Coolant loss MK2 3.4 MOD Pooling on Inlet Manifold

Hi All, after an engine out rebuild and the first 1,000 miles I have noticed a small amount of coolant loss…the car is fitted with a coolant recovery system.

Recently I noticed a pool of coolant, seems like the water has evaporated off, on the inlet manifold roughly adjacent to cylinder 5. Looking at some pictures of the manifold it is near the large water cavity, which is close to two studs.

My guess is this could be a cracked manifold, possibly around the studs…is this a common issue. Or any other thoughts as to the leakage.


…although not clear in the picture, the studs are the inlet manifold studs, not the water rail. I have checked this already

Did you retorque all the bolds of the inlet manifold.
I found out that after about 500Km most of them were pretty loose.

In my experience its not common for the manifolds to crack. (they are pretty chunky). can you be a bit more specific as to where and how you think the leak is?
As Peter has suggested it is certainly worth putting a spanner on all the inlet manifold mounting nuts (you might have missed one?)

Following an engine rebuild I noticed a slight puddling in the same area - I suspected between the head and the inlet manifold. Checking the nuts were all tight however checked again when engine was hot I found a bit of a turn on a couple - sorted - might be worth a go - gloves on!

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I had the same problem but found that the nut was not tight enough and I was getting a false sense of tightness because the socket was dragging on the sides of the casting. A tube spanner fixed it. I thought the worst for a while, as we all do.

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Went over the inlet manifold nuts previously, also removed the water rail and reinstalled with new gaskets a few weeks back.

Earlier today, went for a drive of about 20 miles, then as suggested torqued the nuts, while still hot the water rail nuts each moved about 1/2 a turn…hopefully this fixed the issue. Will try again in a couple of days. Will let the forum know the outcome.

As far as accessing tight space for nuts. What does everyone use to tighten the exhaust manifold brass nuts. I should search for a thin wall wrench as now each one requires a tedious mini step process to tighten them.