Community Forums

JOC1212 · 06-04-2019, 08:13 PM

I've spent over $1200.00 at the West Coast Power Tech service center trying to find a cure for our CD8000 over heating.

Today with an ambient air temp of 88F it over heated in less than 10 minutes.
I had Country Coach service in Junction City install Datcon water temp and oil pressure gauges a year ago.

Today the water temp gauge went to 240F (max reading) within 10 minutes of starting the Power Tech in order to run the roof air while we were checking in to an RV park.

Does anyone else have these over heating issues???

I'm seriously looking at replacing a unit with 340 hours on it with a new Onan.

Smitty77 · 06-04-2019, 10:07 PM

What all did they do?

-Thermostat comes to mind right away. (And, if replaced - well, I've known a few that had new thermostats, that were bad to start with!!)
-Did they flush the system? (When we bought our coach, the generator had been neglected on both exercising and maintenance. About 380 hours on it, a QD8000. The shop I worked at tried a simple drain, and then flush. But knew the flow as not good. So I authorized removal to send to a radiator shop - no cigar, they could not get it cleaned out - too much crystallization/gunking of the radiator. So, had to replace that!) (And as a side note, I did have new hoses put on, thermostat, temperature sensor, pump, fan belt, and a complete change over to Peak Final Charge (To match our the change to our ISL at at the same time.)
-On hoses, I've seen failing hoses collapse in on themselves in various applications over the years - not always spotted by mechanics...
-A competent shop, should be able to disconnect the hoses, and splice in a device to read coolant flow.

OK, that's my 'sitting in the cheap seats' input

! And, will follow the thread to see what else shakes out, and hope someone hits a home run for you with some input that is the actual problem

!

Best to you,
Smitty

2 Stroker · 06-04-2019, 10:09 PM

Well if it has a new water pump and full of coolant, the belt is on and tight the t/stat is good it should cool. There has to be something with water flow.
2 stroker

lwikle · 06-05-2019, 10:13 AM

Air in the system.

hayward3411 · 06-05-2019, 10:53 AM

Air pocket, it’s happened to me.

Smitty77 · 06-05-2019, 06:53 PM

Quote:

Originally Posted by lwikle

Air in the system.

! Yep - a real possibility!

Smitty

JOC1212 · 06-07-2019, 08:55 PM

any suggestions on a easy way to get air out of the system while on the road with limited tools and resources??

Burfman · 06-09-2019, 09:53 AM

Sounds like you have hit all of the mechanical items with out solving the issue.

Does this happen while sitting in one spot or when the coach is moving?

I had a similar issue only when sitting. The inlet and outlet for air circulation is poorly designed. The exhaust for both the radiator and generator windings discharge down and will get sucked up into the so called cool fresh air intake for the radiator. As the genset continues to run the heat continues to climb eventually causing the genset to over heat.

I only had this happen when I would dry camp and needed A/C. My fix was once I got set up was to stuff a firm piece of cardboard between the exhaust and intake so the two wouldn't mix and my problem was solved. I just kinda wedged it between the ground and the bottom of the genset. There is a mudflap style type divider but it doesn't hang down far enough to work well when sitting still.

Hope this helps...

Tmyz · 06-10-2019, 09:48 PM

Mine ultimately needed a radiator even though when the radiator was removed and checked it seemed ok. The mechanic insisted on replacing it, which I did, and it’s been good since. About a year now. Btw I had done everything you have done as well.

funjnt · 06-11-2019, 11:44 AM

I will take the old one! Anyway ours has over 1200 flawless hours on it so there will be some looking that needs done.

Since it doesn't have many hours I would take radiator out and clean it. Antifreeze actually crystalizes and precipitates out in a form of solids if old enough. Had that happen on a truck. Another quirky one I found was we had an old fan belt on a 953 track loader, belt was good and tight but,,, it was glazed on pulley side and would slip a tiny bit so after time it would over heat but slowly. New belt all good.

Ten minutes is quick to overheat. Seems the thermostat would be best start, then maybe radiator. Can you feel if top radiator hose is hot or not so much. I think if it isn't circulating coolant enough the top hose won't be hot. If it is hot and when squeezing it, it feels full and bottom hose is hot the fins are clogged. If bottom hose cold not circulating enough.

There are a few easy things to check but probably something simple. Let us know what you find.

funjnt · 06-13-2019, 05:45 AM

Any luck?

TTD · 06-13-2019, 06:55 AM

I just had a similar problem on my ONAN 10k, after I had someone do a complete service including coolant change.

My unit would shut off and kick out an overheat code (generally after 10 to 15 minutes the first startup... then quicker on subsequent starts). I touched the radiator hose right during the running time and after shut down, and it was cold... which made no sense.

If your hose is cold, it's likely a coolant flow issue.

My fix was to crack the radiator cap carefully - it is under pressure and coolant will spew out (along with a bunch of air). It's not hot coolant, but it does make a mess so have gloves and a container ready.

I did this until no more air spewed out... topped off the reservoir - and has been running perfect ever since (over 20 hours on it since this issue).

Burfman · 06-13-2019, 10:55 AM

Going back many years after rebuilding engines I fill the cooling system full start the engine with the cap off and run it until all of the bubbles quit and the fluid is hot. Add coolant as needed to fill it up and then put the cap on.

This way all the air should be out of the system and if the pump and t-stat are functioning you shouldn't have any problems.

I would think a factory service company would have done this during the $1200 service...but maybe not.

JMO...Good luck on getting it resolved.

TTD · 06-13-2019, 08:22 PM

Quote:

Originally Posted by Burfman

I would think a factory service company would have done this during the $1200 service...but maybe not..

Agreed... you would expect them to bleed the air.

In my case, after it was serviced I used the generator several times without a problem (mostly when driving so not sure if the jostling helped stir up the coolant?).

Then it sat for a month and when I tried to exercise it at a standstill... I got the air lock.