How much does YOUR engine temperature fluctuate?

[univmd]

Newbie here and am wondering if it is normal for engine temperature on diesel pusher to fluctuate more than a car.

On my DP, the engine temp guage is divided into 4 quarters rather than having actual temperatures stamped on. The needle fluctuates between 1/2 and 3/4 on my DP. (On my car, the needle stays still in the center)

At 3/4, I can hear the radiator fan turn on until the needle goes back down to 1/2. The needle then climbs back up to 3/4 (over about 10 minutes) before the fan cycles on again. This is at 65 mph. Is this normal, how much does YOUR engine temp fluctuate-cycle?

With warm regards, James

[kenbob208]

Newbie here and am wondering if it is normal for engine temperature on diesel pusher to fluctuate more than a car.

On my DP, the engine temp guage is divided into 4 quarters rather than having actual temperatures stamped on. The needle fluctuates between 1/2 and 3/4 on my DP. (On my car, the needle stays still in the center)

At 3/4, I can hear the radiator fan turn on until the needle goes back down to 1/2. The needle then climbs back up to 3/4 (over about 10 minutes) before the fan cycles on again. This is at 65 mph. Is this normal, how much does YOUR engine temp fluctuate-cycle?

With warm regards, James

Engine temp on my DP stays at 190, highway or city does not matter.

[David Bott]

You can here the fan that is all the way in the back of the coach? :) (The radiator fan is on all the time I do think and is located behind the massive radiator. .

Actually I think the fan you are hearing is the A/C condenser fan that is located under the coach, center, just in front of the front tires. This will cycle on and off based on outside temp. It has a high pitch that drives me nuts. :)

With that said, diesel engines can move up and down in temp. They do not warm like gas engines. In fact, they really do not get hot at idle. (By hot I mean enough to produce heat at the vents.)

[univmd]

Yes I think I can hear the radiator fan. It is a very faint low roaring sound, in contrast to the cycling high pitched dash AC condensor fan that I know about:-) Maybe I can hear the radiator fan because I have a walk-in closet instead of a rear bath? Also maybe I have a different engine, Cummins 360. I guess my main question was whether your temp. guage needle fluctuates between the 1/2 and 3/4 mark while driving at 65 mph. Thank you for your replies.

[nuthut]

I have a Cat. Once it gets up to temperature the guage never moves. Up hill, down hill, whatever.

[GStream40]

Same here, temperature never changes on my CAT.
Ron

[GO BLUE]

Ive got mercedes and mine never moves once it gets hot but I'm predominately in warm weather Jim K

[David Bott]

You are correct on my layout vs yours and the engine type.

I agree with the others, mine stays more or less the same once up to temp. (Mercedes)

[11B]

Make sure if your pulling hills with a toad your not in the economy gear. I tried that once and heated right up.

[Arthur Hayes]

In over 45 years of commercial driving I have noted that is is normal for engines to rise in temperature when under load and to cool down when not. The hills in the east do not tax an engine very much but out here in the West you will find that they do and it is normal for the temperature to rise several degrees when under load, sometimes as much as 20 or more. They are designed to handle this.

Art

[rdlamb]

My Cummins stays at one temperature (165) whether I'm pulling the mountains of Montana or the plains of Kansas. If your engine is swinging such as you have noted, then a diagnostic evaluation is in order.

There is no information available, but commonly the cooling system has a thermostatically controlled auxiliary fan. I'd guess that yours is not working correctly.

Cooling problems are one of the few things that can wreck a diesel engine. Better have this checked.

[Arthur Hayes]

Hi Rick, I have to say that you are wrong on all three of your statements. If your Gage stays at 165 and does not change, which is kind of cold, then you have a faulty Gage. Yes the fan does come on when called to do so and the temperature will decline. I can assure you that my engine's cooling system is operating as designed.

Art

[rdlamb]

Ouch, Art, I was answering the newbie's question, and I am not incorrect in any of my statements.

First, checking with Cummins, my temperature gauge is correct. My engine fluctuates very little, and does stay around 165, pulling a mountain or roaring the plains. This is just above the 1/4 mark on my gauge.
I cannot hear my Aux fans when they come on, so I do not know how often they run. But, my engine temp just does not vary.

Second, the posted question's author noted their engine was running on the hot side, 1/2 to 3/4, which I took to mean a gauge pointing well past the right of center. That being the case, I stand firm that the individual should contact their dealer, or Freightliner, or the engine's manufacturer (I do not know what engine the Newbie has in his TM). Something seems amiss.

Finally, overheating a diesel is one of the few things that can greatly hurt the engine. Water in the fuel being another. I still strongly recommend an immediate consultation to diagnose the problem.

Finally, check the radiator, make sure you have the proper amount of coolant in your tank. I like to keep mine just below the max line, but well above the minimum line.

[univmd]

It looks like my engine radiator is operating normal based on this thread: http://www.irv2.com/forums/f84/2008-dam ... 48344.html (http://www.irv2.com/forums/f84/2008-damon-tuscany-engine-temp-48344.html) Thank you for all your posts.

[rdlamb]

univmd:

1. what engine do you have? In 2007 the choices were a 330 hp Mercedes or a 400 hp ISL Cummins. Either engine, in the posts on this subject, note that the engine's temperature stays relatively stable.

2. Do you have an engine monitor panel, that provides actual engine temperature readings? My 400 ISL stays below the center mark on the gauge, even in Arizona summer heat w/ac blasting away.

3. The irv2 site you threaded is an excellent site. But, the posts vary on their individual engine's performance.

My worry is that unless this is stated as normal by either Freightliner or Cummins, or Mercedes; should an overheating problem destroy your engine you may experience problems having warranty work performed.

Again, the best course of action, IMHO, is a trip to Freightliner.

Also, if you are not a member, this site is fantastic when wondering about your chassis.

http://www.freightlinerchassisownersclub.org/

Within that site is this thread, related to engine cooling:
http://www.freightlinerchassisownersclu ... %20Ltr.pdf (http://www.freightlinerchassisownersclub.org/Documents/PDF/field_service_letters/SF370%20Own%20Ltr.pdf)

Again, note the ominous statement exonerating Freightliner from paying for warranty work.

[univmd]

I have the new Cummins 360 ISC. This engine came with a new radiator with clutch fan.

No engine monitor panel. Just a guage divided into 4 quadrants, no numbers. Temp fluctuates between 1/2 and 3/4 mark while driving.

In the link above and also other websites, it seems that many owners with my engine already contacted Freightliner with the same question, and Freightliner said it was normal operation of this new engine/radiator setup.

My conclusion is that some engines will maintain a constant temp, while newer engines with newer clutch fan radiators will vary in temperature. Whew.

Thank you for your helpful posts too.

[rdlamb]

Not to rain on your parade, but please go to the link I gave you for the Freightliners owners club.

The link specifically lists service notices, not recalls, by Freightliner. One service notice states that Freightliner chassis with Cummins engines were shipped with incorrect cooling information programmed into the ECM.

Link is here: http://www.freightlinerchassisownersclu ... safety.htm (http://www.freightlinerchassisownersclub.org/recalls_safety.htm)

The reason I am so careful with the so called "service" or "campaigns" is that they are not recalls, and ergo, your engine may be one of the infected without your being notified of same.

If all is well, so be it. I wonder why GS went to the ISC Cummins.....

[univmd]

Here is a link about Freightliner switching to Cummins in 2008: http://www.irv2.com/forums/f26/new-cumm ... 31327.html (http://www.irv2.com/forums/f26/new-cummins-isc-360-specs-31327.html)