Generator

[dale farley]

I ran my generator this morning, and I noticed that after it warmed up and was running the 2 house A/C units, the water temperature was about 210 on both meters. Is that high for a unit sitting in the sun on an 80 degree day or is it about normal? I didn't see any signs of over heating and the antifreeze reservoir is at the correct level.

[truxton]

Dale, I thought someone would of jumped in by now. My Kohler has never run over 195 in 110 degree sun with everything on. 210 seems a little warm to me. I would call Mark and ask.

Later
bv

[Gil_J]

Dale,

I'd say that's outside the operating range. Use an IR gun and check the temp. If the sending unit is bad both gauges will be wrong.

[lbriant]

Dale,
It sure looks shiny, now I have to go wipe mine down again !!!

[Joe Camper]

I would say the high temp sensor is going to shut it down somewhere close to that temp if functioning as designed.

Mine would go to just north of 190 in real hot weather

[dale farley]

Gil,

Where are you talking about shooting it to see the temperature? Maybe if it really starts being a problem, I'll shoot it with my 357 and let some of that hot water out. I hope it is the sending unit.

[Gil_J]

Dale, ideally you'd take the temp off the radiator hose coming off the thermostat. If not accessible, try any coolant hose.
Have you checked the radiator cooling fan to make sure it's working and nothing is blocking air flow?

[dale farley]

The fan is working.

[Tully Garrett]

I wish mine was running.

[Pete]

Dale, my bet is your radiator needs to be cleaned/rodded out.

[lbriant]

Dale ,
This may not be relevant but on my generator once somehow it ended up with like an air bubble in the line and it made it quit pumping coolant it went up hot and I was still at the dealer years ago he started it up squeezed the hose several times and then ended up adding a touch of fluid but it never happened again ? Like an airlock ?

[lbriant]

I think air locks on cooling systems are more common when the radiators have to be mounted lower than usual causing a high point in the radiator hose, but usually happen right after someone drains the system and is refilling it but could also happen if the system was a little low at one time ?

[dale farley]

I appreciate everyone's comments. I will get back on this in a few days. I looked at the water lines, and they are very well insulated so they may not be that easy to see or check temperature. I don't see anything obvious that could be causing the problem. The antifreeze is full and looks clean. I'll report back when I get a chance to get back on the issue.

[dale farley]

I ran the generator for an hour today with both 2 1/2 ton A/Cs running. After about 20 minutes the temperature was 200 degrees according to the gauges. I have 3 different gauges and 3 sensors. They are shown in the picture. The little black knobs attach the wire to the sensor. After an hour, the temp on the gauges said it was about 220 degrees.

I used my temperature gun to check at the base of each of the sensors and the hoses. At no place, could I get a reading over 190. The reading on the hose in the hottest spot was 188. The base of the sensors was between 175 and 182. It isn't feasible to assume that the 3 sensors or the 3 gauges could all be wrong, especially since they were all reading about 220 after an hour or running. My temperature gun is one of the better ones that cost around $75, and it has always seemed to be accurate, but the difference between what it is saying and what the 3 gauges are saying doesn't make any sense.

I looked in the generator book, but couldn't find what the temperature should be or when the thermostat opens. It did say with 50% antifreeze, the boiling point is 226. I assume at some temp, there should be an auto shutdown, but I'm not sure. My generator is one of the standard 17.5K. Everything about the generator looks exceptionally clean, and there are no visible signs of over heating. I suppose I could have a partially clogged radiator, a water pump that isn't working at full capacity or a bad thermostat???

[lbriant]

Can you tell if the water is circulating ? Maybe when it's cold run it with the cap off for a little while , then see if it circulates or will take any more fluid,
You should be able to tell when the thermostat opens up probably around 200 deg,

[lbriant]

It's hard to believe three gauges wrong ?
I didn't notice what the temp on mine was a few years ago when I had air in the system and it had an hi temp auto shut down ?
What temp do the heads read ?

[JIM KELLER]

Dale, If you run the generator with no load does the temp stay at a normal range or increase to the high temps ? I assume you are doing this test with the bay door closed.

[dale farley]

I think I can rule out the gauges being wrong, because they all three read virtually the same and each has its own sending unit coming from within 4 inches of each other. I haven't run the generator with no load long enough to determine what it will do. I am keeping the door closed while running. I will try to see what I can determine with the cap off.

[Gil_J]

If an increase in the sensors' resistance equals a greater temperature reading, I'd check for a high resistance ground. Measure resistance between a sensor's housing and a known good ground. You are looking for 0 ohms. You may want use a hose clamp and attach a wire on a sensor and the other end to a good ground. You may have to make same check at a gauge.

[dale farley]

Here's the latest. I checked the resistance from the sensor to ground and had virtually none on any of the three.

I ran the generator with the cap off until the temperature reached between 210 and 215. As shown in the picture, the radiator cap is angled. Right after I started running it, the antifreeze would slosh out a little at a time. That may have been from the vibration of the generator. Never did I see what appeared to be a distinct flowing of the water, although I am not sure what it would look like from the way the setup is configured. The radiator tank is shown in the picture with the water pump located just beside it. The actual radiator is located under the bus for air ventilation. I looked at the core and it does not appear to be dirty.

I probably ran it about 20-30 minutes and during that time, probably a little over a quart sloshed out the opening. When I shut the generator off, it immediately started blowing water out the opening. When I say "immediately", I mean in one second or less.

I am assuming I have a bad thermostat or water pump. Any suggestions as to how I can determine which one it is before I start removing parts. I can't find the thermostat in my manual, but I assume it is located just below the polygon shaped fixture in the top picture (the one with the petcock on it). It appears there is a housing under it that might have a thermostat in it. I tried to show that housing in the second picture but only a little is visible.

In summary I have two questions: Can I determine if it is the water pump or thermostat without removing the thermostat and placing it in hot water?

Is the thermostat located beneath the polygon shaped fixture?

[Gil_J]

Dale,

Yes the thermostat must be under that polygon housing. Here's the stock engine, before modification.
13173
I'm still puzzled by IR readings being so much cooler than these sensors. The sensors are all upstream of the thermostat. In other words, they won't have water flowing across then until the thermostat opens. That too is puzzling. So, although I said that's were the thermostat should be, I have to wonder if it's elsewhere. Temperature sensors should be on the engine side of the thermostat, not the radiator side.

Have you called Power Tech and asked them?

[dale farley]

Gil,

Thanks for the drawing. I placed the drawing beside the picture, and it appears this is exactly what I have. I assume the two bolts shown on top of the polygon are the ones that go all the way down to the thermostat. I suppose I will pull the thermostat and make sure it is opening the way it should. I guess I could put the housing back together and see if the water pump is working without the thermostat, but I am not sure I can see the water flowing because of the configuration. There is no radiator under the metal tank, so the water does not flow like a typical setup.

[Joe Camper]

Have U looked to see that the rad hoses r not collapsed anywhere?

At what temps is the safety suppose to shut down the gen. Seems to me mine would never get to your temps shutting down sooner but it only happened once and I didn't see how far it went when it did.

Gill mentioned the locations of the sensors and questioned that. Interesting but id guess the potential for that would be slim or at least hope it would be.

[dale farley]

Joe,

I can see most of the hoses, and they look fine. they go into a wall behind the generator where the radiator is laying horizontal and vents to the bottom of the bus. I have looked underneath the bus, and the radiator looks clean with no visible signs of trouble. I think the only way to actually get to the radiator is to remove the generator or to remove the entertainment bay from the other side.

I have not been able to determine when the generator should shut down automatically if it gets too hot. I find it a little strange that while running when the gauges says it is 220 degrees, it never appears to be overly hot. I still don't understand why the 4 way brass coupler and the brass sensors show about 190 when the sensors/gauges are indicating 220?

Do you have any idea what the polygon-shaped component is?

[Gil_J]

That Polygon shaped housing must have been an easier design for Power Tech to add stuff to. It's the same design on my Power Tech with remote radiator. As I've said before, it makes no sense why your IR gun has that polygon housing readin 30+ degrees cooler than the sensors. FWIW, the thermostat fully opens at 204 degrees. I would guess shutdown to be 215, or less.

[dale farley]

Gil,

Do you have any idea how the shut down system works? What senses the temperature and what shuts it down?

[Gil_J]

Dale,

Just doing a little research and few have reported similar symptoms due to air in the line. They opened the bleeder valve on top of that polygon shaped housing and all is well.

I'm not sure which sensor controls the shutdown. I would have thought one of the many hanging from the thermostat housing. However, someone reports it's on the top back side of the head. I'm not sure where the back side is in the reference. http://powertech.myshopify.com/products/05stkub03

[dale farley]

I was wondering what that valve was for. Makes you think this might be a rather common problem. I think I will try that before I do anything else.

[dale farley]

Well, I flushed the lines and purged any air from the system, but it didn't change my symptoms. I talked with Power Tech and they said air in the system is a very common problem that causes over heating. He told me to remove the top radiator hose, connect a water hose and blow water in to force air out the other side. I also ran a bottle of "radiator flush" through the system. No difference.

I think I will remove the generator and rod the radiator. The radiator is behind the wall, behind the generator. It is positioned horizontal on the floor so air can flow through it when the fan is running. Has anyone ever removed one of the slide units? I don't know how much trouble it will be, but I can tell it is heavy.




http://forum.prevostownersgroup.com/attachment.php?attachmentid=13141&stc=1&thumb=1&d=1399391333

[coreygrubb]

Dale, a pallet jack works well. At least you have a slide.

[dale farley]

I haven't looked that closely yet, but I wonder if there is a release on the slide coming out or if the screws have to be removed from the bottom frame and the entire frame removed together.

[dale farley]

ALL IS WELL! With my soul and my generator! I decided that before I would try removing the generator, I would disassemble the bay on the other side and see what I could find. I had previously stuck my head and body in a hole where I removed a TV from the entertainment bay so I could make sure the fan was running. I had a built-in Jenn Air grill that I had to remove and some drawers.

To my surprise when I removed the inspection plate on the squirrel cage, I could readily tell the fan was not turning fast enough. I used a round screwdriver to put some pressure on the belt and the fan sped up significantly. The old one was stretched bad. It was probably the original. Purchased a new one and installed it.

I changed the antifreeze, oiled the fan and put everything back together and cranked it up and it started to get hot again. I shut it down, waited for it to cool, completely filled with antifreeze again and ran water through the top hose to force out all the air. Started again and turned on both house A/C units, the refrigerator, lights, etc. After almost an hour, the temperature was 190. What a relief. Thanks to everyone for the suggestions. I think Vantare uses a similar motor and belt system, so that may be something others want to check at some point.

The first picture shows the components I had to remove to get to the fan.
The 2nd one shows the duct work for the fan that goes to the generator. What is shown in the picture is actually half of the duct. It goes behind the other side of the cabinets also and pulls air from both sides of the generator compartment and exhausts it through the radiator below the plenum shown in the picture. There is also an opening covered by heavy mesh wire that allows air to be forced in the duct from the under the front of the bus while moving. This is a vertical opening right behind the front wheel.

The 3rd pictures shows how loose the old belt was. I was just barely pulling on it.

The 4th shows the new one installed.

[Gil_J]

Great news!

[truxton]

Good job Dale,

I was going to mention something like that but you beat me to it. Only because 2 days ago I serviced the Kohler and took the cover off the belt housing, very easy to get to and found some play in the belt. I believe it was on the verge of a problem. It normally runs 187 to 195 loaded up with outside temps in the low 100's. 2 days ago we were at 108 and I turned everything on for a 60 mile trip and the generator never got over 180 degreees.

Later
bv

[lbriant]

Maybe you should invent an Idler pull for that set up as long as everything is already out of the way .)

[lbriant]

http://www.brewertensioner.com/autotensioning.html#mseries

[dale farley]

That's sounds like a good idea Larry. I assume the reason there is no idler is that the bearings in those motors and fans wouldn't withstand a much pressure.

[Pete]

Dale, I know you must be happy about your findings. I could not imagine you would have to pull the genset to get at your radiator....is that still the case? Sounds like you are about ready to roll now. Congrats!

[dale farley]

Pete,

I can access the radiator by removing the duct. The plenum shown on the left of the picture attaches over the radiator. I hope I don't have to do that any time soon. While I had the antifreeze out of the system, I flushed it with a flush that is supposed to dissolve any deposits rather then send them to the radiator to clog it up. Several times, I hooked the water hose to the top radiator hose and flushed the system. It appeared that water was flowing rather normally, so that is why I couldn't understand how the radiator could be clogged in the first place. I'm glad I listened to common sense and looked for other possibilities before removing the radiator.

[edold]

Thanks for your help Dale

[dale farley]

Ed,

I'm glad I could help. Nice looking bus. Pictures always help.

[JIM KELLER]

Great Thread Dale ! Obviously others agree since it has been viewed 662 times.

[dale farley]

Jim,

If I had it to do over again, I suppose I would go about it in a similar manner if I had an over heating problem. I think I would move through the steps below until I solved the problem:


- Make sure fluid is full and there are no visible leaks around hoses, fittings, or radiator cap
- Make sure there is no water in the oil or that oil seems excessively high
- Make sure fan is running at normal speed (see below)
- Remove top hose and blow water through it and out the other side to remove the air.
- Flush system with a good cleaner that dissolves deposits and doesn't clog radiator core
- Check thermostat
- Check water pump
- Remove and rod radiator
- If none of this works, one stick of dynamite should do the job

Fan - In my case, I verified that the fan was running by taping a piece of tissue paper to a yard stick and placing it under the radiator, under the bus. I could see the tissue blow so I knew it was getting some air through the radiator. At that point, all I knew was that it was blowing, not that is was blowing the proper volume. I did notice that it was not a fast stream of air. I had also removed my TV stuck my head behind the entertainment bay and could hear the fan running. In retrospect, it would have been much better if I had verified the belt was working properly by removing one side of the entertainment bay and checking the belt through the access door. Of course, everyone doesn't have the same setup for the fan as I do, but the steps should be about the same.