clunk or pop when cold

[grimmace]

Hi,

I've recently developed a pop or clunk when the car is cold. Its the best way I can describe. It doesn't matter if i'm moving and happens maybe 10 seconds after startup. Sounds like it is coming from front right side but not 100% sure. Any ideas? Sticky Caliper or air suspension?

Thanks,

Gary

[fastblackmerc]

Hi,

I've recently developed a pop or clunk when the car is cold. Its the best way I can describe. It doesn't matter if i'm moving and happens maybe 10 seconds after startup. Sounds like it is coming from front right side but not 100% sure. Any ideas? Sticky Caliper or air suspension?

Thanks,

Gary

Air suspension is only in the rear.

Does it happen all the time?

Continuously?

[grimmace]

It happens just about every time when the car has sat overnight and its just once....its pretty loud though.

[fastblackmerc]

It happens just about every time when the car has sat overnight and its just once....its pretty loud though.

Might be the exhaust system expanding.

The stainless steel makes alot of noise expanding and contracting.

[RF Overlord]

Need more input.

If it happens when you aren't moving, it can't be a caliper and as Jim said ^^^ the RAS compressor is on the driver's side.

You need to narrow it down a bit...is the clunk coming from under the hood or behind the dash? Does it happen after a fixed time after starting the engine?

Try turning the EATC off completely to eliminate AC compressor and blend door issues.

[Ozark Marauder]

need more input.

If it happens when you aren't moving, it can't be a caliper and as jim said ^^^ the ras compressor is on the driver's side.

You need to narrow it down a bit...is the clunk coming from under the hood or behind the dash? Does it happen after a fixed time after starting the engine?

try turning the eatc off completely to eliminate ac compressor and blend door issues.

^^^+1^^^

oz

[MyO4Rawdur]

The a/c compressor is loud as hell when you first put it on so do like these guys said and shut it off before startup. Even shut off the fan (heat) because you may hear that as well. If the a/c compressor is constantly running even when you dont turn it on then you may have an issue with the electrical side of it. My exhaust dings for like 5 minutes after I get out of my car from the metals contracting from the colder outside temps so if it sounds like metal being tapped with a small hammer and it changes spots then youre fine

[grimmace]

I don't think its the exhaust expanding and contracting. Its too loud of a noise. One that makes you stop and ask yourself what the hell was that lol. Also highly doubt its the blend door. I had that replaced less then a year ago and know exactly what that sounds like. That was a continuous pop that would come and go and would blow hot air only. This is just once when the car has been sitting for a while and has cooled down. I do usually leave the eatc on in defrost mode so I'll shut it down and see how it goes for a few days.

[MyO4Rawdur]

I don't think its the exhaust expanding and contracting. Its too loud of a noise. One that makes you stop and ask yourself what the hell was that lol. Also highly doubt its the blend door. I had that replaced less then a year ago and know exactly what that sounds like. That was a continuous pop that would come and go and would blow hot air only. This is just once when the car has been sitting for a while and has cooled down. I do usually leave the eatc on in defrost mode so I'll shut it down and see how it goes for a few days.

Im pretty sure but not positive that in defrost mode it uses the a/c compressor to remove moisture in the air to dry out the window. Not positive though.

[rocky]

Im pretty sure but not positive that in defrost mode it uses the a/c compressor to remove moisture in the air to dry out the window. Not positive though.

correct.....

[whitey]

Ac will be on when you run the defrost setting. Also, if the temperature control is on automatic, thr ac still runs. Push the floor or vent button, than set the temp. I think that the automatoc button will mix ac with the heater to reach its proper temp and of you dont have the automatic on it will draw outside air to reach the proper temp.

[MMARAUDER]

I have the same issue. sometimes at work ill sit in my car and it'll pop and u think someone tried to scare u by hitting ur trunk lid or something.

[grimmace]

i think its the eatc....shut it off the last couple of days and no problems.

[MyO4Rawdur]

i think its the eatc....shut it off the last couple of days and no problems.

Id just say its your ac compressor. It really makes a loud click when it turns on.

[Paul]

My old Volvo would do that when a clog in the AC line caused excessive pressure, which was released by the high pressure valve (a safety or circuit breaker of sorts). I have no idea if our MM's have this component or not, but your description reminded me of the Volvo.