1.4 TDI (BHC) PCV valve issue

Bordos

Bordos

Member
Poland
Hello,

I am trying to solve an issue with oil within intercooler piping and on the EGR valve (and as I assume on the turbocharger as a result).

I reckon that this might be caused by faulty PCV valve in the engine cylinder head cover - and I am looking for a way to verify this (as the PCV is a part of this cover it makes it expensive to replace not being sure that this is the case...).

Have any of you had similar problem?

At the same point - I saw threads that there is some funny business with the cylinder head cover gasket - do I have to buy a 1.4 TDI (all types) one or do I have to buy a specific one for A2 only ?

The car is running fine, just the turbocharger is "oiled up" together with the EGR valve body and there is a bit oil consumption (about 1,5l per 10k km )...
 
Updates?

I'm having this same issue, after a long drive I noticed an alarming amout of oil on the intercooler pipe joints and around
the EGR valve though no change in performance

Took the valve off and the exhaust side was bone dry while the intake manifold and pipe had a layer of oil,
so it must be coming from the turbocharger?

Also oil sometimes gets splattered on the head cover through the fill cap which could point to excessive crankcase pressure
that could push the oil through the turbo seals

So is it just the PCV valve or something more sinister like a bad turbo or worn piston rings?
 
I have not received any replies …

In my case I am pretty sure that the issue with oil consumption results from this valve - but to replace it I need to replace the entire head cover and as it costs 15% value of the car I will not do it any time soon …

I am considering installation of catch container to see how much oil is going though - in my understanding if “a lot” that will prove that the valve is faulty and not the turbo.
 
Too much oil causes similar issues. Are you sure the oil level is correct and not over filled. Post a picture of the level on the dipstick.
 
Great question about oil in the intake system.
Had this same problem for 5 years.
Suspected cam cover case breather.
Replaced the turbo with second hand units, I'm on my third.
Tried two second hand cam covers.
Replaced the o ring on the turbo inlet hose and fitted a catch can.
There is still oil coming from the cam cover.

Pressure in the cam could be blow-by gas leaking past valve seats and stem seals.


I'm this far in so there's no going back.

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I can add my experience from many years ago on a 1.9tdi (BRE) which might help:

I started getting extreme amounts of smoke from the exhaust but only at idle. I took the downpipe off the turbo to find much oil. I concluded the oil seal had failed in the turbo. Bought and fit new turbo. After about a week it started smoking at idle again. Can't remember why now but I took the rocker cover off and refit it in the dark accidentally with the seal twisted. The smoke at idle disappeared but I got a slightly oily engine bay. Concluded the PCV valve had failed so bought new rocker cover and all was fixed. So it seems the failed/blocked PCV valve caused excess oil pressure which escaped at the weakest point, which for me was the turbo seal to the exhaust. It took a little longer to breach the same, no doubt stronger, seal in the new turbo. After rocker cover replacement the turbo stopped leaking oil without having to be replaced again.

All worn turbo's are going to leak a bit of oil into the air intake. I don't think I've ever seen a completely dry air intake on any of my many TDI's. You might conclude from the above that oil (and hence smoke) in the exhaust is the symptom of a blocked PCV since both my old and new turbo's failed in the same way. However I think a blocked PCV valve will spew oil past the weakest seals and that could be into the air intake. In the case above it was eventually obvious as the leaking oil into the exhaust caused a very identifiable sign (smoke signal) which immediately went away when the oil filler cap was loosened. If the weakest seal is the turbo to air intake you will not get that obvious a signal so the problem will be more difficult to positively diagnose.

If not the PCV I think blow by the pistons is unlikely (depending on mileage), worn valve guides more likely.

@Bordos Re-reading your original message, it's possible there is nothing wrong with your PCV and you just have a worn out turbo with failing seals that is filling your intercooler and EGR with oil. However, replacing/refurbishing the turbo is likely to cost even more than 15% of the value of the car.
 
I have decided to pause my investigation of this issue until the end of winter time (as my garage has no heating ...)

My plan is to remove, clean and inspect the EGR (as my leak starts from the top of it) - and in necessary replace it.

New/refurbished turbo is an expensive bit (about 20% of car value - plus other parts that will come during this job) so for now I will try to avoid it.

A new rocker cover is also 10% of car value...

The part that is the most strange to me is that my Audi "consumes" oil only from time to time: after oil change I can do ~2000 km with no change of oil level, then after 500km I am missing 0,5l, then I do 5000km and is is basically the same, and then once again I am missing 0,5l...

Anyway - thanks for your input :)
 
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