Engine coolant leak

[PxMetro]

Hi All

Hello All

I have posted this on the Chimaera forum looking for help. Thought it might be worth posting here as well in case anyone has some thoughts.

My 4.6 serpentine engine is leaking coolant from the gasket between the engine block and timing chain housing. At first I thought it was the Stat housing, which appeared to be leaking due to the amount of red residue beneath the inlet manifould,so replaced the gasket sucessfully. However, after returning home from a test run, left the car parked to clean off flies etc, I noticed a pool beneath the car which was dripping off the chassis members.
After taking off the power steering pump oil feed pipes to get a better view, I traced the leak to the top of the timing chain housing at the point where the long bolts fit right through from the water pump to the engine block. I cannot see any way of fixing this other than to remove the complete housing assembly.

Has anyone experienced this problem, and is it possible to disassemble the front of the engine while in situ ?

Help would be appreciated

[TimJM]

I'm no mechanic so could be talking rubbish but - isn't a front end engine leak usually always the water pump?

[PxMetro]

Hi. Not in this case. The leak is between the casting that the water pump fits onto and the engine block. (timing chain casing)

[TimJM]

PxMetro said:

Hi. Not in this case. The leak is between the casting that the water pump fits onto and the engine block. (timing chain casing)

Do you have any photos? It is hard to picture it from the description, if it near a water pump bolt could it be as simple as the water pump gasket?

[carsy]

Paul, just take that bolt out. If you dont fancy draining the coolant first, it will empty itself through the bolt hole, When its finished draining re fit the bolt with some Hylomer or similar on the threads and all will be well. Top up with coolant and like i said try n keep an eye on your oil just incase it has leaked internally as well.

If you still then have a leak, then yes you may well have to take the timing cover off but i would try the bolt first, if thats where its leaking from, just in case it has lost its seal.

Edited by carsy on Saturday 7th July 15:56

[PxMetro]

Thanks for the advice, but I tried sealing the threads on both of the long bolts with hylomar this morning, but unfortunately to no avail. The water now appears to leak out faster than it did before, so am contemplating gasket replacement.

[carsy]

Oh well, it was worth a try. Looks like its timing cover off then for a new gasket.

[PxMetro]

Yep...seems that way. It's in the garage now, front up on ramps. Just have to decide on what sequence for disassembly. This should be fun (Not)

Cheers

[Simon says]

The gasket width is a bit marginal on the corners of the water pump water ways on the front cover gasket to be honest and this is generally where the leaks occur 1st when the gasket becomes old and brittle in extreme cases the gasket literally breaks out of the joint completely followed by rapid overheating the bolt drilling's either side of those coolant passage's are blind so if you have leaking from the bolt holes past the bolts then the gasket as already breached

Edited by Simon says on Sunday 8th July 22:19