1982 924 oil pressure question

brandonnathanie · 04-09-2013, 03:06 PM

Hello, i'm brand new here and I recently acquired a 1982 Porsche 924.

issue is that shortly after getting this vehicle, the low oil pressure light began to come on (flicker at first) when the car is idling. the oil pressure gauge reads in numbers (1-10) and it would drop just below 2 (I'm assuming 19psi?) then immediately upon accelerating it will jump back up to the 4-5 integers (again assuming 40-45psi..?)

anyway, i took it in and immediately they said it's a bad oil pump. I've asked 2 friends who know a lot more about cars than I do and both of them have opposite opinions. (one thinks it is the oil pump, the other says its a bearing/rod issue).

im wondering if anyone knows where to get parts for these old cars.. or any 2 cents on the issues im having..

thanks!

emoore924 · 04-09-2013, 04:10 PM

First off, welcome.

Could be several things. Yes, it could be the pump or wear in the mains. But there might be other things...

What's your oil viscosity and when was your last oil change?

The flickering light is nerve wracking but IIRC the factory spec is something like 4 bar at 4000 rpm at 80C.

Also, there is an OPRV (oil pressure relief valve) built into the oil pump. Sometimes the spring fails and that can be a problem.

Go over to 924.org and search there. I believe the spec is posted (as is this flickering light thing).

brandonnathanie · 04-09-2013, 05:53 PM

Quote:

Originally Posted by emoore924

First off, welcome.

Could be several things. Yes, it could be the pump or wear in the mains. But there might be other things...

What's your oil viscosity and when was your last oil change?

The flickering light is nerve wracking but IIRC the factory spec is something like 4 bar at 4000 rpm at 80C.

Also, there is an OPRV (oil pressure relief valve) built into the oil pump. Sometimes the spring fails and that can be a problem.

Go over to 924.org and search there. I believe the spec is posted (as is this flickering light thing).

Thanks!

Well i'm actually not sure of the last oil change. I just acquired the car and the previous owner had said all maintenance was up to date. it wasn't until i checked myself i saw that it was nearly 2 quarts low. So I added 10w40 to bring it up to par and then at that point i took it to the mechanic. Oil pump seems to be the culprit... I'll check out that website!

Rasta Monsta · Rasta Monsta's Garage

Extremely unusual for a toofah oil pump to fail.

924RACR · 04-10-2013, 04:26 AM

Welcome!

That's pretty normal. Only happens when the engine's nice and warm, then goes to idle, right? Like pulling off the highway and stopping at a light?

If you have the owner's manual, you'll see that's quite OK, as long as the light goes away when you blip the throttle.

Oil selection (viscosity and type synthetic) can help with this.

But the only true cure is an oil cooler.

I wouldn't worry heavily about it, though you should definitely do an oil change regardless. Just use the throttle to give it a little rpm's when this does happen, till things cool.

924RACR · 04-10-2013, 04:27 AM

See also:
924.ORG FAQ

brandonnathanie · 04-10-2013, 07:29 PM

Thank you all so much. the car didnt' come with the original owners manual (sad) but I did end up stumbling right on the FAQ's on 924.org RIGHT before you recommended it kind sir! that makes me feel a whole lot better. I think the mechanic honestly is just trying to make a sale because they know that when us novices see a flashing light it must mean trouble. at least that frees up my funds to repair the other things said wrong with it.. which I guess is a control injector? (mechanic speak)

i have to crank the car 4-5 times before she'll turn over.. when she finally does turn on i immediately have to feed it gas to KEEP it on and each piston fires on 1 at a time before it's finally fully going. I'm going to get a second opinion by another mechanic who a friend of mine actually worked for, but other than that she runs beautifully. only wish she was manual. oh well can't have it all! I think i made a good buy overall the car has so much potential for restoration and I didn't want a car payment for the next 4 years... -__-

thoughts on the cold start? thanks everyone!

guru944 · guru944's Garage

Stick with 10w-30 Synthetic (Pennzoil or mobil-1) or better and a really good filter (Purolator)

Later...

ernie9944 · ernie9944's Garage

bradonnathanie____the rigth filter for your car is not the (Purolator) but the Mahle # 931-107-00-M67,available from our host here at Pelican (New Parts Catalog).

924RACR · 04-11-2013, 04:00 AM

Yes - Mahle or MANN are the best, and worth the trouble to get.

Back to the starting problem - best to run through the starting/tune-up stuff in the 924 FAQ. Also, how do the plugs look? I'm wondering 'bout possible oil fouling... fresh plugs will help, but the root cause is usually a touch deeper.

brandonnathanie · 04-11-2013, 08:48 AM

yea i had a feeling about the spark plugs. I need to change them regardless of age etc. I'm sure there is a deeper underlying problem but i think definitely i should replace the temp sensor, idle control valve, spark plugs, get a fuel injection cleaning and i'm told the Fuel Injector Control module needs to be replaced, but the mechanics say that part is 300 bucks plus labor (used, 700+ new) and i'm hesitant that it could just be the smaller problems of the lot where the fuel injector control would make no difference (just another sale for them)

i know they are marking their stuff way high because i found the exact same parts online for a FRACTION of the cost. 172 dollars for a temp sensor? good lord i found one on Rock Auto for 14 dollars.

924RACR · 04-11-2013, 10:24 AM

Temp sensor - no. Thermo-time switch, maybe, but probably not. Probably just a wiring issue, they're very robust.
Idle control valve... also robust, not likely needed.

Add some Techron to a few tanks, consider actually replacing the injectors though (or send them out for cleaning).

Sounds like it's time to find a new mechanic, they must have dollar signs in their eyes every time you walk in...

brandonnathanie · 04-11-2013, 02:09 PM

fully agree. this was a new mechanic to me in the near area. they had cheap diagnostics but I guess they pay themselves back with false repairs. I'm gonna start by getting everything tuned up as soon as possible and seeing if it makes a difference. I don't immediately want to POUR money into mechanical repairs especially if they're not necessary. Do you think the fuel injector control module is really bad? seems like a silly accusation for the car to have problems on a cold start. *le sigh*

other than the aforementioned problems, the little car is SWEET. i got her for a steal and the interior is very nice and clean for such an old classic. I know that if i put money into it, very quickly it will start to shine right up. I want to get a paint job... I want to do it myself as i've had some mild experience doing bumper repair and painting in the past (it's been so long though). anyone have any recommendations on paint they've bought and used, or if those places that paint the whole car for 500 bucks are any good?

Gawernator · Gawernator's Garage

Dude, they're trying to dry butt rape you. A shop quoted me over $1,000 to convert to R-134a and I did it for like, $45? Only K&N/Mahle filters (heard MANN is good but haven't used) Stay with German OEM. You'd be amazed what can change with just going through all basic maintenance and cleaning electrical connections up.