- Joined
- Sep 12, 2015
- Messages
- 8,046
- Reaction score
- 3,149
- Location
- SW Ontario
- My Car
- 1971 Mustang Mach 1, M code, 4 speed.
Reading through all this is baffling for sure as to the cause of the problem.
I came to a theory that may or may not fly, but worth checking into if it were my car. Nothing make sense to me. As I have mentioned many times, I only go from my own experiences and this isn't one of them, but here goes.
1, It pressure tests okay cold. What about when hot?
2, You added 1 gallon of water. Where the heck is it going?
3, All your basic checks appear okay, T/stat working, correct stat with "hat", installed the RIGHT WAY UP? Hoses all new (spring in bottom hose?) etc. etc.
4, it overheats when driving and gets hard to start. Okay, here's my theory.... and it's only a theory.
When the engine is cold, no leaks are visible anywhere including from the cylinders. BUT when the engine is hot, it mysteriously gobbles up a gallon of water!! I believe you have a head gasket leak that is only present when the engine is hot. It may be very small, but it's there. The hard starting and knock is over pressurization of a cylinder because of the water (non-compressible), but which cylinder?
5, Do you see ANY whitish smoke/haze from the exhaust? You may need someone to follow you as you drive to observe the exhausts. Assuming you have dual pipes, your observer could see which bank is smoking. That narrows it down to one or the other head gasket that needs to be changed and SOON!! Major damage could occur and a total rebuild necessary.
As stated, this is NOT something I personally have experienced and I hope I never do on the Mustang. I did once have a head gasket blow on a T-Bird and that left a plume of white smoke behind the car for miles. I had to be towed home. Damn Fords!!
Anyway, I hope this offers some ideas that may not be what you or others want to hear or agree with, but I didn't see any mention of a blown head gasket when hot anywhere else in the posts.
I hope I'm wrong and it proves to be something simple and not as expensive as my "theory" would be.
Geoff.
I came to a theory that may or may not fly, but worth checking into if it were my car. Nothing make sense to me. As I have mentioned many times, I only go from my own experiences and this isn't one of them, but here goes.
1, It pressure tests okay cold. What about when hot?
2, You added 1 gallon of water. Where the heck is it going?
3, All your basic checks appear okay, T/stat working, correct stat with "hat", installed the RIGHT WAY UP? Hoses all new (spring in bottom hose?) etc. etc.
4, it overheats when driving and gets hard to start. Okay, here's my theory.... and it's only a theory.
When the engine is cold, no leaks are visible anywhere including from the cylinders. BUT when the engine is hot, it mysteriously gobbles up a gallon of water!! I believe you have a head gasket leak that is only present when the engine is hot. It may be very small, but it's there. The hard starting and knock is over pressurization of a cylinder because of the water (non-compressible), but which cylinder?
5, Do you see ANY whitish smoke/haze from the exhaust? You may need someone to follow you as you drive to observe the exhausts. Assuming you have dual pipes, your observer could see which bank is smoking. That narrows it down to one or the other head gasket that needs to be changed and SOON!! Major damage could occur and a total rebuild necessary.
As stated, this is NOT something I personally have experienced and I hope I never do on the Mustang. I did once have a head gasket blow on a T-Bird and that left a plume of white smoke behind the car for miles. I had to be towed home. Damn Fords!!
Anyway, I hope this offers some ideas that may not be what you or others want to hear or agree with, but I didn't see any mention of a blown head gasket when hot anywhere else in the posts.
I hope I'm wrong and it proves to be something simple and not as expensive as my "theory" would be.
Geoff.