e 300TD (1999)

[dmcilmoyle]

I would appreciate some advice on the need for additional oil cooling after fitting a towbar - I will be towing a caravan (MIRO 1400 Kgs). I understand that an additional cooling fan is recommended on this model but I have also heard that very few people actually have the additional cooling fitted.
Do I really need it?

Thanks

 

[Cooky]

I don't have the 300TD, but I do have a 250TD auto (1999) which is similar (a little lighter and a bit less power), and I have pondered the same question. I tow a caravan with a max loaded weight of 1460Kg.

The car has a pair of electric fans in front of the radiator which, as far as I know, are original equipment - the car did not tow before I bought it. The temperature gauge runs about 10 deg hotter when towing up inclines; once on the level it gradually drops back to about its normal position (80 deg). I have never heard the electric fans cut in.

What I have observed (typically on motorways) is that if I leave the gear selector in D (i.e. so that the car changes up into 5th) then there is some slip evident from the torque converter. Without the caravan 60 mph equates to 2000 rpm, but with the caravan this can rise to about 2200 rpm. This slip must get transfered into heat, and maybe this is what causes the higher temperature (the transmission oil cooler being part of the radiator).

So, what I have taken to doing is move the gear selector to 4 for most of the time. That gives me about 2500 rpm at 60 mph - which is the same as without the caravan. So now I don't think there is any torque converter slip, and less extra heat is generated.

I'm sorry this is a bit long winded but (IMHO) it's not a straightforward subject. I've been towing caravans for nearly 20 years but this is the first automatic I've towed with and I've been keen to understand what's happening. I'm taking the outfit to France next Friday; hopefully all will be well.

Rgds

 

[dmcilmoyle]

E300TD towing

Thanks for your comments; I have only towed with the 300TD on two occasions and found that the temperature remained around 80 C for the duration of both trips. My gut feel is that all will be ok, but I have the car for just 6 weeks or so and would hate to give myself problems so soon.

I hope your trip goes well, I hope to follow you to France in about 6 weeks time and I expect (hope) that the ambient temp will be at least 10 C higher than it is here!!