Coolant leak above water pump 98 v70

[kmashlan]

Hi all.

I have just finished replacing the head gasket on my 98 V70 and have a wierd issue.

Upon filling the radiator tank the coolant all leaked out within an hour or two. The car had not been started - so gravity pressure only.

I thought it might be the pipe which attaches to the back of the head near the cam belt end but didn’t seem to be.

Taking the cam cover off, it was leaking down the face of the water pump right from the top. It was not coming out the weep hole in the pump, but I cannot see exactly where it is coming from.

I did not remove the water pump as it was replaced recently(ish).

Is it possible that it Is coming from the head gasket? It seems unlikely given that it leaks without the engine running.

I topped it up and started - just to see if it works -it does! Yay! Anyway, when the engine warmed up the leak stopped.

I drove it for 20 miles or so to run it in a bit and it did not leak when I got it home.

However - leaving it overnight it has leaked a little, although not emptying the tank which it did the first time.

Any ideas? It could be the pump - is it possible to damage the gasket / pump when removing the head? If not, the only thing I can think is cracked block/head, although I didn’t see any evidence of that, and given it leaks without pressure at a rate of maybe a drip every second, if it was head / block I would expect it to leak faster under heat / pressure.

Cheers.
Ken.

[RickHaleParker]

Go to a parts store get some Tracer dye (UV fluorescent dye ) and a UV light.

With the coolant low:
1. Add the Tracer dye to the coolant system .
2. Top off with distilled water ( not distilled drinking water ).
3, Run the engine to get the dye mixed up in the coolant.
4. Turn engine off and wait for it to start leaking.
5. Use the UV light to trace the leak back to the source.

Did you check the head for flatness when you had it off?
Clean the block deck and head squeaky clean?
What did you torque the head bolts to?
Did you replace the thermostat gasket, squeaky clean mating surfaces?

[erikv11]

Since you can't see for sure where it is coming from I really suspect that water pipe. It is a complete PITA to get it right and I suspect the paper gasket there is leaking. Can you get a camera back there to record some video while it is leaking?

Can't see any way to damage the pump when removing/installing the head.

Tracer dye can be useful but you are still stuck with the same issue of being able to see into places you haven't seen yet, you're just looking for tracer dye instead of a drip. So I'm not sure it helps in this case. I think I would focus on looking more carefully, try getting a camera to look where you can't look easily.

[scot850]

Check the simple stuff too like the thermostat housing and I once had a leak from the small pipe from the thermostat housing to the header bottle where it attaches on the thermostat housing. Pipe had become porous and clamp would not seal it. When the engine was cooling it would raise the pressure in the cooling system enough to force coolant out there which then ran down into the timing belt area.

Neil.