Variable Valve Timing (VVT) Solenoid-Oil Leak

A6 All/ S6 All
#1

After recently replacing the plugs, coils and valve cover gaskets I was a bit annoyed to have a significant leak develop from the drivers side valve cover. The leak was from the rear of the cover, where is easily drips down on the hot exhaust causing smoke to billow out from under the hood when stopped at lights. Those multiple runs through the gears to redline to hear the JHM exhaust sing did not help matters! :laughing:
Ordered a new valve cover gasket from JHM, thinking I pinched or folded the gasket while installing. Got the cover off and the gasket looked fine. Upon further inspection I observed the VVT solenoid, installed in the rear of the head was the source of the leak. I’ve havnet seen anyone mention this leak yet so I thought I create this post. I acutally didnt know where this valve was or how it operated until now. It’s a solinoid valve that when opened allows pressurised oil to pass into the valve gears to advance the valve timing.

The VVT is located here:
IMG_8928

And looks like this:

IMG_8929

The single o-ring was shot, flat and hard. I opted to replace the valve, about $175 from FCP Euro, as I’m approaching 135K with my S6.

New VVT installed, valve cover reinstalled with new gasket and no more leaks.

Found a torn inner CV boot on the left front while doing this job, rebuilt Axle on order from Raxles…

#2

Forgot to add this picture, shows the value installed with valve cover off:
IMG_8927

#3

I think I have this problem on my car but on the passenger side. Do you just remove the plug and then a single bolt to remove the solenoid? I assume the solenoid is located just behind the last cylinder on the back of the engine?

#4

The solenoid is held in place by one small bolt. Do not need to remove any plugs.

#5

The valve cover doesn’t have to come off to access the solenoid does it?

#6

No, it does allow you a bit easier access to the bolt and to faciltate clean up.

#7

Is there a part number for just the o ring gasket?

#8

O-ring

#9

I replaced all 4 o-rings last time I had my intake out. But now I think I have a problem with that exact solenoid—I’m getting a P0023 fault. I just measured the resistance and it shows 10 ohms, where spec is 5-8 ohms. I also checked the intake solenoid and it read 8.8 ohms. Maybe time to replace both? The ones on the passenger side seem like they are harder to reach.

#10

@Korndog101 I’m looking at the first photo where you showed where the solenoid is located. Was this photo take after you had cleaned up the area? I’m pulling mine out right now and I’m not noticing much oil residue. Based on your first photo yours doesn’t have a lot of oil residue either assuming you haven’t cleaned it yet.
I’m doing this because I’ve got the same oil smell and smoke coming from under the hood when I’m not moving.

#11

So I got all VVT solenoids pulled out today to replace the o-rings. It seems to have fixed my oil burning issue. I was skeptical at first because I was looking around the solenoid and did not see much sign of oil leaking, but I think there is some small channel that is covered by the valve cover that I couldn’t see.

I ordered my parts from FCP Euro and got them much faster than I expected. The part number was WHT002789 and I ordered 4 of them.

The screw that holds the solenoid in place is a T20 Torx screw.

Hopefully this info will help someone in the future when they stumble upon this thread.

#12

Yeah those o-rings get hard and start to leak. Cheap and easy fix compared to the vast majority of issues with these cars.

#13

while we are on the subject, is there a howto guide on changing the solenoids on the passenger side? I just see a tangle of hoses hiding the solenoids.

#14

Just have to remove everything until there is room. Honestly not the best answer but it is true.

#15

I took the intake tube off. moved the coolant bottle out of the way. unplugged all the nearby connectors, took out the coil pack that is right next to it, and undid the PCV tube from the valve cover.

Having a t-handle T20 makes a difference also.

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#16

Thanks for the tip, need to get some of those T-Handle torx wrenchs. I need to get orings replaced on the other three.

#17

Did you try to remove the solenoid? Or Does your T-handle t20 have a “hollow” tip. The one I bought does not, and from the photo it appears that there a dot on that screw.

image
image1817×1507 644 KB

#18

I used a standard torx head socket, worked fine.

#19

I found it easiest to use a 12" extension as I was able to see down in that tight area a little clearer from further back.

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#20

I just had my car re-sealed for $$$$. Still a smoke house asphalt machine driving experience. If it was this dang solenoid the whole time… =)) welp, at least I got new alt, starter and a steering pump pre-emptively at the same time

I’m reaallly hoping the problem is this. Otherwise the engine may not be sealed properly. I find that highly unlikely.

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