engine slam when hot

Hi I have a 96 Riv with the L67 and when the motor is cold it run great but when it starts to run hot it start to slam . Someone can tell me what it can be? thanks!!

How hot does it show on the temp gauge? When does it make the noise, when you hit the gas?

on the idle and when I it the gas! When the temp are near the middle of the temp gauge. My Temp gauge are going just a little bit over the middle sometimes . And by the way I don't have any mod on my car

My question is "what is a slam" ?

Typically that kind of description is reserved for a broken mount...

sorry i'm not very good in english !! I don't know the appropriate word for this . in french it's the verb "claquer" in google translator they give me that "slam,chatter,crack,bang,clap,flap,clatter,crackle,pop off,curry,squeak" I don't know if it can help you

zoot alors! it sounds like a broken tranny mount or motor mount.

Either a mount or the trans is low on fluid causing a delay-bang when hot....or even the TCC solenoid.

Abaddon wrote:

Either a mount or the trans is low on fluid causing a delay-bang when hot....or even the TCC solenoid.

That's a possibility... Frank, check the transmission fluid level, parked on a flat surface, after you've driven the car and the problem has started.

Also, is there a particular gear that this happens in, like only when in 3rd or 4th?

Quote :

That's a possibility... Frank, check the transmission fluid level, parked on a flat surface, after you've driven the car and the problem has started.

And remember to leave engine running when you check!

all the gears and it's not the tranny it's the engine. My first idea was the Rod bearings because it's mostly sound in the bottom of the motor but if it was that, that will sound anytime not only when hot

and today I found that the thermistor does not mean that my fan either :S

So the sound is more like a repeating knock.

can you explain please "Knock"??

There are different meanings for the term.

Spark knock is a sharp repetitive metallic noise caused by abnormal ignition, also called "ping" or detonation. It is common under heavy throttle when the engine is hot, or the air/fuel mix is running lean.

Rod knock is a pounding noise caused by worn rod bearings. It is most common at higher RPM. If this is your problem, sorry it's bad news. More on rod knock here:

http://www.supramania.com/forums/showthread.php?20486-Rod-Knock-Diagnosis-and-FAQ

ok thanks! but if the engine heat a little bit the pcm will run automaticaly the fuel mixture Lean

https://www.youtube.com/watch?v=H1_goqYytHU and it's not sound like this :S

sealk wrote:

ok thanks! but if the engine heat a little bit the pcm will run automaticaly the fuel mixture Lean

frank, maybe you can use a digital camera to post a movie clip with sound of your problem.

Albertj

ok i'll do this on friday or maybe tomorow if I have the time

Take a look at this video of my Riviera when I first bought it. There was a real bad knock in the engine, you can hear the engine start and a very pronounced knock at minute 4:26. Does yours sound anything like this?

where?

Whoops, sorry! A link would be helpful.
https://www.youtube.com/watch?v=UbdCVlRKNK0

no that's not sound like this and it's not knocking when cold and never intense like that Only when hot. My car eating a little over the middle of the temp gauge and I found that the fans don't work and that's the reason why it knocking (fuel mixture too lean because it over eating). I changed my termistor and my fans are not work more. I checked the wiring diagram of the cooling fans and it show that I have 3 fan relay but I only found the #2 and #3 in the relay box my problem now are WHERE are the #1 cooling fan relay :S

This question has come up before... I believe Relay #1 is the gray one on the firewall, near the windshield wiper motor.

Also, there is a large Fan fuse in the underhood relay box, and a small one in the dashboard fuse box.