rory

Hi - apologies for asking for help instantly - hoping I can add some valuable information in the long run as I'm currently running a 600bhp 996 turbo so I'm good with power - but bad with random problems!

My issue is I currently have a coolant leak of some description. When I bought the car it was below the minimum mark - I topped it up and all was well but checked today and its gone down to the minimum again. I know it could just have been an air pocket which has now gone due to the extra fluid in there as I don't know how long the previous owner ran the car with it just at minimum? No warning lights or anything though? No puddles or smells anywhere either. Topped up again so just hae to watch it. No oil in coolant or cream etc.

Should I be worried though? No smoke on start up or when driving hard unless from cold (which I don't do)?

Any help would be appreciated.

Thanks - Rory

neanicu

Front radiators are known to develop small leaks. The expansion tank cap leaks.
Could be a small leak from the water pump.
These are things to consider...

rory

Rads are only 2000 miles old and car not used in wet (or wasn't but the last 600 miles I've used it daily driver) so can't see it being them. Read about the expansion tank cap and replaced it. Water pump - any way I can check that?

neanicu

Look for coolant below the water pump pulley.

rory

No coolant below water pump pulley... Whole engine bay is dry as a bone? It's confusing me?!

neanicu

Then drive the hell out of it and don't worry about it!

rory

I like your style! Haha! Thanks man - ill keep an eye on it and see what happens!

MK_TT

and check to see if you have the updated coolant cap

rory

Ends in 4? Think it's the updated one :-)

Macster

Since you have replaced the tank, the cap, and have eliminated a leak at the water pump (maybe) that leaves, oh about a zillion other places....

Seriously, even with 2K miles a radiator can be leaking. And the new tank can be bad or even the new cap.

Any hose or where a hose connects can leak.

There are of course all of these hose fittings glued into the block any one can be leaking. And these seem to leak/fail more often in cars that are tracked of have engine mod's.

First, you have to be sure the cooling system is fully filled with coolant.

The only way I know to do this is to have the (cold) cooling system put under low pressure with a vacuum pump and then close the vacuum pump off and open a valve to a vented to outside air tank with coolant and let the outside air pressure push the coolant into the cooling system until the level is where it should be on the car's coolant tank.

Once you are sure the system is properly filled -- no air pockets to as they get absorbed make the level drop and mimic in this way leak behavior -- drive the car around until the engine is good and warm. Be sure the A/C is off.

Raise rpms to say 1K and let the engine run at this speed until the fans come on. Then shut off the engine. The heat in the engine will raise the coolant temperature and pressure and this is a good hot high pressure test of the car's cooling system.

If there is a leak you'll know it.

NoGaBiker

I had this problem on my 993TT.

Oh, wait...

Kevin

All three radiators were replaced? I'd verify that..

If you have 1 of the 8 loose coolant fittngs, they can weep prior to blowing out.. The coolant has to be going somewhere. Early 01 and 02 has cylinder head casting issues. They tended to spring pinhole leaks near the exhaust ports.. Look for white staining on the your heads or around your header gasket.

Kevinmacd

Tank could be cracked. This is typical.

rory

Thanks guys - putting the car in for service in 2 weeks so I will get them to pressure test the coolant system and give the car a general check over in this area.

I have the receipts for the 3 radiators and intercoolers were replaced with gt2 ones. Doesn't sound good with the pinhole leaks in the casing though :-( on earlier cars. I don't quite understand how it only leaks a certain amount it seems - hopefully it's just a cracked tank - getting myself under it this morning to see if its leaked anywhere in the last 8 hours.

Very annoying - CBA paying big money to fix it after only running it a month under my ownership!

Macster

Not sure what you mean by leaking a certain amount?