27 March 2020

Audi A3 2.0 FSI Oil Cooler Gasket Replacement

I’ve finally fixed the oil leak on my A3. Once it became obvious that the leak was caused by a collapsed oil cooler gasket and the leak became severe enough to be potentially dangerous to the engine’s health I got to work.
I’ve put off this job as long as I could simply because it appeared to be such a daunting task. And it is, it’s not for the faint of heart; if you’re not mechanically inclined leave it alone and take the car to a professional mechanic. Even if you like doing things like this you’ll probably regret starting it halfway through.

So here goes….

Jack up the car and put it on jack stands or drive it up on ramps, whatever you have
Drain the coolant from the engine. The easiest way to this is by removing the coolant temperature sensor from its housing on the bottom left corner of the radiator.

You DO NOT need to drain the oil.

Now here comes the hard part. The oil cooler on the 2 liter FSI/TFSI engines is out of sight underneath the intake manifold which you’ll have to remove.
Remove the top plastic cover of the engine.
Remove the plastic resonator box thingy. The vacuum line is just pressed in, gently pull it out.
You’ll have to remove the shiny pipe that comes from the EGR valve. On the EGR side it has a very thin washer, make sure you don’t drop it into the engine way or it will be lost forever.

Then you’ll have to remove a large collection of various vacuum lines, electrical plugs and coolant lines. And don’t forget this large clamp that connects the manifold to the air filter box.

Now that we have taken off all the auxiliary things that connect to the manifold it’s time to take off the manifold itself.

The manifold is held in place by 6 things. Two large nuts in the front. You’ll have to get creative to remove those, a flexible socket extension will help.

And 4 clamps that connect the manifold to each inlet port on the cylinder head. There are 2 clamps on each rubber tube, you only need to undo the outer ones. For this job VW recommends using a special clamp tool. The clamps are very easy to unclip with a small screwdriver. Putting them back on without the clamp tool takes a bit of imagination, but it’s not impossible. I managed by squeezing the clamp together with a pair of pliers and pushing down at the same time with a screwdriver. Some people simply throw away the old clamps and install new ones that can be tightened with a screwdriver. Up to you.

Now that everything is removed pull the manifold back from the rubber tubes and gently lift out. Pay extra special attention to the orange dipstick tube. If you break that you’ll have to replace it.

Before you do anything else, stuff the inlet ports with some tissue or clean rags as you really don’t want any kind of debris to end up in there. While you’re here do yourself a favour and inspect or replace the crankcase ventilation tube, they often crack and to replace is a manifold off job.

Now we can start working on the oil cooler. The oil cooler is held in place by 4 torx head bolts and one coolant hose clamp. 

The cooler itself is bolted to the oil filter housing that is made out of plastic. The gasket we are about to replace is between these two parts. There is another gasket between the filter housing and the engine block, but since that one is not leaking, and it rarely does, I’ve decided to leave it alone and replace only the outer one.

So far, so good. Obviously the 2 bolts on the top of the cooler are easy to remove. The 2 on the bottom not so much. The bottom left (your right) bolt is visible and with the right tool you can simply reach in and loosen it. The bottom right (your left) bolt is in a place where you can’t see it, but by using one of these L-shaped torx keys and an acute sense of feel and touch you can locate and remove it.

With all 4 bolts out you can remove the cooler by sliding it upwards. A small amount of coolant and oil will be dripping out, try not to make a mess.

With the oil cooler out you can see that it has a flat mating face. The gasket itself sits in its own groove on the filter housing. With a narrow screwdriver gently pry it out and make sure you remove all of it as often the old gasket disintegrates into many pieces. Luckily mine came out fairly easily in two pieces.

Now compared to the new gasket you can see just how much the old one has collapsed.

Before you do anything else inspect the mating face of the oil cooler. On mine you can see there is some caked oil and rubber residue that formed around the old gasket.

Using a razorblade or fine sanding paper remove all the residue until the mating face is clean and shiny. Be careful not to gouge the soft aluminium or it will leak there.

Carefully seat the new gasket in the groove and reinstall the oil cooler. According to the manual the bolts should be torqued to 15nm + half a turn. I’ve done it by hand. Bear in mind the bolts go into the filter housing which is made of plastic so easy does it.

Now put everything back in the reverse order and you’re done.