Jim bailey - 928 International

One sending unit with two different sensors , one variable resistance for the gauge ,the other open closed for the light . New part about $55. so do not spend too much time looking if you question it's voracity.

heinrich

That ... is the correct question ..... <I-Robot> Yes a lame-ish movie but I love that quote. Appropo....

wds928

I have a '94 GTS. When I start the car, cold in the morning or even when fully warmed up, the oil pressure gauge jumps right up to 4 or 5 bar. The red oil warning light stays on for up to two seconds (one mississippi, two mississippi), then goes out. The oil pressure gauge never goes below 1.9 bar or so., so I believe I have good oil pressure. The red light at startup has me concerned though.

Do I have a bad sender?

Thanks

Gretch

I dunno.......mine does not do that.........and never has. If it did, it would be "pucker time" for me too....

pappy92651

Brian,

I am still assuming that you had good oil pressure before the major service was performed. What were your oil pressure readings? Did you experience noises that are asscoiated with low oil pressure? You said that the car had 15W-50W oil. Are you sure?

My previous shop did two things that caused what you are refering to;
1) They put 0W-30W racing oil in the car
2) They left the rear cam pins out and installed the old cam seals

Symptoms: Noisy lifters, low oil pressure when hot, and higher than normal oil usage. They reused the original cam seals. I had oil leaks from the rear of the valve covers.

IcemanG17

Everyone
Thanks for the responses! I am a new owner on the car & 1st time 928 owner.

The previous owner had a timing belt failure! He decided not to fix the car, so he gave it to DEVEK. I bought the car from DEVEK. DEVEK put in a replacement engine (about 90,000miles on engine) and did all the other maintence work (Timing belt/water pump/ all hoses & gaskets/ pil pump/torque tube/ new torque converter/ trans service/new rear axles/ new brakes & rotors) & basically checked every major mechanical issue in the car. As far as I know the oil pump was replaced just as a precautionary measure. The car does have Mobil One 15-50 and does not leak at all or burn oil (so far). When the low oil pressure warning light comes on the car runs & sounds fine...when you rev the car (I know a scary idea..so I only rev it a little to maybe 2500) the light goes out....then comes back on when the car idles? Once warmed up the car normally has good pressure...2.5 or higher at idle (740 rpm on the smog check) and 4+ while driving. Even right before I shut it off (when the warning light comes on) it never drops below 2 bar at idle....but 5 minutes later it does?

Susan & Mark at DEVEK think that it might be a temperature problem with the stock radiator & cooling flaps. They recommended taking out the cooling flaps to see if that helps?

I guess my best course of action will be to #1 remove the cooling flaps & #2 check or replace the sending unit.
Brian

UKKid35

To see if the cooling flaps are at fault http://www.nichols.nu/tip010.htm

Gretch

Mark and Susan have a lot of experience, so their counsel has a lot of credibility. That having been said, I am very skeptical that cooling, or lack of it, is causing the low oil pressure as you describe it.

It might be a contributing factor though, and unless you drive the car in the snow country, the flaps are a sophisticated, but usless appendage.

My experience, for what it is worth is that these engines have oil pressure, or they do not.....one or the other. If you are seeing interrmittant readings, it is more likely the messaging system that is faulty. The one exception has been the oil plugs in the cam towers. In that instance, when the car is warm, the oil pressure at idle is too low (under 1.5 bar) and there is may be leaks from the cam covers. If you don't have these symptoms.....

The shop manual says go and have the oil pressure checked with a seperate pressure guage. If you get correct readings, then check the output of the sending unit. If the sender is functioning properly, check the electrical connections at the pod.

I am willing the bet this will be the proceedure DEVEK will use to diagnose your problem.

Best of luck.

BTW, there is no easy way to remove the flaps......either cut them out in pieces with a hacksaw blade, or remove the nose to get at the fasteners.......major PIA. Most people pull the fuse while the flaps are in the open position, and then use a plastic cable tie to fix them in an open position. The latter is not necessary unless you remove the flap motor, but done for extra measure.

heinrich

I recommend (as I recall this car was handled in the last year) you return to Devek with a warrantee issue on the new engine and in your case, the car. I know they can easily fix something like this.


The flaps IMHO are not the issue. If there is something else stuck in there, yes you can have cooling problems but you would see those issues in high-stress driving, not only after shutting down. There is something wrong inside your engine, and if it is under warranteee, whoever warrantees it needs to be taking care of it.

WallyP

I said, "The oil pressure gauge and the oil pressure warning light have different senders and really have little interconnection. If BOTH show low oil pressure, you usually have low oil pressure!"

There is one metal lump that contains two sensors. There is no electrical interconnection, and you have two independent indications of low oil pressure. It is not unknown for one sensor to go bad - my point is just that it is unlikely to be a bad sender if you get a low gauge reading AND a warning light.

mspiegle

so does each wire on the sender unit goto a different sensor? I'm having an issue where my oil light pegs when my car is on, and the light intermittently flashes. I've already replaced the sender with a new one from 928intl, but maybe my wires are crossed?

Jim bailey - 928 International

Mike you should switch the two wires . Each gets a ground from the switch one is variable the other on / off .

IcemanG17

One of my problems is the cooling flap motor is gone. Never was in the car. So I leave the flaps in the open position, but as I found out when driving at high speed the flaps will close on thier own. This happened the second time the car did the low oil pressure problem?

I took the car out for a high speed run...got it up to normal temperature, then hit a nice open stretch of freeway and ran it up to 140mph (which was very easy to do!), I was only above 100 for maybe 2-3 minutes at most, then slowed down and drove 70mph for about 10 minutes to home. It was about 80 degrees outside. On the way home I noticed that the temp was climbing, it got to just over 1/2 when I reached home(normally it is right at the 1st white line). I checked the cooling flaps and they were closed. So I opened them and turned the car off. The temp was just over 1/2, but below the second white mark. I cleaned off all the bugs from the car(about 5 minutes) & started it again to pull in the garage and it did the low pressure warning. I rev'd the engine a bit and it went away? Hasn't done it since? The rest of the time the pressure is always good? The engine never sounds different when it does it?

I'm concerned that there might be an internal problem with the engine, but it doesn't burn or leak any oil? Plus it runs very strong with good compression? I'm hoping its an odd electrical problem.
Brian

Chris

Quick question, when you start the car and see the low oil pressure light, does the oil pressure climb very slowly ??

Fix those flaps, either rip them out or fix them open, I have a spare flap motor if you want to keep them.

Chris

heinrich

OK you have just posted the answer, and 2 pieces of information that would have helped a lot to start . Here they are:

1) ...flaps will close on their own...... temp was climbing ........I opened them and turned the car off....waited .... 5 minutes & started it again ...and it did the low pressure warning.

2) Hasn't done it since.

There's your problem. You overheated the car by hi-revving with closed flaps, then turned it off. At this point nothing can cool your engine because no fans are running. Your oil was boiling.