originalmotorhead

Was working on my 84 944 automatic over the nice weekend. Turns out if I drive it and get it up to temp, when I am at idle with the car in gear(idling 800 - 900rpm ish) the oil pressure gauge reads 1bar, if I flop to neutral and the idle jumps to 1g ish, it goes up a little. When driving, I get 3 - 5 bar ish, depending.

Do you think my rod and main bearings are about shout? I've heard when the mains and rods start to wear, you get consistantly lower oil pressure.

Any comments on this, others seen it?

Tom

M758

I have seen oil pressure that low with hot oil.

I have yet to see a good correlation between oil pressure and bearing condition. What oil weight are you running?

originalmotorhead

castrol 20w-50. And I just changed the oil last week, so it's fresh.

when I fired up the car (cold), i got 4-5bar.

The low pressure at idle came after i was idling the car for 10+ minutes or so(was bleeding the coolant) and then a 20 minute drive. Water temp gauge was at the 1st mark, not the cold area but the 1st line past that, which is normal.

Tom

M758

Hmm,
That is a little strange. Do you know if the OPRV is old 3 piece style or updated 1 piece?

Maybe that is sticking open. I have seen 1 bar at idle, but only after a hard run in lots of heat. It can happen with thin oil, but 20w50 in ohio in the fall it not the time.

JohnKoaWood

Have you verified the oil pressure with a mechanical gauge?

originalmotorhead

Honestly no idea what relief valve it has. I only recently acquired the car with the intent of using as a commuter for the winter. Car was rather neglected and I've spent the better part of the past two or three weeks cleaning and fixing things on it. I only had it out for the first real test drive last night.

From the looks of everything else, I'd say it has whatever the car came with from the factory.

I plan to do a reseal the oil cooler and replace the balance shaft o-rings in the spring, but if there is suspect with the pressure valve, maybe I will do those now.. Oh what am I thinking, I should be able to just unbolt the pressure relieve valve right from the cooler housing without having to even remove the cooler. Maybe I will take a peep at that next.

Thanks for the idea Joe !

Tom


No, I am only going off of the factory gauge at this point.

originalmotorhead

Quick update. I've not had a chance to pull the oil pressure valve yet but driving the car to work the past two days(24 miles each way), water temp gets to the first notch and stays there but by time I get to work, when I hit red lights, the oil pressure gauge is dropping to 1.5 bar ish.

I may yank the gauge and install a mechanical for giggles and see what reading I get. I don't have a spare sending unit or I would swap it out.


Tom

John_AZ

In the owners manual, what you indicate is normal.
I use Castrol 20-50 and get the same results---even when it is 110F degrees.

If you get concerned, change both (2) "O" rings in the OPRV and maybe do a oil pressure sender swap.

I say normal.

John

f1rocks

That alone might be reason enough to do the rod bearings How are the belts?

originalmotorhead

Belts and rollers are now good. I swapped them out for used ones that I pulled off my race car

Hoping that I can run er 'as is' for the winter, cause I'm hoping to use the car as my "work car/ski slopes transportation" and then in summer work on the motor a little more in depth. I know thats maybe stretching things but....

Still hoping to pull the pressure valve and inspect that over the weekend. Worst case, I have a spare 83 motor I can 'borrow' the valve or spring from if anything ill is found on the current one.


Does anyone know if there will be a significant amount of oil that will gush out when I remove the valve? I'm thinking at most it would be the oil in the oil cooler or the oil passage leading to the valve since it is higher up then the oil pan?

Tom

M758

If you lift only the pass side very little oil wil come out the OPRV.

originalmotorhead

That's a very good idea : )

thanks !
Tom