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Posted by: 914Bryan Oct 6 2016, 09:11 AM

Please tell me that there are some of you that have battled the same oil pressure issue I have? After my 2256 build, ditching all the stock 2.0 FI and its components and moving to carburetors, I have enjoyed a moderately powerful, fun car to drive. It is a real blast and the money was not wasted. I am happy with how it runs.

The issue is the wild fluctuation of oil pressure that I can't help but watch. I feel like a moth to a light.

Some examples:

Yesterday, idling in rush hour stop and go traffic, it was always about 10 lbs over whatever thousand rpm the engine was at (example, 3,000=40lbs). This is where I like to see it.

That night, during the same drive, but without stop and go traffic, it was about 10-20lb below whatever thousand rpm it was at. When stopping and making a left turn, the oil pressure warning light kept coming on.

Today, mid 60 weather, drove it about 20 minutes, and the oil pressure never went below 50, even at idle.

There is other craziness and inconsistency, cold or hot engine, outside temperature, does not matter, and i am sure you get the picture.
WTF?

Oil level is always checked and I overfill it about a 1/4 to 1/2 quart. As far as I know the oil system is stock with a 30mm Melling aluminum pump. Brand new electronic VDO gauge and sending unit.

I want to say F**k it, disconnect the gauge and throw caution to the wind, but I just cant bring myself to doing it.

Please, any ideas of what I can do to solve this or where to start looking?

Posted by: stugray Oct 6 2016, 12:05 PM

The piston in the pressure relief valve is known to stick in the bore on some older "tired" engines

Simple solution for this is to install Tangerine Racing's oil pressure relief valve replacement.

Or pull the piston out, inspect it and feel the bore to see if it has a ridge.
You should only spill a few TBSPs of oil removing the relief valve.

Posted by: porschetub Oct 6 2016, 12:24 PM

Have you carefully checked the wiring gauge to sender?are you getting 12V to the gauge,is your sender grounded properly?

Posted by: 914Sixer Oct 6 2016, 01:38 PM

Did you REPLACE the wire from the sender to the engine shelf?? If not the high joints in the brittle wire will drive you crazy.

Posted by: pbanders Oct 6 2016, 01:53 PM

I had an oil pressure gauge on my first motor, a 2.2 L built by Garretson's. Watching the gauge drove me insane. When I converted to a 2 L D-Jet, I got rid of the gauge and depended only in the "change engine" light, aka the oil pressure idiot light. That was 31 years ago, I've never regretted the decision.

Posted by: cuddyk Oct 6 2016, 02:05 PM

I just solved a similar problem with my gauge by replacing the ground wire (my sender is at the end of a remote block).

Posted by: Steve Oct 6 2016, 06:59 PM

Do you have a heavy duty pump or stock pump? I think I ran a Melling? HD pump on my 2.4 four. Otherwise throw an ohm meter on the wiring and trouble shoot it.

Posted by: ejm Oct 6 2016, 07:23 PM

If you are using a grease gun or paint ball gun hose to remote mount the pressure sender replace it with something made to handle hot oil. I've seen grease gun hoses swell up internally and cause erratic readings.

Posted by: cuddyk Oct 6 2016, 09:44 PM

I'm using this...

http://www.42draftdesigns.com/vw-audi-oil-pressure-relocation-kit/

Great kit!

Posted by: michael7810 Oct 7 2016, 06:20 AM

That kit looks nice. Can you post a pic of where you mounted the block?
Thanks

Posted by: cuddyk Oct 9 2016, 10:25 AM

Here ya go. I'm running dual carbs. And the piece behind the block is a baffled oil catch.

Posted by: jim_hoyland Oct 9 2016, 10:52 AM

Nice set up - thanks for sharing; been looking for something like this....

How is it attached to the fan housing...?

Posted by: cuddyk Oct 9 2016, 11:04 AM

The PO fabricated a bracket made from L-stock that uses existing holes (I believe for the FI). Before I switched to the tangerine cable linkage it also supported the throttle cable.

Posted by: malcolm2 Oct 10 2016, 09:16 AM

I assume that sender only has 1 wire connection...? Couldn't you buy the sender with 2, one for the green light and one for the gauge?

what is the benefit to including the OEM type oil light sender?

Posted by: rgalla9146 Oct 10 2016, 09:54 AM

I'd try an old fashion mechanical gauge, one that operates using a thin nylon tube from sender to gauge. Cheap and dependable.

Posted by: Jonathan Livesay Oct 10 2016, 09:54 AM

His looks like the 2 pole one to me.

Posted by: malcolm2 Oct 10 2016, 10:05 AM

maybe, but why does he use the OEM sender too? anyone see a benefit to having the OEM sender to light the light? I have a 2 pole and it seems to work the green OEM light and the VDO gauge just fine. Looking for a picture of mine....

Posted by: cuddyk Oct 10 2016, 10:21 AM

Hi guys,

I use the OEM light sender because it trips at a lower PSI than the newer VDO sender (which runs my temp gauge). Mine has two poles, but hooking the light to the other pole caused the oil light to go on more frequently at idle. The remote block had an available port, so I elected to use it. FYI, it was engineered with that in mind (says so in the instructions).

Posted by: malcolm2 Oct 10 2016, 10:45 AM

I have noticed the same thing happening to me this summer. I was thinking that your rig might be the way to go.

So with this kit, the hose threads into the block with no bushing? I'll have to do some checking, but I used a paint ball gun hose and it threaded right in. I added a mechanical gauge (for viewing in the engine comp. and double checking the VDO )with a T, so this would work as an X. 1 in and 3 out....

Posted by: cuddyk Oct 10 2016, 12:06 PM

The port on the engine is M10, which is close but not exactly the same threading as NPT. There's been lots of disagreement on using an NPT hose and the case to me is pretty clear that it's best to stick with M10. The hose in this kit is designed for type IV engines...so the hose is natively M10. No adapter or bushing needed. The remote block has both NPT and M10 ports, which allow you to mix senders as needed.

Posted by: malcolm2 Oct 10 2016, 05:57 PM

Ended up just taking a picture.

Posted by: cuddyk Oct 10 2016, 07:51 PM

If your mechanical gauge is M10 (or NPT with M10 adapter), you could put it, plus the OEM sensor, and a modern sender on that single remote block. I'm not a huge fan of the paintball hose. Heard stories of them bursting as the heat from our oil can weaken the tube...