alright i got a 98 12 valve 5 speed and after i have been on it for awhile and i come to a stop when i take off agian and the rpms just below idle the oil pressure drops to 0... after about 2 to 5 seconds it comes back to normal pressure but i dont know what to think.. it doesnt do it cold. AND it runs about 1/6 inch above the halfway mark on oil pressure gauge and i know my brothers never did that... HELP dont know what to do!!

 

hi
first look for fuel in the oil !

what oil are you running ?

get a mechinical gage on there now to get a accurate reading !

it may just be a sending unit , dont run it hard till you confirm psi or it could cost you big time !

 

i dont know what oil am running yet.. its a new truck to me and it was clean when i bought it but i will drain it tomorow.. what oil do you suggest?

 

hi
i use rotella t synthetic 5 w 40 wallmart 16.50 a gal easier winter starts and great for all year !

also use a napa gold filter <made by wix> 1507 i think or a fleetguard -
3894 stratopore , correct filters are VERY important in these engines!!!

check your old oil for fuel contamination , if your oil level is above full you may have a bad injector !

 

Both my dad and I run delo 400 15w-40 in our beasts engines. This is what we have always run and it works excellent. Anyone else run this out of curiousity?

 

We have it in bulk 500 gal containers, we still use the CI formula.

 

I still haven't found an answer I have been lookin for, but how can fuel from a bad injector get into the oil on a 12v, I know how it can on a 24v, but on a 12v there is no place that I can see you having to worry about fuel leaking into your oil. Can someone please explain this to me!

 

hi
a bad injector allowing too much fuel in the chamber washes the cyl wall and goes past the rings is my guess ?

 

I just ran into this with mine; easy fix in my case. The oil pressure sending unit goes bad! Mine did the exact same thing- just take your engine # to Cummins (there are a few different sending units) and give them about $40. It is located under your injection pump and the wire connection is a pain to get off. I think it is a 1 1/16 socket.

 

The others appear to got you covered on the pressure problem. I agree with oldblues...get a mechanical oil pressure gauge hooked up to see if it's the sending unit or if you need to look elsewhere for the problem.

As far as the oil and filter...I use Rotella T 15w-40 year round and have never had a problem with cold starting. Wally-World(Walmart) has it for $9/gal. I go to the local Dodge dealer and get my oil filter there...Mopar filter, probably made by fleetgaurd. It's usually about $12-$14. I think you can't go wrong with just about any oil/filter combination that is recommended here. A lot of knowledgable people here. The big thing is just follow the service schedule for oil changes regardless of the oil you use. It's every 6000 mi for oil and filter on a 12 valve, so, if you want to try a different oil sometime you know the intervals are reasonable.

 

thanks everybody. appreciate your help

 

I have a question?I was at the local ford dealer and asked about synthetic oil was told that most ford diesel guys use it asked the same thing at dodge dealer and way told most dodge guys don;t what gives?

 

Because the Cummins engine will outlive the Dodge body even without synthetic oil.
There are some avid supporters of synthetic oils for the CTD on here.

AlpineRAM