More coolant woes... what to do now?

[Ross]

Hi guys

I am at a loss with the car... today I bought the engine up to temperature, once again to see steam rising out of the engine bay. I'm sure there must be another issue causing it now, but it's once again definitely coming from the radiator! I fitted a new Behr one.

I am pretty certain it's not from any of the pipes. The steam is coming out from behind the fan on the left side, just as last time. I'm suspecting the radiator is leaking at the join to the top endtank again, but much less this time.

One thing to note, is the top of the rad got very hot as well as the pipe from the water maniofold as it was coming up to temp, and there appeared to be no coolant circulating until it hit about 85-90, then it certainly was circulating as normal - and after that there was less steam escaping.

Would it be possible to ruin the rad by baking the thing? Just seems a bit odd that the temp of the coolant can be boiling at the top of the rad, and until it hits the temp sender at the bottom of the rad it's not going to start circulating properly... yet that's the way Audi designed it, and it only seems to be an issue now, on my car

Any thoughts as to what else could be faulty, causing such intense temps at the top of the rad (or is this normal?) - or could I just have a duff rad and be really unlucky (or lucky, if that's the solution!)... I'm nervous to even start it now before something else breaks

[4WheelDrifter]

Are you sure the steam isn't a previous spillage? Or a dodgy hose joint?
It's normal for the coolant not to circulate through the radiator until the thermostat is up to temperature. The coolant will flow through the heater matrix until it does.

[DJones]

Ross,

Check that you haven't got a cut in the hose from the jubilee clip on the pressure side.

Darren.

[Ross]

I'll check the hose in the morning when there's a bit more light, but it was fine when it went back on! If anything, i was probably over-cautious and under tightened it.

It could be from when i was bleeding the system I guess, there was alot of steam though and the coolant dropped about an inch...

One thought - i wasn't getting any hot air through, surely I should have been baking by the time the temp was at 90 if it's circulating through the matrix right from the start? Does this mean there's a problem and I just cooked the car?

[Error404]

the steam might be just residual coolant evapourating off from previous spills as Stu said...
If you're not gettting hot air in the cabin you've got some air that needs bleeding out - would also explain you 'losing' some coolant as that lot bubbled about. AFAIK the top of the rad gets hot first, then as the stat starts to open it allows circulation through the rad..... If i was you I'd check your hose connections are all good and give the system a proper bleed and see where you get

[4WheelDrifter]

I'm not sure about the ABY, but can you raise the coolant expansion tank while you bleed the system?
Obviously double check for leaks first.

[Graham]

Do a cold presure test; get an old cap from a scrappy, go to a tyre garage and aquire (Buy or just ask the lads) a tyre valve. Remove the guts and drill the scrappy cap. Fit the valve with a nice fat rubber washer inside and pressureise to 5-10psi overnight, if there is water on the floor there is a leak.

[Acidburn]

Also when me and s2driveruk bled his system the coolent bleeding it dropped quite a lot so i'd say you've still got air in the system.

[Fat Audi 80]

When my afterun pump started leaking the car would be cold inside even when the coolant was hot. A few revs and it warmed up. I think it was letting air into the system.

What I am hinting at is, I still think you have air in the system. This may not help your leak situation but could explain the lack of warmth from the matrix.

Take a look at it again with a cool head, dry everything off and check for leaks again. I suspect it will be a split pipe that you have not noticed or a weeping / loose jubilee clip.

Good luck.

Cheers,

Steve.

[Dpicariello]

Ross I am in exactly the same boat as you at the moment. I have just replaced my radiator and my coolant hoses with new parts and after all that I have ended up with a few drops of water on my garage floor.

Firstly, check that your hoses are in good condition with respect to where the jubilee clips fasten around.

Then have a look around the thermostat housing. Mine initially leaked from there. I hope it doesn't leak from there as it's a horrible part of the engine to get to.

Thirdly, check your after run pump. It seems like mine is leaking from here as the bottom of the bracket is slightly damp. Seems like Steve also had this problem.

If it is just a bit of steam then it could be just the old coolant evaporating off the block and surrounding components, mine did that as I got coolant all over the place, especially when I changed the thermostat.

Hope you get it sorted

Dan

[Fat Audi 80]

Also, the afterun pump may only leak under pressure, or when the casing it flexed. Mine managed to hide its symptoms for a few months leaving me worrying about the head gasket for a while.

WORD OR WARNING: If you are checking it when the coolant is hot, it can spray hot coolant out from the damaged body a long way. Ask Mr Casey about that too.

Cheers

Steve.

[shark_90]

I'm not sure about the ABY, but can you raise the coolant expansion tank while you bleed the system?
Obviously double check for leaks first.

Yes you can and that's what I do. Lift the expansion tank up and open the bleed screws on the matrix hose and raidiator and make sure there are no bubbles.

Also remember that your water pump isn't pumping particularly hard until you rev the car so maybe sticking a little spanner in the throttle cam to keep the car revving a little bit might speed the process up.

BTW - I think you've still got air in the system too, so that's a few of us now.

[Ross]

Just to update - still not 'in the clear' but looks like I may have been over paranoid... this has made me realise, i have no confidence in the car ATM! I'm literally waiting for something to break or fail all the time

Ran the engine for half an hour, the top hose was a little loose so perhaps the coolant was running down the radiator and then burning off... bled more air out of the system, the heater is now blowing hot air as it should

Still has wisps of steam coming out the whole time, but I did spill more coolant when bleeding the radiator so pretty sure that's it. I'm at that stage where I just need to go for a run and see if the coolant has dropped when I get home. Wait - darn, no MOT or tax

Ps - thanks for the tips, revving the engine helped bring air through the system and even if there is another leak then I have some motivation again

[KaraK]

stick with it Ross... you are getting there!

[pixsaudisex2]

yeah stick with it my avant had a water leak. and it took me over three years to stop it fully. so dont worry,