C5 4.2 cooling isues

A6 All/ S6 All
#1

Hi all, Im new here and looking for helpfull info to fix my Audi.
So Im located in Europe, Lithunia.
I got c5 4.2 220kw, and mechanic told that car got cooling issues.
He did test from expansion tank ant told that one of my gaskets is gone.
Sometimes it is hard to start engine it seems that cooling liquid is getting to the one of the cilinders and making starter stuck and not turning engine. Sometimes its ok.
So im asking some advices whats the simplest way to get cilinder heads in my hand, to change the gaskets?:smile:
Is it possible to do it without engine removal? Or is it must?
As one of the chain is located in the end of the engine so some guys which I was speaking told that, without engine removal I will not be able to take off the left cilinder head.
Thanks for advices.

Sorry for my english mistakes.

#2

The C5 is just like the B6 and the timing system is on the back of the motor. I’ve done a few timing jobs with the motor still in the car but it’s a pain. It’s just quicker and better to drop the motor. As for the heads it’s the same. I’d drop the motor it’ll give you much more room to work and get to the bottom of what’s really going on.

I’d probably scope the motor and make sure it was the cylinder head that had an issue and not a crank in the cylinder wall.

#3

Easy enough to do the 4.2 chain driven motors in the car. Exhaust manifold should preferably come off, but other than getting to those bolts the head should come off pretty easy

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#4

LOL… Sure super easy go for it then report back… Oh and next time… take a picture of a chain driven motor when you say it’s easy. Not a belt driven. LOL

But yes Jolio has a belt driven in this picture if the C5 you have is a belt driven not a chain as some small euro late 4.2s were you should be good. But if you are a chain then I’d take it out given just how huge the difference is between a belt driven and chain… So basically belt. Not terrible you can pull in your parts with the motor still in the car… Chain less than the best choice to try and do in the car. I’d pull it if it was a chain not only for the fact that it’s going to be less work overall but the motors are so different you really want to be able to look at both sides of the motor.

#5

Lmao. Idiot me gets so caught up in belt vs chain.

Your right. I weaved when I should’ve ducked… not even going to change it; carry on :sweat_smile:

#6

Thanks for the answers, its defo belt driven engine, as my mechanic changed all the belts and water pump in spring. But as I was told the camshaft in the cilinder head is driven by chain, and one chain is located in front of engine, another is at the back of engine, and that one makes it difficult to remove the one of the cilinder head, so they said that better to take the engine out. Anyway nobody wanna do this job, so I have decided to pull the engine out by myself and take it to the mechanic. Hope thats only the cilinder head, nothing more… thanks again

#7

Yes, the C5 4.2’s, including the RS6 are all belt driven 5 valve motors. The C6, B6 S4 and D3 A8 were the first of the 4 valve Chain driven V8’s.
A head pull can be done with the engine in the car. The Timing chain at the back of the Right cylinder head just runs the Exhaust Cam off of the Intake cam which is driven by the Belt in the front. The Left cylinder had is a basically the same head swapped so the chain drive is on the front.
With that said if your head gasket has been leaking enough to Hydrolock the engine and you’ve made repeated attempt that can put a lot of stress on the Connecting Rods, and any Coolant getting into the oil (if you’ve been driving it that way) can do a lot of damage to the Main & Rod bearings). Might be better to do an engine pull and replace those bearings? I’d do a cylinder inspection through the plug holes with a camera at the least. How many miles on the motor might determine what you want to do. The Cam Chain tensioners and guides are usually needed by 150k Kilometers anyways, and the chains are cheap enough that if you do the tensioners you want to do the chains too.

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#8

Hey, thanks for your answer. As I have noticed the coolant and the oil is not mixing , as there are no any signs of coolant in the oil pan or in the coolant tank. Anyway I have decided to take off the engine out by myself, and take it to mechanic to check the heads, because every guy I asked told me the same, I have no time for this kind a job, its a big job and etc.
Its hard to get right man to do this kind of job at these days, so simply I think I just go with gaskets replacement, as engine itself was driving good without any knocking or other sounds, as well chains gonna be replaced too. Just one thing which is worries me how to put back engine without any mistakes :sweat_smile:

#9

The timing belt kit was done 2k km ago, now its 320k km on the clock (if thats a real milleage, not sure about that)…but chains have no any extra sounds, but anyway its gona be changed.

#10

You’ll probably discover how bad the Headgasket leak is once you get that Head off. Assuming you are going to pull just the leaking side off? Pulling the plugs and looking at the tips should tell you which cylinder(s) are leaking. With that mileage I don’t think I’d bother on doing both heads necessarily, just get it running good and drive it.

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#11

I was thinking to do both heads and forget it. On the other hand , I dont know how much €€€€ roughly it takes to recover one head. On other side when this big job done , engine is out, timing belt is new, again you need to take timing out to get to head, and change only the one gasket could be the sin if the another gasket is could go soon… the cheapest method couls be to put another engine and think its gonna be ok, but you never know what problems could another engine have