Cooling system problems

[tim shickle]

Hello all, i have a SRCV8 and i am having far too many problems with her overheating. She has had a new fan, new thermo controller, new thermostat, new filler neck and had the timing re done. I have now been recomended that i should consider having the expansion tank above the level of my filler neck. Is this balderdash???? I was so looking forward to going on the Brighton run tomorrow as i thought i had the problem solved but oh no. I have discovered that the filler neck was aslo not high enough and there was an air lock in the system i am off to do that in a moment when she has cooled down.
Any ideas would be very welcome.

Thanks very much

Tim
:}

[kev]

Expansion tank above the filler neck? The filler should be the highest point in the cooling circuit, preferably part of the expansion tank. If all else fails with removing the air, there is a dodge that you can do. Drill and tap the 2 blind coolant holes at the back of the inlet manifold above cylinders 7&8, screw in tube adaptors, connect small bore tubing and connect them to a "Y" piece. The other limb on the "Y" piece is connected as high as possible in the expansion tank and definitely above the height of the thermostat. Don't forget this is part of the pressurised coolant circuit and should be fastened accordingly.

Above dodge only works if you are having problems with airlocks and ensures that the engine is always filled right up to the top with coolant. To check if you have an airlock feel the temp of the big bore tube coming from the thermostat to the rad, this should be very hot when the engine is hot, if it's not very hot it could be that there is no coolant in it, beware this pipe will get very hot!! Another possibility is that the rad isn't big enough or it may be partly silted up.

Where do you think the problem lies?

regards
Kev

[tim shickle]

hello kev

Sorry for the delay in getting back been very busy at work not really had time to play. I think i have located the problem but it reared its head in a different way. It looks like the head gasket might of gone i have lost compression in one of the chambers and the co2 readings are much lower, the engine will also not tune up any more. I have given her to a classic mg garage nearby as he workes on the v8 frequently. Before i gave her over i dropped the hose with the filler neck in and she did run much cooler for a while. With my limited knowledge of engines i thought you could tell when the head gasket went because you could see water in the oil, which i couldnt't. But i guess you learn something new everyday.
Thanks very much for your help.
Can't wait to get back out again.

Cheers

Tim