924Board.org

[leadfoot]

Migth be a long post but here goes:
Car is an 81 ROW 924 turbo

Problem, Oil pressure reads low at start (7psi) warning light is on.
No grinding noise from engine, tappets seem a little louder than normal though.

Reving does not raise oil pressure to any significant degree.

So far I have;
removed and bench tested sender up to 8 bar ( both resistance readings fell within scope of VDO range. Dummy light checks continuity at below 2 bar and breaks above consistent with it's normal operation.

Replaced wiring and rewired gauges for + , earth and signal wires.
Reconnected sender and tested with compressor signal with both warning light turning off at 2 bar and pressure gauge reading from 0 to 8 bar.

Removed and reffited oiler tube (cleaned) and inspected elbow (no cracks and maintaining a good seal when replaced)
There is also a good amount of oil coming from the oiler tube at idle and rpms.

I also check for blockages behind the sender, all seems clean, no slugde buildup but am unsure of what oilways are around the sender.

Filter is Mahle unit from what I can tell (black body with white german instructions is a give away)

Removed cleaned and inspected oil pressure bypass
piston/spring. (not sticking in bore and spring has good amount of tension in that with finger pressure it is hard to pass the top of the piston down passed the top of the guide tube. Spring looks uniform with good amount of clearance between coils.

So I need some advice on where to proceed or what might be a logical issues.
My thoughts are:
Blockage - In oil pickup or around sender location I cannot see - would applying compressed air at the sender point be of any help?? or using an engine additive to flush system ??

Leaky gasket at the oil pickup (although I think this would aerate the oil to a certain degree?)

Failing Oil Pump - how to confirm / test / repair kit??

Possible bearing issue?? Mains? What to look for
If I want to remove the oil pan with the engine in situ, what's the best method.
Drain sump , Remove breathers / drain tubes etc...
Remove steering shaft at rack (RHD)
Drop lower crossmember ( do the tie rods need to be removed and if so better at the rack end or steering knuckle)

Appreciate the advice
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[!tom]

Is it possible the oil is just too thin?
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78 924 NA
5-lug

[ideola]

Not sure what to suggest regarding the low pressure, but to answer a couple of the other questions:

RE: the steering rack, I would unbolt the rack from the cross member and just leave it intact. You can't remove the tie rods from the rack without also removing the ends, but there's really no need to do this...when you disconnect it from the rack and the steering shaft, you'll have plenty of flex in it to either lower it or pull it forward and zip tie it out of the way. THEN remove the cross member and get it completely out of the way. This should make it fairly easy to get to the pan.

RE: oil pump, if it's failing, there are no rebuild kits that I am aware of. The only option is to replace it with a known good unit, or a new one from Germany. Last time I checked they were nearly $400, but I'm not even sure if they're available. When I prepped my UWB motor, I stripped the guts out of its oil pump housing, so if you'd like to see what's inside I can snap some pix a little later. Hard for me to see how they could fail, I doubt the pump itself is your problem.

Have you considered shimming the spring to see if that has any affect on pressure?

It would be interesting to know what grade of oil you're using.
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erstwhile owner of just about every 924 variant ever made

[leadfoot]

Not sure of oil grade as I have not changed what was in there since acquiring the car, but it looks fresh.

P.O had tried shimming the spring to no affect, I am reworking all the steps that he went through just to cover all bases, what thickness shim would you recommend (5mm??)

"when you disconnect it from the rack and the steering shaft, you'll have plenty of flex in it to either lower it or pull it forward and zip tie it out of the way. THEN remove the cross member and get it completely out of the way. This should make it fairly easy to get to the pan"
cheers, knew if I could get the rack forward an inch I'd have some clearance, this should save my alignment too. nice one Dan.

Can anyone brief me please on the oil pathway from the pickup through the engine or have a pic of the flow path?
Cheers
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[Rasta Monsta]

[drwal]

[Elektrobank]

[PORSCHEV]

I would only worry once I had a mechanical gauge installed. there is too many possible glitches in the stock wiring that can effect the oil pressure reading.

I recall in my car turning the blower fan on would drop my oil pressure in half.
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

[DOCO]

have you put on a REAL presure gauge on the engine to make sure its not electrical?these gauges on these cars use electric senders.check real oil pressure first
_________________
Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
_______
/______\
[+]___[+]
\0 924 0/
[__]..[__]
"WEBB STR"

[leadfoot]

Funny you say that Porschev as I use to have a gremlin in my last car that travelled around from gauge to gauge, I finally got fed up and pulled the dash to rewire the heater fan for a switch as it was not working effectively. I found the orange 10ohm wire to be partially melted.
After that was replaced I never had any electrical issue with the gauges.

In respect to main/rod bearings, if one is spun does it leak excessive oil hence the drop in pressure??

If a mechanical gauge is installed is there another place besides the back of the block that can be tapped into.

The handbook also says use oil 15W40 , 15W50 , 20W50 (not below 15C-)
my temp rang here is 4C-40C , it doesn't go into the negatives and if anything is on the warmer side majority of the time. What would be the best oil to use?
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[DOCO]

If a mechanical gauge is installed is there another place besides the back of the block that can be tapped into.

thread it into where the oil pressure sender came out of and check for real pressure
_________________
Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
_______
/______\
[+]___[+]
\0 924 0/
[__]..[__]
"WEBB STR"

[ideola]

[Slam]

As above re mechanical gauge. Is the VDO dash gauge bouncing?
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'88 944 Auto - may or may not resurrect

[stevekat]

Ditto. I'd confirm actual pressure before tearing things apart.
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"Never get out of the boat. Absolutely goddamn right. Unless you are goin' all the way."

Gone to new home: '81 924T, US version, CGT Intercooler, UTCIS-PT, Euro DITC, Greddy Trust MBC, Forged Fuchs Flat Dish 6's, Factory Recaro's.

[Rocco R16V]

20W50
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"Government exists to protect us from each other. Where government has gone beyond its limits is in deciding to protect us from ourselves. "
Ronald Reagan