Weird issue while idling when its cold engine - Ford Forums

e40water12 · 09-06-2009, 19:10

Heres the deal, I allowed to wait for my 94 topaz 2.3L auto, Ive been noticing, when I start the car up when the motor is cold, I get a weird ping (knock) like low octane sound @ idle, Then the other thing is I drove my car in the morning I allowed it to do idle only 2 mins, Then while idling in the drive thru, Motor idle starting vrrrmmm vrmmm, bouncing up and down, then I rev it yup little bit then it stopped. ran fine and there is no performance issue while warmed up, Runs great. This what has been done: New cap / rotor / Plugs / Wires / Fuel filter / Air filter. Any ideas would greatly apperated.

**rtg143** · 09-06-2009, 21:38

Could the sound be a lifter? They sometimes get a little worn and when the car is first started, they'll make a ticking sound. As far as the running problem cold, it could be the IAC. You can try cleaning it and also the MAF. There's a special cleaner for the MAF.

jglen490 · 09-09-2009, 13:14

Agree with the IAC and MAF analysis. For the noise, try to find out where the noise is coming from, such as the front or the top. If it's the front, you may be hearing the harmonic balancer starting to go south.

e40water12 · 09-10-2009, 15:32

Would the harmonic balancer cause the motor to have a ping sound? low octane ping? thats the sound I am getting. How difficult is the harmonic balancer to change? I am pretty good with mechanic's, Just need a little insite, Ok I will try cleaning out those sensors see what will change.

Thanks for youre help guys.

jglen490 · 09-11-2009, 13:26

I've had it done, but I've not done it myself.

There are some folks who have done it, so you might check:
Tempo - Topaz Owner Association or TempoTopaz.com :: Tempo Topaz Car Club of North America for some experience or guidance. If it is the HB, it will get worse over time, and will eventually sound out when the engine is warm, too.

My understanding is that changing the HB is a lot of work, so you might want to make sure you don't really have a timing issue first.

e40water12 · 09-11-2009, 17:51

Awsome thanks for youre help.