Generator running hot

Good afternoon,

Since purchasing coach (November 06) the gen set runs hot. It will get to 225 degrees when under load. The radiator is far away in the front of the coach. I have bled the line of air multiple times. The line to radiator is at 225 degrees, the line from radiator is at 185 degrees. These are measured by infrared thermometer. The radiator is putting out hot air. Everyone seems to want the gen set not to run over 200 degrees. The thermostat is working else there would be no flow to the radiator (at least that is what I think is correct).

There is fan behind radiator (the radiator lies down flat in front storage area of bus). the fan is working since fairly high volume of hot air leaving radiator.

Amount of antifreeze is correct. Mixture is correct. Any suggestions?

thank you

Kim sloan
02 Vantare XLII S2 (yes it is fixed see separate post)
06 dodge megacab

Suggestion: remove the thermostat, put it in a pot of boiling water and watch to see if it pops open. If it doesn't install a new thermostat, if it does pop open try re-installing it and see if the problem persists.

I know on the Liberty that proper baffle location (for the radiator cooling fan) is critical to mainting cooling for the generator. I don't know if the Vantare has/needs one, but it's worth checking.

Let us know your progress.

Mike

Kim,

Mike is correct and there needs to be a sure-fire way to isolate the heated air exhausted from the radiator from the cool air going into the radiator. As a Liberty guy I'm sure you know how the Liberty baffle accomplishes this. Vantare must be doing this in some fashion also.

I agree with Tuga about the thermostat check, but one thing you said concerns me. If you are in fact running at 225 outflow and 185 inflow the coolant is already entering the engine at the desired operating temperature. If the thermostat is not failing to open, is it possible it is the wrong temperature, or is it possible there is no thermostat? Without a thermostat in some cooling systems the coolant flow through the radiator is so fast the coolant is not losing much of its heat.

Is the radiator blocked or partially blocked? Is the radiator fan functioning properly or is it cycling on an off due to a thermal overload on the electrically powered motor?

What does Vantare say might be the cause?

Good luck.

Lots of answers to this one.

Since you don't have a Liberty, we can possibly eliminate the MangoMike disposable generator baffle as the cause of the problem. Or at least if you can determine that the Vantare conversion didn't have one originally that has now found a home alongside the road.

I would look at a couple of things. Airflow across the radiator is key to the cooling efficiency. Low velocity or plugged fins and the heat comes up.

If you are not adding coolant and you don't see any leaks, then that might preclude pressuring up the system with a tester to see if it leaks.

It could also be likely that the thermostat is stuck or not fully opening. Again, reduced coolant flow thru the radiator could cause a problem.

Lastly, a visual inspection of the inside of the radiator could show buildup that might be the problem. However, this is somewhat unlikely given the age of the coach. By your measurements, you are getting +/-40 delta T between the inlet and outlet, so if you are supposed to run at 185 or so, returning at 185 isn't going to work.

Quote:

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Originally Posted by nrhareiner

Good afternoon,

Since purchasing coach (November 06) the gen set runs hot. It will get to 225 degrees when under load. The radiator is far away in the front of the coach. I have bled the line of air multiple times. The line to radiator is at 225 degrees, the line from radiator is at 185 degrees. These are measured by infrared thermometer. The radiator is putting out hot air. Everyone seems to want the gen set not to run over 200 degrees. The thermostat is working else there would be no flow to the radiator (at least that is what I think is correct).

There is fan behind radiator (the radiator lies down flat in front storage area of bus). the fan is working since fairly high volume of hot air leaving radiator.

Amount of antifreeze is correct. Mixture is correct. Any suggestions?

thank you

Kim sloan
02 Vantare XLII S2 (yes it is fixed see separate post)
06 dodge megacab

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Kim, From what I think you said, your temperatures are correct and your gauge is in error. Your gauge that reads 225 deg. is off. That is if your infrared thermomoter is correct. You said temp.into the radiator at 225 deg., temp. out of radiator 185 deg., and that the unit should run at 200 deg. max. Right! Right!

:D JIM

When you say the radiator is 'far away' from the gen set, is there an auxiliary water pump to assist in moving coolant over that distance? I'd take a look at what the others have suggested and make sure that the coolant level is full at the hot setting and it is moving at the required rate.

Speaking only about Liberty now....At one time the remote radiator had an electric coolant pump located at the radiator. My current Liberty now uses the integral generator coolant pump. On the hottest of days under load I have never seen my generator exceed 180. It sounds like Kim has something wrong that is not yet obvious.

thanks for all of the respnses,

I am going to test the termostat tomorrow. There is almost 30' between the generator and the thermostat. The radiator appears to be clean, at least to visual inspection. there is no baffle since the radiator sits atthe front of the coach in the area at the extreme front of the coach.

Now ofr a quick question, would a thermostat that was not opening fully allow the temp. at the radiator get to the 225 degrees measured. We used 2 thermometers and got almost identical readings.

I will call Vantare tomorrow, but already tried them twice with little idea of problems.

Kim

Kim,

My water temperature gauge showed 220+ when my thermostat was not opening. After removing it and putting it in boiling water it seemed to be cleaned by the boiling water. When I re-installed it, it has worked great ever since. I keep the new thermostat as a spare in case the problem arises again.

It is an easy test, and who knows it may just solve your problem.;)

They make thermostats that fail in the open rather than the closed position. Take the thermostat to a good parts house or garage and discuss this concept with them. This change is probably saving a lot of engines today.
Look hard for a booster pump, that seems like a long run thru a hose with the standard engine water pump to overcome. Keep at it, don't loose that engine.
Check all the hoses, when they get soft the tend to suck shut.

What manufacturer is the Generator? Check the Book ,if you have one, and buy a new thermostat. Replace it and eliminate that as the problem first. Then if you still have problems, the distance beween the radiator and the engine would be the 2nd issue to examine.

I agree with Gary. Change the thermostat. Don't even check the old one they don't last long anyway. Get a fresh start with new. To remove the old is the bigger part of the job. Do not put back old inexpensive perishable parts.
Check out the whole system even when the problem turns out to be the thermostat.
:D JIM

Wil Rogrs said: I never met a man I did't like. ;)

Somebody else said: I never had a thermostat that didn't fail.:eek:

New thermostat in aqnd no change.

Kim sloan

Quote:

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Originally Posted by nrhareiner

New thermostat in aqnd no change.

Kim sloan

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I would call customer support , Your convertor or Generator maker. Also, check to see if you have any other Valves, sensors, backflows in the piping system from the radiator to the Generator.

Quote:

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Originally Posted by nrhareiner

New thermostat in aqnd no change.

Kim sloan

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Kim, on a diesel pickup I had a few years back, I had a similar prob. What it finally turned out to be, was some little piece of plastic in the thermostat housing broke loose and became lodged in the hose out of sight, blocking the flow volume.

You can check for this by feeling the hose with your hand for temp. differentials, or with your infrared thermometer.

Kim,

Your problem is frustrating me. I hope you can solve it and let us know what is going on.

Using your data about in-out temperatures I find myself with no clear direction regarding where to look.

If the problem is a blockage (you ruled out the thermostat) it would act as you described. But if the radiator and fan and pump are not doing their job the results could be the same. To rule them out I think you should see if you have another bus owner near you that is willing to start and load up his generator. Take the same measurements and see if the drop in temperature is about the same. If it is that may rule out the radiator or fan.

When it is working properly, the coolant leaving the generator will likely never exceed 200. But for that to happen the coolant returning to the generator needs to be well below that point. I strongly suspect that the generator coolant pump is not the issue because while poor flow can cause the coolant to remain in the generator longer, absorbing more heat, I am presuming that reduced flow rate will also allow the coolant to lose a substantial amount of that heat before it returns from the radiator.

By that long around about thinking process it brings me back to the radiator / fan area. Is it possible the fan has problems or that the hot discharge air is returning to the radiator preventing proper cooling? This is where measuring another bus radiator set up may provide some clues.

BTW, I am leaving in a little for a couple of days of flight and sim training otherwise I would attempt to get that data from my coach for you. Sorry.

Good evenining,

With alot of looking I found a bleed valve in the line. The valve is around two feet from the radiator at the front of the bus. After bleeding air (and there was definitely a pocket) the temp is down and has stayed down. For how long who knows. The valve was not visible until starting tracing water line.

Kim Sloan
02 Vantare XLII S2
06 dodge

That's great Kim. Another mystery solved.

Quote:

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Originally Posted by nrhareiner

Good evenining,

With alot of looking I found a bleed valve in the line. The valve is around two feet from the radiator at the front of the bus. After bleeding air (and there was definitely a pocket) the temp is down and has stayed down. For how long who knows. The valve was not visible until starting tracing water line.

Kim Sloan
02 Vantare XLII S2
06 dodge

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THAT'S GREAT KIM!!

Makes me think that once a person gets his-her bus sorted and figured out it takes a lot of fortitude and guts to get another and start over.

Kim,

Good news for all of us as it adds another "knowledge" point to the fix it database.

Persistence pays off.

Mike