tsmith944

I just finished replacing my water pump only to start the car up and find lights that werent there previously.

The brake pad indicator light was on, the brake fluid light indicator was on, and worse of all my oil pressure light was on @ 0.

The brake fluid levels are fine, the pad sensors i know are not worn, but i do not know why my oil pressure is @ 0, I do not want to drive the car until it see some pressure on there.

Is there some kind of wiring or something that made all these lights come on.

I did try to prime the pump by turning the engine counter clockwise while pouring oil down the oil filter hole but even still, the oil pressure is 0.

lastly, i was afriad i did not tighten the crank bolt enough seeing as i read that the oil pump gear wont turn the oil pump if the crank is "loose", i tightened it to, what i think is, 150 ft-lb (that was as high as my torque wrench goes) waiting for the click but it didnt come because I didn't think i could tighten it much harder.

if anyone has any ideas on this i would greatly appreciate it, i was so excited to drive my car again only to find this new onslaught of issues.

944_S_TYPE

I would suspect a ground wire? Also, Double check the leads on the oil pressure sender.

Butters944

Had to replace my oil pressure sender last month. Was a $70 part (autozone, but it came with a lifetime warranty ), only a ~10 minute job

John_AZ

The leads to the oil Pressure sender go over the water pump to the top of the engine. The sheilding could have been damaged or cracked. Could you have pinched the wires behind the belt sheild?

Be careful of the oil pressure sender posts. They are hollow and brittle--they will break easy.
A local price is expensive. Web prices are normal

I am concerned about what you said about the 150 #s on the torque wrench.
Did you have a flywheel lock installed?
My torque wrench also goes to 150 #s but I give it a nudge extra with a 2 foot extension on the Breaker Bar with a 24mm socket. Not a lot. Has your torque wrench ever been calibrated at 150 #s? It may be off.

It would be nice to know what year, model car you have to make a better guess.

GL
John

John_AZ

Update.

Are you positive you put the crank pullys , new "O" ring , washer bolt on in the correct order and direction?

John

tsmith944

the wires could be pinched behind the cover, i will try and wiggle and free them and inspect.

its an 86 n/a

i checked the leads on the OPS, the leads are very clean and still had the rubber shield on them.

the torque wrench was brand new, i had one that went up to like 100 so i bought a 1/2" that goes to 150 specifically for this job. the flywheel lock was installed.

i dont know what you mean about the o-ring on the crank or washer, im pretty sure i put it all back exactly the way i took it off. i dont believe i took the washer off the crank bolt so it must be on the right way. but what is the o-ring you are talking about?

thanks for the quick replies!!

John_AZ

It is the "O" ring infront of the oil pump sleeve to prevent leaks.

If you had the crank bolt out, it would have been a good time to replace the "O" ring (part #4)

John

zerMATT951

Here is a pic with the oil pump drive gear backed out slightly for illustration purposes. The only thing not in the photo is the belt gear/pulleys, and they slide on AFTER the washer in the photo. The washed presses the o-ring into the oil pump drive gear.

Question: you went as far in as the water pump, but you didn't replace the seals (and o-rings) too? It's cheap insurance and pretty easy with all of the belts out of the way.

tsmith944

yea i should have done that knowing now, i never looked up the oil seal replacement, i assumed it would be harder than i thought and was very pressed for time to get my car back on the road. had i known it was stupid simple i would have. ignorance.

that photo is super helpful btw.

i kinda dont think it would be the OPS since it would be pretty coincidental if it went from doing a water pump job or at the same time. it seems like it was due to working on the job.

would you suggest i put the flywheel lock back in and torque it a little more?

zerMATT951

I dunno... it's easy enough to reinstall the flywheel lock and re-torque the bolt, so that is probably a safe thing to do.

Although I agree with the others that it sounds like an electrical problem. Look for a pinch as planned... doesn't hurt.

Since you have other waning lamp issues too, it might not hurt to check all of your fuses and any other wiring that you disturbed.

I'm also wondering if there is a way to check the OPS with a meter for voltage or resistance with a brief engine start or with the coil disconnected while cranking. I dont know what the signal is, but I would think it's some sort of variable DC voltage with 5v or 12v in, and something else out.

tsmith944

i put a balloon over the oil filter hole and had my brother crank the engine over with the coil plug out to see if oil went in the balloon, it cranked for maybe 10 seconds and no oil went into the balloon.

would this indicate the oil pump is not turning hence the 0 pressure?

i want to agree with you about it being an electrical problem, since there are multiple dash lights that weren't there before (brake pad/fluid light and ! light).

i did check the OPS wire that goes behind the belt cover and it is free not pinched or anything from under the intake manifold all the way to the OPS so i do not think its that wire.

I looked at fuses but did not see any fuse associated with oil or brakes that would cause the lgihts

Mike C.

If you start it with no oil pumping the lifters will begin to clatter very quickly (just a few seconds). Chances are if you didn't hear anything abnormal it is an electrical problem. I think if you remove the power steering pump you can get to the pressure sender.

John_AZ

A couple of things.

If you just crank the engine, also remove the DME/FUEL pump relay. If you do not, you are putting a lot of gas in the cylinders.

Try the "compressed air in the dip stick tube" idea.
PorscheDoc is a pro.
https://rennlist.com/forums/924-931-...-oil-pump.html

There could be an air bubble in the oil passages.

If nothing happens then it may be possible the oil pump is not spinning.

GL
John

tsmith944

i torqued the bolt properly so i know it's probably not that, i am almost certain everything went back on just as it came off.

i was going to take the OPS out and crank the engine to see if oil came out there, but my 15/16" isnt fitting.

ill post back my findings

thanks!

Jay W

I seem to remember that the lower belt pulley can be installed on the crank incorrectly causing the crank bolt to tighten without properly making contact with that washer. This lack of complete contact lets the oil pump sleeve slip on the crank causing low or no oil pressure. Double check that the pulley is on straight, or loosen the crank bolt, shift around the belt pulley and tighten the crank bolt again.