Oil pump & Pressure

[No More Landy]

Hi guys

I recently replaced worn valve guides and fitted new rings to my beetle and she drives great but when on a hot day I get to operating temperature the oil light comes on at idle.

The only thing I noticed was there was no gasket on the oil pump cover, only sealant so I am assuming with the new gasket I fitted from the kit there is bypass on the gears because the pump is tired.
The pressure switch is also new from some time back.

Is it time to change the pump, and if so, where is the best place in Cape Town to find one ?

Sent from my SM-A107F using Tapatalk

[retrovan]

There may be two issues here,

One, if your old pump had no gasket, it must have been machined to not have a gasket, this means the thickness you added with the gasket, is now a oil passage past the gears.

The 2nd could be that you are using the incorrect oil for an old engine.

Change over to Shell HX3 20w-50, this will give you the correct thickness at any temperature. Its got the most zinc for aircooled protection and its rated as a diesel oil being able to take high temp. without breaking down.

OMO

Herman

Just for interest sake;-
As a youngster there was no money for a new oil pump, so every 50 000 miles we removed the oil pump, stripped it and removed the gears, took a Gunston cigarette packet liner, removed the gold foil which left you with a high quality tissue paper that did not disintegrate in water.

One layer was put under the gears and the pump surface was then surface ground with the gears in place.

When the gears and pump body was cleaned up, we removed the paper and refitted the gears.

Then we ground the cover plate till smooth.

assembled the pump with shellac or you can use thin layer of form-a-gasket, and refit to car. ......no gasket......

You can do all this on a table with a flat sheet of glass and Vim souring powder or valve seating compound.

[Tony Z]

20W50 is too thick for our cars, but this is likely something that Retro and I will never agree on.
I use 15W40 in most of my engines and 5W30 in one of them. All with stock oil pumps, none with oil pressure problems. I even tested one engine by running 15W40 and a smaller than stock oil pump (21mm instead of the stock 26mm = 20% smaller) on a late case - this engine also didnt have oil pressure problems and is still running after 6 years (in someone elses car).

I'd hazard the guess to your low pressure as follows:
1) idle speed set too low
2) your new oil pressure sender is the wrong type/pressure. I cannot remember the values now, but I think the beetle sender lights up around 0.15bar, whereas most other vehicles come on at 0.4 bar. This is nearly 3 times higher than the beetle, thus your light will come on even if you dont have an issue.

[No More Landy]

Thanks Chaps

I have always used Shell SAE 40 oil without any issue.
Idle speed is fine and the oil pressure switch never had issue before.

I whipped out the pump earlier and checked with a straight edge and the gears are flush with the pump housing. The cover plate is still good with only slight polishing and the gear faces are very slightly grooved so no obvious issues. I will refit and just use a thin layer of hylomar or similar and see if it resolves.
Was a mission getting all the tins and rear pulley off again with engine in place but made a few home made tools and bit of patience.

Sent from my SM-A107F using Tapatalk

[No More Landy]

That lapping idea with a piece of glass worked a charm to remove slight scratches in the gears and back plate, thanks Herman.

Sent from my SM-A107F using Tapatalk

[retrovan]

You more then welcome.

Have you installed it yet ?

Herman

[No More Landy]

It's back again but I am fighting to get the rear tin back under the engine bay seal as my son refitted that himself while I was under the car last week, and he's not here to help me today.
Tomorrow is another day as the air is turning blue

Sent from my SM-A107F using Tapatalk

[Dawie]

Maybe you can look if there is some code on the oil pressure switch. Then see on internet if there is some reference to pressure.

[No More Landy]

I bought it at Flat Four so should be ok.

Will check tomorrow but it worked fine before

Sent from my SM-A107F using Tapatalk

[No More Landy]

All sorted.

Oil back in and today being very hot the light did not come on again at all after highway run not even a flicker, even when I dropped the idle speed a little.
Thanks all.

Sent from my SM-A107F using Tapatalk