1987 944 Oil Level Idiot Light On

[klinker]

Does anyone know where the oil level sensor is located on the engine? I had the oil pressure sending unit recently changed to fix a problem with the pressure guage. The Mitchel Repair book describe an oil level switch in the Wiring diagram but I can't find the part on the web or in any parts catalogs.

[JagIndian]

Hi,
Its the Oil Pressure Sender Unit. One can term as a sensor also.
You can get to it from under the car. Located below the oil filter, screwed dirctly into the block. Its a circular stubby unit with two posts (one straight and the other spaded) protruding out of it. ...If Turbo assisted, then the darn power steering assembly blocks access..so you will have to unbolt and let hang the power steering unit.
by any chance you reverse the wires, you get a max gauge reading, however a low pressure is signaled, hence the warning light

Also before you proceed please post the symptom, couldnt derive from you post as to what actual problem is. You mention gauge, which is up in cabin, and then prssure sending unit which is engine bay...

gluck

[xveganxcowboyx]

I'm going to use this opportunity to ask a question of my own. My oil light pops on sometimes at idle or when the revs drop from letting off the gas. The idle was set by the last owner at about 1000 rpm. Below that the light comes on as the pressure drops to just below 1 on the oil gauge. It tends to come on a little more as the oil gets hot, but only slightly. It never stays entirely on, but will flicker like it's right on the verge of being too low pressure. Apparently it's been this way for a while.

The oil gauge works fine most of the time, starting from 1 and moving up to almost 5 at high revs. Every once in a while the needle pops all the way to the right and stays there. At the same time the MPG gauge will do this, but it usually only lasts a couple minutes.

Is this a sign of a failing pump, bad electics, or something else? I currently have 5w30 synthetic in it. Should I just run heavier oil and see if the problem goes away? I would prefer 10w40 anyway.

[klinker]

I had 2 problems. First the oil pressure gauge was pegged at 5. Replaced the oil pressure sending unit and now the oil pressure guage registers correctly. 2nd, my oil level light is illuminated. The oil level is correct on the dip stick. The wiring diagram to the oil level light on the instrument cluster shows a white/yellow wire coming from the oil level switch. Where is the oil level switch located and where can I find the part?

[neo the hacker]

It could be a wiring fault on the dash, somtimes my oil level warning light comes on very rarely, i just switch off and start engine again and its ok. as for where the level sensor is i'm not sure? could be on the oil cooler somewhere. It may be worth you changing the O/P/R/V, just to be sure. As for yours xvegan, you should change your O/P/R/v as well to be sure, and it does sound like you have very low oil pressure. The 944 motor is a very strong unit and does not need anything thinner than a 15w40, (comma) do a semi synthetic 15w40 called xt2000 and workes very well, 5w30 is far to thin and normally used in the likes of the ford zetecs to stop there sticking valves.

[xveganxcowboyx]

O/P/R/V?

Wow, 15 weight even in winter? Not that I plan on driving it in the snow. I would have gone with the 10, but they were out. Is there any particular reason that oil would work better than a fully synthetic. I always thought the blends were bs.

[JagIndian]

To Klinker.
Unless someone has actually seen a oil sensor....
Hope this helps, earlier model 944's only had the Oil Pressure Sending Unit, no seperate Idiot Lights indicators or sensors (as they were called with the rear engine's). If Pressure is low enough the OPSending unit triggers the light.

Low oil pressure in early engines was sometimes caused by sticking pressure relief valves . The steel relief piston/spring in the oil cooler would at times get stuck. I think the 87's had a one piece relief valve. Now typical Idiot Light Sensors as you call it are triggerd at 4 - 5lbs, way to low No matter what the dipstick states or the pressure gauge states.

"" Porsche began producing model year 1987 engines in July '86. These engines received a new type of one-piece oil pressure relief valve. Unfortunately, in engines produced between July and October, the relief valve was not anit-corrosion treated. Porsche recommends that when servicing these engines, the oil pressure relief valve be replaced with the corrected, anti-corrosion treated part.""


"Problems with the oil pressure indication are commonly caused by a failing oil pressure sending unit. Normally, at startup when the ignition switch is turned on, the oil pressure will indicate 5 bar. Upon starting the engine the oil pressure should indicate between 4.5 - 5 bar. As the engine heats up the oil pressure will gradually decrease until the oil reaches normal operating temperature. At that point the oil pressue will normally indicate around 2.5 - 3 bar. On very hot days the oil pressure could indicate as low as 2 bar. If the indication falls below 2 bar and remains consistently below 2 bar, it could indicate a problem with the main or rod bearings."

gluck

[neo the hacker]

O/P/R/V= oil pressure relief valve. Yes 86 and later have a one piece relief valve, if you remove the oil cooler for any reason make sure you align the cooler up with the hole in the block, because if it aint, the relief valve will not work and the oil pressure will go up and up and up up up up, until it pops the oil filter seal out and drops 6ltrs of oil all over your dads garden twice, after going 12ft in the air, i found out the hard way on startup from a top end overhaul.

[xveganxcowboyx]

Mine is an 85 N/A. Is this info still applicable?

[neo the hacker]

what bit?

[xveganxcowboyx]

(Post #7)

To Klinker.
Unless someone has actually seen a oil sensor....
Hope this helps, earlier model 944's only had the Oil Pressure Sending Unit, no seperate Idiot Lights indicators or sensors (as they were called with the rear engine's). If Pressure is low enough the OPSending unit triggers the light.

Low oil pressure in early engines was sometimes caused by sticking pressure relief valves . The steel relief piston/spring in the oil cooler would at times get stuck. I think the 87's had a one piece relief valve. Now typical Idiot Light Sensors as you call it are triggerd at 4 - 5lbs, way to low No matter what the dipstick states or the pressure gauge states.

"" Porsche began producing model year 1987 engines in July '86. These engines received a new type of one-piece oil pressure relief valve. Unfortunately, in engines produced between July and October, the relief valve was not anit-corrosion treated. Porsche recommends that when servicing these engines, the oil pressure relief valve be replaced with the corrected, anti-corrosion treated part.""


"Problems with the oil pressure indication are commonly caused by a failing oil pressure sending unit. Normally, at startup when the ignition switch is turned on, the oil pressure will indicate 5 bar. Upon starting the engine the oil pressure should indicate between 4.5 - 5 bar. As the engine heats up the oil pressure will gradually decrease until the oil reaches normal operating temperature. At that point the oil pressue will normally indicate around 2.5 - 3 bar. On very hot days the oil pressure could indicate as low as 2 bar. If the indication falls below 2 bar and remains consistently below 2 bar, it could indicate a problem with the main or rod bearings."


O/P/R/V= oil pressure relief valve. Yes 86 and later have a one piece relief valve, if you remove the oil cooler for any reason make sure you align the cooler up with the hole in the block, because if it aint, the relief valve will not work and the oil pressure will go up and up and up up up up, until it pops the oil filter seal out and drops 6ltrs of oil all over your dads garden twice, after going 12ft in the air, i found out the hard way on startup from a top end overhaul.

Soory, I guess that's what I get for jacking a thread. I don't know what applies to me and what applies to the original poster.

[dpsatx]

Originally Posted by klinker

Does anyone know where the oil level sensor is located on the engine? I had the oil pressure sending unit recently changed to fix a problem with the pressure guage. The Mitchel Repair book describe an oil level switch in the Wiring diagram but I can't find the part on the web or in any parts catalogs.

The oil level sensor is a little and above the oil drain plug on the passenger side, their is a heat sheild covering three bolts in a triangle behind the sheild that is the oil level sensor, a new one is kind of pricey, the cheapest I have found is $259.00, I need one to
Regards
Don