I lost my original thread but I wanted to give an update to my
It was titled "air pump". I want to thank all that replied. My problem
was that I had a knocking sound every time the engine would get hot
after a long ride in the very hot weather and the knock would go away
when the engine cool'd off.
I have a '90 Grand Marquis for those that hadn't seen the thread. I
was going to flush out the coolant and replace with new coolant since
the thermostat was new. I went on Saturday to do so. I went to a
radiator/air conditioner only shop which is in Coney Island Brooklyn,
for those who know the area it is Larry's Radiator.
While examining the radiator before flushing it a crack was found in
it. It has a plastic radiator. It was the kind of crack that didn't
create a leak but was more like a squashed in crack closing off some
of the radiator from operating. Being plastic it could not be soldered
and boiled so I replaced it.
The car is running so cool now even in the 90 degree heat and with the
a/c on the highest the temp. needle goes is half way. There has been
no knocking since I replaced the radiator but I really haven't driven
far until today. I am taking a ride to Atlantic City, approx. 120
miles each way and I have a good feeling that the problem has been
Again, thanks for all the replies.