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I have an '86 Vanagon Synchro with an oil pressure problem, maybe. It has a freshly rebuilt 2.1L, new senders,properly installed. I've replaced the module in the dash as well. The problem is, at full operating temp, the oil pressure warning light/buzzer will come on from 2000-3000 RPM. It doesn't come on when accellerating from a stop, and it will go off if you blip the throttle to above 3500 RPM and allow the revs to fall quickly below 2000. Once the warning light/buzzer sounds, it will stay on as you slow down to an idle/ come to a stop as at a traffic signal. As anyone with a Synchro knows, almost all of your driving is done between 2-3 thousand revs. Most frustrating. I run 10w40 full synthetic oil. Anyone got an idea?

What oil filter are you using, and exactly what oil?

Some oil filters cause headaches. (Try Mobil1 or Purolator One, MANN, WIX, Bosch--- NO ORANGE FILTERS)
Sometimes the wrong sensors get installed.

There is also a long standing problem with aftermarket oil pumps pertaining to the issue you are seeing--
Most (all?) are too small/loose in the case and suck air+leak oil pressure internally hot, and or have excessive end play and possibly other issues.
They ARE easy to install

The wrong oil will wipe a flat tappet cam in a few dozen to a few thousand miles, depending on luck.
This "sands" the rest of the engine with finely ground hard metal shrapnel.

I'd hit the builder up for an immediate fix unless it was you.
Disconnecting (or is it grounding... been awhile) the high pressure switch is not the right fix.

The dynamic oil pressure warning system usually works right if the motor is right.
Your description says it's working ~properly, you just have low oil pressure hot.

have you measured actual oilpressure with a gauge?
what does it read @ what:
RPM
Oiltemp

I would be concerned about your rod bolts. They stretch on these engines with time causing oil pressure problems and eventually the big bang when they let go.

Their are two oil pressure senders on the engine, one is normally open and operates at a fairly low pressure and the other is normally closed and operates at a higher pressure. There is a little computer in the dash that only reads the normally close circuit once the engine rpm's get above 2000 rpm's. So what this is telling you is that you do not have sufficient oil pressure at and above 2000 rpm's.

You should check your oil pressure with a gauge to verify that the switches are both working correctly. If you oil pressure actually is below spec, you should quit driving your engine so you don't destroy the block when the rod lets go. You will want to buy a set of rebuilt rods that will come with better rod bolts.

wildthings wrote:I would be concerned about your rod bolts. They stretch on these engines with time causing oil pressure problems and eventually the big bang when they let go.

Their are two oil pressure senders on the engine, one is normally open and operates at a fairly low pressure and the other is normally closed and operates at a higher pressure. There is a little computer in the dash that only reads the normally close circuit once the engine rpm's get above 2000 rpm's. So what this is telling you is that you do not have sufficient oil pressure at and above 2000 rpm's.

You should check your oil pressure with a gauge to verify that the switches are both working correctly. If you oil pressure actually is below spec, you should quit driving your engine so you don't destroy the block when the rod lets go. You will want to buy a set of rebuilt rods that will come with better rod bolts.

True, the big ends go all egg shaped on 2.1s, didn't consider that on a "fresh rebuild"

If the "fresh rebuild" didn't include remanufactured rods it was just a freshen up.

The SCAT I beams (in 5.4") can be modded for 24mm piuns by any competant shop, possibly even SCAT, are 4130 steel, and have (or can be had) 3/8" ARP2000 bolts.
Not the cheapest solution, but likely to hold up far longer than reman stock or even OG rods.

This is what kills most 2.1s.

I should have stated that all the internals rods, crank, etc, are new/reman. crank was a 10/10, new oil pump, Wix filter and Castrol full synthetic oil. The engine I replaced displayed the same symptoms after 85,000 mi. though less frequently. I have not checked pressure with a gauge yet as i'm still not quite clear on how to hook one up.

Banzai wrote:I should have stated that all the internals rods, crank, etc, are new/reman. crank was a 10/10, new oil pump, Wix filter and Castrol full synthetic oil. The engine I replaced displayed the same symptoms after 85,000 mi. though less frequently. I have not checked pressure with a gauge yet as i'm still not quite clear on how to hook one up.

I would suspect the pump clearances first, as I haven't seen a good "new" pump in many years.
(Search here for oil pump, use Google site search )

A gauge goes on a flex hose where the second sender goes, on the main oil gallery under 3/4, between the pushrod tubes.
There's a nice how-to out there somewhere, probably Google for "oil pressure gauge install vanagon"

http://www.vanagon.com/info/articles/oi ... /index.htm

Many good links there.

Also: research your oil, you have a flat tappet cam/lifter setup.
API SM oils are liquid death to cams/lifters, with one known exception, Rotella T synthetic 5W40. It has enough zinc/phos to keep the lifters/cam alive.

If your machinist was one of the kind that likes to set you oil clearance at .002" on you rod and mains you will not get sufficient oil pressure. Been there done that. You need tighter clearances to get good oil pressure on these engines.

when the bigends go oval in shape
i asume they get "hammered" out so the internal circumference actually get larger , so the area increases and making lower oil pressure asa result
or
do they just get oval,(same internal circumference) but then making them "Pinch" on the crank journal??

Some I have measured did a bit of each, but most just bigger.

I wouldn't use a stock wasser rod for that reason in any application other than perhaps a 1.9, the material/cross section isn't up to the task.
(Same goes for stock T1 rods on stroker cranks--- OTOH most motors like that are relatively short lived anyway)

Thanks for the leads. I'll post the results of the mods when completed.

The other uestion would be did you use a gasket on your oil pump cover if you did that is mostlikely the issue no gasket is used there.

I've had plenty of trouble with the oil pressure, but I just want to postpone the engine rebuild as much as I can. Ever since I started using 10W60 the buzzer has been quiet.

https://www.youtube.com/watch?v=Pl477GxEXFs

A miss on no 1 cylinder caused mine to sound the oil alarm it had a short in the injector it can also be the connectors in the cuircuit along with many other good suggestions above.

Also check the big connector at the base of the instrument pod clean it with a biro rubber might help.