No oil pressure after water pump change

stogie25 · stogie25's Garage

I spent the last two days installing a new water pump along with timing and balance belts in my 1988 944 n/a. The car fires up great, and it seems to be containing radiator fluid. The oil pressure which used to come up after about 3 seconds does not come up at all.

I did not have any left over bolts. There is plenty of oil in the system.

Thanks in advance for any good ideas.

v2rocket_aka944 · 09-01-2017, 01:03 PM

if there was really no oil pressure youd hear it.

did you perhaps unhook the wires to the oil pressure sender when you removed the belt cover/water pump?

stogie25 · stogie25's Garage

Quote:

Originally Posted by v2rocket_aka944

if there was really no oil pressure youd hear it.

did you perhaps unhook the wires to the oil pressure sender when you removed the belt cover/water pump?

Good thought. I went down, pulled and put the sender wires back on. No change though.

I think I am going to pull the crank pulleys back off and put them back on tomorrow to see if that helps.

9FF · 09-01-2017, 05:36 PM

Quote:

Originally Posted by stogie25

...I think I am going to pull the crank pulleys back off....

Why did you pull the crank pulley off if you were just replacing the belts and water pump?

Did you torque it back to 155 ft lbs?

If not then that is your oil pressure problem right there.

v2rocket_aka944 · 09-01-2017, 06:06 PM

Mike, you need to remove the crank pulley to get the belt covers off to change the WP.

Ga 951 · 09-01-2017, 06:46 PM

+1 on the crank bolt. The OP sender wires go around the the back side of the top cover...iirc. Possible pinch?

My money's on the crank bolt

9FF · 09-01-2017, 07:36 PM

Quote:

Originally Posted by v2rocket_aka944

Mike, you need to remove the crank pulley to get the belt covers off to change the WP.

Oh yes belt covers, I vaguely remember my cars having those at one time.

jderimig · 09-01-2017, 08:03 PM

Also check the washer that's between the crank pulley and the oil pump drive. If installed backwards you will get no oil pressure. Ask me how I know this.

djnolan · djnolan's Garage

Yes ask me how I know... Pulley was not centered, didn't fully seat, and got caught under the bolt. Got about half normal oil pressure.

stogie25 · stogie25's Garage

Quote:

Originally Posted by jderimig

Also check the washer that's between the crank pulley and the oil pump drive. If installed backwards you will get no oil pressure. Ask me how I know this.

That is high on my suspect list.

stogie25 · stogie25's Garage

The washer was in backwards. The pulley is wallowed out a little. I am going to find a nice used one before I put the car back together. The holiday weekend is a bad time to find used Porsche parts.

peteb · 09-02-2017, 08:30 PM

Hi,

Does the oil pressure light work? On before starting the car and going off when the car starts. That would be good news.... It would have been very easy to hurt an oil pressure sensor wire as they run right by where you were working.

My background is in electronics, so I would give the wiring a quick check first. This could an example of "if your tool is a hammer, every problem is a nail".

Best of luck for something simple,

Peter

stogie25 · stogie25's Garage

The light does come on. It stayed on when running. I am hoping it is the direction of the washer.

My background is in electronics as well.

v2rocket_aka944 · 09-03-2017, 09:12 AM

remove the bolt, ditch the messed up PS pulley and then re-tighten the crank bolt with the washer the right way around just to verify if that fixes your pressure problem.

it's easy enough to undo/redo it all again when you get your new PS pulley.
i might have a spare - if so you can have it for cost of shipping.

stogie25 · stogie25's Garage

My new pulley came in a couple of days ago. I finally had a day off today to put the car back together. Flat side of the bolt towards the block torqued to 153 ft/lbs. It started right up with perfect oil pressure.

Thanks for everybody's help.

martsink · 07-01-2021, 04:56 PM

Hey Guys,

Could someone please post a picture of what the thrust washer orientation should be? I'm struggling to get pressure on a rebuilt S2 engine (plugs are out, oil filter channels prefilled, oil filter prefilled, tried 10psi though dipstick).

I can see a bit of oil coming out when filter is removed, but its not much. I'm thinking i may have the washer backwards and the gear is slipping, but not sure which way it should go when i check.