PDA

View Full Version : 20KW Kubota 4 cyl Generator Overheating


Barry Rooker
09-22-2011, 10:45 PM
I've been reviewing the posts on generator operating temps. Even after re-coring the radiator, this summer with triple digit temps, my generator would run over 200.....when moving. I stop and the temp drops 20 degrees.

There were several earlier posts about the Road Air discharging into the genset's blower area. Mine does that. Another post mentioned blocking off part of the intake grille on the side of the coach. By the way, the rubber skirt that connects the radiator's shroud to the fixed shroud under the coach is in good condition.

Both my engine & genset seem affected by strong side winds, perhaps robbing cooling air from being pulled in & through the radiators.

Any ideas?

2001 Newell Coach 20KW Kubota 4 cyl

tuga
09-23-2011, 01:30 AM
Barry,

What year is your Newell?

I also have been unable to get my temps down in extremely hot weather. Mid 90s to 100 degrees and my generator will run around 215 to 225.

I have changed thermostats, the water pump, & cleaned the radiator twice. After I changed the water pump and had filled it with new anti-freeze it ran at 175 degrees for 4 hours (while parked) in 95 degree ambient temps. I thought I had it licked at this point.

Then, we took a trip to North Carolina and it ran at 210 degrees in 90 ambient temps. The series 60 was running at a cool 180 degrees. I also experienced low operating temps when not moving.

In my previous 2 Newells ('87 & '93) the generator temps would match the engine temps.

I am going to contact John Clarke with Newell, maybe he can help us.

rheavn
09-23-2011, 11:32 AM
My genset runs at 180 degrees whether I'm moving or not no matter the outside temperature. With that said I'm not a fan of the VDO gauges and especially the water temperature gauges. Have you verified your coolant temperatures with an infrared gun?

express1
09-23-2011, 12:28 PM
I second that Steve!!! I wish my VMS had Gen-gauges.....

tuga
09-23-2011, 12:42 PM
My genset runs at 180 degrees whether I'm moving or not no matter the outside temperature. With that said I'm not a fan of the VDO gauges and especially the water temperature gauges. Have you verified your coolant temperatures with an infrared gun?

Steve,

You may be onto something with the infrared gun. I have one and I did check the temps with the gun when the gen was running at 180 degrees (VDO gauge reading) - the IR gun confirmed the VDO reading so I didn't go any further with the test.

I think next time the gen temp is around 210 degrees I will shoot the IR on the 2 hoses.

I'll post the results.

Boy, would that be a simple fix!

But why would the VDO gauge read correctly @ 180 degrees and erronously at 210?

rheavn
09-23-2011, 01:45 PM
Tuga,

" But why would the VDO gauge read correctly @ 180 degrees and erronously at 210?" __________________

I can't explain why the gauge works and then reads wrong, but I've learned someone on the forum will. My water temperature gauge on my Country Coach & now my Newell are both VDO gauges and both have read higher than actual temperature on an intermittent basis. I was heading for Dallas in cool weather and the gauge went up to 230. I stopped, used the infrared gun on the radiator and it only read 195 degrees. I smacked the gauge with my finger and the needle immediately dropped to 195 degrees. The same thing would happen in my Country Coach occasionally. I just can't explain why.

folivier
09-23-2011, 01:51 PM
When I first start my generator the VDO oil pressure gauge will peg out to the right. After a few minutes it will settle in where it should. Gotta love them VDO's!

afrench45
09-23-2011, 04:14 PM
Mine generator usually runs around 200-225. I've called Newell multiple times and they have said sometimes they do run that hot, or the gauge is off. I've shot mine with a temp gun a few times and usually seems to be around 195 or so. Newell told me that if the generator overheats, it will automatically shut itself down. I usually don't worry about it, and been running 7500hrs strong!

Richard and Rhonda
09-23-2011, 11:59 PM
The squirrely gauges are almost always a ground problem. Newell chose to daisy chain the ground on the instrument gauges. If you look into your panel it is evident.

Saves wire, but leads to this kind of problem.

Solution, do as Tom has done and run individual ground wires to the gauges. Or, live with squirrely readings from time to time.

Barry Rooker
09-24-2011, 05:11 AM
Tom French, glad to hear of your 7,500 hour genset. Mine's right at 4,000 so I'll stop being concerned. Before we bought our coach seven years ago, it had maybe 3,600 hours. I thought that was high, so I called Power-Tech and they said they called it their 10,000 hour unit, but with proper care it'd go farther.

My friend & fellow Newell owner Don Freymiller says his refrigerated truck trailers use the same engine as our generators and exceeding 13,000 hours is common.

Newell always uses the best stuff available and it pays off with longevity, given proper maintenance.

HoosierDaddy
09-24-2011, 02:07 PM
As long as the maintenance is done these gensets will run a long time because they run at a constant speed and load. Most engine wear is attributed to start-stop cycles. If we can keep clean high quality fuel and oil and service the cooling system they'll run for years.

Wally Arntzen
09-24-2011, 06:18 PM
On my 88 I had my generator running 24 hour a day for 5 days and it never ran over 185 degrees. These generators are installed in many large boats and sometimes they run for weeks at a time as expected. All you have to do is check the oil once in a while and let them do what they are built for run, run, run.

tuga
07-31-2012, 09:25 PM
I've been reviewing the posts on generator operating temps. Even after re-coring the radiator, this summer with triple digit temps, my generator would run over 200.....when moving. I stop and the temp drops 20 degrees.

There were several earlier posts about the Road Air discharging into the genset's blower area. Mine does that. Another post mentioned blocking off part of the intake grille on the side of the coach. By the way, the rubber skirt that connects the radiator's shroud to the fixed shroud under the coach is in good condition.

Both my engine & genset seem affected by strong side winds, perhaps robbing cooling air from being pulled in & through the radiators.

Any ideas?

Barry,

I don't have a rubber skirt that connects the radiator's shroud to the fixed shroud under the coach - there is nothing there! I wonder if that could be the cause of my overheating problem?

I know for a fact that my dash AC dumps hot air into the generator blower and that air is blown into the generator bay; that has to increase the operating temps.

I am going to Newell at the end of August for service, and I am going to ask them about the rubber skirt and also about installing a metal shroud to re-direct the dash AC hot air so it doesn't dump into the generator blower.

My generator will run at 200 degrees in 100 ambient with the dash AC OFF! If I turn on the dash AC on the generator operating temps goes up to 225+.

afrench45
08-01-2012, 03:00 AM
Just a thought... These temps y'all are giving, is that off the gauge inside the coach or a heat gun? I was driving back from Florida last week and mt gauge was showing 250+ which obviosuly would be a problem. When I pulled off the road the gauge dropped to 230 and with my heat gun the genny shot around 210. The gauge was picking up a lot of road heat. It was 100+ outside. Ran fine for 24hrs, at night it dropped down to 180s-190s

tuga
08-01-2012, 12:59 PM
Andrew,

I have compared my VDO gauge temp to using an IR thermometer; the temps are the same. I really believe my problem is two fold: the rubber skirt at the bottom of my radiator is missing completely and my dash AC unit exhausts hot air into the blower squirrell cage fan and then dumps the air into the generator compartment.

Once I have both of those things corrected, my operating temps will drop.