Retorque head bolts?

[meerkatmag]

Since fitting a turbo to my early na di I've got a light oilly seep from the head gasket on the intake side of the engine around cylinder 3. I think what's happening is at full boost (10psi) the cylinder pressure is too high and I get some cylinder gasses escaping to outside. Also had high blowby at full boost but this has been solved with enlarged pcv hoses.

I didn't think 10psi was too much for these na pistons and cams? I was wondering if I should check the head bolts are tight around cylinder 3. Good or bad idea?

Any advice appreciated.

[MinorMatt]

You shouldn't have any issues with the engine for adding a turbo

You can try to tighten the head bolts a little (I might do that myself) but they are stretch bolts and if taken too far they will fail).

If you think there are only 1 or 2 at fault, then I might be inclined to slacken and then retighten (70NM Plus 90 degrees from memory - but double check that) one at a time.

If any more than that I would take the head off and fit a new gasket.

Bolts can be used up to 3 times

[meerkatmag]

I can't get anywhere close to these bolts with my large torque wrench. I'd need to remove injectors and they are all truly stuck. I did get a small basic wrench on a couple of head bolts and they are tight af. I couldn't get them to budge at all. I'm nervous to loosen them without knowing I can get a torque wrench on to reset them. So look like I'll just have to hope it doesnt get worse.

[cherniy_chack]

If there is no breakthrough of gases from the combustion chambers into the cooling system and the release of coolant from the expansion tank, then do nothing.

[meerkatmag]

No evidence of coolant getting contaminated. It used to overheat if I powered up a mountain fully loaded. But since fitting an auxiliary water pump and electric rad fans it keeps it in the norm whatever i do.

So I guess leave it be? It's rather alarming the amount of oil leaking down side of block but I'll turn a blind eye.

[Chug]

It's not too much trouble to remove the head and see what the problem is. Probably cheaper than topping up oil.

[meerkatmag]

I've been doing some investigation and although there's no sign of overheating or oil/coolant mixing I did find the coolant level to be low. I topped it up a couple of months ago and it needed 1l of coolant to bring it back to full. So I'm wondering if there's a defect in the head gasket just at the edge of cylinder 3 and it's blowing through and pushing coolant out of the side of the block. It looks like the coolant passage is right there between the cylinder and place it's seeping out. So maybe what I'm seeing is a mixture of coolant and oily/soot. I've cleaned it all off and I'm going to take it for a long drive and see how quickly it's coming out.

I agree with Chug that I probably should just take the head off and replace head gasket. I've never done it before so a bit nervous to dig so deep. But I will have a go if there's no other solution. I've been thinking back to what might have caused it and there was an occasion when the intercooler pipe came off and I couldn't get it to stay on due to loads of oil in the system. I had to drive it home like this and the EGTs were really high driving like this. I've got sensors and a display so I can see the values. Maybe it was too much for the gasket? That was over a year ago but it may have been slowly getting worse.

Thanks for the advice so far.

[Chug]

Well, what happened after the long run?

[meerkatmag]

I went on a 1hr drive approx 50miles and everything looked pretty good to be honest, only light oil on the surface which could well be still there from before I cleaned it. The heat of the block makes it show up much more than when it's cold. The coolant hadn't dropped any noticeable amount. I think If it's blowing it's only really small amount and hardly noticeable on this length drive. Picture below of the block after this drive. I'm going on a 900mile camping trip end of May so will see what it's like after that drive. I wish I'd taken a photo before I cleaned the block because it was covered in oil.

WhatsApp Image 2025-05-01 at 14.05.38.jpeg

[MinorMatt]

Its not oily stuff blowing out of the inlet manifold is it?

[meerkatmag]

I've always thought it was oil. I retightned the inlet manifold bolts with this in mine and it didnt seem to help. It really looked like head gasket seep rather than leaking from inlet. But i guess its possible. Except there's no explanation for where the coolant is going?

[Chug]

I would clean it up and wedge/tape kitchen towel around manifold and around the suspect head seep and then run the engine at mid throttle whilst watching for the first signs of wet towel.