1997 Mali with 3100

[IanSzgatti]

Okay... I'm buying this car, and I know it has a coolant leak, but it's not the gasket covered by the TSB... regardless, my co-worker said he saw some coolant on the trans under the hood.

Another question... I've seen 3100 engines that have a ribbed looking plenum, and a flat plenum... both saying 3100... what is the difference??? hope you guys get that question.

I'm a little nervous going from my ever reliable 90 degree 3300 Cutlass to this 60 degree engine, but the Cutlass has really had it's day... it's so battered people have literally made comments like.... one day walking into a store, some young people came out as I was entering... they got into thier car and my wife said she heard them say... "looks like we're in a trailer park"... HA!!! damn right... but i'll tell ya, while they pay 350 a month in new car payments, I'm not spending a damn thing! the best part is when I put my canoe on the roof, i can literally throw it on there and strap'er down.. I wont be doing this to the Malibu!
Anyways... This looks like a great forum, and I cant wait to learn more about this motor.. thanks

[IsaacHayes]

Check the oil fill cap to see if it looks like mayonnaise underneath it. If so then it's leaking coolant into the oil. The bearings could be shot if it's gone long like that. But it sounds like the leak is outside the motor, which is good. But it could leak in both inside and out though.

Plenums with the lines are small port 94-98 3100's.
Ones with large block text and no lines (or nothing on top at all) are large port like 3400's. 99+. They make more power due to the larger intake runners. Also they got the same heads as 3400 which have a bit larger intake valves.

Replacing the lower intake gasket with the metal fel-pro problem solver gasket will prevent it from leaking again.

[IanSzgatti]

alright... thanks. No sludge in the oil cap. thanks for answering about the different plenums.. now i know that means i could only put 3400 heads on the newer motor... i'll be stuck with this one for a while im sure, but i dont think im going to do anything to it... as much of a nut as i am about cars. I can also use my bay on the weekends and have a shit load of tools available to me in the shop... i suppose if there was something i could do.........

[johnnymossville]

you can put the large port 3100 or 3400 heads on your motor to make more power, but you will also need to use the large port lower and upper intake manifolds

[IsaacHayes]

Yup search it's been talked about a million times what the little details are. A 1997 has roller fulcrum rockers so the large port manifold clears no problem.

[IanSzgatti]

interesting.... thanks.. I realize that these things have been covered a million times, but it's sometimes more helpful to hear an answer to a specific question rather than searching through a large volume of info... I have looked around on this site, yet until it was mentioned hear.... i thought my motor was not upgradeable.... anyways, thanks guys

[IsaacHayes]

When I get time I will make an article detailing all the differences and what's needed to swap this or that on your 3100.

[Hell_raiser]

plz i want do the same now my car has a knock some where. its in the valve train i think but lol im only 18 who knows. its doing weird stuff