when the car is started in the morning the oil gauge doesnt move.As soon as the car warms the pressure drops.stopping in gear its around 8psi driving 25psi
i took it to the chevy dealer and they recommend a new engine only $5000.00
I bought the car about 3 weeks ago. I have replaced the water pump alternator starter.Could the oil pump be bad ?? or is it something worse? The car drives fine has good power. I just have to roll the window down so i cant hear the "death rattle"....... 3.4 L v6

 

How many miles on the car? Sounds like bearing clearance from wear. You can have it rebuilt for $1400 if the block and heads are good, get a donor engine from salvage yard. Make sure it has the right weight of oil and good oil filter. You can increase the weight of oil to get a little better oil pressure but that will not cure the problem The rattling is probably the lifters.

 

20W50 is where I would start. Its a band aid. No clue how long it will hold. Don't rev it over 3K and keep your foot out it. I have seen customers nurse a car like that for a year or even a little more. I have also seen car that did not last a week once the rattling started.

 

It has 91,000 miles on it.

 

With that many miles it could be the oil pump. ITs risky cause the only way to be sure is to try a new oil pump. That could be about $1000 if you pay someone to do it. If you do it yourself it would only cost $100-200 depend on what else you change while you are in there. It not a small project.

 

Personally i would search for a 3.4l motor that u can hear run. Id say u can pick one up for prolly pretty cheap. ive seen some cars around here with 80k side impact motor/trans $500 bucks so i would prolly look for somthing like that. Pull that motor out and have someone put it in. Unless someone could pin point ur problem. Cause an oil pump with someone doing it is prolly gonna run u like the guy above me said 1,000. mise well get a good used motor and have it installed for prolly under 1,500 and than you know that the motor is fine. You might have damaged the motor even if its the oil pump. So if u replace the oil pump and than somthing else is wrong well ur dumping money into a dyin motor.

 

i put a high volume pump in the lt1 when a lifter started rattling and its still goin almost a year later, no rattling. i also started using 10w30 oil too. holds pressure at about 20 at idle, 60 at operating speed. i just wanted it to last till i have a motor ready and the pan gasket needed changed bad so when i had it off i did the oil pump. i dont think the 6s are any easier than the 8s and there not fun. i took my time and in three days i had it done.

 

in for a penny, in for a pound as the saying goes. When the oil pump went, my motor got rebuilt.

 

did you drop the oil? were there any metal shavings in it?

 

If the 3.4 is dead, do you really want to put another in it? This is your chance to bump it up to a 3.8 or 5.7...