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Topic: two "problems" (Read 974 times) previous topic - next topic

two "problems"

We just recently bought a 1994 Mercury Cougar and there are two issues we are trying to figure out.
First the car is idling at about 800-900 RPM and is ok, could be maybe a tad smoother, but when in gear and at a stop it idles at 600-700 RPM and is kinda rough (you can feel yourself and the car shaking some).  Any clue?  We just had the pressure regulator change (before that it was doing the same thing but much worse to the point of stalling).

Second, We are hearing a wierd, kinda sing/grinding noise at 20-21 MPH.  The only time is does it is when you turn the car on and first drive off.  From there on when you stop and go it does not do it anymore, but if you stop at the store and turn off the car and come back out and turn on the car and leave it does it again at 20-21MPH.  Any clue what that could be?  (The car is not shiffting gears at the time of the noise).

Thanks and any suggestions would be great!
 

Re: two "problems"

Reply #1 –
problem 1
ill assume you had the fuel presure regulator changed? 
for problem number 1,, id highly suggest you have the codes pulled first and post the results.  It could get expensive to shot gun a rough running condition.

problem 2
you got me,, where about does it sound like the noise is coming from? rear,front,engine,under the car ,,where?

my first thoughts are a brake pad is loose or caliper is loose. Once you hit the first stop , your line presure reseats the caliper pins or pad for the rest of the drive.  When the caliper and pads cool down, there may be separation due to the cooling down period. something like a warped rotor comes to mind as well but this seems to be a confussing issue.

maybe a belt,,? smog pump going bad

OH< by the way,, i had a smog pump on my car that was going out and i did not know it.  My car tossed its serpentine belt twice in one day so i was like hummm.  By chance i was trying to rotate the smog pump pully to add the belt and i noticed the pully was hard to turn.  I deleted the smog pump and this instantly cured the low idle and the once in a while stalling i had.  In a nutshell, the smog pump was locking up.
maybe both your problems lead to one part being bad.  Remove the belt and see if all your pullys rotate free.  its an easy check but this would cause both symptoms.  Remember, the hotter it gets, the more pr0ne it is to being hard to turn.  If you can, check the pullys with the engine warm, you'll feel the difference best then.