99 grand am 3400 engine chattering

I have a 1999 grand am 120,000 miles 3400 that will start but chatters like crazy and the oil light stays on...but it has enough oil...It will run in park but if it is but into gear it will cut off immediately..I'm thinking oil pressure.

its a car that i wanna mess with and i have tools what should i do next? Do you think its the oil pump if so how hard is it to change? Any suggestions on what i should do next. Thanks

Very common for the intake gaskets to leak coolant externally and internally. The engine oil gets contaminated with coolant and if left too long, causes premanent engine damage. Try looking at the oil or draining it to examine.

A used engine may be the least costly repair.

I was just wandering when u check the oil on the dipstick after u start it does the oil level move any or stay the same? If it doesnt rise its very possible you have a bad oil pump. you could also remove the front valve cover and start engine for a few seconds to see if the motor is oiling. If the engine dies when u put it in gear i would think that is kinda like a fail safe thing .

I check that and get back to you Thanks

1199 grandam 150,000 ....Well i started the car and the oil level on the dip stick did move...also i did a compression test on the front three cylinders the first 1 was 210 2nd was 208 and the third was only 35 then i added oil and it jumped to 70...I guess thats the problem...

My questions is, this pretty much means theirs no point in checking the back cylinders right? And th engine needs to replace?

HUMM since the oil level is movin it would seem the pump is workin the bad pressure in your cylinder makes me wana think loose or broken rocker arms or stuck valves. I would pull front valve cover and checkrocker arms

ok will do.... but would that stop the car from running once its in gear and turn on the oil light?

Im not 100 % sure but i think the car is stalling in gear to protect the motor from more major damage. The low compression on the cylinder tells me that 1 bad rings or bad piston 2 headgaskets or lim gasket blown 3 Valves not openeing or clossing right The chattering is lack of lubrication or totaly worn engine parts. When u pull the valve cover off besure check the tightness of the rocker arms by tryhin to wiggle them and it wouldnt even hurt to start the engine with cover off for few seconds just to make sure there moving up and down , DO NOT REV ENGINE with cover off especially . IF all parts are movin " rockers rockin " check to see if they are oiling. I would advise to start engine less as possible metal on metal banging is nor good.

Or the head gasket is also could be the problem to.

got the valve cover off the too rocker arms in the front third cylinder are not moving at all....

Pull the heads off (will require removal and replacing of intake manifold gaskets as well). Take the heads to a shop and have them do a valve job. You may also be leaking oil from your oil pump drive (hence the low oil light due to low oil pressure). Replace the o-ring on the oil pump drive. I HIGHLY recommend a Haynes manual for this procedure as well as taking a look at some of the intake manifold/head gasket how to threads.

Order the Felpro head gasket kit or buy it at an auto store. Be sure to get the one that uses the metal/rubber and not the plastic design.

I am in the process of completing this job right now so if you have any questions let me know.

While the heads are off you should also manually turn over the engine to check for clearance.