Volvo MD2020B Overheating

[tjc]

I have follwed all the threads concerning the heat exchanger problems as my VP2020B overheats under loads at about 3/4 throttle. So armed with that advice I took mine out expecting it be full of crud. It was fairly clean and is now soaking in vinegar to get rid of what bit is there.

When I drained the fresh water through the tap very little came out despite the system being full. Could the blocakge be in the fresh water channels?

Could it be the thermostat, if so is replacement of the thermostat just a matter of unboltring the heat exchanger manifold and swinging it out of the way or do I need to take of the exhaust?

Should I descale the raw water system with Rydlme or similar although the flow through the system seems fine.

One other think I have noticed is that the temperature may rise quicker if I turn off the feed and return to the calorifier.

Any other advice or tips welcome.

Thanks

 

[alan]

I had overheating of 2020 because of a fouled prop (feathering type); this only happened at about 3/4 throttle when the propellor wasn't able to 'absorb' all the power; throttling back solved the problem untill I could get under and scrape the prop. Of course if yours is doing it when in neutral, then that is not the problem! Just a thought ...........

Alan.

 

[aztec]

Hiya,

Had a cracked head on one of these, ran fine untill loaded, then overheated an lots of smoke/steam... took me ages to find the problem.

Hope yours isn't. although easy to fix... not trying to be scaremonger, but just something to bear in mind.

good luck.

 

[tillergirl]

According to the manual, you remove both exhaust hose and alternator.

 

[Carduelis]

Similar problem on my 2040 was a jammed thermostat.

I assume you have a good raw water flow BTW?

 

[tjc]

Hmm thinking it is the thermostat so off it comes this weekend. Thanks for the advice