blitz20202

ok i just recently put a refurbished motor in my 97 camaro, now im having a couple issues with it after a month of driving. first after the engine warms up it makes a sort of fluttering noise around 1-2 rpms after it goes past that the noise goes away, I have very little experience working with engines so i have no idea what this could be, second after my engine warms up the hottest it gets is 228 and it stays around that temp even with the air conditioning on both fans are working and i recently had the radiator bled and checked for any blockages and my mechanic said there wasnt an issue, i have checked the coolent levels and replaced all the sensors and it stays around that temperature. lastly after my engine warms up if i stop at a red light it feels like my engine is reving slightly its barely noticable but it has me worried, all these issues i have brought up to my mechanic and he says its normal.

i have only put 850 miles on the engine since it was put in.
the car sat for a year while i was deployed to iraq and i had all the fluids drained and replaced last month when i got back stateside.

i have a blk 97 z28 auto transmission all stock

any help would be appreciated thank you

Chaos1187

One thing that everyone always asks, is the service engine light on? If it is put a scanner on it and get some codes.

blitz20202

No there is no ses light on and one thing I forgot to mention was while driving after I start the car my oil pressure is at 50 after my engine warms up it drops a little below 40 when braking to a red light my oil pressure drops to below 20 but climbs back up to 40 after I accelerate I'll put a scanner on it later today If I get a chance during work

rclearyiii

Oil pressure sounds completely normal for a lt1.

Injuneer

You say it "makes a fluttering noise". Is that accompanied by any difference in the way the engine runs - misfire, stumble, sluggishness? Or is it just a "sound"?

The fans come on low speed at 226*F with stock programming. So those temps don't sound too unusual, assuming its hot where you are.

Oil pressure varies with RPM. That's normal. High RPM/high pressure, low RPM/low pressure. Oil pressure varies with oil temperature - high temp/low pressure, low temp/high pressure. Factory spec accepts as little as 6psi at idle - below that the "check gauges" light comes on. But a new engine should see at least 30psi at hot idle.

If you mean that the pressure drops to about 20psi at idle, that would seem a bit low for an engine with only 850 miles on it, assuming it was "new" when it was "put in".

You say "it feels like my engine is reving slightly".... what does the tach tell you its doing? The PCM controls the idle speed using a stepper motor that bypasses air around the throttle blades. A variation of +/-25 RPM is normal. Since you have an A4, and its stock, the stock idle speed is 550RPM in drive, and 650RPM in neutral. But the stock tach usually reads 100-200 above actual engine RPM.