jason89i

How long should it take for oil pressure to build after sitting for a week?

Here is what I have noticed:
Hot start-up (parked less than 2 hrs.): 1/2 second max.
Warm start-up (parked for 3-8 hrs.): 1 second.
Cold start-up (parked overnight.): 3-5 seconds.
Cold start-up (parked a few days.): 5-7 seconds.
Cold start-up (parked 7 days.): 10+ seconds.

Passes oil analysis with flying colors after 5-6k miles.
No smoke at start-up. 1/2 qt oil consumption after 5k miles.

This seems like an long period for the motor to build oil pressure. Is this common? Do these motors have an oil drain back valve?

Thanks, Jason

Quadcammer

shouldn't take that long.

lazy sending unit?

Seamless

Mine spikes up before I release the key regardless of temp. Possible pressure sensor issue?

P-daddy

Should be immediate, hot or cold start.

nine9six

...And if its not? Is this a bad sending unit?

jason89i

I like to know what's wrong (and why) before I "throw parts" at it.

Anyone experience a consistently lazy gauge?

I think I will test with a mechanical gauge for more insight. Don't feel like spending ~$100 on speculation.

cheers, Jason

nine9six

Since you like to know what's wrong (and why) before "throw parts" at it; I am curious, and in the same vein of the lazy gauge; did you search on "oil sending unit" ?

Awww, come on....That was at least a little funny

TMc993

How long has this condition existed?

Any noise from the engine on cold start-up that wasn't there before this started?

What weight oil?

EMBPilot

yeah you know... since you asked on the internet and all.....

axl911

Does your gauge twitches and move to the 0 position when you turn the key to "on" without starting?

If so, that would mean the initial zero resistance value in the sensor is still good and/or the wiring to the ECU is good.

Next step would be (on a cold car) to use a hair dryer or heat gun to heat up the sensor itself. Since you mentioned it moves faster on a hot car. Once heated up, start the car to see if it behaves the same. If it takes the 3-5 seconds, then it's not the sensor.

But best bet is to put a mechanical gauge on it and see what's going on.

I would pee in my pants starting the engine and not seeing oil pressure for 10 seconds. When changing the oil, I crank my engine with the fuel pump disconnected to prime the oil. And I still clench my teeth until the oil pressure gauge start to twitches.

jscott82

Since mine sits for long periods between starts (>7 days) I pull the DME relay on initial start and crank until there is oil pressure. Then reinstall and start the car.

I don't know that that really necessary.. but it makes me feel better...

jason89i

zero noise.
m1 15w50.
coldest at 60degf

Owned the car since January. It came to me with a loose connection where the gauge would bounce. Dropped the motor in February for maintenance. Cleaned, tightened and used dielectric on all connectors. Never bounces now.

I just noticed this two weeks ago. (not to say it has not been going on for awhile.)

I think your on to something.

just went down to the car (its only been sitting for an hour.)
from "off"
turn key to "acc"..... needle does not move.
turn key to "on" ...... needle does not move for 3 seconds, then jumps up to "0".
Immediately re-try "on"....... needle immediately jumps to "0". no laziness.

I too run the starter to build pressure after an oil change. yes, I just about pee'd my pants when I saw no oil pressure for 10 seconds. I had an accusump on my last car, so I was a bit more religious on watching the gauge at start up.

yea, that is funny. Funny like me spending 3 hours here combing through inconclusive posts. Maybe I should ask what is the best oil? Now that would be funny!

Thanks all. I think we may be on to something.

J

jason89i

Does anyone have the wiring diagram for the cluster?

I did some more testing. Good oil pressure immediately at startup. I believe it is a power / grounding issue... possibly within the gauge. I opened the gauge, all connectors were cleaned and properly seated.

You are definitely on to something here. However the oil pressure and temp gauge seem to "jump" to "0" at the exact same time, with the same delay.
Do the oil pressure AND temperature gauge have a common power / ground?

After car has been sitting for awhile....

Key is "off."
Oil PRESS and oil TEMP needle are at -1. (below the normal "0" position.)

Turn key to "acc".
Oil PRESS and oil TEMP needle remain at -1.
Both needles will simultaneously jump to "0" after 5-10 seconds.
OR both needles will simultaneously jump to "0" exactly when I tap the gauge.

Anyone with a wiring diagram?

Thanks, Jason

nine9six

Jason,
My apologies...But it really didn't take you 3 hrs looking through these few replies, did it?

I hope you get things sorted out soon and take the time to post your results of your findings.
Cheers!

jason89i

Certainly no apologies necessary. I took it with humor.

Not 3 hours on these replies. But, I must admit, I actually spent hours using the search function for: sending unit, oil pressure ohms, etc. Nothing but poor sending units and zddp oil debates.

I will definitely post the remedy when I find it. It's the least I can do to help the next guy. This place is great.

cheers, Jason