strange and scary oil gremlin, temp drop to zero! Options

[iankarr]

Hi Guys,

Finally getting the 2056 running great and took it out for a 15 minute drive around the hood.

As I'm climbing a hill at about 3000rpm, I see the green light come on and I immediately lay off the gas. I check the VDO mechanical oil gauge and it's reading zero. Not sure if I imagined this part, but I could swear I heard a slight metal-on-metal friction sound in the engine for a few seconds. There was a line of cars behind me, and being on a hill, no real safe place to pull over, so I put it back in gear and gave it a little gas to get me to a safe place. The green light went out, the VDO gauge read 35 and all seemed well. Was able to drive the remaining 10 blocks home without incident and at normal pressure.

I checked the grounds on the gauges and all seems fine. The light sender and VDO sender are in different places, so little chance both grounds went bad at the same time.

I let the car cool down a bit and checked the oil...a quart low. I guess the slight drip from the taco plate and all the tuning and testing I've done used more than I thought.

Wouldn't it be weird for the oil pump to just stop and then start again? or could that possibly be a sign of a failing pump?

Or could it be something simple like driving up hill while a quart low on oil?

Def something I don't want to experience again!

Ideas welcome. Thanks!

[wndsrfr]

Are you running an oil cooler with a thermostat in the lines? Mine would momentarily go low when the t'stat switched and the oil was cold.....

[iankarr]

Thanks for the response. no t-stat. it's a stock oil setup. really strange

[somd914]

I've seen this happen in hard cornering, especially if low on oil, but going up a hill shouldn't cause this.

Based on your post I'm unclear if your gauge is mechanical or electrical? If electrical, I assume you are running a combined sensor for the low pressure light and pressure gauge? If so is there a hose between the sensor and engine? If there is a hose, check to see if the sensor is grounded since the hose can isolate it from engine ground. But I do not recall if a ground issue would drive readings high or low. I'm sure others will chime in soon...

[iankarr]

Thanks, Somd.

I'm running a 42 draft designs pressure relocation kit (link with details below). Really beautiful machined block with separate ports for the original sender and aftermarket VDO sender. (So, not a combined sender). My pressure gauge is electrical and the billet block is grounded to the engine. It's been rock solid to this point...and after the zero pressure blip...was fine again.

Another thought...is there an "official" rule on how much more oil the 2056 needs vs. the stock 2.0? I've always just put 4 full quarts in instead of 3.5. Is it possible that the "quart low" mark on the 2.0 dipstick is actually significantly lower in a 2056 engine? That might explain the pump having no oil to grab while going uphill?

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

[somd914]

Thanks, Somd.

I'm running a 42 draft designs pressure relocation kit (link with details below). Really beautiful machined block with separate ports for the original sender and aftermarket VDO sender. (So, not a combined sender). My pressure gauge is electrical and the billet block is grounded to the engine. It's been rock solid to this point...and after the zero pressure blip...was fine again.

Another thought...is there an "official" rule on how much more oil the 2056 needs vs. the stock 2.0? I've always just put 4 full quarts in instead of 3.5. Is it possible that the "quart low" mark on the 2.0 dipstick is actually significantly lower in a 2056 engine? That might explain the pump having no oil to grab while going uphill?

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

Nice relocation kit.

As for a 2056, that's what I'm running and just keep it full according the dipstick. Don't see a reason for more oil since the sump isn't changed or anything else that affects oil volume...

[r_towle]

I would suggest you look for major grounding locations
Tranny strap
Battery terminals
Fuse panel ground
Relay panel ground

Oil
With stock cooling and stock filtering, nothing has changed so your oil requirements should still be the same as stock

[iankarr]

Thanks Rich. Unfortunately (fortunately) All grounds check out fine.

Makes sense that the oil requirements would be the same.

I've topped the oil level off and will drive it around a bit tomorrow to see if all is well. For now I'm guessing the pump struggled a bit due to the low oil level and long, steep hill. Maybe wishful thinking...but that's the most logical explanation I can come up with for the sudden drop and just as sudden return to normal at the top of the hill.

If the pump was bad, I assume the noise would be super obvious, no?

Next oil change I HAVE to get that taco plate area dry. I thought replacing the o-ring this winter would do it, but nope. Ugh.

Somd - just noticed your signature. Ravenna green 2258? Love that color. And motor!

[r_towle]

Dump the oil through a coffee filter to see if you find anything.

[PancakePorsche]

+1 drain and inspect oil and sump. Do not run again till this is done. The mention of a noise no matter how insignificant usually translates to something. 35 PSI is too low. Oil pumps either work, or they don't work at all assuming oil level is correct. They do not stop and restart unless pick up is being uncovered. Possible spun bearing(s).

[iankarr]

Thanks Pancake and Rich. Will strain the oil and see. It's always something, isn't it?

If the oil pump needs to be replaced, is that something that can be done with the engine in the car? Or do I get another opportunity to use my Tangerine jack plate? Hoping the case halves don't need to come apart....

I'm still betting (hoping) on low oil level which caused the pump to pull dry for a few seconds. Will keep ya posted!

[ChrisFoley]

Make sure that extension hose isn't collapsed internally.
A quart low on a steep hill could cause short term pressure loss IMO.

[iankarr]

Thanks, Chris.

Probably not related, but I did install your relief valve upgrade over the winter. Any chance that could contribute?

[ChrisFoley]

I don't see any way either the stock or my relief valve could contribute to an anomaly such as you described.

[iankarr]

Thought so. Just considering everything that changed. Thanks Chris!

[914Mike]

...

Next oil change I HAVE to get that taco plate area dry. I thought replacing the o-ring this winter would do it, but nope. Ugh.

...

Do you have the copper washers on the bolts? (Same as a type 1 oil screen washer.)

BTW, has anyone ever seen a "taco plate" folded up by tightening the bolts? Mine won't do that as there is a flat surface it presses against.

Something to try after getting the copper sealing washers. If it still drips get some oil stop leak and coat the o-ring before assembly. I've been doing that to pushrod tube seals, and rarely get leaks even there. Makes them swell a bit...

[era vulgaris]

As someone else mentioned, 35psi at 3k rpm is too low. Fully warm you should be between 50-60 psi at cruising between 3k-4k rpm.
I pass by 35psi somewhere around 1500-2k rpm.

Is that psi typical for your engine?

[iankarr]

Honestly my attention wasn't very focused as this was happening and I was trying to stay safe without blowing up my motor (or thinking that i might blow up my motor). It's quite possible the pressure was 50psi...or my revs were lower. All I'm 100% sure of is that the gauge showed way more than zero (IMG:style_emoticons/default/wink.gif). Will check the scale against my memory and re-post.

[stugray]

My car has sucked an air bubble on the track on a long RH sweeper.
You could see it in the datalogger and the dash idiot light in the video.
At the point where the oil light comes on, you can hear a loud Click from the engine which I assume was the actual air bubble moving through the system.

It only did it for about one second, but if you sucked in more than one bubble's worth, I believe you would hear it as a 'racket' from the engine (kind of like water hammer effect in pipes).

[ChrisFoley]

As someone else mentioned, 35psi at 3k rpm is too low.

Baloney.
Standard old school rule of thumb was 10psi for every 1000 rpm.
I don't mind too much if it gets as low as 7psi for every 1000 rpm at peak oil temp.