2056 with 26mm Schadek blueprinted oil pump, running Brad Penn 15w50 oil. VDO oil pressure gauge with dual sender. New sender was installed when engine was rebuilt. Start up, oil pressure reads 60 lbs. Running when hot, at 2800 rpm the oil pressure is 20 lbs. At 1050 rpm idol, the oil pressure light comes on? Is there a way to check the sender with an ohm meter? I had no issues with the old sender and the same oil pressure gauge before the rebuild. Also running a Setrab remote oil cooler.

I'd check with mechanical gauge before doing anything else.

I agree.
Double check

Is it the same case?
Was it line bored?

Have you double checked the grounding on the sender. I ended up stuffing copper tape between mine and the strap. Got 10 psi out of that.

+1, my vote

I don't think the VDO gauges are that accurate. I found the electrical gauge read about 6 psi low compared to a mechanical at hot idle. Can't remember the numbers, but the error increased with rpm/oil pressure.

Purchased a cheap Bosch mechanical gauge at Advanced Auto parts. Started the engine and the gauge read 70 lbs. After warm up at 1050 rpm it read 8 lbs. At 3000 rpm, it reads 28lbs. There is air in the plastic line, if that makes any difference. Forgot to mention in my first post, I also installed the Tangerine racing oil pressure relief valve.

One school's rule of thumb is "10 psi for every 1,000 rpms". Personally I prefer a bit more than this. How long ago was the rebuild completed? and how were the bearing clearances? Is the motor running well otherwise? Have you changed the oil? any debris?

New build, less than 100 miles. bearing clearances were right on, the machinist commented that the 2.0 crank was pristine. All he had to do was polish it. Oil was changed, no debris. The motor runs strong .

Does your engine have the secondary relief piston near the #1 cylinder? If you do, and it’s stuck open, that might be a contributing factor.

Was the oil pump o-ringed?

Ian, is the secondary hard to replace with the motor in the car? Curious.

Not difficult. You just need access to the triple square cover. a 3/8 socket extension works in a pinch. Then you need the piston slug from european motor works.

@iankarr ,
I've got the part on hand. I assume this can be done without dropping the oil, correct? Do you remember which end goes in the piston side? It looks like it's the shorter side. This just replaces the spring to prevent the piston from moving, correct? Why are there no instructions?!

Click to view attachment

That's the bit. It just replaces the spring and forces the piston closed all the time. No need to drain the oil. I don't remember which side is which, but I think one side fits better.

You mentioned you had air in the plastic line ?,is it like that all the time when the engine is running or was that just when first fitted the gauge ?.

My apologies in advance to the OP ( @Geezer914 ) for [again] hijacking this thread. I installed the high pressure relief slug. No difference, hot oil pressure is low. However, I just read that that my 150lb VDO dual-pole sender and 150lb gauge is not the right set up for the 914. The dummy light will signal at 7-8lbs. AirCooled.Net says I should use a single pole 80lb sender and gauge. Going to install a T and run the stock OP sender/idiot light and the VDO sender/gauge side by side.

Just went through the trouble to install a VDO mechanical oil pressure gauge and the gauge is stuck at 30lbs. Returning the gauge for replacement. Can't win!

I have a mechanical on my mustang and it has bubbles (large pockets of air) in the line when I look at it, normally not running when I am looking at it. not a problem at all. Works great.

Oil pressure lines with sender.Click to view attachment

Installed the new VDO mechanical gauge.

Cold start 60lbs.
Engine hot, oil pressure reads 22lbs. at 3000rpm.
Hot idle at 1050 rpm is 7lbs.
Oil light no longer comes on at idle, but will flicker at 700 rpm.

Joe Gibbs15/50 oil.
Setrab series 1 19 row oil cooler.
8AN lines with 180 inline thermostat fan switch.
Setrab oil cooler sandwich plate
K&N oil filter

Would 15W/40 give me more oil pressure or less?

Probably less. Some synthetics hold up pressure better under heat but 22lbs hot at 3000 is a little scary. My ancient old motor has 50 hot at 3k. 12 10-12 HOT at 950 and 20 hot at 950. That's with 5w40 Mobil 1.

@Geezer914 - 40 weight is thinner so probably not. I'll post specs on my readings as soon as I receive my ordered parts and get a chance to install everything. I'm running 5w-50, the Tangerine low-pressure relief, and a high-pressure piston/slug combo from European Autowerks (recommended by Ian)

it sounds like bearing tolerances to me.
once everything expands the oil escapes out of internal gaps
I had a motor I rebuilt and failed to line bore, that did the exact same thing.

I wonder if the shop line bored this?

brant

I might have missed it..
but did you put a higher volume pump in when the rebuild happened?

is your cooler in front or in back?
I know I always increase the volume of the pump, when using a front cooler.

Replaced the pump with a Shadek 26mm blue printed pump. Cooler is in the back.

dang... right parts...
I am still thinking...
brant

Still no glitter in the oil right?

What is the oil temp when the oil light flickers. My infrared temp sensor reads 225 degrees at the top of the case and that hot. This is after an hour of driving in Miami where its always hot. My light doesnt flicker. Buy a fluke infrared temp gauge and try it out.

225F is not hot for an air cooled engine case.

Typical oil sump temp for air cooled engines can be as high as 240-280F without issue. Since oil resides in the case, at equilibrium, you an expect the case to be as hot as the oil within.

Even a water pumper, the block could easily be in the range of 190F - 240F (pressurized cooling system allow water hotter than 212F without boiling).

No need to be concerned with an air cooled engine case that reads 225F.

I hate to say it but Especially since it's already running a 26mm pump.

Same condition led me to rebuild my very 1st T4 engine way back around 1989

In hindsight it was a blessing. I learned a lot. I took my 1.7L out to 1911 and had a better engine for it. That rebuilt engine ended up going over 100K miles before car was totaled by a rear end accident.

Question -- did you verify the oil pressure relief valves? Saw this referred to earlier but no response from OP

One parting idea. Can you easily bypass the external oil cooler? You may be getting excessive pressure drops across the lines and the external cooler that the 26mm pump can't accommodate. It's a stretch but might be interesting to know how much the cooler itself is contributing to the oil pressure problem not knowing if lines are too small / too long / what sort of plumbing is involved to the cooler.

OEM arrangement is oil pressure sender before the cooler but not knowing how external cooler was plumbed, I'm not sure if pressure senor is before of after the external cooler.

I see OP is in New Jersey. There is zero need for an external oil cooler with a 2056 engine in New Jersey.

Agreed, a separate oil cooler should not be necessary in NJ, also, check the pressure relief valves prior to breaking it down.

Best of luck

you might want to take it back to the builder...

having them involved in the final diagnosis is more likely to get some sympathy from them in the repair....

vs... if you don't involve them now... it will be really hard to bring them in later.

I am the builder. I too am wondering about the size of the oil pressure lines. Searching the posts, people are using 8AN, 10AN, up to 12AN. Lines are plumbed with Earls 8AN fittings with Earls Pro-lite Ultra black braded hose. I didn't think 1/2" oil lines would be restrictive and effect oil pressure, but I could be wrong. Before I changed to the mechanical oil pressure gauge, I switched out the Tangerine oil pressure relief valve for the LN Engineering piston. I am going to reinstall the Tangerine valve and ordered a secondary relief valve block off rod from EMW. If that does not work, I will block off the remote cooler and see what happens. As far as needing a remote cooler in NJ, it gets damn hot in the summer!

Thanks to everyone for their input

(said in the kindest, gentlest manner I can muster - )

914 was designed to run at temps you see in NJ. I ran my 1st teener as a daily driver for over 10 years all over the hot / humid mid-west without need for an external cooler.

Traveled all over the place including several trips to southern Florida and back.

Regularly was driven 75-85 (during the 55 era speed limit). I drove an entire summer back & forth between Lansing MI and Detroit and there is special section of road that is long, straight, has limited access where the Po Po can't get on or off and has a tall divided median for miles that keeps them from turning around. I used to make it a point to hit 100+ each day that i could when traffic was light and weather / visibility was good.

You don't need an external oil cooler in New Jersey.

Everyone needs to stop trying to keep air cooled engine oil at the same temperature as water pumpers. Even water pumper oil goes well beyond 200-210F when taxed with towing and/or high aero loads. The 914 Factory gauge STARTS the red zone at 300F. The red danger zone was put there by the engineers that designed the car. Air cooled engines like VW's and air cooled motorcycles can run oil temps 240-280 all day long. Change oil every 3000 miles. No problems.

I just recently looked at data from work a week ago for an AWD PTU that i was testing on track back in 2011 to see if we needed an oil/water cooler in the PTU. Test abort temperature for the oil was set at 160C (320 F) for short term excursion. Not saying anyone would run there long term, but, the bottom line is that oil can take more than it's given credit for.

Points well taken. Will keep everyone posted on my progress.

good plan...
not sure how you attatched the remote lines... but taking them out of the equation is a good verification.

I've always been told -10 for a /4 and -12 for a /6

but we put in -12 on our 4 also, with good success for 20 years.
brant

There was a cool chart on pelican I found once, it showed how long oil was good for at certain temps. Basically the hotter you got the oil the quicker it would break down. I do agree 250+ is probably fine. My issue is I feel like the more you go over 230f the more leaks you will end up with down the roads.

Just look up the particular oils and check the viscosities. The higher the number the more oil pressure you will have. Not all 15w40 or 20w50's are the same between manufacturers.

Aluminum or steel cover?
I'll only use the heavy cast iron covers, I've seen the T1 pump gears drilling into aluminum covers within few hundred miles.

Steel cover on the pump, ground flat.

Just for nothing, I installed a stock pressure relief piston and went for a short ride.

Cold start pressure was 70lbs.
Hot was 20lbs. at 3000rpm.
Hot idle is 7lbs.

At this point I am beating a dead horse. So, I have decided to drop the engine and do a tear down. I have a set of new bearings and gaskets ready to go. Kobleschmit rod bearings and Silverlite steel backed main bearings. I should be able to reuse the cam bearings.

VaccaRabite, you have been through this, what did you find that caused the low oil pressure? Mark please chime in also. Maybe the best bet is to have the machinist. build the short block and I can install the pistons and heads.

I'm not VaccaRabite
but I had a similar experience

mine was diagnosed as line bore
I put 47 miles onto that motor and never got the warm oil pressure I was expecting.

in the end... I did what you are describing... I had my engine builder(also my machinist) do the line bore and reassemble for me

He also told me that I was using too much case sealant and not working fast enough during case assembly. he felt that I also had too much sealant that did not squeeze out, causing my bearings to be even more loose... than they should be.. and contributing to my oil pressure problem in addition to the line bore.

honestly, I'm running a different motor now
I have this fully rebuilt 2.0/FI motor sitting on a shelf and have not run it since having it professionally built. only because the shop took a year to do the build due to race season... so I put a different motor in for the mean time to keep using the car. haven't had the need to pull it again since.

(good reminder... I need to rotate that motor tonight)

is your aux cooler before of after the oil pressure sensor?

If sensor is on the far side of the oil cooler, I'd bypass cooler before tearing down the engine.

How are you dong the take-off for the external cooler? Direct from the oil galley or with one of the oil filter adapters? I'm not 100% sure but I think the oil filter take offs, end up putting the oil cooler before the oil pressure sensor. Would depend on your particular product but I'd check that before a tear down.

When I broke in the engine, the oil pressure was not that great, I think only 25lbs. I figured it was because it was 30W. oil. I added the oil cooler later. I did a lot of research on the 914 world site. VaccaRabite is running a larger Setrab cooler with 8AN lines and a filter adapter. I have the same set up with the smaller cooler. My oil cooler thermostat is a switch mounted in an AN fitting just before the cooler. He is getting 50lbs of oil pressure at 3500 rpm!!! I don't know what oil pump he is using. I have good pressure on start up but as it warms up and things expand the oil pressure goes to shit.

By any chance is your oil light hooked up to a dual pole sender so you can run a pressure gauge?

The stock idiot light lights up really low. Like 3-5 PSI low. The dual pole sender lights up much higher, giving you a false positive for low pressure. Some people say this is a good thing. Gives you a margin for error. I think it causes stress when you may not really have an issue to begin with.

That said. I fucked up my first build because I did not get the bearings right and had excessive clearance leading to low pressure. And I solved it by rebuilding the engine and getting the bearing clearance right.

But before you do that. Put a stock oil light in your car and see if it lights up. For my car now I have a single pole sender for the pressure gauge and a stock idiot light sender for the dash light.

For my engine right now, I am producing excessive oil pressure. My 80PSI gauge pegs on startup and i can get oil getting pushed past the seals.

I have a feeling that your car is maybe on the light side of acceptable but still within the acceptable range. But you can also go to a 20w50 oil and having hot oil a tad thicker will raise your hot pressure the touch that you want to see.

Zach

Running Joe Gibbs 15W50 oil. I can't believe I have 70 lbs. a start up and it goes down to 20lbs. when hot. . I have a 3AN oil line to a T fitting with a Bosch idiot light sender and the 3AN oil pressure line going to the mechanical gauge.

I would really take the oil cooler and lines out of the equation first and see what happens.

I have to disconnect the oil cooler before I remove the engine so I will give it a shot. When I broke in the cam, I think the oil pressure was around 20lbs. At a little over 2000 rpm. I assumed that to be normal for 30W oil.

Yeah, I don't hold out much hope but you never know. Would suck if it were all fine and you tore it down.

You know... Just thinking here. Oil doesn't go to the cooler until it's hot (in a regular type4). You have good pressure cold. There is an ever so small chance that the diversion of the hot oil to the cooler could be it. Pressure obviously drops as oil heats, but perhaps that combined with some cooler issue (location, diameters) is what we are seeing.