High oil pressure. ‘73 914 2.0L Now leaks oil.

[Trick-e]

Hi all.
I’m new to this forum and sporting a 1975 914 with a ‘73 2.0L. I’m hoping for a little help to resolve a high oil pressure issue. Any help would be much appreciated.

Here’s where where we are…
-The case is a replacement ‘GA.’ Supposed to have performance parts added, but that’s undocumented.
-I’ve driven the car for 3 years. Has always started and ran smoothly, idles 900RPM. No smoke, but oil pressure has always been about 62 psi at idle, after warm up and at all RPMs.
-Had low oil pressure light go on a number of times during spirited street driving, so added an oil sump extension ( https://img1.wsimg.com/blobby/go/53f04177-c2aa-4f3...2703560484 )
-After a day at Grattan Raceway, car leaks a lot of oil. Leak starts at 10 minute warmup mark.
-I’ve replaced the oil seals, pushrod tube seals, oil filter, oil cooler, pressure relief spring (stock).
-Running 20w-50 oil.
-‘PCV’ seems to be functioning.
There’s a bit of dirt/grime in the top of the case where the oil filler box meets. (Could be a bad cork gasket, but it’s info.)
-Oil pump is stock.

Appears to be leaking from the oil cooler seals or from cylinder-case between #3 and #4, but hard to tell for sure. Just lots of dirt/grime buildup.

Engine is now out of the car, and I’m out of ideas. I’ve stripped the tins, so the next step is to bench run it.

Any thoughts on why it would run at such a high oil pressure?

[Starbucket]

20w-50 oil was never used by dealerships if it won't run on 10w-30 it needs an overhaul. Oil is not used it fill excess clearance it's used for cooling and lubrication and the quicker it gets back to the sump and back through the oil cooler and slung back under the pistons from the crank to lube and cool them the better off you are.

[[email protected]]

if it has high oil pressure certainly the oil pressure light would not go on. If the oil pressure relief valve just drops out when you remove the big slot screw then it is ok, so clean the engine fix the oil leaks and put a mechanical oil pressure gauge that you know works on the engine and see what you read

[Trick-e]

I can certainly try a little thinner oil, and have confirmed the pressure using a mechanical gauge.

I’m still scratching my head. What could cause high oil pressure, and why is it just now blowing seals.

[raygreenwood]

[Trick-e]

Ray,

Thank you for your help! Going point-by-point…

1. Will lighten the oil.
2. I’ve changed the cooler seals and later the cooler. No spacers and never leaked before. Not sure it leaks from the cooler. Do use wider and thicker washers on the outside. I’m gonna read your other post that you linked. I’d heard that spacers were an old wives’s tale, so am curious to what you found.
3. Pressure relief spring has been replaced. When pulling the piston/spring it came out easily. Found no gouges/marks so don’t think it was bound up.
4. Correct fan assembly bolts/screws/ washers used, but as I’m still nailing down the exact point of the leak, fan impeller could be blowing it back. Will find out when I run it without the tins.
5. Pump is a Type IV stock. Didn’t measure the gears, but the inner and outer parts IDs match the stock IDs.

I did discover that the bottom driver side engine bar mount bolt hole intrudes on an oil passageway. (Factory designed that way.) In the bolt holes are helicoils, which, along with a bent engine carrier bar, seems to support that the car ran over something, bent the bar and pulled stripped the bolt holes. Long story short, if the helicoils are too deep and intrude on the oil passageway, that could increase pressure. I’ll measure that tomorrow.

I talked with George Hussey today (Uber friendly and helpful). He reminded me to not worry about the pressure (engine has run just fine for years), solve the leak.

Next step is to bench run it and narrow it down where she’s spitting from.

[Starbucket]

You say the leak started after some "Spirited" street racing and the oil pressure light hade come on several times so you may have scored a cyl. and are now pressurizing the crankcase blowing oil past the seals, time for a compression check.

[[email protected]]

[Trick-e]

Very good. Will do.

Thanks for the help. 🙂

[raygreenwood]