I'm helping a friend work out some bugs on his 1990 Regency. It has a 220 Cummins with a radiator mounted in the front. The temp gage goes to almost 220 on any long climb and it doesn't matter if something is being towed. Does anyone else have this configuration with an overheating problem? We just changed the themostats and it didn't make any difference.

Ron

I've had more than one rig, including my current Barth, that showed high temps on long climbs.

With a proper antifreeze mixture, and a proper pressure cap on the cooling system, you're not going to boil at 220 degrees.

If you're not losing coolant, and the gauge returns to normal on a level road, you're probably OK.

The time to worry is when you're losing coolant and/or the gauge continues to climb past 220.

There's a good reason why your radiator pressure cap warns you not to open it when the engine is hot. Release that pressure on any modern engine at normal operating temperatures, and it will boil over on you.

I can't address Cummings engines as I have no specific experience with them.

On the other hand, basic mechanicals being what they are, I would suggest a couple things to your friend.

One would be to back flush the engine to make sure a deposit is not blocking a passage, making a hot spot.

Second, replace your present coolant with a fresh 50/50 mix and add some "Redline Water Wetter" to the mix.

Water Wetter is a surficant that breaks up surface tension and improves heat transfer in your radiator.

The other option (expensive) is to change to an inhibited propylene glycol system.

This substance is a stand alone coolant that does NOT use water at all. The coolant has a boiling point of 370 degrees without pressure! Therefore your radiator and hoses operate without the normal 10-15 PSI that water/glycol mixtures

It IS expensive, but because there is no vapor, it increases the efficiency of your cooling system, and does not contribute to rust or bearing failures since it has no water and therefore electrolysis is negated.

Here is a link:

http://www.evanscooling.com/index2.html

This probably doesn't pertain to the cumins, but we just finished a trip accross the country from Florida to California in our 31 ft 460. On long climbs our engine and tranny always seemed to experience higher temps 220+ and 275-300 respectively. The worst was driving through the Mojave Desert at around 4:00 pm in the afternoon. The worst of conditions: extremely hot and long steady climbs. The temperatures pushed to 240-250 degrees and 300+. Scarey !! I actually pulled over at one point and waited for the sun to go down and only drove when I could take advantage of the morning or late evening outside temperatures. Once we got through that horrid desert the engine and tranny temps leveled back down and ran extremely cool for the remeinder of the trip.
I always kept a watchful eye on my coolant levels and ran a cooling fan mounted on the front of the AC condensor. Seventy five dollars from Autozone.


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Jack and Daiva
1988 Barth Regal

Golly, Jack, that is awful hot. Did you do synthetic fluid before the trip?
In any case, sounds like you need a bigger tranny cooler and a fluid change.

Out of curiousity, may I ask what grade it was that caused all the heat?

No Bill I had contemplated using the synthetic fluid as you suggested, but we were on somewhat of a budget and I thought we could chance it and make due with what we had. I did speak to a tranny man at Cottman over the phone and he said that as long as our fluid was still a redish color(as opposed to tan) we were in good shape. And he said that our particular tranny should be able to tolerate around 275 degrees before fluid break down. I think ours is a C-6 or C-4. I don't remember which. We're not moving for a while but I have yet to pull the dog house cover and check the fluid color. I did check it around mid-trip and it was fine. Have not checked it since the Mojave Drive though. Comments ?
The grades varied throughout the trip. The temperatures were actually caused by a variety of factors. Outside temperatures, wind velocity against the coach, and the length of the grade. I should also mention that we were weighed to the max-just at gwvrw which is 18000 lbs for our coach and pulling a Mazda, Miata. Honestly though the temps seem to run about the same whether we were pulling the car or not. The short steep grades weren't as much of a problem. I learned as we traveled that it was best to maintain at least 65-70 mph through mountainous or hilly country so as to take advantage of our weight and momentuum and velocity going up the hills. The engine and tranny both ran cooler and I didn't bury the vacuum gauge needle as often. The long constant grades were the worst, especially in the hotter areas like the Mojave. Our speed would dwindle down to 45 mph with the gas pedal floored, and engine and tranny temps would soar. Our next Barth will be a diesel.
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Jack and Daiva
1988 Barth Regal

[This message has been edited by brandman (edited June 24, 2004).]

[This message has been edited by brandman (edited June 24, 2004).]

[This message has been edited by brandman (edited June 24, 2004).]

If you were reading 275 at the pan, the fluid coming out of the torque converter was much hotter, by far. I would really recommend a fluid change and a bigger cooler. 250 is a little hot for the engine, too. Red Line Water Wetter can help that. Was your fan roaring like a P47 when the engine got hot?

A little more like a P-57. How does that fan operate ? I didn't hear it all the time. Does it only engage when the engine reaches a certain temperature. I was always under the impression that the fan ran all of the time the engine was running.

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Jack and Daiva
1988 Barth Regal

[This message has been edited by brandman (edited June 26, 2004).]

This applies to front-engine gassers. I don't know about diesel pushers.

Most fans have a thermostatic clutch that engages around 210-220 degrees. They turn whenever the engine is running, but they're just idling from the drag of the disengaged clutch.

If you're climbing a hill in second, and the temp hits 220 or so, you should get that P-47 roar that Bill talks about.

They do go bad, and should be checked occasionally. You can do this yourself by running the engine up to normal operating temperature, shutting it off, and turning the fan blades by hand. There should be little resistance.

Then block off the radiator with cardboard or a blanket, and run the engine at a fast idle (1200-1500 rpm) until you see about 230 on the temp gauge. Shut it down and try turning the fan again (PROTECT YOUR HANDS WITH GOOD GLOVES OR A RAG, THAT SUCKER IS GOING TO BE HOT.)

It should now be hard to turn the blades. If they turn easily, as before, you need a new clutch.

I had my fan clutch go bad at the beginning of the trip. It turned itself on going over the mountains in Vermont, and then stayed on. It sucked up more power than I could give up and caused the fan belts to scream. I really was limited to about 50 mph, so actually removed it in a rest stop in the rain, and then went on my way. Eventually replacing it in an Advance Auto parts store parking lot someplace in NY State. All part of the adventure.

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On the road.

89 Barth Regal 32
Runs like a Deere
New Hampshire