smoking before and after replacing turbo.HELP!

[UPSIDE-DOWN-FACE]

i developed a smoking issue on my '88 Z. smoked after start up and at idle. doesnt smoke when driving or in boost. just when i let off the throttle and idle. found that the turbo was bad. lots of in and out and side to side, fins broke and exhaust housing cracked. replaced it and i still have the same problem. the new turbo is fine. spools good and real tight. what could be the problem?

thanks
kyle

[CSXT802]

Intercooler full of oil would be my guess.

[UPSIDE-DOWN-FACE]

i thought that too. but its been 3 weeks since i replaced the turbo. oh and there is still oil coming out the side exit exhaust.

[Chris W]

i thought that too. but its been 3 weeks since i replaced the turbo. oh and there is still oil coming out the side exit exhaust.

After 3 weeks of driving any residual oil would have burned off.

Chris-TU

[tryingbe]

What are you doing for the PCV system?
What are the compression number?
What are the leak down test number?

[UPSIDE-DOWN-FACE]

pcv tube goes to the ground.
compression is 140 on all cylinders
havent done one yet.

[cordes]

pcv tube goes to the ground.
compression is 140 on all cylinders
havent done one yet.

You need to get that hooked up to the air intake pipe with a catch can in between. It's just good sense.

[tryingbe]

And you're not using a PCV valve, right?

[UPSIDE-DOWN-FACE]

nope.

[CSXT802]

2nd guess Bad valve guides and or guide seals.

[Chris W]

I put together this checklist. Hopefully it will help you out.

EXHAUST STILL SMOKES:

There are many things, which could cause a new or rebuilt turbo to smoke.
Here are just a few common causes and their solutions:

#1
Cause: Existing oil in exhaust system still burning off from previous turbo
failure.
Solution: Continue running car until smoke disappears. Plan on replacing
Catalytic convertor soon because burnt oil will quickly restrict air flow and
lead to other problems later including turbo failure.

#2
Cause: Oil pressures build up in Turbo Bearing Housing caused by one or all of
the following reasons:

1) Restriction in oil drainback tube/line.
2) Oil feedline pressure exceeds drainback tube capabilities.
3) Blow-by in crankcase caused by worn engine, cracked pistons,
rings, faulty PVC systems, etc.

Solution: 1) This could be caused by one or all of the following three things:

a) Wrong type of drainback hose.
Verify there are no foreign objects in drainback tube/hose.
This could be the paper towel or duct tape you placed there during the
removal of your original turbo to prevent anything from falling in to your
oil pan during the swap. This also includes not using the factory silicon
drainback hose. These are heat and oil resistant hoses where most other
hoses cannot withstand these extreme conditions for very long. Most
automotive hoses are actually 2 hoses (inner and outer) separated by braided
nylon. When this is used in place of the silicon hose the nylon can actually
shrink from the heat restricting the inner hose while leaving the outer hose
looking perfect from the outside. Use the factory hose whenever possible.
There are no advantages to using any other type of hoses for this
application. Turbo removal not required. Once issue is addressed piston
seals should reseat on their own and oil seepage will no longer be a problem.
b) Oil return flange gasket issues
This is a “dry” gasket so do not use RTV on it. Even the slightest bit that
may get squeezed into the flow of the return oil will impede the gravitational
flow of oil back into your oil pan. Pressure will build up in the turbo bearing
housing to the point where oil is pushed past the seals. Remove all RTV from the
area and replace the gasket. Seals will reseat on their own.

c) Wrong oil drainback line angle.
Turbo oil drainback is powered only by gravity. Angles in excess of 20
degrees will impede oil return flow and pressure build up in the bearing
housing may result. Also be sure to maintain a smooth curve from turbo to
engine and prevent any kinks in the line, which may cause a back-up and
eventual pressurization of the bearing housing.

2) Verify oil pressure is not excessive. 60 PSI at idle for a
warmed up engine is WAY too much. 10psi per 1000 RPM is a good rule of
thumb. To much oil can pressurize the turbo bearing housing if the gravity fed
drainback cannot keep up. This pressurization will force the oil past the turbine
shaft piston seals and into the exhaust or compressor side of the turbo.
Over time, too much pressure can actually be harmful to your entire engine.
With excessive pressure, impurities in your oil can actually eat away at your
bearing surfaces and increase tolerances much like extrude honing works.
Conclusion: Don't use the MP Oil Pressure Relief Spring Kit unless you
absolutely have to but remove it right away if your turbo smokes. Turbo
removal not required. Once issue is addressed piston seals should reseat on
their own and oil seepage will no longer be a problem.

3) Crank cases pressurized by blow-by can also cause oil to be
forced past the turbine shaft piston seals. Complete a compression check and
leakdown test to check the condition of your engine. There is also a blow-by
detection tool which is placed over the oil cap opening while the engine is
running and measures crank case pressures. Be sure to inspect your crank
case evacuation system to make sure the issue is not being caused by a bad
PVC valve. If you find your oil dipstick out of the tube a few inches after
some spirited driving you are most likely experiencing blow-by. Turbo
removal not required. Once issue is addressed piston seals should reseat on
their own and oil seepage will no longer be a problem.

If you have any questions about the above don’t hesitate to contact us.

GOOD LUCK!
Chris-TU
602-76-BOOST

[UPSIDE-DOWN-FACE]

wow thanks Chris that is real helpful. i have noticed my oil pressure is way high for a while. just below the H. stays there till the car is driven for about 15 minutes than goes normal. what could cause that?

[Chris W]

wow thanks Chris that is real helpful. i have noticed my oil pressure is way high for a while. just below the H. stays there till the car is driven for about 15 minutes than goes normal. what could cause that?

Your oil pump spring may have been upgraded or you may have a Mellings high pressure/volume pump.

Chris-TU

[OmniLuvr]

i put the wrong oil in my omni, 20w-50, and the oil pressure shot up past half at idle and i had blue smoke coming out of the exhaust ( i think the turbo seals were pissed ). switched the oil back to 10w-30 and the smoke went away.

[UPSIDE-DOWN-FACE]

i run 10-30 syn.

[MopàrBCN]

I'd like to add on Chris' comments:

1. I ran the PCV a while like you did (I.E. don't use one at all and lost that way on one trip (1000 km) 2 and 1/2 quarts through the dipstick and any place oil can get out. My solution was to reconnect the PCV System as Stock and did not lose any more oil.

2. When I replaced my turbo we poured easily 2 liters of oil only from the intercooler. So if you did not clean that out be prepared to have oil to entertain your intake for a while. Maybe just take one free afternoon and get busy cleaning!

[UPSIDE-DOWN-FACE]

i took the IC hoses off and sprayed air in the top and hardly any oil came out the bottom. is air enough or what should i do to clean the IC? it is stock.

[cordes]

i took the IC hoses off and sprayed air in the top and hardly any oil came out the bottom. is air enough or what should i do to clean the IC? it is stock.

I would remove it from the rad and drain any excess oil out of it. I might even shoot a little carb cleaner up there to get some of the residue out.

[capeglh]

Kyle,
Did you ever figure out the problem?
I'm having the same exact issue!

Thanks

[rosie]

I would remove it from the rad and drain any excess oil out of it. I might even shoot a little carb cleaner up there to get some of the residue out.

Just weld a drain plug to the bottom of the IC!!

I run heavy oil and no smoke. If you have oil (you mean smoke?) out the exhaust AFTER you fix your PCV system (don't have to run it to the intake but put the mopar PCV valve back in! ) then I would go through Chris's list.