SlowMaro

bad oil pump?? bad sending unit for the gauge?? i rev the engine, it shoots up to full pressure, let go of the gas, and it drops to zero. yes, i checked the oil, its fine....how much work is involved in changing the oil pump? how much would a shop charge?? and is it really the oil pump??????

Drakar

My cutlass has a bad oil pump, and from what I understand it is a PITA to change, you have to drop the oil pan, and so on.

(never done it but had my mechanic explain and groan about it )

I would check and replace the sending unit first as it is most likely the easier of the two.


You could always hook up and pressure gauge to the line to see.

breathment

well since an oil pressure sending unit is easier and cheaper to replace then an oil pump. if u can get ur hands on a mech. guage then thats even better..

llvll4l2c91350

I'm with everyone else. Confirm your oil pressure is low first,,,with something a little more reliable than our stock gauge,,,before doing any work that may not be needed.

SlowMaro

where is the sending unit located?????

llvll4l2c91350

The sending unit on my 88 TPI was behind the intake near the distributor, and on my 91 it's down near the oil filter. Yours is a TBI but it will probably be in either one of these places.

SlowMaro

--looked through the entire haynes manual-- i see no *oil pressure sending unit* or whatever, ...is this the exact name of it? and what does this alleged *oil pressure sending unit* look like??

llvll4l2c91350

http://www.yearone.com/serverfiles/p...G&hid=G14AO169

http://www.yearone.com/serverfiles/p...G&hid=G14AO169

The first pic would be the one near the distributor. The second pic would be the one near the oil filter.

SlowMaro

it says .. GM oil pressure/fuel cutoff switch......fuel cut off??? this what i need??? if so ill go pick one up tomarrow .....

llvll4l2c91350

Yeah that's the one mounted on my car and should be on yours too since it's a 92. Part ain't cheap though,,,at the dealer it was like 35 bucks I think.

SlowMaro

blah, my dad works at napa, ill get that sucker for 10 bucks im just hoping like hell it ISNT the oil pump cause thatll be hard as hell to swap out....it just seems liek the pump cause the pressure shoots up --on the guage-- when i rev the engine

llvll4l2c91350

I'd recommend getting a REAL oil pressure gauge with a dial from Napa and hooking it up to where the one for the dash goes to first. This will tell you for sure what the pressure in the engine is. Even new sending units are not very accurate on these cars.

Redline

same thing happened to me... 6000 miles after rebuild came blown engine #2. the timing was all jacked up too. i dont know which of these to blame it on.

84 Z-28 350

I've got a mechanical gauge attached to the oil passage in front of the engine, above the timing cover, I used brass tubing to plum it to the gauge which I mounted to an extra hole on the intake manifold. the oil pressure is a more accurat indicator of engine health from there, it is one of the last places the oil goes. The accual pressure dosen't really matter as much as how seady your pressure is, if their's a rymythic flucation with engine RPM that means you have a worn, bering if if just jumps around your engine is worn, ect (I have nice stedy oil pressure 30 at idle and it goes to 50 at the rev limiter(6000)). My sending unit is behind the intake, to the left of the distributar, I'v had to replace mine 3 or 4 times.

SlowMaro

ok, replaced oil pressure switch thinggie wtf ever it is.....oil pressure stays at 25 lbs when the car is in drive, so far all is good.....turns out regardless the old switch was bad, the needle stayed parallel with my damn dash, where if it had numbers, it would show like 100 lbs of pressure --lol-- anyways thanks .....hope this stays like this ...