Low oil Pressure on Startup

[MattyJoe]

I've noticed lately that when I start my truck up my oil gauge on the instrument cluster registers nothing. Once I get the truck warmed up and drive it around a few minutes, the gauge reads normal pressure. It takes longer to reach this point in colder weather. I have not noticed any abnormal increase or decrease in the temperature, and everything else seems fine. The motor is high mileage 197K. I'm clueless. Any ideas?

Thanks,
Matt

 

[rurouni20xx]

get a mechanical guage and check the oil pressure, may be a bad sending unit switch or a lil corrosion in the wire causing extra resistance making the gage not register. if you dont have oil pressure after having it checked then you have a serious problem that should be addressed immediately or you could have a dead engine and 198k.

 

[MattyJoe]

Ouch, thanks. I'll check that pressure asap.

 

[Rearanger]

Oil grade?

 

[MattyJoe]

As always 5W30 not full synthetic.

 

[Wicked_Sludge]

its *probably* just a bad sending unit. they are known to be a little flakey. but as rurouni20xx said, varify your pressure right away with a mechanical gauge, because if it is an actual oil pressure problem you could have a very dead engine very soon.

 

[cr_the_machinist]

It's a bad sending unit. My 4.0 did the same thing. Popped a new one in and problem solved!

 

[Wicked_Sludge]

its *probably* a bad sending unit. dont make assumtions on other peoples doller

 

[cr_the_machinist]

My bad..... I'll send him $20 via paypal.

 

[Wicked_Sludge]

were are you finding running long blocks for $20?

 

[rurouni20xx]

thats my question right there (+1)

 

[betomonroy]

+2

 

[nedirtbikr]

Had the same thing on my '99. Replace the sending unit last week and all is good. Took about 15 minutes and the sending unit was $9.

 

[ati190]

Install a mechanical oil pressure guage, or at least test your pressure with one, and remove it. Takes about 15 mins and you will know for sure. They run between 10-15$ depending where you buy it from. Make sure it's a mechanical guage and not electric.

 

[Toms01PSD]

I have the same damn problem on mine and its only got 180k.