Smoking turbo info from another forum

[amascio]

for what it's worth..Here's a post I found on an SRT forum:

If you have a car that resembles a James Bond tricked out SRT-4, please take the time and check this out.

A turbo drains its oil from gravity, nothing more and nothing less. If there is any restriction in the turbo's drain path back to the pan, oil will build up in the center housing. This oil is going to take the path of least resistance and will leak out of the turbine's side piston ring and turn into blue smoke coming out of the exhaust.

Most of your friends are going to tell you that you have a blown seal, and that your turbo needs to be rebuilt. 99% of the time, there is nothing wrong with the turbo. We get turbos in the shop everyday for rebuild because of the mysterious "blown seal" theory that lingers around every intarweb forum that deals with any turbo vehicle. These turbos are perfectly fine, and don't need a rebuild 99% of the time.

I'm putting this explaination together to help all of you save time and energy before you feel the need to send a turbo back to us for rebuild.

Lately, we've noticed a trend with some of the available "check valves" in this market that some shops are selling. Moreso, there are part numbers floating around this forum from industrial supply companies that many people are buying and installing. Most of these check valves will not work properly to allow enough crankcase venting so the turbo can sufficiently drain.

We've done some testing here with a local car and we were able to figure out what was going on. The very popular 1/4"NPT check valve has a .200" valve that is insufficient in allowing the engine to pull enough crankcase pressure when in vacuum. This extra crankcase pressure under vacuum conditions will cause the turbo to leak oil past the piston ring and results in blue smoke out your exhaust. Get rid of this size check valve as all your are doing are causing more problems for yourself.

That same company offers a check valve with 3/8" NPT ports and the valve size is .460". This valve is FTW, period.

We put the 1/4"NPT check valve on the car, let it sit at idle for 30 minutes. After about 20 minutes, the car started smoking, and got progressively worse over the next 10 minutes. Keep in mind, this is on a car that never smoked before. We then installed the 3/8" NPT check valve on the car and let it idle for 30 minutes. No smoke at all. We then put the smaller check valve back in, and instantly started smoking again.

 

[MS3_Kendall]

for what it's worth..Here's a post I found on an SRT forum:

If you have a car that resembles a James Bond tricked out SRT-4, please take the time and check this out.

A turbo drains its oil from gravity, nothing more and nothing less. If there is any restriction in the turbo's drain path back to the pan, oil will build up in the center housing. This oil is going to take the path of least resistance and will leak out of the turbine's side piston ring and turn into blue smoke coming out of the exhaust.

Most of your friends are going to tell you that you have a blown seal, and that your turbo needs to be rebuilt. 99% of the time, there is nothing wrong with the turbo. We get turbos in the shop everyday for rebuild because of the mysterious "blown seal" theory that lingers around every intarweb forum that deals with any turbo vehicle. These turbos are perfectly fine, and don't need a rebuild 99% of the time.

I'm putting this explaination together to help all of you save time and energy before you feel the need to send a turbo back to us for rebuild.

Lately, we've noticed a trend with some of the available "check valves" in this market that some shops are selling. Moreso, there are part numbers floating around this forum from industrial supply companies that many people are buying and installing. Most of these check valves will not work properly to allow enough crankcase venting so the turbo can sufficiently drain.

We've done some testing here with a local car and we were able to figure out what was going on. The very popular 1/4"NPT check valve has a .200" valve that is insufficient in allowing the engine to pull enough crankcase pressure when in vacuum. This extra crankcase pressure under vacuum conditions will cause the turbo to leak oil past the piston ring and results in blue smoke out your exhaust. Get rid of this size check valve as all your are doing are causing more problems for yourself.

That same company offers a check valve with 3/8" NPT ports and the valve size is .460". This valve is FTW, period.

We put the 1/4"NPT check valve on the car, let it sit at idle for 30 minutes. After about 20 minutes, the car started smoking, and got progressively worse over the next 10 minutes. Keep in mind, this is on a car that never smoked before. We then installed the 3/8" NPT check valve on the car and let it idle for 30 minutes. No smoke at all. We then put the smaller check valve back in, and instantly started smoking again.

I have experienced white smoke only at idle.

 

[wisniaPl]

maybe try it you will know if it works

 

[ericrapp]

That explanation is significant in detail and reasoning. thank you amascio

 

[Super Unique]

I have had my own theory about the smoking issue but haven't mentioned it before. This post definitely got me thinking again. Clearly the stock PCV design is suspect, and this discussion re: check valve certainly puts further ammunition behind my chain of thought. What still puzzles me is why sometimes it doesn't show up until people start getting into heavy exhaust mods. I guess more flow through the engine leads to an overwhelming of the stock designed PCV system. The aftermarket company who seriously dives into the PCV system on this car is guaranteed some good sales.

 

[john blutarski]

I posted that on the other forum. I was thinking we need a way to increase the flow of the turbo oil drain line or the PCV system is suspect also. The oil is probably on the verge of getting by the seals and then when you open up the exhaust with a DP, all hell breaks loose.

 

[SharkDiver]

Where are they saying we need to install this CV?The one that goes to the TB Intake or the one coming out of the block going to the intake mani. or are these not even suppose to take the place of our stock pcv?Also Im wondering if this 3/8" NPT check valve will fit our car.

 

[ericrapp]

subscribed

 

[john blutarski]

How about this theory... at idle oil flow through the turbo is the lowest and since your not boosting, there is no pressure on the compressor side of the turbo. Having an aftermarket downpipe/free flowing TBE creates more of a chance for this:

"The turbo's oil seals depend upon a positive air pressure inside the compressor and turbine to "push" the oil inside the bearing housing and keep oil from seeping into the outer housings. In an inlet restriction situation, the vacuum wants to "pull" the oil past the oil seals. Prolonged oil leakage into the compressor can lead to oil seal damage and excessive engine smoking."

"Prolonged engine idling also can cause turbocharger oil seal failure, this time on the turbine side. Continued idling causes the turbo to rotate without producing boost. Consequently, a vacuum condition on the turbine side tries to "pull" oil past the turbine-side oil seal and into the turbine housing."

 

[viper117630]

Has there been any stock MS3's with the smoking turbo or just ones with a modified exhaust? I thought about a Turbo Back but dont want to risk it if thats the reason.

 

[lestat13]

I've heard of stock/stock exhaust mazdaspeeds smoking. I was worried but went dp/rp and so far so good!

 

[john blutarski]

Some people have smoked stock, others with DP's. I think I'm just going to get a damn DP since eventually the thing will smoke no matter what. I'll just cross that bridge when I come to it.

 

[lestat13]

Go for it, I did and I wasn't disappointed.

WARNING!! You might need to replace one or both oxygen sensors. The threads have a tendency to strip on their way out. Mine did and I only had 6k on the car! At least check and see if the shop can rethread if needed.

 

[dkswim]

white smoke it up