Blow-by from turbo causing detonation? B/S or possible?
05-23-2009, 09:44 AM
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Blow-by from turbo causing detonation? B/S or possible?
Well my mom just got some work done to the Z.
She took the car in b/c it was making a funny sound after 4k rpms, and only under boost. She assumed it was the turbo, took it to the shop and they test drove it and claimed the motor was detonating.
They had the motor out and sent the turbos off to get checked out (PE1420s). Passenger side is newish, so it was fine for sure, the other has been leaking oil for over year and half now. The fins on the compressor side of the driver turbo are chewed up in the middle of the fins, yet the turbo place said they are fine, and all the seals are good. WTF.
so they put her motor back in yesterday. Started the car up w/o cats and noticed smoke coming out of the driver side. So they do a leak down test on only 2 cylinders (weird). Cyl 2 has 60% leak and Cyl4 has like 5-6%. So they don't even bother to leak test the rest of the motor which i think is total B/S. And i talked to them today and they refused to test the rest of the motor, b/c he claims it is pointless and to much work.
The shop owner claims that the oil vapors from the leaking turbo are cause the motor to detonate under heavy load. I've never in my life heard of something so unbelievable.
Also the motor sat around the shop for 3 weeks while the turbos were shipped off. Not once did they even bother to pull off the the heads to check what kind of damage may have been caused by the detonation. He claims there was no need for it. Which i think is total crap.
What are your opinions?
for reference, list of mods:
PETT kit
APS tall boy
borla TD
Deatchwerks 600cc injectors that were just installed( replace 390cc)
UTEC
car was tuned for 5psi making about 350whp
motor has about 60k miles
VQ35DE(2004)
at this point it looks like she might just go back to stock motor, or rebuild it. not really sure either way the car prolly wont move for the next year or so.
She took the car in b/c it was making a funny sound after 4k rpms, and only under boost. She assumed it was the turbo, took it to the shop and they test drove it and claimed the motor was detonating.
They had the motor out and sent the turbos off to get checked out (PE1420s). Passenger side is newish, so it was fine for sure, the other has been leaking oil for over year and half now. The fins on the compressor side of the driver turbo are chewed up in the middle of the fins, yet the turbo place said they are fine, and all the seals are good. WTF.
so they put her motor back in yesterday. Started the car up w/o cats and noticed smoke coming out of the driver side. So they do a leak down test on only 2 cylinders (weird). Cyl 2 has 60% leak and Cyl4 has like 5-6%. So they don't even bother to leak test the rest of the motor which i think is total B/S. And i talked to them today and they refused to test the rest of the motor, b/c he claims it is pointless and to much work.
The shop owner claims that the oil vapors from the leaking turbo are cause the motor to detonate under heavy load. I've never in my life heard of something so unbelievable.
Also the motor sat around the shop for 3 weeks while the turbos were shipped off. Not once did they even bother to pull off the the heads to check what kind of damage may have been caused by the detonation. He claims there was no need for it. Which i think is total crap.
What are your opinions?
for reference, list of mods:
PETT kit
APS tall boy
borla TD
Deatchwerks 600cc injectors that were just installed( replace 390cc)
UTEC
car was tuned for 5psi making about 350whp
motor has about 60k miles
VQ35DE(2004)
at this point it looks like she might just go back to stock motor, or rebuild it. not really sure either way the car prolly wont move for the next year or so.
05-23-2009, 10:05 AM
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First off. You're mom is cool for having a turbo z.
Second, I dont think detonation can occur from blowby.
and third, 60% is wow. And taking off these heads are really a pain in the *** so i can understand them not wanting to take it off. Now is everything being done for free or are they chargin you?
Second, I dont think detonation can occur from blowby.
and third, 60% is wow. And taking off these heads are really a pain in the *** so i can understand them not wanting to take it off. Now is everything being done for free or are they chargin you?
05-23-2009, 10:17 AM
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Not all of this applies, but some good info
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: This could be caused by one or all of the following three things:
a) 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) Crankcases 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 crankcase 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.
#3. Further diagnosis:
Check the plugs to see if they show any signs of oil.
If the plugs are dry then the source of oil is either from the exhaust valve seals or the turbo. Replace the exhaust valve seals and hopefully the problem will be cured. If not you may be in the market for a new turbo or rebuild.
If all the plugs are wet then check the turbo to throttle body hoses for signs of oil.
If the hoses are wet inside the oil could be coming from either the turbo or PVC system. Check the PVC system and replace any items which may be faulty and causing the problem. Clean the hoses and see if the oil returns after some driving. If signs of oil return in the hoses then you may be in the market for a new turbo or rebuild. If the hoses remain clean but you are still burning oil then you need to look at the combustion chamber for the source of oil. Complete a compression check and leak down test on all cylinders. You may find that the plugs showing signs of oil are the cylinders with the lowest compression. Squirt some oil in each of the low compression cylinders and recheck compression. If it goes up then you have a ring/cylinder wall related issue. If the compression remains unchanged then you have a valve or head gasket related issue. In either case the head needs to come off to visually inspect to determine the cause.
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: This could be caused by one or all of the following three things:
a) 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) Crankcases 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 crankcase 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.
#3. Further diagnosis:
Check the plugs to see if they show any signs of oil.
If the plugs are dry then the source of oil is either from the exhaust valve seals or the turbo. Replace the exhaust valve seals and hopefully the problem will be cured. If not you may be in the market for a new turbo or rebuild.
If all the plugs are wet then check the turbo to throttle body hoses for signs of oil.
If the hoses are wet inside the oil could be coming from either the turbo or PVC system. Check the PVC system and replace any items which may be faulty and causing the problem. Clean the hoses and see if the oil returns after some driving. If signs of oil return in the hoses then you may be in the market for a new turbo or rebuild. If the hoses remain clean but you are still burning oil then you need to look at the combustion chamber for the source of oil. Complete a compression check and leak down test on all cylinders. You may find that the plugs showing signs of oil are the cylinders with the lowest compression. Squirt some oil in each of the low compression cylinders and recheck compression. If it goes up then you have a ring/cylinder wall related issue. If the compression remains unchanged then you have a valve or head gasket related issue. In either case the head needs to come off to visually inspect to determine the cause.
Last edited by coachk; 05-23-2009 at 10:21 AM.
05-23-2009, 09:16 PM
#6
If the turbo seals are leaking significant oil on the compressor outlet side of the turbo and blowing oil into the motor... it can cause detonation. You would likely see oil in the intercooler pipes if this is the case.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
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05-24-2009, 07:17 AM
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If the turbo seals are leaking significant oil on the compressor outlet side of the turbo and blowing oil into the motor... it can cause detonation. You would likely see oil in the intercooler pipes if this is the case.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
the car is down in Florida where she lives.
I never knew blow by/oil leak could lead to detonation. I usually dump a half a qrt of oil out of my SR ever couple of months, but that got alot better after i replaced my blown turbo and got a catch can. But i guess the engineered boosted motors withstand the punishment better b/c when i did my h/g the pistons and cylinder walls still looked really good.
05-25-2009, 06:13 PM
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Well my mom just got some work done to the Z.
She took the car in b/c it was making a funny sound after 4k rpms, and only under boost. She assumed it was the turbo, took it to the shop and they test drove it and claimed the motor was detonating.
They had the motor out and sent the turbos off to get checked out (PE1420s). Passenger side is newish, so it was fine for sure, the other has been leaking oil for over year and half now. The fins on the compressor side of the driver turbo are chewed up in the middle of the fins, yet the turbo place said they are fine, and all the seals are good. WTF.
so they put her motor back in yesterday. Started the car up w/o cats and noticed smoke coming out of the driver side. So they do a leak down test on only 2 cylinders (weird). Cyl 2 has 60% leak and Cyl4 has like 5-6%. So they don't even bother to leak test the rest of the motor which i think is total B/S. And i talked to them today and they refused to test the rest of the motor, b/c he claims it is pointless and to much work.
The shop owner claims that the oil vapors from the leaking turbo are cause the motor to detonate under heavy load. I've never in my life heard of something so unbelievable.
Also the motor sat around the shop for 3 weeks while the turbos were shipped off. Not once did they even bother to pull off the the heads to check what kind of damage may have been caused by the detonation. He claims there was no need for it. Which i think is total crap.
at this point it looks like she might just go back to stock motor, or rebuild it. not really sure either way the car prolly wont move for the next year or so.
She took the car in b/c it was making a funny sound after 4k rpms, and only under boost. She assumed it was the turbo, took it to the shop and they test drove it and claimed the motor was detonating.
They had the motor out and sent the turbos off to get checked out (PE1420s). Passenger side is newish, so it was fine for sure, the other has been leaking oil for over year and half now. The fins on the compressor side of the driver turbo are chewed up in the middle of the fins, yet the turbo place said they are fine, and all the seals are good. WTF.
so they put her motor back in yesterday. Started the car up w/o cats and noticed smoke coming out of the driver side. So they do a leak down test on only 2 cylinders (weird). Cyl 2 has 60% leak and Cyl4 has like 5-6%. So they don't even bother to leak test the rest of the motor which i think is total B/S. And i talked to them today and they refused to test the rest of the motor, b/c he claims it is pointless and to much work.
The shop owner claims that the oil vapors from the leaking turbo are cause the motor to detonate under heavy load. I've never in my life heard of something so unbelievable.
Also the motor sat around the shop for 3 weeks while the turbos were shipped off. Not once did they even bother to pull off the the heads to check what kind of damage may have been caused by the detonation. He claims there was no need for it. Which i think is total crap.
at this point it looks like she might just go back to stock motor, or rebuild it. not really sure either way the car prolly wont move for the next year or so.
That you feel the advice given is BS or crap may merely speak to your inexperience in a garage (I know that you have 1 1/2 yrs in automotive school, but still...) and not to the facts of this VQ engine and this PE turbo as I know you are pretty well read on the two.
The car will be up and running sooner than 1 yr though. I don't want my Z sitting that long. So keep your eyes/ears peeled
Thanks for enlisting the My350Z community in my issue...curious to see where this thread goes in a few days.
If the turbo seals are leaking significant oil on the compressor outlet side of the turbo and blowing oil into the motor... it can cause detonation. You would likely see oil in the intercooler pipes if this is the case.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
That being said, it sounds like the shop is not very cooperative and somewhat giving you the run around. The heads are not easy to take off and inspect, but they could be a little more thorough it sounds. We are only about 3 hours away from Lima if you need anything.
Thanks Hal...when the car was taken apart there was approx. a quart of oil behind in the innercooler pipes and oil was found behind the compressor wheel. There was smoke after 4.5-5k under boost (or after boost...I wasn't there for that). Oh, and the shop ran the car without cats and oil came out of the drivers side turbo (the one that leaks).
I am dealing with the shop daily as my son currently lives in Ohio. He merely called and spoke with the shop owner and felt the need to make a post. Make no mistakes this shop is taking very good care of me...
I have been informed that another leak test will be performed on that #2 cylinder since a base map has been put on my car now (I had 600cc injectors installed and a tune was needed) and if necessary any other testing that I feel will warrant an accurate diagnosis without wasting money.
Last edited by shezzzhot; 05-25-2009 at 06:16 PM.
05-25-2009, 06:14 PM
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Abzolutely Zexy
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the car is down in Florida where she lives.
I never knew blow by/oil leak could lead to detonation. I usually dump a half a qrt of oil out of my SR ever couple of months, but that got alot better after i replaced my blown turbo and got a catch can. But i guess the engineered boosted motors withstand the punishment better b/c when i did my h/g the pistons and cylinder walls still looked really good.
I never knew blow by/oil leak could lead to detonation. I usually dump a half a qrt of oil out of my SR ever couple of months, but that got alot better after i replaced my blown turbo and got a catch can. But i guess the engineered boosted motors withstand the punishment better b/c when i did my h/g the pistons and cylinder walls still looked really good.
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