R33 Rb25det Smoking Purple/blue... Help!

[Nick378]

Hey guys i have a major issue with my car i think.

Here it is: each time i'm going in boost (over 4300 rpm) and i release the accelerator, there's a cloud of purple/blue smoke that come out.

I thinked first that it was the turbo's seal but i don't think since it's the 3rd turbo i put in and i still have the problem.

Fact i know.

There's always oil in my intake piping (where the maf is) before the turbo.

I took a compression test. 110 psi on all cylinder and 140 psi with oil in.

Turbo (journal bearing) have a small shaft play after only 10 minutes of running. Maybe it's normal for a journal bearing, if not, i don't know what can cause this.

So what do you suggest?

Change the motor? i got stock internal on my setup so it's not a issue for me.

Can i still run the car with ticker oil? maybe 5w50 without killing my turbo again?

I know that with 110 psi, the engine is gone. but what can explain the oil in the intake piping and the turbo shaft play?

Thx if any of you have some clues.. i'm totally lost and without money...

[R34GTFOUR]

110psi? The motor sounds like its very tired and ready for a rebuild. My guess is that the rings (both oil and compression) are buggered.

If the rings aren't sealing its going to have excessive piston blow-by which will result in your cam cover breather throwing oil into your intake. If you took out your intercooler you'll probably find that its got a lot of oil in it aswell.

Cheap bandaid? A well setup catchcan

To fix, it needs a freshen up rebuild.

Personally i would keep driving it until it said no more

[MR FLWLSS]

Dude dont jump to conclusions and dont stress. the simpleest answer is often the correct one.

First thing is first:

1. check the PCV (Positive Crank Case Ventalation) Valve is in good woring order. quite common for them to get full of crap and jam up. if this is the case, soak it in carbie cleaner for about half an hour to an hour.

2. have any of the breather pipes been changed? if so check the one between the passengers side rocker cover and make sure the brass pill (restrictor) is still in it.

3. Have u performed the compression test right. and by right i mean did u remember to diconnect the crank angle sensor, and have the throttle wide open when doing the test.

4. Do you have a Blow off valve venting to atmosphere, if so as you back off the throttle, the air bypasses the airflow meter and is unmetered. the air flow meter takes into account the air that is dumped back into the inlet of the turbo on a standard set up, however if u vent to atmosphere the afm doesnt know that air isnt being pumped back into the system, causing a rich mixture and inturn smoke, stalling or rough idle on stopping..... so if you have changed the bov, change it back.

5. Bum fuel pressure reg. (regulator not functioning correctly)

and etc, etc,

perform process of illimination, and if your unsure or dont know what u are doing take it to a mechanic that does.

as a mechanic thats the best advice i can give without seeing, hearing, or driving the car.

hope this is of some help.

[Nick378]

Dude dont jump to conclusions and dont stress. the simpleest answer is often the correct one.

First thing is first:

1. check the PCV (Positive Crank Case Ventalation) Valve is in good woring order. quite common for them to get full of crap and jam up. if this is the case, soak it in carbie cleaner for about half an hour to an hour.

2. have any of the breather pipes been changed? if so check the one between the passengers side rocker cover and make sure the brass pill (restrictor) is still in it.

3. Have u performed the compression test right. and by right i mean did u remember to diconnect the crank angle sensor, and have the throttle wide open when doing the test.

I did the test at wot. But i did not disconnect the sensor, i never disconnected it on any car before so i didn't knew.

4. Do you have a Blow off valve venting to atmosphere, if so as you back off the throttle, the air bypasses the airflow meter and is unmetered. the air flow meter takes into account the air that is dumped back into the inlet of the turbo on a standard set up, however if u vent to atmosphere the afm doesnt know that air isnt being pumped back into the system, causing a rich mixture and inturn smoke, stalling or rough idle on stopping..... so if you have changed the bov, change it back.

I have a atmospheric BOV but i did the tuning perfectly with it. The problem appeared on the highway when i was boosting it at 19 psi. If it was the BOV i would have appeared at the beginning i guess.

5. Bum fuel pressure reg. (regulator not functioning correctly)

I dont have fpr. But again the tunning was perfectly done without one.

and etc, etc,

perform process of illimination, and if your unsure or dont know what u are doing take it to a mechanic that does.

as a mechanic thats the best advice i can give without seeing, hearing, or driving the car.

hope this is of some help.

I'll look at the first and second point this afternoon.

Someone else told me about the blow by and told me that a catch can would be effective.

What is the best catch can setup for my case?

I think the turbo has shaft play because of the oil he's absorbing, oil that don't have to be here.

[hypergear]

Well when you are accelerating the manifold pressure forces the shaft to sit against its seals to prevent any leaks plus with great exhaust flow you probably wont notice it.

When it slows down the manifold pressure drops, by that point bit of oil slips. So you see smoke.

If this only happens to the turbine end then it means turbo need overhaul, or If you have breather or crankcase problems turbo would be leaking though both ends.

[James_03]

Check that you have performed the comp test correctly, if it still comes up at 110psi then just start saving for a rebuild IMO. Do check the PCV valve as mentioned but, blow into the hose and insure air moves through OK in the direction shown by the arrow on the PCV itself. If it's OK just re-install it.

Oil residue before the turbo is not so much an issue, just clean the intake pipe with de-greaser and put it back on. Most cars will have this after racking up a few ks. Excessive oil after the turbo but or in the intercooler can indicate turbo failure. I think it's unlikely in this case but if you have replaced the turbo with a good unit. Most journal turbos will show a small amount of shaft play, just remember if there's no oil in the cooler piping then 9 times out of 10 you can rule out turbo.

I would skip the catch can all together, it's a bandaid fix that more than likely won't fix the issue anyway which is excessive blow by due to bad rings. Take the money you would have spent on a can, and put that towards rebuild money.

Or just pickup another wrecker rb20 again, comp test it, then get back to limiter smashing.

Edited July 9, 2009 by James_03

[Nick378]

Alright guys... i will begin to save for a rebuild. I will do it by myself so it won't be too pricy.

While i put the money aside, i will run the car no matter what i have no choice... do you have any advice on the kind of oil i can run? I was thinking about a thicker oil like 5w50 non synthetic. But i'm not too sure...

As for the rebuild.

What do i need to buy exactly?

Main bearing, new ring, connecting rod bearing, head asket, arp stud, what else?

Thx for your help guys it's more than appreciate

[Guilt-Toy]

i have a question.

What if the compression tester he is using is 20 or 30psi out ? maybe its old or reads low?

the engine has the same compression across the whole board so the engine should still be in workable condition, especially if the compression tester is out.

my opinion would be to install a decent oil catch can setup and take the turbo off and get it checked then see how you go with it.

[James_03]

You would think after swapping 3 different turbos in that you could probably safely rule out the turbo. Unless all 3 that went back on all had issues.

A tired motor can still show up a fairly consistant result if no major ringland/bore damage has occured. Then add to the fact that the compression ratio raised to 140 when he used oil, that in most cases = rings

By all means try a catch can, I just don't think it even has half a chance of fixing a motor with bad rings. Add to the fact that your just avoiding the inevitable anyway. As for the rebuild, you need to know what power figure your going to chase before you start making your list of items to purchase.

Edited July 10, 2009 by James_03

[Nick378]

i won't chase anykind of power. I still have 454 whp at 19 psi. But i run that power on a oem rb25det so i will have to buy a tomei headgasket and arp stud for sure. I think i'll go with oem bearing and ring since i have no money left. I need it for the university

Maybe you have a better idea.

My compression tester is very old but i did it last summer and i had 145 on all cylinder with the same tester. So there is obviously something going wrong.

Any idea on the kind of oil i can run to make the motor last a little bit longer? I won't push it to the limit no more. I run the boost controller off at 10 psi.

My idea is to run it a couple of week with thicker oil while i'm buying the parts for the rebuild.

I just have to make sure i won't break something else like my head or my turbo.

I think i can do the rebuild without spending more than 1400$

[Nick378]

i droped 20w50 valvoline non synthetic today and it's way better!! The engine is running very well and the smoke is almost gone. I know it doesn't solve the problem but i think i could do a while whit the engine! I fund another one to rebuild. This way i won't lose my car for 3 weeks!

[GT-RZ]

Go and find some Rb30's in a wreckers and rip it apart until you find a perfect one. rebuild it with new bearings and rings with a hone and your done. will be an improvement and cheaper . Or if you really have a budget go and do some comp tests on some Rb30's untill you find a nice one then just chuck the head on.

Far rather do that than buy a 25 and rebuild that, unless you got it for less than $150 my shortblock cost me $88 from u-pull it. Got two now.

[kwickr33]

For bugget option, Get your self a dead R34 turbo send it to HyperGear for $800 high flow. Seen plenty of good results. They are traders here.

Edited July 14, 2009 by kwickr33