I've had my p38 about 2 months now and mpg has always been low it was 7 when I got it I found a few split pipes and a sticking rear caliper and it's up to 19.6 mpg now even on a motorway run I'm only seeing a small increase 19.8 mpg . I'm not running a viscous fan using electric so the fans not over cooling it's got a new stat in and a new aliminium rad but my temp gauge only goes to about the 11 o'clock position and wondering if this is why I'm not seeing the few extra mpg or is there other things to check I've got hawkeye diagnostic and no faults but wondering if that will show me what temprature its actually running at thank you
Datatek
Well-Known Member
Gauge should be just to the left of 12 oclock. However the gauge temperature and the EDC temperature come from 2 different sensors. You should be able to see the actual engine temperature from diagnostics. If the EDC thinks the engine is cold, it will over fuel. Do you have a power box fitted?
On the motorway cruising at 110Kph, mine gets close to 30mpg on a brim to brim basis, long term average is 24mpg, however on the crowded UK roads it drops to 21/22mpg.
No tuning box fitted or any mods I'm wanting to fit a ton box soon and thinking of egr delete
Datatek
Well-Known Member
To delete the EGR, you just need to pull off the vacuum tube at the actuator and block the tube with an M5 screw.
Fitting a power box will eat the gearbox if it's an auto and if the oil & filter have not been changed recently, it should be high on your to do list
I've only just done the auto box last week and added some lucas transmission fix and it's done it the world of good but I think I'm going to look at upgrading the gearbox in the summer to the 24 but still looking into what's involved
Henry_b
Think outside, no box required.
You need the later 065 HP24 box if you're intending to "upgrade".
You've cleaned the intercooler out, changed filters and checked turbo hose? Plus, is the MAP pipe connected and clear?
S
I've not cleaned out the inter cooler as it seems to be boosting fine and I replaced the map line not long ago as it was split that's when my mpg was down to 7 mpg
Doesn't take long and always makes a difference.
RangeRoller dt
Well-Sprung Member
Should get 20mpg easy 
Intercooler flush does make difference if it’s not been done. small amount of oil gets pushed through from the turbo, builds up and cakes the baffles over time.
Pipes start to delaminate inside at this age too
No viscous fan should give you bit more mpg
I get about 30 and I have oversize tyres which won’t help.
Intercooler flush does make difference if it’s not been done. small amount of oil gets pushed through from the turbo, builds up and cakes the baffles over time.
Pipes start to delaminate inside at this age too
No viscous fan should give you bit more mpg
I get about 30 and I have oversize tyres which won’t help.
Datatek
Well-Known Member
Sorry that is not correct, the longer early box also fits but without the spacer between the end of the auto box and the transfer box. IMO the early box is stronger.
Datatek
Well-Known Member
You have to use the diesel bell housing & torque converter and it may be necessary to swap the oil pump, other than that it's a straight swap.
Henry_b
Think outside, no box required.
Yes but the 065 fits without modification, only the TQ is different.
There is no mechanical difference between the 065 and the early box,
RangeRoller dt
Well-Sprung Member
Someone on here did one explaining the oil pump swap.
I read it long time ago before I was a member so may be in another (Disco?) section?
I read it long time ago before I was a member so may be in another (Disco?) section?
Datatek
Well-Known Member
In both cases the bell housing has to be changed and in both cases the pump/torque converter interface may be different in which case the pump has to be swapped from the HP22. There are no other mods apart from removing the spacer for the early box.
I've had a mess today with the diagnosis plugged in and figures dont seem right at all . Max boost under full load is 1941 hpa think that's about 29 psi I expect thats not standard figures ? And my temperature is dropping to around 76degrees when moving and under load rises to about 83 and when parked my electric fan kicks in at 90.7
RangeRoller dt
Well-Sprung Member
Boost should be 10psi iirc.
Would think 29 would kill it pretty sharp
Would think 29 would kill it pretty sharp
That doesn't sound right. What diag is this?
RangeRoller dt
Well-Sprung Member
Nanocom 06 you want for EDC
