1.8T inlet gasket. Best?

[Roverconfident]

I've had my 75 for a month. It keeps losing a little coolant. The cooling system isn't over-pressuring, the oil is clean and the coolant isn't oily. There's no coolant smell inside the car. It isn't overheating. Incidentally, what I took to be the overflow pipe isn't, as it goes to a t-piece at the top of the rad and to the inlet manifold, so where would coolant come out if the system over-pressured? The pressure cap wasn't tightening up properly,being very stiff and uneven to turn, so I replaced it and the new one feels as it should, but still it lost about 20-30ml in 30 miles. There looks to be a little weep on the inlet gasket at the timing belt end of the manifold, where there is a red trickle-stain about 20mm long, so I'm thinking that may be it and it is evaporating almost as fast as it leaks. It had a new manifold gasket 1 year and 3000 miles ago. Could it still be that? If so, is there a preferred gasket that won't fail? Thanks.

[SD1too]

Hi Terry,

The first thing to check is that you're not unwittingly over-filling the expansion tank. With a cold engine and the cap removed, when you look inside can you see a tab marked 'MAX' towards the bottom of the tank?

Simon

[suzublu]

There is, or was, a stainless t piece available as this was prone to leak, check dmgrs for a replacement viton inlet manifold gasket. For belt and braces I fitted a vvc aluminium inlet manifold as well, never had a problem since 😎

Sent from my SM-A145R using Tapatalk

[Roverconfident]

Originally Posted by SD1too

Hi Terry,

The first thing to check is that you're not unwittingly over-filling the expansion tank. With a cold engine and the cap removed, when you look inside can you see a tab marked 'MAX' towards the bottom of the tank?

Simon

I'm not overfilling the expansion tank, just to MAX. Thanks.

[Roverconfident]

Originally Posted by suzublu

There is, or was, a stainless t piece available as this was prone to leak, check dmgrs for a replacement viton inlet manifold gasket. For belt and braces I fitted a vvc aluminium inlet manifold as well, never had a problem since 😎

Sent from my SM-A145R using Tapatalk

There is no leak from the T-piece. I understand that they can break, but it is fine now. Is it common to get leaks with the original type of gasket, even so soon after replacement? Thanks.

[planenut]

Roverconfident, welcome to the Club.

When my inlet manifold gasket was losing a small amount of coolant, when cold I could feel under the back of the block to find "the dribble", which maybe is how you found yours? Due to the expansion of metal with heat, I lost less on long journies.

I can't remember where I got my gasket from but a good point when fitting was to rub some grease or vaseline all over it. While the manifold was off, it was a good opportunity to check the operation of the jiggle valve.

Good luck.

[Roverconfident]

Originally Posted by planenut

Roverconfident, welcome to the Club.

When my inlet manifold gasket was losing a small amount of coolant, when cold I could feel under the back of the block to find "the dribble", which maybe is how you found yours? Due to the expansion of metal with heat, I lost less on long journies.

I can't remember where I got my gasket from but a good point when fitting was to rub some grease or vaseline all over it. While the manifold was off, it was a good opportunity to check the operation of the jiggle valve.

Good luck.

I'm now thinking it isn't the inlet manifold gasket at all. After a more detailed look with a bright inspection torch, I see that there are dry dribble residues at intervals along the head joints, which I think may have occurred after the new HG was fitted, before the 1st heat cycle. There's no fresh leakage. I reckon it loses maybe 1ml per mile, which is very little, but I really don't know where from. I could just add a small tub of black pepper to the coolant, which I've previously found brilliant for tiny seepages and it doesn't block anything up otherwise (I hope!). What is the 'jiggle valve'?

[planenut]

Hmm, pepper? Not come across that one.
The jiggle valve is only exposed with the removal of the inlet manifold. There is a smaller hose that connects it to the header tank; it's a tiny ball bearing which allows coolant to return if needed. One can test it by blowing through that hose, hearing it operate. If you do get to it, it's worth cleaning any debris out to ensure it's operation.

Other suggestions will come along soon I am sure.

[Roverconfident]

Thanks. I've been reading up about the jiggle valve. I have found black pepper, which is cheap and consists of tiny grains, very effective. It wouldn't stop a serious leak, but it stopped a water pump leaking on my old Wartburg!

[DMGRS]

I'd strongly advise against putting anything in the cooling system other than coolant - the K Series has lots of very small passages in the cylinder head which are very easy to block.
In addition the heater matrix of these cars is already prone to blocking leading to poor heating performance - adding pepper wouldn't help this either.

It'll be something easily resolved I'm sure - if you're struggling to see any external leak, start with the Inlet Manifold Gasket.
The Viton version is the strongest replacement available: https://www.dmgrs.co.uk/products/k-s...sket-lkj101110

Make sure all mating surfaces are clean as a whistle, and you'll be good to go.
It's worthy of note that the inlet manifolds themselves can warp, leading to leaks here - I always check them against a straight edge when replacing this gasket.

Good luck!