Looking for some help. My 525d msport e61 which I've owned for just over 2 years is driving me mad lol. I've had an issue with turbo lag, power and MPG since buying the car. I'm about to give up on the car and sell it but am having one final push to sort it out.
Since owning the car, apart from very regular oil changes and servicing I've done the following:-
Swirl flap removal and blanking kit fitted
EGR valve cleaned every 5,000 miles or so
Regular use of DPF cleaner and RedEx injector cleaner
All 3 thermostats replaced
K&N Air Filter
Engine carbon cleaned (3 times in 40,000 miles)
Glow plug control unit replaced
Brand new turbo charger fitted
Remapped with a reputable company
Replaced fuel filter
Replaced fuel heater
After all of this, it still doesn't seem to run right and was lacking a bit of power, making an air whooshing sound, slight turbo lag and in and out of limp mode (most annoying). It's booked back into a local specialist independent garage today for a couple of O2 sensors to be replaced, the intercooler pipe to the EGR valve has a split and that's being replaced too (seems you can't just replace the rubber part, it's the whole pipe right from the intercooler to the EGR valve). One of the drive belts is also looking frayed and cracked so that's being done at the same time.
I've tried unplugging the MAF to check it's working and it would appear to be fine (I cleaned it anyway).
So, my question is really is it time to get shot or is there anything else that from experience anyone can also suggest?
With the car unloaded, and driven at 70mph on the motorway, I'm only seeing 34mpg. Temp seems fine - 90oC plus (accessed via hidden menu). When I stop the car, the only thing I have noticed is that the car smells (and sounds) really 'hot' if that makes any sense.
Thanks in advance from a frustrated 525d owner lol