PISTON SLAP IN 93' 3800

[RICK YOUNG]

I'm looking at a 93 lesabre with the 3800 for a work car for our son.

I can hear piston slap (one hole) at idle. Apparently this is a common trait of the 3800. I've been told it will run forver that way.

Any comments/thoughts????????????

[JohnD1956]

I've know of several high milage 3800's and never heard piston slap. What you may be hearing is a rattle on the counter balance shaft rear bearing, which will run for quite a while, but noise is noise. Unless you have an external noise ( my 93 had a drive belt noise that would go away with a new serpentine belt and return in a few thousand miles) an internal noise will have to be dealt with eventually.

BTW, our 93 was up to 160K when we sold it to our son who is still driving it. Dougs 89 Lesabre T was up to 201 K with that damn rattle and still going.

JD

[GMPARTSMAN]

There was a TSB regarding some 92 M/Y 3800's having a piston pin clearance problem resulting in engine noise.

If I remember correctly the bulletin came out about 1995.

The TSB said that it would not affect engine durability but may be objectionable to some owners.

I had a Regal that was affected with it. Cold only noise. The car had just under 45K on it when purchased used. Drove it to 160K until Michigan rot (salt) got to it. Everything else went to pieces but the engine.

[Guest dabecker65@gmail.com]

I have a 2002 Century w/ 3100 - has some piston slap cold - goes away warm....

Biggest surpise I got was with the 3800 in my low miles '95 Riv - found out the hard way that some 93- 95 3800s develop a front main bearing knock - GM campaign was to replace front lower main bearing half with a 0.001 oversize bearing - did that - still have the annoying knock - dealer said "live with it, lot's of people do". Drives me nuts - putting in a crank kit next month...get rid of the noise one way or another!

[JohnD1956]

Dad, are you sure that knock in the Riv is not the harmonic balancer?

[RICK YOUNG]

Great comments. I didn't have my stethoscope to listen, but using the ol' screwdriver/stethoscope trick the sound did seem to be coming from the block. I've had several 3800's also and these comments jogged my memory. Yes , that rattling noise.

I did buy it. Compared to the 91 Eldo... he had this should be a workhorse.

Thanks RY

[Guest dabecker65@gmail.com]

Thought about harmonic balancer early on - not it. We're just going to jerk it, put in crank kit, new oil pump, timing chain & gears, harmonic balancer, water pump - basically everythnig down below and up front while its out.

[Guest Albert]

I have heard that the 3200's alse have the same problem, i have a 3800 in my 92 Bonniville with 280,000 km on it and so far so good, except for the error 42 (cam sensor) which has only been on for about 4 years now, cant seem to find the time to replace the magnet on the sprocket, have the parts, no time..or too cold out there,,

[RICK YOUNG]

3-10-2008 UPDATE

Well just when I thought I was so smart.

I got the answer to the noise last Saturday.

Drum Roooooolllllll.

Water Pump bearing.

I should have took my stethoscope along when I bought it.

Thanks to AAA and a chance meeting of a mechanic who was a friend of my son's where they hauled it to.

$215.00 (reasonable) later he's on the road again.

No, I wasn't going to change a water punp in a parking lot in downtown Des Moines.