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Old 30th August 2017, 23:57   #4
alanaslan
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75 Tourer Automatic conn, 75 Saloon Automatic Conn, The Monograme Spice Tourer

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Quote:
Originally Posted by mmz View Post
I really would like to get my 75 CDTI to run smoothly but it seems to be quite difficult. Do the following symptoms tell something to somebody more expert than myself?

- engine vibrates too much at idle even when warm
- fuel consumption is around 7 l/ 100 km at normal highway speed
- turbo seems to come along quite late
- engine feels a bit powerless especially when accelerating from a standstill
- in practice you can not use 6th gear below 60 km/h due to lack of torque
- heavyish buzzing sound from somewhere in the engineroom when driving and putting on power
- engine "rumbles" and vibrates slightly on highway when putting on power at speed (like the mountings were broken which they are not)
- fuel moisture at the bottom of cylinder one injector
- cleaned EGR and inlet manifold pressure sensor with no effect
- replaced MAF and air cleaner with no effect
- replaced fuel filter with no effect
- replaced engine temp sensor with no effect
- engine temp stays at "eight a'clock" except only when idling for a longer time e.g. in a traffic jam
- TOAF live data shows that injectors 1 and 3 are correcting flow values more than others when idling

There are no local Rover garages with analysers here anymore and others seem to be a bit reluctant to take my case. Rover really seems to be a dead and gone brand outside UK nowadays.


The engine vibration described is a classic description of bottom engine mounting failure. I would recommend you change the bottom engine mounts bushes both the big one and the small one.
Personally I would fit polly bushes.

There is no Diesel Rover 75 with a six speed gear box as standard, if yours has a six speed box, I would investigate the mounts on the conversion. If it is a Six speed box please check the gear ratios as the box may have ratios incompatible with the turbo range on finial drive ratio. The 75s Diesels turbo range is quite a tight band. I.e. Comes in late drops out early. Very different to Ford and Vauxhall.

The Diesel engine fitted to the 75 is a very good example of a high torque over a wide rev range. The lack of torque you describe sounds like an intercooler hose rigidity problem. Again I would recommend changing the intercooler hoses. These are available in quality multi ply silicone, I would recommend changing the intercooler hoses for quality new ones. Once the turbo can breath with out change of hose diameter I think you will notice a difference. Personally I would also run the intercooler through a parts bath, making sure all the grunge and crud is removed from the inside of the unit.

The description of engine temperature sounds like a thermostat problem the Diesel engine in these cars is a naturally cold running engine. I would replace the engine thermostat with a new unit if that fails to bring the engine up to correct engine running temperature, then a popular way to fix this problem is to fit a Renault 5 in line thermostat in side the top radiator hose. This is done in tandem with the existing Rover thermostat. Either fit an 88 or a 92 degree thermostat from a Renault 5, this supplementary thermostat will ensure the engine reaches correct running temperature.

The BMW diesel lump we have in our cars perform much better when at the correct temperature if the car is running cold when you get it up to temperature you will notice a marked decrease in the amount of fuel used. Possibly as much as an extra 70Km on a full tank of fuel.

I personally drive Rover 75 Diesel automatics. The estate is my main tow car. It is a 158 Bhp remap. When towing my 1.4 tonne caravan I use sports drive. As it shifts the rev band more into the turbos operating range, for pulling the extra weight. She does this returning 8.7 ltrs / 100 km. running without the load she returns about 7.7ltrs/100km.

My saloon is remapped to 135 Bhp my wife uses her about town only she returns about 7.8ltrs/100 km.
Both my wife and I love our Rovers, don't know what will be the following act hopefully I will have them for another fourteen years.
By which time it is doubtful if I will still be driving. That age thing again.

Hope you get your problems sorted soon. Once you have her running smoothly you will see why so many of us love our Rovers
A very hard act to follow.
Alan



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