Cylinder Head Problems?.video attached

[Knight Rider S4]

I am reving the engine when you see the water bubbling
The car runs fine and there is no water from the exhaust, is the water pump that strong that it will cause that to happen ,never noticed this before

Have shot the rear of the Cylinder Head as it has always seeped at the back and was told that this happened on allot of them.

Cheers

[s2dude]

I am reving the engine when you see the water bubbling
The car runs fine and there is no water from the exhaust, is the water pump that strong that it will cause that to happen ,never noticed this before

Have shot the rear of the Cylinder Head as it has always seeped at the back and was told that this happened on allot of them.

Cheers

There are only a few reasons that I can think of why this could happen .....and they arent that good I'm afraid

Exhaust gases in your cooling system can suggest a head gasket leak, a cracked block, or a warped or cracked head.......

A few tests//

Grab hold of your coolant hoses once the car is up to temperature adn doing the bubbling trick you videod......(taking care to wear protective gloves so you dont burn yourself!!!) say the main one from the main rad and see if they are Rock Hard...they shouldn't be!!!

If they are and they may well be then this is a good idnetifier as to the possible cause...pressure leaking through bad head gasket into water jacket and pressurising the coolant system....

Also, you need to buy a combustion leak testing kit which is a simple probe type device iirc that tests the contents of your coolant reservoir and identifies if there are combustion gases present (which there should not be!)

Any half decent garage will be able to do this test for you also.

Also, you could undo the radiator bleed valve carefully and when the car is up to temp if foam starts coming out then this is another pointer to combustion gasers in your coolant.

Once you have these answers it will be a lot easier to diagnose!!

Whichever garage (or whoever) said "ohhhh....a lot of them do this!" is talking rubbish...
it MAY be a common problem on this car (I dont know S4s that well) but it is not one that should be ignored IMHO as it could cause much worse damage down the road......


HTH

[Knight Rider S4]

Cheers for the response

Pipes are not hard but the car sits at 95c just a little higher than it should...had in Cameron Motors Audi Dealers when i first bought the car as it was overheating all the time and they said it was temp sensor fault and the they Changed POS and a few sensors ,Thermost and housing and charged me £880 for the pleasure.......

Looks like i will be doing the head gasket soon .....is there a write up on this i.e as in tools ,torque settings so on

[lune]

I've been thinking my Head Gasket has been a problem for a while now, I have similar symptoms the leak round the back in exactly the same spot and I'm sure my coolant is doing something odd! Yesterday I had the indicator flash on the dash indicating low coolant, stopped to top up with kettle in hand and slowly unscrewed header cap, was lots of gurgling and a ***** load of pressure to let out and when cap undone the water had risen nearly back to normal!!
Have been having to top up coolant all the time and no leaks on the engine? However no tell tale white smoke from exhaust?
Weird stuff, anyway going to drop into garage for a few tests, hope just HG and not cracked head
On upside if heaad doeshave to come off it's an opportunity to fit my new RS2 EM and replace my cracked one.
If I pop up to Perthshire you don't fancy doing 2
Keep us informed if it defo ends up being HG.

Ben

[Knight Rider S4]

sure come up and i will fit the RS2 EM on the Green Car.........lol

Will keep you posted doesnt look that bad a job the only pain will be Timing belt and exhaust Manifold bolts been siezed plenty of room to work in

[T2Andy]

LUNE my car had the same problem the water level going up and down ,i cured mine by releasing the nut on the top of the rad every ime id been for a run,i seemed to have lots
of air in the system because the heater would sometimes run cold did the trick for me .
it took about 5 atemps to cure it .

[lune]

I'll give that a whirl Andy, I have to admit I've had problems with air locks before, same kinda thing no hot air in winter etc. I was hoping the garage had sorted this while doing the cambelt a while ago, possibility I haven't been that lucky
Typical if it is the HG and I only had my belt done 4 month ago! At least the bolts should come out a bit easier, bloke at garage snapped his "Snap On" breaker bar and rapped his knuckles removing pulley
Keep us updated Knight Rider.

Ben

[lune]

Had a better look tonight, defo a coolant leak going on
From what I can see looks to be weeping at HG back left/EM side and looks like might be worse under the EM were I can't see. The coolant seems to be running down the block onto an engine mount and pooling around the starter motor
This would explain it's occasional refusal to start.
What kind of waterways do I have round that side? I can't see any which leads me to believe it's passing from the HG.
Gonna book into garage next week and get a hypothesis.

[merlin's S4]

Yep, it's quite common for the headgasket to fail at that point for some reason. most, if not all the AANs were fitted with the paper type headgasket whereas the RS2s and I believe many late S2s had the metal headgasket. Audi don't sell the paper version anymore so any replacement that you buy should be the stronger metal gasket. I've had mine replaced as it was leaking in exactly the same place as you described but be very careful who you get to do the work, as unfortunately I think mine needs doing again! It's also worth cleaning the head up and replacing the valve stem oil seals while you're at it!

[Doug_RS2]

Are you sure it the the HG and not the water adapter on the back of the block at that point - the o rings go hard and they leak.

[Knight Rider S4]

Will be checking this out tomorrow night but would it cause the air in the system? as in the video

[Graham]

I found when you switch the car off the fluid which leaked out while hot creates an imbalance in the system so when it cools the car sucks in air through the leak. The water adapter broke on mine as it was very brittle and weeping for ages.

[lune]

I checked out the water adaptor and still on joy, looks like it's leaking from the left side more than the back
Gonna pop into my local garage tomorrow and get them to have a sniff about from underneath.

[Knight Rider S4]

Tell us your findings .....i would love it to be the seal save me allot of money

Did not get a chance to look at S4 have a A4 as well and spent most of the evening replacing track control arms

[lune]

The findings are, that the HG is shot and leaking coolant More so on the back left corner, but was totally obvious when the car was in the air to have a good look
Took car to my local garage this morn for them to have a spy, was gonna take a week for them to get it on the ramps! Think everyones car broke at once up here
Thank goodness for my friendly exhaust manufacturer who whipped it straight in the air and said yep we can sort that, do you want a port & polish too
It's gonna be 6+ weeks before I get everything sorted, but I'll report back and let you know how it goes.