We rebuilt this engine after cam belt failure damage in 2019, head was skimmed and valves replaced. It has a 5 hole gasket which has just blown and pressurised the water system big time.
I put the gasket on dry and tightened the bolts as per Haynes. Did I do something wrong?
Is there a tip in fitting these gaskets.
Any help would be appreciated.

 

Did you replace the head bolts when you installed the head? IIRC, the bolts are TTY (Torque To Yield), and they might not give you the same results as new bolts if you re-used them (lots of opinions on this, but I'd say that it would be prudent to use new bolts just in case).

Also, any chance that the engine simply overheated (again?)?.

I'm assuming you used the classical "star pattern" sequential pattern, and used a known good (calibrated) torque wrench to install the head.

 

Yes, new bolts were used, these are tightened with angle which we followed and there was no overheating. It just let go suddenly?

 

Could be the shop missed a crack in the head, or perhaps there was just a random failure (where did you get the head gasket from?).

 

Hi, I got the head gasket from where the head was machined. I am now suspecting the gasket, the layers have come apart and the coating seems to have had a reaction. I have got another gasket from a engine parts supplier which looks different and better. Would it be an idea to use a little Hylomar as well?

 

I suspect you're right about the bad gasket from the machine shop. That's one area where you want to go OEM. I'm not at all familiar with Hylomar, but would suggest not using any kind of sealant on that head gasket, unless it's just a dab in non-critical areas to hold it in place during the installation of the head (if that's an issue).

 

Finally found the problem, this crack has opened up with it sitting so scrap.

 

Ouch. I doubt that happened when the engine was sitting still (unless maybe if there wasn't any antifreeze in the system freezing could cause a problem like that). Otherwise, I'd guess that it probably started the crack when the engine trauma that killed your previous head happened, even if it didn't propagate enough to cause problems for a while.

But yeah, it's scrap now!.

 

There was no sign of the problem when we sorted the head gasket last time, there was anti freeze in it at 50% so something happened meantime. I meant with it opening up was after I had stripped it, rust started to appear and when I started cleaning it today could see the problem.