generator overheating?

[redprevost]

Leaving tomarrow morning,started the genset temp guage climbed quickly to 230 degrees/shut it down and took out the thermostat,tested good in heated water at 170 degree opened/put back in,bleed fitting on top of thermostat hsg. same results/does not appear to be overheating by using lazer temp guage,get reading on head of gen set of 190 tops.does not shut down/fan is running pushing air thru radiator/coach is a 98 vantare h 45/anyone have any ideas?

[Jon Wehrenberg]

The generators are very difficult to bleed. If the coolant was recently serviced I would suspect air in the system making circulation through the pump difficult if not impossible.

If the coolant was not recently serviced (as in just prior to the problem) and you checked other things as you describe make sure the pump belt is OK, the hoses are not collapsing on the intake side of the pump blocking flow, or the pump itself is not bad due to a damaged impeller for example.

I do not think the temperature sensor is bad (causing shutdown) because I believe the gauge and the over temp shut down are two different senders and it is doubtful both have puked at the same time. Unless heavily loaded and operating in extreme temps I suspect the normal operating temps are going to be in the 170 to 180 range, some lower than that.

[RussWhite]

Just so I am clear..... When the indicated temperature reached 230 did you shut it down, or did it shutdown on its own?

It sounds a bit like you might need an additional temperature measuring device to determine what is really going on. I suggest you look for something like a flat surface thermometer as pictured below. It can be easily checked with boiling water and then you will get some confidence about your IR device. Good luck. Russ


Leaving tomarrow morning,started the genset temp guage climbed quickly to 230 degrees/shut it down and took out the thermostat,tested good in heated water at 170 degree opened/put back in,bleed fitting on top of thermostat hsg. same results/does not appear to be overheating by using lazer temp guage,get reading on head of gen set of 190 tops.does not shut down/fan is running pushing air thru radiator/coach is a 98 vantare h 45/anyone have any ideas?

[redprevost]

The overtemp sender did not shut it down,but I did ground the sensor wire and that shut it down/I will look at water pump suction hose,belts on waterpump look good and remote fan is working/how does one go about bleeding air pocket?

[Jon Wehrenberg]

Prior to the use of this tool I used the old fashioned way of running it, adding coolant , running it, adding coolant, running it, adding coolant, etc. Long, slow, painful process that I knew was over when it would run without the temp going beyond normal levels.

With all my cars and other engine powered stuff I bought one of these: http://buy1.snapon.com/catalog/item.asp?store=snapon-store&item_ID=66765&group_ID=12500

The first time I used it was on a car that was somewhat difficult to bleed, but with the use of the tool I had no need to bleed it. When I used it for the first time on my generator, I had already changed coolant in my generators about 8 or so times over the years and hated it every time. This last time I never had to bleed it.

It is kind of neat seeing the hoses sucked completely flat and when filling watching them slowly go back to the original shape as the coolant is filling. I know of no other easy way to fill.

[rahangman]

Jon, interesting looking tool. Question is, could you use this also to alleviate air or other voids when replacing a radiator or other component in the engine cooling system??

[redprevost]

I guess you would use vacuum on top of motor?to allow water to fully

[Jon Wehrenberg]

The radiator filling device is excellent for smaller systems. I tried it on the coach and even using my big shop air compressor many minutes of use failed to show a significant vacuum was being pulled on the coach system. The coach has 10X the volume of anything else I used it on so it is doubtful it is practical.

If you use it on a system that is almost full of coolant and the connection point is above the coolant level so no coolant is pulled through it while attempting to vacuum the system I suspect it will work to some extent. Never tried it. Maybe others have.

[RussWhite]

Jon,
I have not tried that either, but I suspect the collapsing hoses will reduce the volume of the system and quickly push liquid to where ever you have made your vacuum connection. Russ

[Jon Wehrenberg]

Russ, There is more to it's successful use than the collapsing hoses which represent a very small portion of our bus coolant system.

First, it will not collapse the smaller hoses, like the 5/8" ID hoses used on things like the Webasto heat exchangers. On my coach the larger hoses on the engine are very short lengths so they are unlikely to collapse significantly, so I don't envision a large change in system volume. But where it will help immensely is in vacuuming the various nooks and crannies that trap air and make refilling difficult. On my coach most of the places that can create a bubble or make draining difficult are provided with a bleeder valve although access is very difficult (like removing a sofa or disassembling a bed). For the coach I have had the greatest success filling by using the Webasto and its circulating pump. It is still difficult, but less difficult than accessing all the bleeder valves.