Engine/Transmission (1994 - 1998) Oil Pressure?

[surfbeetle]

This morning it was colder than usual, in the 40's. My truck has 216,xxx miles on it and has a Napa brand oil pressure sending unit on it. I broke the factory sender many years ago when doing the vacuum pump repair. Now on to the question, I started the truck, let it idle for a minute and then started driving the 1/2 mile to the freeway. As I was accelerating, I noticed that the oil pressure went down to Zero and stayed there. I stopped accelerating and let it idle in neutral and the pressure gauge went back up to 40psi. Then I got on the freeway for a couple of miles to my offramp and it was fine. Once I got onto surface streets for the rest of my commute, I continued to notice that if I accelerated hard, the oil pressure went down and if I went easy on it, the oil pressure would stay around 40.



I am due for an oil change this week and was planning on doing that this weekend also I don't know exactly how low the oil level currently is, I'll check that at lunch time. Also, my commute is a total of 7 miles and takes me less than 15 minutes. Normally when the weather gets cooler, I start using the engine block heater because if I don't the cab heat never happens until I get to work. I'm just wondering if the oil was too cold the whole way and was triggering a pressure relief? The oil I use is Shell Rotella. I will see how the oil pressure does on the way home when it's 80°. Any ideas?

Thanks

 

[AH64ID]

Colder oil should be running near 70+ psi at 2000 rpms.

I would verify your level, and then your sender.

 

[surfbeetle]

I just went out and checked the oil level, it's in the safe range on the dipstick so that's not it. It's still time for an oil change so I'll probably do that this afternoon. Other than replacing the oil pressure sending unit, anyone have a way to test it? Also do oil pumps on these ever need changing or wear out?

 

[GAmes]

Next to the turbo oil line on top of your filter is a plug. You can plumb a manual pressure gauge there. I have never heard of a 5. 9 oil pump failure. When my engine was rebuilt we didn't buy a new pump either.

 

[Bob4x4]

Both the oil pump and the bearings are very robust on the Ctd,oil senders not so much

 

[surfbeetle]

Thank you for the replies. On the way home, the gauge had pressure the entire way, but nothing over 40 psi on the gauge. Ambient air temps were in the mid 80's. So I'm going to get a sender and install it. I called Cummin's Cal Pacific in El Cajon, they said that they don't carry the sender, that it was a Dodge item. I called Pep Boys, they would have to order one but it's $80, ouch! Napa said that they carry a Chinese one for 26 and an American made one for 40. I'll be buying the American sender from Napa. With Wednesday being Halloween, I don't see the sender getting installed until Thursday or Friday. I'll report back what happens.
Thanks again
Craig

 

[Moe]

Check the bottom of the vacuum pump to see if it is cracked or broken. I lost all my oil pressure and oil because the vac pump lost a large part of the casing. According to Gould Parts, its a common occurance if you have around 180,000 miles or so. Good Luck, Moe.

 

[GAmes]

surfbeetle, in case you haven't ordered it yet, Genos has the Cummins sender for about $37 IIRC.

 

[surfbeetle]

Moe,
That's definitely something to check but I'm not losing oil, good suggestion, thank you. Games, I called Cummins in El Cajon and was told that the sender was not a Cummins part so I didnt' even thing to check Geno's, my mistake. Yesterday on the way home, I went to Napa and bought their $40. 00 American made sender yesterday so maybe it's the same one and since it's an electrical part, I can't return it. With the AAA discount at Napa, it was $36. 00. I'll get it installed today or tomorrow and report back.

 

[budnate]

Surf handle that pos like its fine china... . been through 3 of them in 6 months, black plastic cap falls off and wrecks the whole deal, no putting it back together either. biggest pos i have seen lately and at 45 bucks a pop highway robbery! can you tell i am cranky, lol.

 

[GAmes]

I went thru a couple after markets from CarQuest rather quickly after breaking the original. They both started leaking out the connector hole. I bought one from Genos, and it has held up well.

 

[Bob4x4]

Cmons cal pacific el cajon has not been the same since they shut down the rv shop

 

[surfbeetle]

Bud and Gary, I'll be careful, hopefully all will be okay. You know I can't return electrical, but if it comes apart, I would think that there'd be a better chance to. Bob, I had no idea that they closed the RV Shop. I used to like the older gentleman in the parts shop before the remodel. If I have issues with this one, I'll have to go with Geno's. Just that right now the timing with the east coast storns and all I figured a local purchase was a better bet.

 

[budnate]

I must have a hex on me then, 1 Geno and 2 Napa units... moved the truck tonight first time in 2 weeks... . guess what oil press zero and the truck chiming gauge problem... . all the ones i have been getting if you even look funny at the plastic cap over the electrical it falls off and when it does it takes the wiring at the top of the unit all screwy with it and kills it dead.....