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Generator Overheating

This past weekend we had the coach out and were running the generator (Powertech 10K).  It ran for about 24 hours and then overheated and shut down.  When it shut down it pushed antifreeze out the overflow.

This happened to me last year after running for about 48 hours.  In March, I had MOT do complete maintenance on the unit.  I also had them put in a new thermostat on the thought that maybe the old one was sticking.  Obviously, that wasn't the problem.

Any ideas on what to check next?

Thanks ... Jimmy
1998 U295 36'
Jimmy

Margie and Jimmy
2003 U270 36' (one slide)
1998 U295 36' (Sold 2019)

Re: Generator Overheating

Reply #1 –
Thoughts:
Maybe marginal cooling?  What time of the day/outside temp was the shut down?  Long shot - if you have a belt driven fan, can you turn the blade by hand (=slipping).  If you have an elec fan, is the breaker popped?  (could be a marginal breaker which gradually overheated.)
Dave and Nancy
1999/2013 U270 36' Xtreme
Motorcade # 16774
2013 Subaru Outback
KD0NIM

Re: Generator Overheating

Reply #2 –
It ran all day .... temperature range was from 75 - 85 ... was very humid but not all that hot.  I am out of town on business this week but will check the fan this weekend. 

Thanks for the suggestion.
Jimmy
Jimmy

Margie and Jimmy
2003 U270 36' (one slide)
1998 U295 36' (Sold 2019)

Re: Generator Overheating

Reply #3 –
Jimmy,

Do the two shut downs have anything in common? Time of day? Direct sun on the compartment?  High load with high ambient temps? Does it use any coolant? Have you pulled it out to check radiator dirt blockage? Air cleaner, belt OK? You could install a mechanical temp gauge in place of the plug facing you on the top radiator hose housing. Could compare readings with compartment door both open and closed. Synthetic oil may give a little better high temp protection. Non-contact IR temp thermometer could check across radiator for partial blockage. Inexpensive at Harbor Freight.
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Generator Overheating

Reply #4 –
We have found an unusual problem on a Kubota engine that was rather hard to find.
The crankshaft pulley with the V Belt groove was slipping, meaning not fully turning the water pump to speed. had worked on it for a good while before realizing the problem.  Had to replace the pulley on crankshaft.  With the old pulley off and in hand, it was easy to understand as the way it was made with rubber between the center and the pulley, like a damper pulley, it was free turning with the rubber acting some what like a bearing.
One of the more amazing things I have seen, and most difficult to find.
My point is simply make real certain your crankshaft pulley is firmly attached and not slipping.
I do not know if the 10 kw Power Tech uses the same configuration, but I would have a real good look see by trying to turn the water pump, you should be able to rotate the engine by rotating the water pump pulley if the belt is tight enough.
The engine that had the problem was a 8 kw, 3 cylinder diesel. used on the Onan DKD like used on some Foretravels, seen them on the U300 series. A great generator setup .
FWIW

Re: Generator Overheating

Reply #5 –
The radiator might need to be rodded.  I did mine at about that age.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Generator Overheating

Reply #6 –
Thanks for all the ideas ... looks like a full weekend ahead of me.

Jimmy
Jimmy

Margie and Jimmy
2003 U270 36' (one slide)
1998 U295 36' (Sold 2019)

Re: Generator Overheating

Reply #7 –
Quote from: jimmy_walther –
This past weekend we had the coach out and were running the generator (Powertech 10K).  It ran for about 24 hours and then overheated and shut down.  When it shut down it pushed antifreeze out the overflow.

This happened to me last year after running for about 48 hours.  In March, I had MOT do complete maintenance on the unit.  I also had them put in a new thermostat on the thought that maybe the old one was sticking.  Obviously, that wasn't the problem.

Any ideas on what to check next?

Thanks ... Jimmy
1998 U295 36'

Coolant expansion or combustion gas entering the coolant are the causes for "pushing coolant out".  Expansion combined with boiling can be the result of slow water pump speed especially if it is a belt drive pump.  If it is a gear drive water pump, the impeller may be loose on the shaft.  Also, check the lower radiator hose to the pump to see if it is unusually soft or has an inner liner that has separated.  Coolant hose inlet restriction is usually from an older hose.  Boiling coolant is the result when flow is interrupted by a pump problem or a flow problem like the hose.  Worst case is a blown head gasket.

Gary Spires
Fleetguard Service Engineer
Gary Spires
Coolants, Cooling Systems, Filtration, Diesel Engines

Re: Generator Overheating

Reply #8 –
Got to thinking about your post further so decided to check mine. Same exact generator. My hoses are a bit soft (could be bad inside), no wire inside either but the main issue is the belt. Mine is pretty loose. I can easily turn the fan by sticking my fingers up through the bottom. The belt contacts the pulley over a good percentage of the area but it still is too loose. When belts slip, they can easily "glaze" over making the contact area slippery instead of the nice sticky surface they have when new. Easy to remove the two bolts and just pull the whole generator out on it's slides and change the belt. Hoses are short and probably inexpensive so why not replace both while you are at it?

A radiator shop can easily check for products of combustion and eliminate the possibility of a leaking head gasket. Just because you paid to have maintenance done does not mean it was done. When I was a kid, I worked for a shop that would tighten a few bolts, steam clean Jaguar transmissions and charge for a complete overhaul. Not to say every shop is waiting to take advantage but it can depend on anything from the mechanics mood to the overall operation of the shop. I know a couple of members who were charged for items that were not done (not by Foretravel) in shops.
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Generator Overheating

Reply #9 –
Jimmy, I assume you have a remote rad like my 99, as others have said make sure your blower fan is running. The generator has a belt drive W/P with no engine fan the belt is a bear to get tight the Idler is on the back of the engine. To get to it remove to bottom cover under the gen comp, 2 3/8 bolts (9/16 wrench) in the front, 2 5/16Th's (1/2 inch socket) in the back. Be carefull with the cover I leave one of the front bolts in to hold the cover just swing it out of your way, then slide Genny out you can then get an eye on the belt and adjuster from under the coach. It's kind of a pain but it's about the only way you can tighten the belt unless you have long skinny arms and fingers. After you do it once it only takes 10 min to get the cover off.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Generator Overheating

Reply #10 –
I have the same generator.  My overheating problem turned out to be a weak circuit breaker for the cooling fan motor.  It would trip at odd times for no specific reason because of the vibration of the generator.  With the breaker tripped - no air through the radiator - overheat with loss of coolant.  The circuit breaker was located on the box that sits on top of the generator and after ten years and several hundred hours run time it just got shaken to death.  The simple (and inexpensive) solution was to simply replace the breaker. 

I chose to relocate the generator controller electronics as well as the field circuit breaker and the fan circuit breaker to the bay beneath the driver where the radiator for the generator is located.  I thought it beneficial to get them away from the vibration of the generator. 

Sometime in the past the auto start electronics had been relocated from the box on top of the generator to this bay, therefore it seemed reasonable to do the same with the rest of the somewhat delicate stuff.  The only thing left in the box on top of the generator are the two main power breakers. 

 

Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
The selected media item is not currently available.

Re: Generator Overheating

Reply #11 –
Just got the coach back from the shop.  They said the regulator was bad.  The regulator would overheat and then shut down.  When it shut down, it would stop the fan blower which then led to the overheating.  They replaced the regulator and we ran it for 48 hours with no problems.  Since we are about to leave on big trip and will be using the generator extensively, I had them change the oil.  The cost was better than MOT. 

The shop is Parker Power in Carrolton, TX (Dallas area).  They work on all types of generators and seem to know what they are doing.

Thanks for everyone's help.
Jimmy
Jimmy

Margie and Jimmy
2003 U270 36' (one slide)
1998 U295 36' (Sold 2019)

Re: Generator Overheating

Reply #12 –
Jimmy, In the future when you have a problem like the one with the generator, where IF you had noticed the generator was not working (Not making voltage) THEN shut down, it would sure help and save a lot of guessing.  So in the end you did the best thing, take it to a shop where they could trouble shoot the problem, not just start throwing engine cooling issues at it.
Cheers

Re: Generator fault code

Reply #13 –
Just changed the fuel filter and left the drain valve open so of course it took in air and Kubota 10k gen stopped. I have now bled line and lots of fuel but FAULT red light in dash will not go off. Any ideas what to do or is it a time out issue. Book does not say a thing about fault. Thanks
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Generator Overheating

Reply #14 –
John, The dash light should go out when you reset the controller on generator panel.  Al least it works that way for my 2001 10 kw when I had a fault.

Re: Generator Overheating

Reply #15 –
Thanks Dave it worked. I had never had the problem before. Thanks
John
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Generator Overheating

Reply #16 –
Three comments to make:
1.  In a single failure occurrence it is sometimes not easy to tell that A follows B.
2.  While the answers did not apply to Jimmy's problem they are certainly good things to know if you have a generator overheat, I would have never thought about a pulley slipping on its center section.
3.  It sounds like Jimmy found a very good generator shop and I will note it for future reference.
John Cooper
'91 GV 36'
Oshkosh chassis
Cat 3208T 300HP

Re: Generator Overheating

Reply #17 –
On the front of the control box on top of the generator is a toggle switch (on mine) that turns off the blower motor.  Of course that causes overheating.  I feel it was added by a prior owner.  Check for such a switch, and its position.  Saves a bunch of time.  ;)
Bob Thomas
Sacramento, CA
Present:  1997 U320 '40
Previous: 1997 U295 '36
Bluegrass fan, and festival emcee
 

Re: Generator Overheating

Reply #18 –
Quote from: Bob Thomas –
On the front of the control box on top of the generator is a toggle switch (on mine) that turns off the blower motor.  Of course that causes overheating.  I feel it was added by a prior owner.  Check for such a switch, and its position.  Saves a bunch of time.  ;)
Our 1997 U295 also has a toggle switch that turns off the blower for the radiator. I expect it may have been installed as original equipment. Indeed the generator will shut down after a short run if the the blower is off.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX