Clicking diesel heating pump

[ian81]

We have a Webasto heater which we find most effective. However we find the clicking of the pump a little loud. Crawling under the MH I note that it is attached via a rather rigid and inflexible rubber mount to the floor which then amplifies and resonates the clicking.

 

It seems a fairly light pump and I was wondering about replacing the mount with some rubber loops similar to those used to suspend the exhaust, or moving the mount onto the metal chassis.

 

Has anyone got any thoughts or ideas?

 

Thanks Ian

[mirage]

There have been several references to the noise some heaters make ours can be heard outside but the heated air leaving the vent at full blast is the only noise inside. Excellent in heat production, running cost and flexibility of use i.e.on site and road without the problem of running out of gas. Not heard of anyone having to go to such lengths to dampen any noise.

[Derek Uzzell]

ian81

 

These heaters are really designed for vehicles where the pump clicking won't much matter. Whoever installed your Webasto heater will have just used Webasto parts and followed Webasto's instructions, and probably won't have considered pump noise.

 

There was an earlier forum thread about this (I think the heater was Eberspacher-made) and the intrusive clicking noise was said to have been much reduced by a revised fuel-pump mounting.

 

As the pump is light, you could first experiment by running it with no mounting and, if the clicking noise lessens dramatically within the motorhome, then you'll know you are on a winner. If it doesn't, then you'll probably have to box the pump in an insulated box (or something!!)

 

Not sure about your rubber-loop idea, as it might not provide sufficient support for the pump. You might try a less rigid mounting - like a foam 'sandwich' - that would both support the pump but not transmit the noise. Like most DIY problems there will be many different approaches to a solution.

[Stuwsmith]

I downloaded a copy of the repair shop manual for the Air Top 2000 several years ago from the Webasto site. The bit relating to the dosing pump says it is to be attached with anti vibration mounts. It also says the pumps installation location is limited to certain positions shown in a couple of diagrams to ensure sufficient self venting capability. Not sure exactly what this means except that if you change the pumps position beyond certain limits shown in the diagrams you may have problems in operation. My pump is mounted in the engine compartment near the battery (VW T4) I can hear it on start up before the heater is going full blast and can hear it if the heater is on low heat ie slow fan operation but it is not intrusive. I am pretty sure it is fairly flexibly mounted.