Strange coolant loss

Have a strange small water leak overnight but can find out were its coming from !.had this leak for a while now because every now and again, there is a small patch under the car seams to run down the gear box seam at the rear side of the engine(thought it was clutch fluid at the start because it was near the clutch arm but fluids level is fine).uses a small amount of coolant a week bit sick of remove the engine cover trying to trace this,was thinking could this be the inlet manifold gasket and when the car is running,the gasket is sealing or water is evaporating but when cools down starts to leak.
going to try and look under the manifold with a mirror this morning.

any ideas..

before you say oil is fine and head gasket replaced

regards

todds

at a guess, I'd say you've got a split hose somewhere.

Do you hear a hissing noise of steam escaping, like a kettle, without the whistle.

Running down the engine when cooling, is just condensation.

I'd be checking the hoses, or maybe ones just not connected correctly, worked its way loose.

The usual culprit for odd coolant losses is the inlet manifold gasket, especially if you have the plastic manifold They warp over time.
The best way to see is to jack the rear of the car, put a couple of axle stands in and slide yourself under the engine with a torch(flashlight) Look up under the inlet manifold you'll see staining from the coolant drying on the hot engine. Usually at the throttle body end.

Hot engine evaporates the leak, so you only see coolant on the floor as the engine is cooled down.

I swapped my plastic manifold for an alloy one off a TF.

Great advice from David :broon:

If that doesn't get you sorted here is a diagram of the cooling system which would hopefully let you identify the hoses and joints where leaks could occur. As you can see there are quite a few bits to check.





Let us know how you get on

That diagram fills me with dread every time I see it.

:lol: :lol: :lol: your not kidding Rich. It shows just how many chances there are to get a leak :dry:

Thanks guys,

Checked all the hoses,no leaks or hissing sounds,for the price of a inlet gasket,just ordered one,so looks like thats what i going to try next weekend.Any thing i should no prior to changing the gasket that may help.

Regards

todds

If you have the plastic manifold I would seriously consider the TF alloy manifold conversion.

If the plastic one is warped it will leak again, mine did!

I got an alloy one for £50.

Though the plastic one is a bit of a pig to get out as it's one piece. (the alloy one is two piece) I seem to remember having to take off the throttle body and air filter box to get it out.

Here's a few pics of my plastic manifold leak.




The redline shows where the plastic manifold was warped.

I have a very similar leak on my F and have diagnosed it as intake manifold leak. I have a very early car and do have a plastic intake manifold.

I hadn't heard that the plastic intakes were prone to warping. I had heard that the very early plastic intake manifolds had a black coloured gasket, which prone to failure.

Thanks for the pictures David, they are very helpful.

Rich in Vancouver wrote: That diagram fills me with dread every time I see it.

Especially as you were going to change to silicone ones :omg: