uglyscout

What should my normal coolant operating temp be on my 1995 bone stock 2wd, auto, 12 valve?

Air temps have been around 50 - 60 degrees.

Stock gauge is reading about 160-170 degrees at crusing speed (65-70) and never goes above that.

I've had it for a whopping 6 days so I am very new to the whole 'diesel' thing.

I have no other aftermarket gauges to clue me in on engine operating conditions.

Thanks.

JKM

The operating temperature will never go much above that until you hook something big and heavy on the back , and pull it up a long steep hill. The cooling system on these trucks is very large , and made for when the engine is working at 100% engine load.

I have pulled some medium sized trailers with my truck , up some hills where i could hardly hold 60-65 mph even after my power upgrades , and i have still not got mine hot enough to make the fan come on.

somis13

I live in southern california and we have steady inclines here and I pull em daily. my truck tows 6000 lbs. plus, on these grades at speeds of 45mph sometimes at w.o.t. and mine never goes over 190*.

Willdsl

Not to highjack thread but my temp, unloaded used to go to 190 and back to 140 now it goes up to around 210 and back to 160. Should I be worried? or could something have just gone out of wack/adjustment. Thanks for any idea's.

JKM

Do you have an infared heat gun? check to see exactly how hot/cold it is getting. If indeed it is getting up to 210 degrees , you could change out your thermostat, it might be beginning to stick...

I would question your gauge after that , it may not be working properly. Pull the wire off of the sending unit ( it is located WAYYYYYYYYYYY at the back of the head on the drivers side) and ground the wire with the key on. If the gauge goes full field (far to the right) with the wire grounded , the gauge itself is fine.

If that checks out, then your next step would be to replace the sender , i don't think that it is too spendy.

infidel

Willdsl, your radiator could be plugged up with bugs.

fschiola

Also check for debris between the intercooler and radiator.

Willdsl

Thank you very much for all the advice. JKM, No infared heat gun, been thinking of getting one though. Will check gauge and sending unit. Infidel, Fchiola, I have not cleaned my radiator or intercooler since I bought it 2 years ago. Any good way to clean them without removeing them other than water sprayed through them? Thought about this but wary of a pressure washer through the radiator. Would Simple Green and a water hose be enough? I'm wary of a scrubbrush also.

SoTexRattler

Willdsl: The cycling up to 210* points to a sticking T-stat if you've still got coolant and airflow. My old stat used to normally cycle fast and shallow between 185-190 down to 160. when the 'stat began sticking, it'd briefly dip downwards and then start climbing to 200-210+ and would get gradually higher and higher while cycling slower and slower. Finally, it decided to never open up one afternoon headed home from work..

Easy to change... Just get the right one and not the colder "superceded" stat from DC. Go to a Cummins shop and get the exact one. Your wallet will thank you .


K.

Willdsl

Thanks SoTex, Sounds like a good cleaning and thermostat and things should be good again. Found other posts on correct PN and have a "Cummins" shop nearby.

TravisDj

Right now my temp gauge doesn't get above 140*. The highest I have seen it get is 160* I believe. It has been cool out since I bought the truck. I was just worried my gauge was messed up and the motor might be getting Too hot. From what I've read it all seems normal.

xtoyz17

Seems so. On my last highway trip doing about 70mph My motor stayed halfway between 190 and 140 the entire trip and never moved.

macattack_ga

so is there a consensus on the optimal operating temps? I understand there is a 195 t-stat available for big block gassers that will fit the CTD... is that too hot?

I just pulled a ~10,000 24' tall enclosed trailer 1200 miles and my temps hardly got over 160f. Personelly i don't think this is warm enough.

running empty my guage will go back and forth between 140 and 190.

stock '97 4x4 dually 3.55 clubcab ~130k
egt guage

infidel

You worry about nothing

Cummins says,

THE COOLING SYSTEM USED ON THE CUMMINS DIESEL ENGINE EQUIPPED VEHICLES PROVIDES THE CAPACITY AND PROTECTION OF THE HIGHER GVWR AND GCWR RATINGS AVAILABLE ON THESE VEHICLES. OWNERS SHOULD BE ADVISED OF THE NORMAL SLOWER WARM UP AND LOWER ENGINE OPERATING TEMPERATURES ASSOCIATED WITH DIESEL ENGINES.

THE COOLANT TEMPERATURE GAUGE WILL FLUCTUATE ON DIESEL ENGINE EQUIPPED VEHICLES. IT IS INFLUENCED BY VEHICLE LOAD, OUTSIDE AMBIENT TEMPERATURE AND EXTENDED IDLE TIME. THIS FUNCTION IS CONSIDERED NORMAL
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CarlJensen

I have a wetting agent in mine and it slows down the fluctuation a lot. Noticed it right after I put it in. Also seems to run cooler under load, guess that's what it supposed to do.