Damn It, Water Squirting Out Of 1.6

[Richie-Van-GTi 70 2 Cars]

bit of an odd one. done a head gasket and fit a 4 branch mani to a 1.6gti for a friend today. Head was all done up tight etc, correct settings, new bolts etc etc. Anyway under hard load it blows white smoke. So we popped the bonnet to be greeted with the bulkhead and back of engine soaked. We cant get it to force any water out at standstill. It seems to only do it when the engine is warm and under load. It seems to be more at the gearbox end of engine. The water block at the end of the head wasnt removed and the head wasnt skimmed as the it wasnt blowing before, we just had to remove the head for removing the mani studs that had snapped.

 

Really looking for suggestions where this could be coming from. I dont suspect H/G fault as head is known good etc and gasket is brand new and correctly fitted. Also car runs too well for such a problem. Oil is fine etc. I know there is no longer a bolt holding dipstick tube (13mm in back of head) Could it come from here as I didnt think this hole was right through to water jacket. Or could it be one of the snapped mani studs we drilled out we have gone too far (doubtful as care was taken) and hit a water jacket. But then would it squirtonto bulkhead given its got a stud in, then a gasket, then the mani to get passed.

[Grim.Badger 15]

Probably a patronising question but have you checked the thermostat?

Where the leak is and the fact that it happens when the engine is warm suggests thermostat to me.

It could also be one of the hoses, I have known them to only leak/blow when the engine is warm and the rubber becomes more flexible and a pinhole split widens.

[Richie-Van-GTi 70 2 Cars]

Ive put a different stat house on it and it made no difference. Checked all thew hoses and they appear to be fine, also wouldnt explain why they do it under load and not stationary. The more I think about the more I think its pressure related which would mean gasket or cracked head etc. Also its down the back not at front where stat housing is.

[jonah 1]

Sorry to say but it definitely sounds like the h/g is blowing. When mine started to let go a few years ago, it would force coolant out of the top of the header tank past the cap, but only when the engine was warm and under full load. Could it be coming from there on this one?

 

When I took the head off I found evidence of a slight blow between cyls 2 & 3 and the water jacket. It wasn't enough to affect performance (the car still ran perfectly) or compression readings, and even a sniffer test came up negative with the engine being revved up unloaded. I guess that under heavy load, the combustion chamber pressure was enough to open the gap and force high pressure gas into the coolant. I reckon the same thing is happening on yours.

[Richie-Van-GTi 70 2 Cars]

its definatley not from the header tank but it could be between haed and block at the rear corner. I'll have to try and get it to replicate the fault somehow and work from there.

[Alastairh 47]

Bit of a stange one. Not something like a air leak in the system and pissing out water out the overflow or something.

 

You did use all the correct spacers for the head bolts?

 

If in dought jack the car up on axel stands and run the engine in like 2nd gear so its under load but you can see its activitys.

 

Alastair

Edited February 20, 2007 by Alastairh

[Richie-Van-GTi 70 2 Cars]

no bled the system 3 times now, no airlocks or anything and definatley not from the overflow, thats bone dry.

Does the 13mm bolt that fastens the oil filler neck go right through to the water jacket?

 

definatley used correct spacers with new head bolts. Im wondering if the new HG is a faulty one.

Edited February 20, 2007 by Richie-Van-GTi

[Alastairh 47]

I've got no bolt in mine for the oil dipstick, as i've got one of these manifolds. I don't have any problems. Thats a 8v btw.

 

Alastair

[steve@cornwall 100]

I've always been told to skim an ally head without fail as they often warp slightly on removal- the one time I ignored this was on a gti. It leaked

[Richie-Van-GTi 70 2 Cars]

well mate rang me last night, its stopped leaking itself which is bizarre. Ive told Him I still want to check it all over properly at the weekend in case something is gonna go pop again when hes not expecting it.

[lagonda 41]

Hi, I followed Puma Racing's recommendations when refitting my head. This involved bolting the head down to a set torque, leaving for 24 hours, then loosening & fully tightening each bolt in turn. This allows any stresses to work themselves out & I had no leaks (head had been skimmed). Of course you might have already done it that way, but if not it might be worth loosening & retightening each bolt as suggested.

Another thought is that a flake of rust/debris could have fallen out of the head as it was being refitted .. it does happen ... preventing a proper seal.

Incidentally the dipstick tube stay drilling is blind, it doesn't go through to the water passage. Could just be worth checking someone hasn't tried to put a longer bolt in & cracked through there however, if you remain suspicious.