Mark 97 Cutlass Coupe Posted June 13, 2011 Report Posted June 13, 2011 Hey guys, I have a 97 Cutlass coupe with 140,000 miles and the 3100 motor. For the first 5-6 minutes after startup (only after sitting all night, or maybe 6 hours) there is a lot of valve clatter. Like I said, after 5-6 minutes it goes away, and is then quiet. Even when it clatters it runs very smooth, and once that noise is gone the motor is absolutely silent. I am running the reccomended 5-w 30 (as stated on the motor). Is this just what these motors do, or am I looking at a problem? Thanks. Quote
skitchin Posted June 13, 2011 Report Posted June 13, 2011 Yeah my 3100 has done it for a few years now. Ive been told a variety of things it could be, lifters valves etc. Havent had any problems, but its definately made me wonder about the health of my motor. Quote
xtremerevolution Posted June 13, 2011 Report Posted June 13, 2011 Sounds like lifters could be gummed up. I'd say run a can of seafoam in your crank case for about 50 miles before you change your oil, and see if it improves anything. What kind of oil filter are you using? Quote
Mel87 Posted July 17, 2011 Report Posted July 17, 2011 My Cutlass only has 66K miles on it and it does it... it's almost as if the oil runs off the lifters after it sits and when you go to run it again it clanks. I have had 2 W body Cutlass', and both did the same thing. Never caused a problem. I drove my other 95 Cutlass for a year and a half with that happening every morning I would start it up and it never lead to internal engine damage. Just something about the 60 degree V6 I guess:shrug: Quote
WhatTheFehl Posted July 17, 2011 Report Posted July 17, 2011 Welcome to owning a 3100. Mine has been doing this as long as I've owned it (almost 2 years now), including on some VERY cold days where it tends to last a bit longer. Never had a problem. Quote
Mel87 Posted July 17, 2011 Report Posted July 17, 2011 I don't know if anyone else does this but I like to be extra cautious about the situation. I normally let the car run (warm or cold outside) until the tapping goes away. Not sure if it is necessarily needed... but I like to baby it Quote
urbex Posted July 17, 2011 Report Posted July 17, 2011 I don't know if anyone else does this but I like to be extra cautious about the situation. I normally let the car run (warm or cold outside) until the tapping goes away. Not sure if it is necessarily needed... but I like to baby it Yeah you should never just start it and go, especially when it does that. Letting it sit too long isn't always good either. Quote
AL Posted July 17, 2011 Report Posted July 17, 2011 The 96 GP I had sounded like a diesel starting up Quote
19Cutlass94 Posted July 17, 2011 Report Posted July 17, 2011 Even my 3400 does this a little bit. But the 3100 that was in my car was horrible! But when I tore it down and looked at everything, there was no signs of damage at all. So its basically harmless noise. Quote
urbex Posted July 17, 2011 Report Posted July 17, 2011 Like I said, it's probably just piston slap which every engine does. Just some are designed better to hide the noise than others. Quote
RobertISaar Posted July 17, 2011 Report Posted July 17, 2011 someone was running a turbo 3100 for a while.... when they everntually replaced it, the pistons seem to have shrunk 1/8" in the bore, and it still ran. Quote
Mark 97 Cutlass Coupe Posted July 17, 2011 Author Report Posted July 17, 2011 I don't know if anyone else does this but I like to be extra cautious about the situation. I normally let the car run (warm or cold outside) until the tapping goes away. Not sure if it is necessarily needed... but I like to baby it I do the same thing! On a cold winter day in Pittsburgh it might rattle for 5 minutes or so until it quits. Has anyone ever switched to synthetic oil to see if it stops? A friend of my brother's is a mechanic, and he says it should stop it. He also said that the 3100 was known for being noisy when cold, and that the motor should last 200,000 plus miles with proper care. Quote
Jprice90 Posted July 21, 2011 Report Posted July 21, 2011 these engines are known for that, along with the 3.4's..my aurora was known for piston slap, after 5 mins it went away..its normal, but as someone said, run either seafoam or the GM engine cleaner in the oil before your oil change, run it for a few miles before changing it so it can work Quote
Mark 97 Cutlass Coupe Posted July 22, 2011 Author Report Posted July 22, 2011 these engines are known for that, along with the 3.4's..my aurora was known for piston slap, after 5 mins it went away..its normal, but as someone said, run either seafoam or the GM engine cleaner in the oil before your oil change, run it for a few miles before changing it so it can work What is seafoam?? And has anyone used synthetic oil in a 3100 and had the noise go away? Quote
Mel87 Posted July 22, 2011 Report Posted July 22, 2011 What is seafoam?? And has anyone used synthetic oil in a 3100 and had the noise go away? Seafoam cleans your engine and injectors, you let it suck in the engine and it creates huge clouds of white smoke (it's awesome I have seen it done) Quote
white4d96 Posted July 22, 2011 Report Posted July 22, 2011 I run synth in my L82 and I still get the noise. It will not go away. Although someone mentioned a mix of 10w30 and 5w30 making it quieter/ not last as long. Quote
Mach 5 Posted July 22, 2011 Report Posted July 22, 2011 When I worked at Chevy a couple years ago we had a few corvettes with the same issue. GM had a bulletin on this for the vette's and for pretty much all of there engines. Its something to do with the coating on the skirts of the pistons wearing off and the increase in the gap between the piston and cylinder walls cause the noise on startup and cold idle. Im gonna see if I can find it somewhere. I know that when GM crashed some of these little bulletins seemed to disapear into thin air I think to protect themselves or something. -Jarek Quote
RobertISaar Posted July 22, 2011 Report Posted July 22, 2011 i can pull them via alldata, but yes, i believe it was a tin coating on the pistons? from the factory, it was only applied to one side or something like that, the replacement parts have it all the way around. Quote
jman093 Posted July 22, 2011 Report Posted July 22, 2011 (edited) It wasn't just vettes, but anything an LS engine. Pretty damn annoying but it doesn't hurt anything. Ditto on the 3100/3400. My brother's 3100 GP he just bought with only 80,000 miles on it already clatters. Edited July 22, 2011 by jman093 Quote
Mach 5 Posted July 22, 2011 Report Posted July 22, 2011 I was saying vettes because usually those customers are soo anal about anything to there cars.. Quote
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