Lack of power

jugglia

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310D 1992 OM602
Hi all, new to the forum and to the world of Mercedes Benz and engines in general. I've just bought a 310d motorhome which needs a lot of work, but thought the engine sounded lovely. I've spoken to a chap who seems to know about these things and he thinks I'm not getting the fuel economy that I should (currently about 15mpg I reckon), top speed (absolute max is around 55mph downhill with a following wind), or general power (slows to less than 20mph at the slightest gradient). I've changed the fuel filters, and it seems to pull away a bit better, but top speed is still slow. It's an automatic, and the thing that has struck me is that it appears to have four gears, and gets into fourth at around 25mph, which means it has one gear from 25mph up. Is that normal? Does anyone have any suggestions where I should start with this? Please bear in mind I know nothing about engines, but I'm keen to learn. Thanks in advance!
 

turbopete

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2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
ive never had any dealings with the auto versions but the 310d is an asthmatic thing at the best of times. in the manual versions ive driven, 1st is nothing more than a crawler gear, and top speed is about 70 (just!) in EMPTY VAN form!!! add to that the weight of all the stuff that goes into making it into a camper, and the fact that you dont want to be sat hour after hour listening to the engine screaming from under the panel in the cab floor, and id say 55ish is probably about right for top speed!
0-60 (even in an empty manual van) is times by calendar rather than stopwatch, and yes, any hills and you dont have the momentum or power to get up them without the speed dying off as these engines were ridiculously underpowered for the vehicle! ive not spent enough time with one to know what MPG they should do.
 
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jugglia

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Really? It's soooooo sloooooooooooooooooow. I can't believe anyone would make a vehicle that slow! Surely there must be something I can do? How hard is it to fit a turbo?
 

turbopete

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2017 '17' Ford Mondeo 2.0TDCi ST Line X 180 (sorry)
ive fitted a turbo in the past to the bigger 410d and although much simpler to do on those older engines, its still not easy. in the case of the 410 it needed an exhaust manifold/turbo etc from an early (pre electronics for turbo etc) sprinter, the exhaust system modified, oil feed and return pipes fitted for the turbo, minor modifications to the floor to get clearance for the turbo, a whole host of boost pipework made, injector pump opened up to allow sufficient fuel on boost etc.
yes it can be done, but its not a 2 minute job and, unless you can DIY and lay hands on the parts cheap, its not exactly a cheap job either. the conversion i did, the guy had brought the vehicle for an engine rebuild anyhow so asked if it could be done whilst we had it apart. it STILL wasnt an overly quick motor, but it WAS at least quick enough to cope wth the traffic instead of holding everything up! 0-60 id estimate to be down to warrant a watch rather than a calendar! probably 20ish seconds, about similar to a non turbo 2.5 DI transit
 
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jugglia

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Well thanks for that. Someone I spoke to suggested that the rear axle could be changed as they often had one that was designed for pulling power rather than speed. But then I would imagine the top speed would be greater but it would struggle even more on hills... Not that I have the foggiest idea about these things to be honest. But I am going to pimp this sucker out over the next year so that come hell or high water it will do ... 60mph! Might need a bit of work.. Thanks again for your help.
 

jpmellish

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HYMER 310D 1990
I have 310d auto hymer motorhome, cruises at 50-55 top speed is about 70 -75

Did you change the inline fuel filter, that can cause a problem as it can be missed.

I had the injectors cleaned, which made a difference with mpg.
 
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jugglia

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310D 1992 OM602
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Throttle cable

Sigh. Should've checked the throttle cable first shouldn't I? Getting at least 10mph more now, 20 on motorways! Thanks for the helpful advice anyway guys!
 

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