Clack, Clack noise on cold startup

Sounds like an accessory belt slap to me.

 

+1 -- try a little belt dressing spray (unless there's some other obvious physical problem). The AC belt layout design on the 3.0L engine is terrible...

 

Just a guess: something is "clacking" when it is cold. As it warms up and expands, it stops clacking. So what could this be? Some clearance somewhere, a bearing in dry grease until it's warm and the grease/lubricant works, etc.
Warning: I am not a mechanic. Furthermore, I didn't even stay in a Holiday Inn Express last night.

 

Experiment trumps theory. The next time before a cold start, spray some WD-40 on the A/C belt. I'll bet the sound goes away.

One of the nice things about making things on an assembly line is that the products all have the same problems.

Also, if you're not mechanically inclined, get someone else to change that belt for you, because it's not easy. If your A/C doesn't work anyway, you could probably just cut the belt off. Neat workaround.

 

The belts (at least on a 3.2) are covered but easily accessed. Jack up and remove right rear wheel, remove about 10 screws holding on the fibreglass wheel well liner, remove the belt cover, and there they are.

 

There is no cover over the A/C belt that would prevent you from spraying belt dressing onto it. WD-40 will not make the belt slip, or damage anything else. Not sure if water would work. Never tried.

The problem with the belt is that it is old, hard, dried out, and cracked. An oil based dressing will soften it up. Running the engine will soften it up.

You might have easier access if you remove the air filter housing.

IIRC, there was a video on youtube of a red 328 making the same noise.

 

Normally, the accessory belts get changed along with the timing belts. I would look into the last time the timing belts were changed. It's probably been a while, if that A/C belt is old enough to be making noise.

 

It could also be the A/C compressor bearings. Mine make a chattering noise between 3K and 4K RPM. I know it's the AC because the noise disappears completely when I turn the AC off.

Since the noise stops at 4K, I have great incentive to keep the engine wound up!!!

sid

 

Because the belt surfaces heat up with use and get more "sticky" (so only a problem at cold startup). The wrap angle on the AC belt idler pulley is so low (which is the terrible design part) that the belt can creep up one side of the idler pulley groove and then "snaps" back down.

Belt dressing is a real thing (any autoparts store should have it, and if you do an internet search on "belt dressing" that should get you plenty of images) -- you can't use it habitually to resolve the issue, but giving the V-belts a quick shot every 3~6 months wouldn't be a sin IMO (of course, assuming there isn't some other obvious problem).

 

I too have heard the belt noise theory but couldn't justify why....now I know. Snapping back makes perfect sense. My 3.2 made the same noise before and after performing my major. The A/C belt was the only one I didn't change primarily because my system is discharged and the belt was relatively new.

Thanks Steve.....

Brock

 

The belts are not very wide and have a stiff plastic type of reinforcement in them, the ac belt is a typical cause of the belt slap. They are fine for a couple of years, and then presumably from heat soak they must loose some flex and do the slap when cold, disappears after a warm up. The slap is not going to harm any thing, but a new belt will solve for this. The belt dressings do work, but only temporarily. But shouldn't do harm, so give a try, use the belt dressing to diagnose the problem.

 

Need new AC belt!

 

What they said......

AC Belt....... A little dressing will prove the theory.

 

makes me remind of a battery that doesn not provide enough volt, so should be recharged. Are you able to start it up?

 

Disable the cold start circuit by shorting the connector under the water header tank. That worked for me.

 

Hi, has any of you been able to conform the AC Belt theory? My 88 3.2 Mondial has what i believe the same issue. Clacking noise on right side of the engine after cold start - dissapears after about 2 minutes of driving. Thank you, Kay

 

Believe it or not, my 87 3.2 is now doing the same! bringing it in tomorrow to hopefully get it sorted.

 

yes most likely belt noise. could also be a small exhaust leak that seals as it gets hotter. The exhaust leak is more of a click, click, click.

 

See video attached. Is the noise on yours similar? Let me know what you find. Thanks!

 

Unfortunately belt dressing does exist and he is not pulling your chain