straight, being part of the drag strip and prepped with VHT, does not mix well with water. Over the years, I've seen about 10 crashes and 3 writeoffs in the rain on the front straight!

The civic wasn't noticable, it's pretty beat up, doesn't look fast. With 35% less boost in 1st and 15% less boost in 2nd to control wheelspin, I was able to run a few 13.6's even though the charge piping is coming loose and loosing boost in 4th and 5th. Not bad for 195's street tires! Aiming for mid to high 12's once the car's sorted out on street tires, should be able to run low 12's with slicks.

IanM

Okay Rage...focus!!

So, from Vitesse John's response, I'm assuming this may be the turbo afterall? I'm still confused as to why it would not smoke at startup when cold, then start smoking for a bit when first reaching operating temp, then no smoke while driving (unless stuck in traffic and have to sit at idle for several minutes). If it was the turbo seals, why does it stop smoking when I'm driving normally and only smoke in a vacuum (idle or very light cruise) situation?

I guess I'll take it from here, and let you guys know what the problem is once it's been solved. Thanks.

- Ian