XUD9 Coolant air locks or head leak? Help please!

[Phils99XUD9]

Hi, new to posting on the forum but I have been here for help many times before, great site, thanks!

I am now stuck with filling the coolant system since overheating last week, I fear I may have damaged the head or gasket. The engine runs & seems fine but coolant pressure blows the rad pipes off before long.

I've tried the various methods & tips for filling, I think I'm successfully filling it.

Now have stat removed, have bled fully etc, and with a little space (water to the 'notch') in the tank, it still pressures up when driven & pushes a top or bottom rad hose off. It is a cheapy rad but it was fine for quite a while til overheating the first time on the motorway.

With extra 3ltr bottle on tank for greater head, the system fills as far as I can tell, but whilst ticking at 900rpm it constantly pushes bubbles out of the tank, albeit it slowly. It increases slightly with revs, water is drawn also with revs & level rises again quite quickly when revs are dropped so I think pump is working. Stat opens in hot water &rad fills if fitted, without fitted the rad fills fine too.

Still it produces bubbles or pushes hose left sealed, no matter what I do.

I think the head is cracked or the gasket is leaking.

Do I have any way of telling myself? I have heard of a 'sniff test' on the tank cap to test the bubbles for emissions from the barrels, is it accurate? Is there anything more I can do myself to test the head and gasket?!

Should I just use Araldite & jubilee clip the hoses on & let it run at such pressure??!!

Thanks in advance

Phil.

[jasper5]

Hi, and welcome

It sounds like you have a blown head gasket to me, especially if there is pressure with the thermostat removed.
Sealing up the system with araldite and a jubilee clip will not work.

Cylinder head removal and examination is required!

[Phils99XUD9]

Hey, thanks for replying. I fear you are right sadly. I'm looking for a way to check without starting proper work on it if possible, like pressure testing the water system - but it sounds to me like it'll find another leak before the one in the head if I try that. I'm also wondering if K Seal really works, the leak is definitely very small & K Seal supposedly will be drawn back through the leak & set on contact with air in the barrel.... not convinced... :/

[PeterN]

If you have that much pressure in the system I would think that head gasket failure is certain, if you try and prevent it venting anywhere it will likely destroy the radiator and or heater matrix. The only thing you can do is to try running it with the cap loose so the pressure can escape but if the water escapes with it you are out of options I'm afraid.

Peter

[Phils99XUD9]

Hi Peter, thanks.

I'm pretty concluded that it is a head leak causing the pressure. I'm going to try my luck with K Seal tomorrow, there's enough good reports of it out there that it's worth the £10 for a try.

The question failing that will be whether the head is likely cracked, cos it's curtains for the car imo if so. If it's a almost certainly 'just' a gasket change I might just go ahead with it.

Thanks again so far:)

[jasper5]

You would appear to have a large leak if you have so much pressure in the system and no amount of K seal or anything else will make any difference at all.

[PeterN]

The cheapest way out would be to fit a secondhand head, there must be lots of them about.

Peter

[Phils99XUD9]

You would appear to have a large leak if you have so much pressure in the system and no amount of K seal or anything else will make any difference at all.

Seems you're right, 1 x bottle used today with no effect

The cheapest way out would be to fit a secondhand head, there must be lots of them about.

Peter

Yeh sounds like a plan man, if anyone happens to have a nice recon'd or good s/h head then please let me know!

Thanks.

[lozz]

K-seal is only any use on the early stage of H/g failure,
ive used it in the past ..just to get a few more weeks out of an old banger,

Only one thing for it imho on a good car, C/h off and send it away for a skim,