No Oil Pressure....need help

[chapstic2001]

I just got my 951 off jack stands from four months of off and on manitenance. After turning it over for the first time, I noticed that the oil gauge didn't even budge. It was fine, between 3-4, before I started working on it. There is pleanty of oil in the car, but the lifters are clacking which leads me to believe that there is a no oil cycling. Clarks mentioned that it may need to reprime.....any suggestions.?

[tab tanner]

When a 944 sets for a long time [i.e] three to four months it's not uncommen to have the cam follows tic and rattle. If you have oil pressure let the car run, as it warms up they will quiet down. I promise, it has happened to me.. So dont worry

[chapstic2001]

I drove the car home, 30 miles, and the gauge didn't move nor did the ticking die down. I drove it again today to try to cycle it again....still nothing.

[Panzer909]

Still ticking?

Okay, fire it up and take it to grab a burger at Bullfeathers in Alexandria and drive home. Then drive it some more. It will quiet down eventually - just give it time and be patient.

A four month sit is a long time for any car. Mysterious shakes, ticks, and rattles are to be expected because nothing was kept lubed. This could go on for days. If your oil pressure is still motionless, just replace the sensor located near the filter. I'm going to do this to mine soon. Its an easy fix.

[Cebu]

http://64.226.197.185/Paragon/Tech/944_oil_pressure_relief_valve.htm

[drew1]

Tigten up belt pulley & if still no oil pressure, try to make a mess by pulling fuel pump relay & oil filter, then crank the motor & see if oil comes out.

drew1

Just this past week, my friends at Santanas in Gwd, SC worked on an 89 944 with your symtoms. The car had been bought for $800 from a finance company. The owner had already spent over $2500, including a new pump, trying to get the problem fixed. The front crank pulley bolt was a little loose.

[ronin]

sending unit disconnected?

[F18Rep]

I wouldn't be driving it, engines without oil pressure have a very limited life. I wouldn't even run it except for quick assessments of the problem.

Question: did you have the crankshaft pulley off? If so, is the ps pulley now wobbling when the engine is running. If yes, and this is a very common mis-step in re-assembling the engine, you've found your problem.

If no wobble, did you have the oil pick-up tube disconnected (maybe for swap out of rod/main bearings)? Try the priming thing but if that doesn't help, I'ld guess you're going to need to drop the pan to check it. The oil pump is a very good design but pulls oil from the back of the engine. The slightest leak along the feed line, means it cannot create the vacuum and cannot suck up the oil. ...Bruce

[drew1]

Bruce,

The car I was speaking of,89 944, had no wobble in the pulleys. This was first thing checked. Relief valve in filter housing was checked next, then the filter was pulled and motor cranked. Ray, mechanic, was going to take the pulleys off to check for free play since some of these pumps need a spacer & maybe it was left out. HE put a breaker bar on and pulled on it before sticking on his pipe to break the 150 ft lbs. The bolt was snug but not tight. So he tightened it, poured oil in the filter/cooler housing and cranked. Oil pumped. After putting cooling fans and the stuff he had to pull to get to the crank pulleys, Ray cranked the car & top end chatter was still there, even with oil pressure. The noise quieted and eventually quit during a test drive.


drew1

[SoCal Driver]

Driving with no oil pressure = parts car.

Wires on the sender are on wrong or loose.

Filter has locked up.

Oil pressure valve is locked up.

Crank bolt is not torqued to 150 pounds.

Oil intake tube has fallen off.

No oil in the engine.

Never run an engine unless you can confirm oil pressure. I remove the spark plugs and disconnect the sensors then crank the engine till I see at least 1 bar of oil pressure on the gauge. If I don't then I go back through all of the above list and try again.

Better hope your 30 mile jaunts has not burned out the bottom end, bearings, on your engine.

[chapstic2001]

Wires loose - could be, would that cause the lack of pressure?
Filter locked up - I will check that. Would a new filter solve that?
Pressure valve locked - How do I trouble shoot that?
Crank not torqued - I definately did that, my back still hurts from pulling 150lbs on my back.
Intake tube fell off - Not likely, I don't see oil all over the place (unless it is in the oil pan)
No oil - Pleanty of oil, measures up to the top tick on the stick.

Now you have sparked a fear....how would I know if I burned out any bearings?

Originally posted by SoCal Driver
Driving with no oil pressure = parts car.

Wires on the sender are on wrong or loose.

Filter has locked up.

Oil pressure valve is locked up.

Crank bolt is not torqued to 150 pounds.

Oil intake tube has fallen off.

No oil in the engine.

Never run an engine unless you can confirm oil pressure. I remove the spark plugs and disconnect the sensors then crank the engine till I see at least 1 bar of oil pressure on the gauge. If I don't then I go back through all of the above list and try again.

Better hope your 30 mile jaunts has not burned out the bottom end, bearings, on your engine.

[chapstic2001]

One last thing I forgot to mention. When bringing it home, the 30-mile drive, the guage did go up to between 1-2 for a little bit.

[ae1969]

DId you check the wires on the oil pressure sender?

..... how can you tell if you have burnt out your rod bearing .... the rod sticking out the side of the block is a good indicator.

[chapstic2001]

I have not had the chance to check the sender. Again, would that case the lack of pressure? I hope to be able to get to it over the holidays. As far as the bearing goes, I have not noticed any rods coming out of the side (read: scarcasm) so that's a good thing.

[ae1969]

#1 If you have no reading ... the sensor has a loose wire/ or faulty...... If the wires were reversed the guage is normally pegged.
#2 or you actually have no pressure.


Lets hope its #1

[chapstic2001]

My concern with the ticking lifters is a sign that there is truly no pressure. Assuming that the sender does not control the pressure, rather reporting it (or lack there of), that the sender is not the culprit. I will check none the less.

[SoCal Driver]

Originally posted by chapstic2001
My concern with the ticking lifters is a sign that there is truly no pressure.

Then why are you driving it?

[Kirby2]

I thought the old axiom was to assume that any engine turnover without oil took thousands of miles off the engine life. Squirt oil down the plug holes, prime anything you can, and initially fill 1/4 over full for all the areas that should retain oil that are now dry if the engine is out of service for extended times.

Have you put assembly lube on anything rebuilt?

Did you switch from a parafin(regular) to a synthetic oil - this can screw up the pressure sending unit.

Unscrew the cap bolt next to and just infront of the oil/water intercooler to access the pressure regulator (the "o" rings must be in place on the newer model; the older one is just a spring and plunger).

[ae1969]

.... if you had no oil pressure I don't think the car would of lasted to long..... It would make a great slick 50 commercial........

Just for kicks how about you pegged the tach and drop the clutch ?

** dont drive this car anymore and prime that oil pump ..... You wouldn't have sport seats on this car would you ? Just in case it becomes a parts car .... <---- vulture J/K

[Kirby2]

Just for fun, what was the "off and on again mainainence" that was done prior to the current situation.

(Physicians are always trained to work a diagnosis backward; first rule out the most obvious and most sererious possibilites. When you have eliminated everything else, you are left with the one true diagnosis).