740 td UK, idle speed?

Hi I recently bought a 740 turbo diesel , got it through an MOT, and started
using it as my daily driver. The fuel consumption seems poor-28.4mpg over
238 miles mixed use.
The brakes aren't binding, the tyre pressures are ok ,there are no fuel
leaks, the car passed its emissions test, so what am I missing. The idle
speed seems high at 1000 rpm, most diesels I've driven are slower, could
some form of cold start system be to fault?
Also does anyone know where I can get technical info about this engine, a
workshop manual would be ideal, failing that even just a list of clearances
and torque settings would help.
Thanks

Stuart Hosie.

 

That sounds like typical fuel consumption for that car, I've encountered
one running 760TD so far and it seems that's about what the owner said
he was getting for mileage. The car was an automatic though as most 700s
here are.

 

should be 830 +/- 50 rpm. Mine did 1:13- 1:14 if I stayed of the motorway.
First thing to check is probably injectors (min opening 140 bar, torque
70 Nm) and timing (0.9mm)
valveclearance is 0.2 and 0.4mm (cold)

Engine is also used in the VW LT, and err you've found the overdrive i hope?

 

Gearbox is ZF so there is no overdrive. However it is a four speed box with
torque lockup over 57mph in fourth, which is like an overdrive.
Stuart you need to go to your dealer (Volvo) and order part number
V97000164, pay him the £30:00 up front and it should reach you by the next
working day. Oh yes, it is the Volvo Green book for the D24 diesel engine in
it's three guises (diesel, Turbodiesel and Turbodiesel with Intercooler);
with power levels of D 85bhp, TD 109bhp and TIC 122bhp. How many miles are
on the clock? There are some tips to keep it running nicely. If you e-mail
me I can let you know the tips. I run a 945 with TIC on 100% Biodiesel fuel.
I have just replaced the Injectors and one glowplug and stuck a new battery
on it. It now runs better than when new at 168,000 plus miles.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Thanks for the comments guys. OK it's a1988 model 163,000 miles/ manual 4
speed transmission with electrically activated overdrive. Looks like I,ll
just have to put up with the fuel consumption , but thanks for the input.

 

I don't think I ever managed 1:10. even on the German Autobahn. A diesel
specialist should be able to check and adjust all the basics in two hours.

 

I have had a 1990 740 TD manual Estate since last September.
It has just over 240,000 miles on the clock, and has 'allegedly' a
replacement engine.
The engine looks old enough to be original, however, so presumably from
another vehicle, perhaps even a van as it has VW on it.

I have had 'interesting times' with it, mainly due to lack of
engineering skill on the part of the company which sold it to me.

It seems to be running fine at the moment, apart from some problems with
oil smoke on starting from very cold, or after a long period of slow
driving (around 1,000 rpm).

The tickover is about 900 rpm, which is a little high.
I have had it given the once over by a diesel specialist and in general
the injectors etc. seem O.K.

On the subject of MPG:

when I first started driving it, I drove it much like my previous TD (a
Peugeot 405 TD) i.e. much like a petrol vehicle; rev the engine to get
more power, more than 10% over the 70mph limit on long runs.
This didn't seem to affect the MPG (40-42), not even towing made much
difference.

I was getting 29-31 mpg and wondering what was wrong.

I have now modified my driving style. I pull away slowly, change up as
soon as the revs get to 3,000 (turbo really kicks in at 2,000) and go to
overdrive as soon as possible. I try not to use more than half
throttle. Keep the revs below 3,000 on the motorway. This doesn't seem to
slow me down much - although I am slower away from lights and roundabouts,
the vehicle just keeps accelerating because of the torque and gets to
70mph almost as quickly.

I am now getting around 35mpg, which is not bad for such a large vehicle
with such an unsophisticated diesel engine.

So, keep it in the 2,000 to 3,000 rev range wherever possible.
Avoid full throttle - it doesn't seem to do much apart from throwing
unburnt fuel out the back.
Smooth and steady does it

HTH
Dave R

 

<snip>

The engines were supplied to Volvo by VW. IOW they all had VW stamped
all over. The fuel and oil filters did say Volvo when they were new.

Bob

 

However they are slightly different. Volvo put their own crankshaft pulley
on and drilled and tapped a hole to take the dipstick tube. There are a few
more minor differences. I had a VW commercial garage swap out one on my 760
GLE turbodiesel that didn't take kindly to a repair by a non-VW/Volvo
repairman. Cost was £3,200 (in UK).

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).