Interesting head bolt discovery...

[tony750cc]

Having another play with my overheating and pressurising motor today. Firstly took the rad off and flushed it through, it wasn't actually that bad and the water that came out was pretty clean. Then as a thought i went round and checked the head bolts. The rear lower bolt on the offside head wasn't tight...in fact it was loose! i thought first the bolt had snapped as it turned so easily. It did tighten up readily. I have checked the others on that block 3 were i reckon around 10 maybe 20 ft lbs certainly not tight. I have taken them all up to 40 ft lbs and run the motor to get it warm (around 60 degrees) and im going to let it cool right down. Probably tomorrow if i get chance i will try and push them up to 55.
Im having debates about whether this would account for my overheat/pressurisation issues and whether running it like this would have caused further damage. I suppose the one good thing is that the bolts should all come out if i decide to lift the heads to do the gaskets.
I know the motor was rebuilt in 1991 so the heads have certainly been off once albeit 20 odd years ago. Its only done 20k since the rebuild

[Bandit1200]

Hi Tony

Glad you've found this maybe a quick fix.
You must be the only Stag owner to find head bolts loose. It's usually the opposite causing the bolts to shear.
I'll keep my fingers crossed for you
Steve

[stag157.7]

Hi Tony

Glad you've found this maybe a quick fix.
You must be the only Stag owner to find head bolts loose. It's usually the opposite causing the bolts to shear.
I'll keep my fingers crossed for you
Steve

I know plenty of stag owners with loose head bolts
alan

[GDPR]

I know plenty of stag owners with loose head bolts
alan

and a few with looser morals......

[MarkTwo]

Yes, I have had the same issue. Firstly antifreeze on the floor overnight, thought it was the overflow bottle venting it. Then a hose leaking, but fixed by tightetining the hose clip and at the same time a dribble from the radiator. On checking the head bolts after seeing a suggestion on the forum, some were quite loose. 2 moved with the torque wrench set at 30lbs. All now tightened and tried Radweld on the radiator, which has not worked. I need to repair or replace. It was a Hart supergill from 1993 - £153 then.

Hopefully we are making progress. Best of luck Tony.

Mark

[4x4]

I had my rad (a Supergill) repaired by Serco (my local branch was Oxford). Multiple problems - all solved for about £85, and looked as good as new.

[flying farmer]

Loose head bolts are not uncommon. People forget they are supposed to be retorqued regularly because the head gaskets compress, then lo and behold the gaskets blow.
Eventually the gaskets stop compressing, an annual go with the torque wrench is still a good idea.
When fitting new gaskets I retorque after the first time the engine has run (when stone cold), again at 500 miles, then at 1000, then annually after that.
Lets hope you are lucky and the retorque will solve the problems
Neil

[tony750cc]

What are the thoughts about any damage by running it with the bolts loose?? im thinking it may have eaten the gasket and tried to spit it out. Would be really nice to think this may resolve the issue but ive got a feeling i wont be that lucky! I have formed an idea that whilst i thought the pressurising had got worse since i flushed the system it could be that it got worse as the car was being used and the bloody bolt was getting looser and looser!!. The big test will be after ive re-torqued them down and see how much pressure is being pushed into it. I wait with baited breath!!

[wilf]

Fingers crossed.

Sometimes the engine gods are benign.

[StagManiac]

Good luck with it. Hopefully it's sorted now.

Paul

[elvimto]

I had a thought about getting a pressure gauge into the cooling system attached to a long bit of hose and back to the car so that when you are driving you can look and see if thte pressure is above the cap pressure, this would be another way to show if the head gasket was leaking and pressuring up the cooling system. Just as a test set up.Does this make sense ?

cheers Stuart

[wilf]

No needfor such complexity - if the head gasket is leaking, a "block tester" (which just senses combustion gasses in the coolant) is a tried and tested way to check. And your local garage should be able to do it.

[martin]

Even easier, my local garagiste, if asked, will stick the exhaust analyser probe into the expansion bottle, instant reading, and free. Martin.

[singapore stag]

Even easier, my local garagiste, if asked, will stick the exhaust analyser probe into the expansion bottle, instant reading, and free. Martin.

Cool!

[V Mad]

I had a thought about getting a pressure gauge into the cooling system attached to a long bit of hose and back to the car so that when you are driving you can look and see if thte pressure is above the cap pressure, this would be another way to show if the head gasket was leaking and pressuring up the cooling system. Just as a test set up.Does this make sense ?

cheers Stuart

Stuart, if the cap is working, it will release any excess pressure, so I would not expect this to work unless the gasket had failed really badly, but then you would probably already know.