I have a 91 Fc, I was on the highway, heard some detonation, and pulled over, now the thing does not want to idle at all. I thought I blew an apex. But when I get under way, over 2500 RPM, it runs strong as always. I noticed a little coolant between the inake and the rotor housings on top of the motor. I am having it compression checked tomorrow to see if there is blow-by into the coolant jacket or if that leak is a totally different problem. The car runs cool and even a little rich, does coolant cause detonation? Its a fresh motor that was just recently completed with all the best stuff internally. Any help would be appreciated

 

I got it compression checked. The front rotor was great, but th rear rotor has one good pulse and 2 low ones. does that mean the apex seal shatered or just wore extremely fast. It was running great not a single problem, then I got on it and it started acting funny. I pulled over and it wouldnt idle. How could it still be so fast with a blown apex seal. This didn't happen slowly, It did it all at once. It might have felt a little weak, but there was no sudden jerk or loss of power when it happened.

 

for some reason the cars sometimes run beter blown, no one knows why, get it rebuilt and ported.

 

well what could of happend is you had mild detonation, and may have just cracked or chipped a apex seal....

if the compresion is still pretty good on that one good face on the bad rotor
i would stop driving the car imediartly!! as the housing probably survived and the apex seal is just cracked and stuck in the grove! but it could fly out and cuase extra damage the more u drive it

 

Probably because you get to an RPM where the effect of the blow by is so small due to the limited time spent under compression.


BC

 

Turbo or n/a? What mods? Why did it detonate?