parmblagan

hi guys

i have this problem with low MPG with my car (average through town is 20 MPG from auto 525D 2005) want to get it solved as its costing me a packet. i have had a new air mass sensor put in and the MPG remains the same. had it remapped but the mpg remains the same. so after reading this topic i checked the temp. of my car and it gets to max of 84-86 depending on my speed, but usually takes about a 6 mile journey to acheive these temperatures.

this week end i removed the egr thermo, and exaimed it. i too can blow air through it.

so my question is my car is getting up to 84-86 but i can blow through the EGR thermo, do i need to replace it?

Phantom Mark

You really are having a torrid time of it Parm........you have my sympathy mate, best of luck, I really hope you track this mofo down

Bob525D

Just remembered something to check, when i got my A6 2.5 TDi. I was getting poor mpg (10MPG), this was due to a loose boost hose. I would double check that you dont have any air leaks anywhere. After tightening the hose I got 32MPG on average. I plan to take my 525d to bits to inspect the hoses for any signs of wear. This can be checked without spending anything.

parmblagan

do you have any diagrams of the boost hose, where an i find it.

what mpg do you get out of your 525

Bob525D

I dont have any diagrams but you could look at realoem, basically you want to follow your air hoses from the Turbo to the intake looking for any splits or loose clips. I currently do mostly 30 and 60 limit driving with loads of stops, I am getting around 24-25MPG. I had no idea that this car would drink Diesel as if it was petrol, otherwise i may not have bought it. I'd probably have went for a 530i Petrol instead.

Live to learn I suppose. I am a bit p!ssed with the garage I bought it from at the moment, I have just had to shell out for a new front tyre due to poor alignment + a vehicle check service + wheel alignment = ?450 out of pocket. Only had the car since 5th Feb, there is alot to be said for buying from a larger garage.

pigapumbu

+1.

my 535d fuel consumption is crap. I get 21mpg in town and 38 cruising at 75mph. Operating Temperature is spot on so why I get poor fuel consumption is anyones guess. I know taking it to the dealer to sort will be a total waste of time. Experience tells me these sort of complaints can never be sorted acurately.

Next time I change car it will always be a petrol. BMW petrol cars have gained a milestone in terms of fuel economy and with the price of diesel vs petrol here in our island, unleaded is the way to go. In a few years time, I am sure the price of diesel will be a lot more than unleaded.

cheers

mini_me

My 2004 525D runs at 90C ish on a 20 mile highway trip. Maybe an auto tranny (i have a manual) makes a diff.? Or maybe a stuck EGR valve?

But still; a diesel should have an operating temp of about 90C, so please keep this rule of thumb in mind!

BingoBonzo

I just installed the AGR Thermostat and now the temperature is at 78degrees celsius and it was in the low sixties (just tried it om a 10 minutes trip, but it stabilized at 78). There might be more here, but there is one down. I could blow air through the old one. By the way, I was not able to remove the vacum hose so I had to remove and insert the AGR while the hose was in place. Took a little more time and cursing but I managed after some time. Thanks for the instructions!

BingoBonzo

How do you know when the DPF is kicking in?

E61530DAT

I`m finally reaching normal operating tempereature 90 - 93 C ! After first replacing the EGR thermostat temperature improved from 62 to 78 C. Now I have replaced the main thermostat (not as easy as EGR!) and temperature are stable at 91 C !!!

Replacing the main thermostat took me 4 hours and I had to remove two airducts and the exhaust cooler to get to it. ...

I drove to work today 100 km with both higway and rush traffic - now using average 7.1 liters /100km - before 8.3 liters /100km