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 07 IC RE bus heater issues?
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United States
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Posted - 01/22/2013 :  09:41:27 AM  Show Profile  Visit wjbusguy's Homepage  Reply with Quote
Hi all, I have an 07 IC rear engine bus with a 466 motor. It has a webasto heater on it. The heater valve is unhooked from the control cable and is full open. With the webasto, the water temps come up fairly fast while idling, waiting to go on a trip and the heaters blow hot air. When you head down the road with it, the air from the heaters goes from hot to luke warm. We are a rural district so all of our trips are a hundred miles plus round trip. When you get to town and slow down for city driving, the heaters all get hot again. The water temp gauge doesnt cool off when driving down the freeway and it maintains water temps driving in town but will drop some while idling after you get to your destination. I am guessing it stays about 150-60 when idling and the webasto will kick back on to help maintain temps. I did run the heaters on low speed and the kids said they were a little warmer than when the heaters are on high. We have been 15 to 20 below for overnight temps since we came back from Christmas so its been a chilly month for us so far and when you come back late at night it can be an easy 10 below for temps. Our front engined IC buses work good on trips and dont cool off like this rear engined one does. I'm thinking I have a water circulation issue thats causing the heaters to lose capacity at high engine rpms. The webasto heater was installed by an aftermarket place and they also did 3 other buses for us. In all 4 cases, they had the webasto hooked up wrong as the circulator pump on the webasto was pushing against the booster pump/water flow from the engine. They installed them in the summer and didnt run the webasto's with the engine running so nobody knew there was an issue till we went to use them when it got cold. I switched the hoses on the webasto so the water is running the right direction now. Webasto told me that since their units have a circulator pump that the bus circulator pump wasnt needed and could be a restriction in the heater circuit so I removed the IC circulator pump on the RE bus to see if that made a difference but it didnt.
Is there a "best way" to have a webasto tied into the heater circuit to get maximum heat to the heaters? I havent done any research on it yet, but I am going to assume that on my RE bus, the hot water should hit the front driver heater/defrosters first then go through the mid and rear heaters on its way back to the engine? If thats the case, would the webasto be best tied in after the front heater/defroster but before the mid and rear heaters? Anybody else ran into this particular issue?
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