No oil pressure/cold mornings

[jobar]

Heys guys, like the title says I have no oil pressure on cold mornings. When I crank my truck up in the mornings to let it warm up, I have no oil pressure for the first 1.5-2 minutes of idle. Then I get oil pressure. No problems after it warms up. No valve train noise. I have already replaced the cam sensor synchronizer. Bad guage maybe? Or is there something more serious I need to be looking at? I know this question has been asked a lot but I didnt want to thread jack anyone.

 

[martin]

it's more than likely a sticky pressure switch. It's highly unlikely a motor would run without oil pressure for a couple of minutes without protesting quite loudly.

 

[adsm08]

Yeah, you would know about it if you actually had no pressure for that long. Once an engine gets o many miles it will clatter pretty bad even from the first start after an oil change. No way you are running with no pressure for two minutes and not hearing about it.

 

[Rearanger]

no oil pressure on cold mornings.

How cold and what grade of oil you using?

 

[jobar]

That's what I figured. I guess I will replace the switch and see what happens.

Rearanger- 10w-30, temperature has been in the low 30s at night.

 

[Rearanger]

10w-30, temperature has been in the low 30s at night.

Not out of line. Oil gets thicker with use and thick oil can prevent flow (pressure) from getting to oil switch - but I'd have to know the oil circuit to see if that's a possibility.

When you remove the switch you can turn the engine over without starting to blow out any obstruction that may be preventing pressure reaching the switch. I would not recommend T-tape, but Permatex High Performance thread sealer.

 

[4.0B2]

or just put a manual gauge on it and have true readings!

 

[SenorNoob]

Obviously the gauge/light isn't right if you don't hear it, but the oil used makes a huge difference. I put 10w30 in an 88 2.3 thinking it's probably worn enough that thicker oil would be good, turned out that when the temp was below 40F it took about 1 min for the oil to reach the top of the engine. I definitely heard it. 75 miles and did an oil change back to 5w30.

 

[jobar]

I haven't had any problems with the 10w-30. At least not that I can hear.

4.0B2-Taking your advice and using a bad gauge as an excuse to install manual ones. Headed up to summit racing today to get a pillar mount and some gauges.

 

[ab_slack]

Had this same issue last winter on a 99 ranger with 3.0. Having had the oil pump fail the previous year while driving causing sever damage, we shut it down immediately when we saw zero pressure. Sometimes we saw it took just 4 or 5 seconds for pressure to appear, but if longer than that we turned it off.

The gauge in the dash is phony hooked up to a switch to show mid scale. We plumbed in a T and put a real gauge to read as well the pressure switch. After doing the work we found pressure was fine. Also, from re-plumbing the switch or pulling the connector and putting it back on the pressure switch started working fine again.

I agree you probably don't have zero pressure. Easiest thing is to pull connection from pressure switch and put back on and see if exercising the contact brings it back. Even better, pull connector off switch and spray some contact cleaner before putting back. Otherwise it is probably the switch (or gunk inside) keeping the switch from activating.