My brothers 99 auto 4x4s oil pressure gauge goes to zero pressure while driving along at speed, then back to 40+ then to zero again. It's full of oil and has 160,000 on the OD. Any suggestions would be appreciated, Also it runs fine, just like a Cummins should. Thanks

 

zeek:

It could possibly the oil sending unit to that gauge. That unit is mounted on the side of the block I believe on the drivers side. Mine has done the same thing on my 2002.

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John_P

 

What John said. Sending unit is toast.

You can see it here (# 22):

http://www.dodgeram.org/tech/dsl/mt_...l_sys_comp.htm

Generally, if you have enough oil in the crankcase - you have oil pressure.

 

thats what we were figuring, but you never know. It's better to be causious then sorry. Thanks for the quick response. E Zeller

 

Dr. Evil:

Hey buddy, thanks alot for the nice posting of that engine schematic!
Man, that image is so clear.

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zeek:

One thing I forgot to tell you. A Cummins Engine Technician advised me on my 2002 that the oil pressure gauge is NOT REALLY a true oil pressure gauge.
Apparently, the newer Dodge CTD 2nd Gen, 24 valve trucks (2001-2002) have an oil sending unit that is reading and sending a "signal only" from the sending unit to the gauge and IS NOT actually reading true oil pressure. Your truck may be different, I am not sure. My older 1996 Dodge CTD DOES read actual pressure as yours might. In my 2002 Dodge CTD I installed a REAL Isspro Oil Pressure Gauge and the readings between the in-dash Dodge gauge and my A-pillar Isspro Gauge are different all the time. The thought of not knowing what my REAL oil pressure was scared me! Especially with the way I drive and run my trucks!

I wanted to let you know about this in case you want to install another oil pressure gauge if yours is like mine.

Take care.

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John_P

 

Thanks John, It's a 99 so it would be same as yours? Might be a good idea and I'll let my Bro. know. My truck has both. Thanks for the reply. E Zeller..

 

zeek:

You are very welcome!

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John_P