Oil Leaking to Intercooler :S

Combine17

Veteran Member
Joined
Aug 14, 2010
Location
Ontario - Hamilton
TDI
2001 Golf GTD
So recently I took apart my vnt15 to clean the vanes. everything went well.

replaced the oil feed line
replaced oil return line
new actuator on the turbo
new silicone vaccum hoses

during all this i noticed the lower intercooler hose was getting disconnected between the pancake hose...so i put it all together again.

After the car was all done it boosted great...spiked to about 23psi in about every gear then went down to 18psi...pulled great

by the way...before all this work it would spike close to 30 psi.

NOW

after driving it around for a month ...and i mean really giving it sometimes i noticed it started spiking a bit more then 23psi...but it would still drop down to 18. It would now spike to about 25/26 psi.

I looked at the lower intercooler hose and noticed there was oil all over it...wasn't dripping but it was covered in oil. Looked like it was coming out of the connection that i put together before (close to the bolt where the lower intercooler bolts up to the car)

is it normal to have that much oil?? i will be talking the intercooler out and disconnecting all those intercooler hoses again to see how much oil there really is...but anyone know what the issue is?

car still drives great...spools up and i can hear the whooshh sound too (with a straightpipe)
 

Corsair

Veteran Member
Joined
Aug 17, 2003
Location
Weedsport, New York
TDI
2002 Jetta GLS TDI 5M
wasn't dripping but it was covered in oil.
That could mean a small amount of oil, or something more. Does the engine dipstick appear to indicate oil consumption? It could be a turbo oil seal going bad and dumping oil into the intake tract. Good idea to inspect the intercooler for oil as you mentioned, sooner rather than later- you don't want to encounter a runaway or hydrolock, if it does happen to be the case that the turbo seal is putting oil into the intake tract. But these setups are known to have normally a small amount of oil wetness in the intake tract. Check the intercooler contents asap!
 

Combine17

Veteran Member
Joined
Aug 14, 2010
Location
Ontario - Hamilton
TDI
2001 Golf GTD
it does burn a bit of oil.
I took out the pancake tubes and there wasnt TOO much oil...not enough to drip. But when i stuck my fingers inside the intercooler there was quite a bit of oil...enough to drip out i would say if i was to tip the intercooler.

I didnt take out the intercooler..i THINK i gotta take off the whole front bumper for that.

And what about this turbo oil seal? where is that located on the turbo? can it be replaced?
 

Corsair

Veteran Member
Joined
Aug 17, 2003
Location
Weedsport, New York
TDI
2002 Jetta GLS TDI 5M
search this forum for runaway
The turbocharger can be thought of as two fan wheels on a shaft, supported by bearings. One of the fan wheels gets spun by the exhaust. The other fan wheel spins because it's on the same shaft, and that's the one that does the compressing of the fresh intake air for your engine. The wheels spin very fast, and they get hot. The turbo has pressurized oil fed to it for the purposes of lubrication and cooling. (That's why it's especially important to use the correct type oil and follow reasonable startup and shutdown procedures with a turbocharged engine).

So, the turbo has oil seals on the shaft to keep the oil inside the intended oil passage. Those seals can fatigue and start to leak (sometimes very slowly, sometimes very abruptly). Depending on which side of the turbo (exhaust or compressor) oil seal begins to leak, the symptoms are different. Exhaust side seal leaking means the lost oil goes out the exhaust. If the leak is small you may not notice it much. If the leak is large you'll notice a large (sometimes embarrassing) plume of smoke in the rearview mirror. This generally doesn't harm the car unless you drive so far that the engine empties of oil, in which case the problem encountered is same as running the engine without oil (and also the turbo without oil).

Perhaps more risky is if the intake (compressor) side of the turbo oil seal is the one to leak. Small leak, just takes more time for the "bad event" to happen. Large leak, the "bad event" happens sooner. What is the "bad event" ? It can manifest itself in one of two ways:

[1] The oil slowly accumulates in the intake tract (intercooler and pipes). (edit- while it's accumulating, you have no knowledge- there are no driveability symptoms) At some point, some mist of oil gets up into the engine cylinders. Remember oil is combustible and the engine can actually run on this oil mist. Typically what happens is the intake tract slowly accumulates the oil (unknown to the driver) and some event comes- such as the driver revving up the engine a bit higher than usual, which serves to increase the engine's breathing and bring the accumulated oil mist up into the cylinders. What happens in this case is that the engine runs on the oil (and the injected diesel fuel) and produces Herculean power such as never felt before. The tachometer will climb and the car will accelerate hard, even with foot off the accelerator pedal. With auto transmission, there is often little recourse to save- shut off the key and hope the anti shudder valve chokes the engine sufficiently to kill it. 5-speed has some hope- immediately shift to a high gear and stand on the brakes to a complete stop, hoping to stall the engine. And DO NOT START IT AGAIN. Must go to mechanic. (edit- this is known as "runaway", and it's scary when it happens.)

[2] The engine injests oil rapidly, not in combustible mist form, but in liquid form. The pistons try to compress the liquid (which isn't physically possible) and results in expensive metal parts bending. Engine will immediately become "sick", typically requiring a full rebuild.

If you are noticing the engine appears to use oil, must ask the question where is the oil going? Maybe past the valve guides and piston rings and out the exhaust, as is the common perception. But also note maybe that is not happening so much, and what you have is a leaking turbo seal which is slowly filling your intake tract with oil, preparing you for the dreaded runaway. The right-side of the intercooler as you're looking at it in the wheel well- is the lowest portion in the system. You can stuff paper towel in there (or suction tube) to suck out oil. Common opinion on this forum seems to be a small qty of ounces (sorry, USA) is acceptable, but anything more than a few ounces may indicate leak in the intake side seals of the turbo. Prudent to watch this very closely, to avoid the dreaded runaway. Don't take my word- just read the other posts on here.

Sadly, from what I read, it's not possible to replace turbo oil seals or rebuild the turbo. Remedy is to replace the turbo. I practice what I preach- at this time I have a replacement VNT-15 turbo en route from idparts.com for my 2002 jetta. Car runs fine, but have noticed over the past couple years, increased "apparent" oil consumption by watching dipstick, and have found significant quantity of oil in my intercooler (well more than 8 ounces). Car uses about 1qt of oil in 5K miles, which is considered above normal for typical vehicle. My engine has high miles- 290K. But has had proper oil changes and maintenance and treatment from day 1. I am looking forward to learning if my oil consumption goes down after replacing the turbo. Point is- if you notice your TDI using some oil, don't immediately assume worn engine and normal usage burning some oil. Could very well be a leaking turbo oil seal. Sometimes the leak starts small and progresses slowly. Sometimes it gets worse rapidly.

For my jetta (and I suspect probably very similar for Golf), it's actually very easy to get the entire front fascia off (to access intercooler). About 20 minutes work, total. You can probably get away with NOT doing that, just stick paper towel into intercooler or suction tube to get oil out. If you use paper towel, be sure to get all the paper out, don't leave any foreign object in there that could get sucked into engine !

Good luck to you, hope all this blather doesn't put you to sleep. Your description sounds strongly like you might have a turbo intake oil seal leaking. Recommend closely watch your oil level, and watch the amount of oil in the lower intake pipe. Get it taken care of if necessary. The engine itself has very long life if the ancillaries are kept healthy.
 
Last edited:

who1981

Member
Joined
Jun 3, 2010
Location
Rainier OR (North of Portland)
TDI
1996 Passat TDI Sedan
Yikes

This will be off model...
I recently had a small puddle of oil (2~3 ounces) of oil come out of my B4 Passat's intercooler when I checked it for the first time (I've had car 11 months). I thought it could have been condensed there from PVC oil vapors. (posible?) The car did use 1.5 - 2 quarts in 7K miles, but it had an oil leak around the oil filter/cooler, so I though that was the cause.

I guess I'll keep a close eye :eek: on the oil level in my intercooler, and save up for a turbo... My GT154 turbo isn't rebuildable is it?

Thanks for the timely warning.
Cheers,
Stephen
 

speedymofo78

Member
Joined
Oct 15, 2008
Location
minneapolis
TDI
2000 jetta
Ok i found one locally that I am going to get tomorrow in the morning and put it in. Im getting nervous aboit it and just want to get it done. Thanks for the replies!
 

dieselmax

Member
Joined
Oct 24, 2012
Location
Montana
TDI
2003 Jetta and 2006 Jetta
I have a 2006 Jetta TDI with 165K KM and I recently noticed an oil leak near the front of the engine, below the radiator on the drivers side of the car. My guess is that it's leaking oil at the intercooler?? I also noticed a slight amount of black soot above the exhaust on the rear bumper.

Any feedback will be much appreciated!!
 

vanbcguy

Veteran Member
Joined
Feb 22, 2013
Location
Vancouver, BC
TDI
'93 Passat - AHU mTDI with GTB1756VK
I have a 2006 Jetta TDI with 165K KM and I recently noticed an oil leak near the front of the engine, below the radiator on the drivers side of the car. My guess is that it's leaking oil at the intercooler?? I also noticed a slight amount of black soot above the exhaust on the rear bumper.

Any feedback will be much appreciated!!
If there is oil leaking at the intercooler you have a boost leak for sure. That will also cause more smoke, resulting in a sooty bumper. The oil leaking out will be either just oil from the CCV (not unusual for higher mile engines) or a leaky turbo.
 

dieselmax

Member
Joined
Oct 24, 2012
Location
Montana
TDI
2003 Jetta and 2006 Jetta
If there is oil leaking at the intercooler you have a boost leak for sure. That will also cause more smoke, resulting in a sooty bumper. The oil leaking out will be either just oil from the CCV (not unusual for higher mile engines) or a leaky turbo.

Thank you for your quick response! What would be the recommendation for this? The repair auto shop that I took it to suggested just leaving it but I travel long distances to Canada sometimes twice monthly and don't want to get stranded on the hwy in the middle of winter with my family. I would think that it would make sense to get the CCV fixed??
 

jsmcrawler

New member
Joined
Aug 31, 2015
Location
Ct, usa
TDI
A4 audi 2.0T Quatro gas
Can rebuild turbo I have the same problem.

search this forum for runaway
The turbocharger can be thought of as two fan wheels on a shaft, supported by bearings. One of the fan wheels gets spun by the exhaust. The other fan wheel spins because it's on the same shaft, and that's the one that does the compressing of the fresh intake air for your engine. The wheels spin very fast, and they get hot. The turbo has pressurized oil fed to it for the purposes of lubrication and cooling. (That's why it's especially important to use the correct type oil and follow reasonable startup and shutdown procedures with a turbocharged engine).

So, the turbo has oil seals on the shaft to keep the oil inside the intended oil passage. Those seals can fatigue and start to leak (sometimes very slowly, sometimes very abruptly). Depending on which side of the turbo (exhaust or compressor) oil seal begins to leak, the symptoms are different. Exhaust side seal leaking means the lost oil goes out the exhaust. If the leak is small you may not notice it much. If the leak is large you'll notice a large (sometimes embarrassing) plume of smoke in the rearview mirror. This generally doesn't harm the car unless you drive so far that the engine empties of oil, in which case the problem encountered is same as running the engine without oil (and also the turbo without oil).

Perhaps more risky is if the intake (compressor) side of the turbo oil seal is the one to leak. Small leak, just takes more time for the "bad event" to happen. Large leak, the "bad event" happens sooner. What is the "bad event" ? It can manifest itself in one of two ways:

[1] The oil slowly accumulates in the intake tract (intercooler and pipes). (edit- while it's accumulating, you have no knowledge- there are no driveability symptoms) At some point, some mist of oil gets up into the engine cylinders. Remember oil is combustible and the engine can actually run on this oil mist. Typically what happens is the intake tract slowly accumulates the oil (unknown to the driver) and some event comes- such as the driver revving up the engine a bit higher than usual, which serves to increase the engine's breathing and bring the accumulated oil mist up into the cylinders. What happens in this case is that the engine runs on the oil (and the injected diesel fuel) and produces Herculean power such as never felt before. The tachometer will climb and the car will accelerate hard, even with foot off the accelerator pedal. With auto transmission, there is often little recourse to save- shut off the key and hope the anti shudder valve chokes the engine sufficiently to kill it. 5-speed has some hope- immediately shift to a high gear and stand on the brakes to a complete stop, hoping to stall the engine. And DO NOT START IT AGAIN. Must go to mechanic. (edit- this is known as "runaway", and it's scary when it happens.)

[2] The engine injests oil rapidly, not in combustible mist form, but in liquid form. The pistons try to compress the liquid (which isn't physically possible) and results in expensive metal parts bending. Engine will immediately become "sick", typically requiring a full rebuild.

If you are noticing the engine appears to use oil, must ask the question where is the oil going? Maybe past the valve guides and piston rings and out the exhaust, as is the common perception. But also note maybe that is not happening so much, and what you have is a leaking turbo seal which is slowly filling your intake tract with oil, preparing you for the dreaded runaway. The right-side of the intercooler as you're looking at it in the wheel well- is the lowest portion in the system. You can stuff paper towel in there (or suction tube) to suck out oil. Common opinion on this forum seems to be a small qty of ounces (sorry, USA) is acceptable, but anything more than a few ounces may indicate leak in the intake side seals of the turbo. Prudent to watch this very closely, to avoid the dreaded runaway. Don't take my word- just read the other posts on here.

Sadly, from what I read, it's not possible to replace turbo oil seals or rebuild the turbo. Remedy is to replace the turbo. I practice what I preach- at this time I have a replacement VNT-15 turbo en route from idparts.com for my 2002 jetta. Car runs fine, but have noticed over the past couple years, increased "apparent" oil consumption by watching dipstick, and have found significant quantity of oil in my intercooler (well more than 8 ounces). Car uses about 1qt of oil in 5K miles, which is considered above normal for typical vehicle. My engine has high miles- 290K. But has had proper oil changes and maintenance and treatment from day 1. I am looking forward to learning if my oil consumption goes down after replacing the turbo. Point is- if you notice your TDI using some oil, don't immediately assume worn engine and normal usage burning some oil. Could very well be a leaking turbo oil seal. Sometimes the leak starts small and progresses slowly. Sometimes it gets worse rapidly.

For my jetta (and I suspect probably very similar for Golf), it's actually very easy to get the entire front fascia off (to access intercooler). About 20 minutes work, total. You can probably get away with NOT doing that, just stick paper towel into intercooler or suction tube to get oil out. If you use paper towel, be sure to get all the paper out, don't leave any foreign object in there that could get sucked into engine !

Good luck to you, hope all this blather doesn't put you to sleep. Your description sounds strongly like you might have a turbo intake oil seal leaking. Recommend closely watch your oil level, and watch the amount of oil in the lower intake pipe. Get it taken care of if necessary. The engine itself has very long life if the ancillaries are kept healthy.



This is very helpful thank you.
I just rebuilt my turbo- you can get turbo rebuild kit-I got mind from gpopshop.com but there are 100 places you can get them from just google it.

I will say there must be another issue that can cause this cause my oil seal looked perfect condition (i assume you mean the one inside of the turbo itself-or are you talking about the oil feed line? the metal part from the oil pan to the turbo?)-I rebuilt it anyways and still have this problem.
I noticed the valve cover gasket is leaking and I will replace that now and bought an emissions kit and am going to replace the pcv and erg valves to see if that helps. I know there are ways to clean them but for 125 USD it didn't seem worth the time.
Anyone have any suggestions/feedback?
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
We removed my intercooler pipe when my car was fairly new, we were shocked at the tablespoon or 2 we found in there. But it's normal.
You should be able to get your cover to seal. Check it for damage, clean everything up, put small dab of sealant at the 90˚ corners. Get new bolts if needed, torque to spec.
 

TDIWings

Well-known member
Joined
Jan 17, 2016
Location
Sol System
TDI
05 Jetta
K, I'm not a TDI guru so, what has been posted goes first. But I feel like chiming on this one too.

Chatting with a mechaninc (NOT a TDI guru either), he mentioned a further reason for an oily intake tract is the engine vent line. On AXR engines (dunno about BEW), the ASV is powered by an electric motor that partially closes it under half load to create a vacuum and draw more EGR in. A side effect from this is that the engine vent line, which also goes into the intake will draw up a little oil. On worn engines this seems to be rather the norm than the exception. And since the vent line tees in at the very top of the intake tract, it can flow down all the way to the intercooler. He said this is normal and expected and that there's nothing to be done except taking it appart when gunk buildup is heavy enough to start clogging the IC or ASV. A worn turbo seal only compunding this issue.
 
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