Mako 928

I got the engine back into the car and started it up today. Fired right up and let it idle for a while. The oil pressure gage stayed at 5 bar and went to 4 bar after it warmed up. shut it off topped off fluids and went back to work. Later today I took it out for a shake down run and all was fine. On the way back home the oil gage drops down to 1.5 bar. It flutters between 1.5 and 2 bar. I tap the instrument pod several times and no movement it just flutters. I get back home and look at the connection at the front of the oil pan and it is connected. Then look at the 2 connectors at the oil sender next to the oil filter and looks good. Did a search and it seems oil senders peg at 5 bar when going bad which this is not doing. Oil level is normal engine temp stayed just above the first white line and oil pressure warning light did not come on. So what should I look at next?

David L. Lutz

What all did you do to the engine while it was out?

Mako 928

Pulled it for a external leaking head gasket and the timming belt was wandering forward and rubbing.

Big Dave

What kind of oil are you using?

Mako 928

Valvoline SynPower full synthetic 20W-50. Have been using this for a few years now.
( This is'nt gonna turn into a Amzoil thing is it?)

Big Dave

Was it reading 1.5-2 just at idle or while driving?

Mako 928

While driving. RPM's did not change the reading.

RyanPerrella

i was going to say 1.5 2 is normal for warm idle. But it should be 5 bar or pegged when you get over 2,000-3,000 RPM

Odd

Mrmerlin

you might want to remove the cam covers and check the rear cvam journals for a missing oil block off pin that is if you have a 32 valave engine other wise the themo spriongs in the oil filter housing may neeed to be replaced

Mike Frye

Before digging into the engine, I'd just re-check the connections on the sender. Make sure you've got good clean connections. If you can get the gauge to peg by manipulating the wiring and the connections are good I think you can assume the sender is accurate since it did work when you hooked it back up initially.

It would be a shame to take apart the top end only to find there is a loose connection on the sender or there's oil dripping on a loose connection and causing a weird reading.

Jim bailey - 928 International

The 85-86 has the long camshafts there is no pin..."remove the cam covers and check the rear cvam journals for a missing oil block off pin that is if you have a 32 valave engine" . The plastic/pin started in 87 supercedes to the longer pin about 1989 as I recall.

Mrmerlin

Thanks for that bit info Jim B

IcemanG17

Greg
That doesn't sound right...but replacing the oil thermo springs above the pressure sender is pretty easy & it solved a hot restart low oil pressure problem I had....

At Thunderhill last week I never saw under 2.5-3 bar at idle...even after a full 20 minute session...but thats with the "magic" oil too...it was cool that day and the temp barely got over the 1st line too

Mako 928

Brian
I am thinking of removing the pressure sender and looking at the springs, other wise I am going to remove the instrument pod and give it a good cleaning. I now remember that the speedo was dead under 30 mph last year a couple of times and giving it a tap would get it going again. Also will replace a chewed up odometer gear.

IcemanG17

Greg
It does sound like there is some electrical possibilities....thats the easiest fix...but the springs are cheap & fairly easy to fix as long as you have a stubby 32 or 27mm wrench (I can't remember?) to get the sender out