Oil Pressure help from the gang.

[Idually]

Hey guys. I have an opportunity to get a second truck. It's 1991 Non IC, auto, 4x4 w/ approx 200k. I went to see it for a short time today... Sounds healthy, idled great. The owner drove it 10 or so miles to get to me, so it was warm. I peeked into the cab to look at the guages and noticed no oil pressure. I asked the owner if the guage was not working. He said yes, got in, gave it some gas and sure enough the guage started to rise. after 10-15sec of a bit of gas no gauges, but I'm thinking 1400-1500 rpm, not WOT, the pressure was about where mine reads cruising down the hwy. He let off of the idle abit and held, the pressure started to drop a bit and then just fell off. I'm concerned, for obvious reasons. I remember a thread about an oil pressure switch on the CTD, so I'm wondering if this could be the problem?

How does this switch work? Fairly easy to install a new one? Sending unit?(I wouldn't think it would act like that) Is there an easy/accurate test for oil pressure? See where I'm going?

I like the truck over all, but oil pressure is not really something that I'm in the mood to tangle with. Is it worth the risk? What do you guys think? Any isight would be greatly appreciated. This is an important purchase for me.



Thanks in advance!

Andrew

 

[boatpuller]

I would see about buying an oil pressure sending unit for the truck and installing it, sounds like everything is probably ok if the engine isn't making any bad noises, and the senders have been known to fail that way, it would be worth the money to hook up a new sender or a mchanical gauge to really know the condition of the engine before you purchased it unless he's giving you such a screaming deal that the money for a rebuild is available if necesary.

Just my $. 02

Good Luck,



Caleb

 

[Idually]

He has been driving this truck quite abit, from what he says. No troubles. I couldn't drive it today, but will. Replacing the sending unit is a great idea and probably the most in expensive. The pressure was good with thottle, so that made me feel better, but no, a rebuild is NOT in the budget. Maybe in a year or two.



Thanks!

 

[TKingsbury]

A mechanical gauge would be best. If you have one, or know somebody with a gauge that isn't mounted in something, hook it up on top of the oil filter boss. It would take all of 5 mins to put it on, verify pressure, and remove it again.

Travis. .

 

[Idually]

"A mechanical gauge would be best... "



Agreed. Now to find one...



Andrew

 

[TKingsbury]

"A mechanical gauge would be best... "



Agreed. Now to find one...



Andrew

If you don't have any mechanical type friends who would have one on the shelf, just buy a cheapie at your local chain auto parts store and hook her up. If you think you're gonna buy the truck, you could get a good one and install it after puchase.

Travis. .

 

["Mad Max"]

Concur - only way to know for sure is having a gauge with numbers on it. Simple and cheap peace of mind. If pressure is good then it's probably a bad/dying factory sending unit.

- Max

 

[bgilbert]

It's 1991 Non IC, auto, 4x4 w/ approx 200k

Hmm sounds familiar, I recently left one like this in Colorado. What color? I really miss it too :{ .

 

[DSteimle]

happened to me

this just happened to me a couple weeks ago-on way home from work came to a stop sign and caught movement out the corner of my eye. looked down just in time to oil pressure gage on zero :--) . freaked out and shut it off. wife came and got me and we towed it home- i screwed a tee into side of block and ran a mech gage along with factory sender. mech gage at idle-30 psi-factory zero-replace sender and all ok at this time. try sender first and see what happens.



daryl

 

["Mad Max"]

Good catch Bill. Andrew, does it look like the one in this link? If so both Bill and I can vouch for it .



- Sam

PS - we're on for Saturday bud!



https://www.turbodieselregister.com/forums/showthread.php?t=125563

 

[Idually]

Thanks again, guys. I'm very close to nabbing this one. I will know for sure tomorrow.



Sam, Bill. I WISH!!!!. Nope... it's not that one. I should have jumped on that one a LONG time ago.



Again, I thank you guys! I will keep you informed.



Andrew

 

[BushWakr - RIP]

Man... . you guy's are SOOOO easy... ...

If you attended "church" a little more often you'd of heard the confession of a 92 CTD..... and I paraphrase here... ... ". . pastor, I have sinned... . " "... . I occasionally generate erroneous readings on my guages to keep the sleepy guy, who takes us for granted some times, from falling asleep... "...



Geezzzz..... you guy's need a school principal here... .



pb...

 

[DSteimle]

you're right

you are correct pb. i need some churchin up after an oil pressure gage at zero. the pucker effect is unreal. it is a comfort to know that my hand can find and turn the ignition key before my brain even reacts.



daryl

 

[RWWinslow]

Oil pressure sending units are notorious for dying on the early 91's . . . . . they are at a mounting point on the block where they can really vibrate - and they will behave exactly as described. I am on my second sending unit. Dodge dealer in PA looked up usage on this part and said it was very high for this installation - note that the sender is a Dodge component, not a Cummins part.

 

[paccool]

RW, not just the 91's! I had to replace the sender on my 93 recently. When I was having the head gasket problems I had a sudden drop in oil pressure on the dash gauge. Scared the crap outa me! Didn't go to zero but was way lower then it had been running and was floating around. Got a mechanical gauge and hooked it into the port on top of the oil filter mount and was relieved to see 80 PSI at 1500 RPM. Went to Dodge and got a sender, problem is gone. Gauge on the dash is reading higher than it ever has. BTW, I paid $36 for the unit. Sure I could have got it cheaper at NAPA but wanted to be sure I had the right one.



I noted that the original sender had a very tiny hole where the pressure entered the sender and the new one had a slot that was a much bigger opening. I suspect they have made a change due to the problems.

 

[Idually]

MINE!! Mine, MiNe, Mine! GOT IT! Did I say it's mine?



Stay tuned!!



You guys are the best!

 

["Mad Max"]

Sweet! So - you bringing it down tomorrow?? :-laf

- S

 

[Idually]

Sam. I want to, but it does need a bit of TLC. Brakes mostly. They are really bad. Drove it pretty hard for about forty miles on the hwy yesterday. Ran like a top. No overheating, no leaks. No too bad. Perfect for what I'm going to do to it!



Andrew



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