Hi All

i have a cooling problem that i have been researching on the site and have found the following common symptoms with my 94 FD.

1. mysterious loss of coolant.
2. overfull overflow bottle
3. often empty AST
4. residual pressure in the cooling system. after allowing the car to cool overnight, when i open the AST or filler neck cap, there is a bubbling sound and a burst of air pushing out the cap.
5. the car overheats under "track racing" conditions. after the 4/5th lap of a short circuit the temps fly over 110C. temps stay around 88C to 92C with normal road use and occassional bursts of accelleration.

i am told by another RX7 owner that with a vented bonnet my overheating issues will dissipear.

my gut tells me something else is wrong.

i dont see too much white smoke from the exhaust and i have tried a cooling system pressure test, however not over a significant time like overnight. i have replaced both caps too.

any other tell tale tests i can do to make sure??

i really dont feel like spending money on a vented bonnet only to find i have a busted o-ring and need a rebuild.

any other advice

thanks

Greg

 

u tried pressure testing the system? might have a leak

 

take it to a shop that can test for hydrocarbons in the coolant.

 

thanks guys

will conduct an overnight pressure test and see if i can get someone to do a hydrocarbon test.

if the water jacket has infact failed, what are the chances of a warped housing?? guess i should start looking!!
are any other parts other than the housings or irons in danger of damage??

if i can keep the water temps at around 92C will i cause any further damage??

thought i might give this "block weld" option a go too.

Greg

 

Dont know about South Africa, but here you can rent the equipment from Autozone to do the hydrocarbon test. You have to buy the chemicals.

You may ask at your local car parts store, possibly they can help.

 

Had the hydro-carbon test done today , and it confirmed there are indeed exhaust gasses in the coolant. mixture turned from dark blue to green to yellow.

what a bummer.. im quite sure the car has been like this since i got it 6 months ago, which is a bit frustrating to accept. i was hoping after all the upgrades that the problem would have been solved. none the less, i have a re-built streetported motor waiting for the transplant
i just hate the down time, and im sure the "running in" period is going to be a bit painful too.

thanks for all the advice and feedback.

i still love this car!!!

 

well if i owned an fd i'd get a vented bonnet as a reliability mod either way.