Anyone good with BMW's?

[UNICRONICUS]

Ok, so I gave up on the BMW forums because they look at themselves in the mirror whilst they type and I don't usually get a straight answer out of them...(shouldn't be posting here really then, but hey, you guys are funnier)

I have the 2.5 litre M50 engine in my 525 and it doesn't run as well as I would hope. In colder weather, especially when it is raining, a lot of white smoke/steam will come out of the exhaust, more so if I floor it. It also feels sluggish and not as responsive as opposed to the weather being warm and dry where the engine doesn't really smoke at all. My MPG is also pretty bad, it's roughly returning 18mpg at the moment which I consider to be piss poor, this is under light load, low revs, slow speed etc... basically very conservative. What do you think would cause these problems? Faulty air mass meter? Dodgy cat? Something German?

Any help is much appreciated, or any other comments

Tears!

[paul b]

air mass meter,lambda sensor,coolant temp sensor would all cause the above...

also, poor wiring connections, any damp terminals,green corrocion on pins/connecters..

they have a heated lamdda system, this can cause problems too....

also, check your basics, crank breathers pipes, air pipes etc.......

[UNICRONICUS]

That's the thing with these bloody cars! To get a lambda sensor or an air mass meter costs a shed load of money (air mass meter = £170, lambda probe = £50) I have checked some oil breather pipes thinking that this might be the problem, and although there was some gunk in the pipes the problem didn't clear after I cleaned them out. It's just strange how it only gets worse when the air is more moist...

[Alex]

I have the same motor in my BMW. It sounds like possibly the lambda sensor as you say. Are you getting any engine check lights at all?

Have a look on www.bimmerdiy.com (if you haven't already) I've found it quite useful in the past. Keep use posted if you get it sorted as I'd be interested to know myself...

[UNICRONICUS]

I have the same motor in my BMW. It sounds like possibly the lambda sensor as you say. Are you getting any engine check lights at all?

Have a look on www.bimmerdiy.com (if you haven't already) I've found it quite useful in the past. Keep use posted if you get it sorted as I'd be interested to know myself...

No engine check lights at all. The BMW guys say that it's common for the E34's to smoke for at least an hour before the massive exhaust system heats up, I think different... One of them mentioned the water temp sensor too, but on the same comment he also said that, 'The excess white steam is probably the car overfuelling'. I thought black smoke meant the car was overfuelling...

What's your mpg like in your motor then Alex, circa 18mpg when driving slowly?

[Alex]

I don't think steam will be overfuelling. Thinking about it my car tends to blow out quite alot of steam when the engines cold in this cold/damp weather...

I haven't really worked my fuel consumption to be honest but I get around 300 miles to a tank - £51 on the last fill (presumaing the 5 series tank is the same size as the 3 series?)

[UNICRONICUS]

So presuming that your £51 filled up the car from empty at 92.8p per litre I work out that your car gets 27mpg, which is a lot better than mine!

[UNICRONICUS]

Paul, do you know which coolant sensor I could order from GSF that would fit? I.e. is it the one that fits into the head I take it?

[Alex]

Just worked out I'm getting around 25 mpg. That's driving pretty slow...

[UNICRONICUS]

Yep, still kicks the crap out of my mpg

[Alex]

Sure does. I guess the best thing to do is start with the basics/cheapest suspect parts first. I take it the cars been serviced as it should have been? Failing that I think I'd go for the coolant temp sensor and see how you get on.

[UNICRONICUS]

Cool, well I've ordered a new coolant temperature sensor, plugs and new air filter so I'll see what difference they make if any... In all fairness though, I hate my car and want my old GTT back Although it is comfortable...

[Alex]

I use mine as the daily hack. I actually quite like the car and it's practical and comfy as you say. I think once my GTT is back on the road I'll be using that more though!

[UNICRONICUS]

Fo sho