[LondonThing]

There's the good newsand the bad news... put the 300TE into the shop for a bit of winter care and found that what I thought was worn suspension bushes at the back were simply dry bushes: a bit of lube work by the mechanics and the ride is silent and smooth. They also changed the propshaft donuts and the whole transmisison response is hugely better: no more thumping into gear from idle, smoother idling, smoother shifts: it's an easy and speedy job and well worth it on cars over 100,000 miles.

The bad news... for some weird reason, the heater stops giving hot air once on the motorway! It's fine around town but get it up to speed and the heat dries up. Any guesses what this could be? Heater pump or duovalves?

 

[georgeeight]

Hello mate

How much did the service cost you? Sorry don't know much about heaters[]

 

[spanners]

It's an unusual one that. Don't think it would be the duo valve, because it is letting the heat through on idle. Sounds like a bad water pump, but that's only and educated guess.

 

[LondonThing]

I think it was a couple of hundred to put the propshaft joints in, have the bushes looked at, and attempt to put the engine mounts in. Haven't had the bill yet...

 

[LondonThing]

so to be clear, I should go after the electric pump on the chassis rail?

 

[spanners]

LondonThing - 2/6/2005 7:53 PM

so to be clear, I should go after the electric pump on the chassis rail?

No, if I am right, the electric one only helps to circulate the water on idle when the rpm's are low.

I was thinking of the main water pump. I have heard of water pumps where the impeller has snapped causing the type of symptons you are having, but I don't ever recalling it happening on an MB.

 

[LondonThing]

Interesting...

The water temperature seems to be accurate, and rock-steady: it sits marginally above 80 all the time since I changed the thermostat. I don't know to what degree the W124 coolant system is self-circulating.

 

[spanners]

Has the problem only occurred since you replaced the thermostat?

If so, I would be looking at an airlock.