Community Forums

wa8yxm · 07-20-2012, 04:01 PM

First make sure you have a proper coolant, WATER alone, is not the proper coolant (Though it is good if you have no other choice) Antifreeze is also anti-boil Not everyone makes that clear. Water, is a most unique chemical in this respect.

If the radiator and the engine's coolant passages are all clean and coolant is flowing properly (Sounds like he may not have cleaned the engine, then again he might have), there are a number of things on the engine that can make it run hotter.

Plus it's very hot out which does not help.

Plus SLOW DOWN. For that vehicle you are pushing the limits a bit hard.

SteveLevin · 07-20-2012, 04:25 PM

Quote:

Originally Posted by Damon92

Ok so today we went to put new thermostat in. Before we did I got it on the interstate and drove it hard (70-75mph)

One thing to keep in mind... depending on the tires you have, their maximum continuous speed rating may only be 75mph. I know that's true of the 22.5" on my coach...I wouldn't want to cruise too close to that speed myself.

Steve

RSchleder · 07-22-2012, 07:38 AM

In the late 90's I owned a Gulfstream DP'er with the 190 hp Cummins. During that time we made several trips from Iowa to Ca towing a car hauler with my classic car loaded on it. The temp always hit the top level while going up mountains/steep hllls so I know exactly what you're talking about. I believe it's just the nature of the beast as the 5.9L engine is really working hard to pull that much weight up a incline. Probably the best you can do once you're sure the cooling system is up to snuff is to shift the tranny to a lower gear when going up an incline to allow the engine to operate at a higher RPM. This helped to a degree for me! Good luck.

Crabby Mike · 07-22-2012, 08:19 AM

Try to get a digital temperature gauge, which will show you your actual coolant temperature, not just "in the red." I don't know what your options may be with a '92, but a lot of folks on here like the Silverleaf, which I understand can output to a laptop. (I'm lucky, my '08 has digital readouts on the dash.)

Cummins can tell you what your temps should be, but I know my ISL 425 runs at 185-195 all the time -- that's its normal operating temperature. On long hot climbs I've seen 205 or so, and have been told not to worry.

Also, pay heed to the advice about downshifting. I'm able to let Allison take care of that for me, but I have 6 speeds to your 4, so mine is better able to stay in an optimum RPM range. You may well have to manually downshift to keep your revs high enough to keep the engine cool on climbs.

Damon92 · 07-22-2012, 08:50 PM

Good info. Its nice to hear from others that are towing with my setup. Thank you. Ive got the radiator out and I am taking it to shop first thing in the AM to get a quote for a recore. I found a brand new unit but it was $1100.00! I bought new hoses, thermostat, belts, filters. This thing should be good as new when i put radiator back in. I will keep everyone posted on my efforts. I would like a digital gauge but I would also like to keep stock look with a mechanical one with actual numbers. I just can't wait to start using this beast!
Brandon

JimM68 · 07-22-2012, 09:13 PM

Get that charge air cooler good and clean, too.
sounds like you're doing all the right stuff.

Damon92 · 07-23-2012, 04:22 PM

Is that the same thing as the intercooler? Or after cooler? I'm confused...does just air flow thru this? Also...the shop said they could recore it for 550. Can anyone tell me what all is attached or built in my radiator? I know a trans cooler but is there also a AC condenser? Thx

Damon92 · 07-23-2012, 04:31 PM

Here is a pic...What do ya think?

RSchleder · 07-23-2012, 04:40 PM

Someone mentioned a digital temp gauge. A few years ago I built/owned a 1929 Model A street rod that I installed a complete set of digital gauges. Perhaps that is the worst thing I did to that beautiful car, that temp gauge drove me nuts. I never thought that I'd be fixated on that dang gauge as it slowly,but surely, crawled upward with me shuddering at EVERY number on the gauge! Never again, sometimes, more info is not always good!!