Cat Diesel engine temp

Your coolant temperature should NOT rise about thermostatic control on minor grades.

Have you cleaned the FRONT of your CAC?

Have you checked the tension on the water pump belt?

How old are the thermostats (Caterpillar calls them regulators)?

What coach do you have?

It is a Damon Ultrasport 1999 year.

I would highly recommend you buy a Scangauge since you have idiot gauges. This will give you your exact temperatures and a lot of other information.

It should work on your MH, but since it's a 1999, make sure it has the OBDII Port before buying. It's well worth the $160.

Amazon

Bill

Thanks Bill. I just looked around under the dash and left firewall around the fuse panel and no luck finding a obd port. Maybe someone out there knows if a 1998 model has obd ?

Sorry I ment 1999 year

I concur with Wolfe. My 05 doesn’t budge above normal whether it’s on flat road or up 7% grades in West Virginia.

I have a different CAT than you do (a 3126E 330 HP version 2003). I tow a 5,000 lb Nissan XTerra behind a 36' Safari Cheetah RV. Now have 55,000 miles on the RV and live in Reno, NV where everything starts at 4,500' and goes up from there. Many, many times I have climbed 0ver 8,000+' in the summer and my temp gauge never moves over normal range. You need to start by checking your thermostats, belt tension and the water pump and its belts as well as possibly draining and replacing your radiator fluid. Remember, most CAT and diesel engines also use the fluid to cool the tranny. Try washing the radiator, charge air cooler and tranny cooler. I wash mine after every trip to clear out the road junk etc. Your CAT should not get hot pulling your load.

Newer Cats run hotter than the older ones. Lets see, 1999 you have EGR and some emissions hardware. Keep the CAC and radiator clean and forget about it.

You have a Freightliner chassis, and depending upon the build date of the chassis, you may have the old one piece dash gauges or could have the system III with separate round gauges. If you have the separate round gauges, then you can estimate the temp fairly accurately.

Freightliner Service Bulletin 54-12 outlines this with a picture of the temp gauge with related calibrated temps. You can find SB 54-12 here:

Freightliner SB 54-12

The temp gauge is pictured on page 5. The remainder of SB 54-12 is excellent information about how the instruments and the vehicle data computer work.

On the 2000 model chassis, the engine will lose power to protect itself at 220 degrees. I'm not sure about your chassis.

We had the 2000 year Freightliner chassis with the cat 330. The front of the CAC must be cleaned frequently to keep the temps in range. The slobber tube also must be extended behind the radiator to reduce fouling.

Keeping the rpm's up on the hills will help. The shift points on the allison transmission do not keep the water pump spinning fast enough to keep the temps down on a hard pull.

If you change the thermostats (regulators - 2) be aware that the early engines came with 180 degree thermostats but my cat dealer sold me 190 degree regulators when I changed the coolant & thermostats.

Fred

fcooper wrote:
If you change the thermostats (regulators - 2) be aware that the early engines came with 180 degree thermostats but my cat dealer sold me 190 degree regulators when I changed the coolant & thermostats.

Fred

Thermostats (regulators) should be sold for your specific engine serial number. Would be quite surprised that it came from Caterpillar with a 180 and parts book now calls for a 190. Wonder if someone changed them or if they actually were OE.

Just my GUESS, but 190 sounds more like the correct one.