Running Hot

I had the same problem for ages and after checking almost everything involved it turned out to be a faulty temp gauge. Got a spare one from a scrapyard and presto!

Have somebody to accurately measure the actual temp, it could well be the sender or the gauge itself.

I don't know but I had my mechanic check it for me. He used a digital thermometer which had a probe that he put into the cooling fluid. The tem gauge was clearly approaching the red zone while the actual temperature was 85 degrees, which is more or less the optimal working temperature.

I recently completed a full cooling system overhaul and had my rad rebuilt which included descaleing. It has made an amazing difference so much so that the kenlowe fan i fitted in place of the viscous one hardly ever needs to come on, the temp always stays between the quarter and the half mark where as before it was halfway creeping up to nearly 3quarter mark when towing of climbing a steep hill

I changed the radiator antifreeze to Mercedes own product and the gauge dropped a whole segment.

Probably too late to be of any help now, but maybe useful to others. The primary function of a radiator is to act as a heat transfer, it does this by transfering heat to colder air passed through it drawn by a rotating fan behind a matrix through which the heated water is passed.
In order to function efficiently the air must pass through the radiator matrix in sufficient volume and speed as to transfer or cool the heat contained in the fluid. Also the water must pass at sufficient speed and volume through the matrix core to pass its heat to the air.
So check first that the air flow is not impeded by dirt in the matrix, just the simple acumulation of dead flys over the years will disrupt this flow. second is the viscous coupling of your fan engaging if not then you will not get sufficient air at low speed high work loads.Is the belt that drives it tight enough it also drives the water pump.
An obvious but often missed problem. has some one fitted two huge search lights in front of the rad blocking the air flow.
When you have checked all these, then get technical. but first simply drain system, flush and refill. In my 45 odd years of vehicle engineering the only thing I have successfully descaled is a kettle, think about it, if you move the scale from the internal suface of the radiator how do you get it out.
Answer, you don't it just moves elsewhere and causes another blockage.
A very simple test is this.
Remove the drain plug from your radiator, with it out try to refill it, if you can't keep up with it running out then its probably ok, if you fill it before it runs out, get it recored.

Depends what you call power It is free revving now I also get about 2MPG more.
Where I notice it is: I live near Dover docks and the Jubilee Way which is a 1:4 I used to get up it at 45mph at the most now I can manage it about 55 :roll:

It is the Kenlowe 2000series Fan B16 (16 ") It cost me £138 for the whole kit.. everything needed but I also had rad rebuilt and recored.
Kenlowe can be reached at 01628 823303

and getting about 25mpg too

Jesus,
Mercedes are very conservative with their power output and fuel consumption figures(or were up to 1989 shall we say).
Their engines take ages to run in and loosen up. If rups has got road-orientated tyres, keeps them up to good pressure, regularly changes all filters, uses not too heavy synthetic oil in the gearbox and diffs and engine and keeps the engine finely tuned in a bit on the lean side, then I genuinely believe him.
By comparison with official figures, consider a recent trip I did with my sprinter:
We went through France, Belgium, bit of Holland, through Germany, Austria, Switzerland, Italy and back to London. During this entire trip I accurately recorded mileage via GPS and litres of fuel used. The van is a high-roof MWB and was loaded with tools, enduro bike and camping gear. Driving was all country roads except Germany where I couldn't resist the temptation of the Autobahn(foot to the floor genuine GPS 99.8mph) for extended periods. Other times were relaxed sight-seeing trips. Others included going up Stelvio(1st and 2nd gear foot to the floor traction control light flashing nearly all the time). So a good mix of driving conditions. Overall for the entire journey was 36.4mpg - well above any of the official figures!

Jesus,
You are so right - especially concerning the diesel models! I was employed by MB many moons ago and I can confirm that their strategy was always to develop an engine to its full potential, do all endurance tests with it like that and then deliberately decrease the power output so that it can last in the hands of the not-so-careful drivers. I once drove a director's-spec W123 300d. This basically had been optimized by MB for maximum power but without turbo - governor altered, fuel pump timing changed and a few other things... It was scary! Had a proper roar to it with the go to match. Never driven a diesel with such effortless wheelspin pulling away from the traffic lights. Apparantly was good for 130mph+.
Sadly these cars were always detuned before being released to the customer market or crushed or disassembled by the factory for research.
Along similar lines was the unimog they used for rally support on the Paris Dakar. With little work the factory more than doubled the power output and were doing over 100mph on gravel in a unimog! If I remember correctly, they actually won their class in that but it never got recognised because it wasn't entered officially as a competitior.
Fact is MB know a thing or two about their diesels but they have always put durability before outright power.

Gosh, didn't realise it would make such a reaction.... but truly that is what I was getting, going from Godalming up to Putney on the A3 about 65=75 mph and a bit around town... ok maybe 23mpg.
Also had the timing set right and the vacuum lines all replaced so it was pretty efficient.
Sold it now but Redmond drove it back to Ireland, can you confirm mate!??