330CI - Sluggish + Poor MPG

[clio007]

I have recently purchased an 2002 E46 330CI Auto with 85k. I cant help but feel the car should feel alot quicker than it actually is. I have driven my fair share of cars, and this feels more like 150bhp than 231bhp.
It is also average 17 MPG and thats with me taking it easy
No funny lights on the dash, which is why I cant quite work it out.
Any ideas?

[E30M3SE]

Get fault codes read and see if that brings anything up would be my first move.

[benny.c]

I thought my 330 never really felt that fast. The performance was a bit of a disappointment actually but that 17mpg is terrible. Driving carefully I used to get 28 ish if I remember correctly.

[cslwannabe]

I got 18mpg when I test drove a 330 - stuck in traffic for a lot of it. Used to get 28-31 mpg out of my 330Ci manual. If you want to check performance try timing it 30-70 or if you have access to a private racetrack say 60-100, as much better than trying to match quoted 0-60 times.

[Gaygle]

There will be something wrong with it. It should be getting 25mpg+ (i'm on 28.8mpg at the moment with fast A road driving inc overtaking etc). And it should feel faster than a 150bhp car.

As said, get the fault codes read and go from there. It may just be in dire need of a service or it might have a broken O2 sensor.

[tgr]

Even with the automatic gearbox I would investigate that mpg - it's too low. Don't rag the engine until you find out what's wrong

[8Tech]

Sounds like a MAF meter fault to me, that would not bring up either a fault code or an EM light.

[nvm]

A simple fault reading wont highlight issues such as this, you will need a full scan of sensors with a datalog.

[Patrick Bateman]

Performance is more linear, it doesn't half shift though once you're up at 5000rpm.

[rich85uk]

in terms of pace you should be the same as a golf R32, seat leon cupra R (225 model) i have a manual but im sure an auto isnt that much slower

generally average around 33mpg in manual so would expect atleast mid 20's in an auto

where abouts are you? could be a good indy garage nearby

[R26Andy]

MAF, CAT or COILS is usually the answer to those symptoms.

[PJ S]

Things you can do first are:
BG Products 44K as per instructions over 2 tankfuls
Their engine flush with an oil change
Their MAF cleaner used on the MAF
Change air filter
Disconnect battery for a while to force the ECU to relearn air-fuel mix
Check current oil level

If its still poor/sluggish after that, then MAF itself or/and thermostat sensor.
Don't think 3ers suffer known brake-binding issues, but should be easy to rule out.

[Gaygle]

PJ S said:

Don't think 3ers suffer known brake-binding issues, but should be easy to rule out.

Oh it does. Many E46 owners have had to replace calipers due to binding. However, if it was to the degree of the OP only obtaining 17mpg and it feeling like a 150bhp car, i can't help but think the brakes would be on fire after about a mile.

But definitely try the rest of the stuff PJ S mentioned - a good starting point which shouldn't cost too much at all.

[j44esd]

I know a few have suggested other stuff, but my (2001 330i Manual Touring) was a cam position sensor when it exhibited those symptoms (Actually, it was both sensors, but hey ho...) - Good luck getting it sorted though!

[Gaygle]

j44esd said:

I know a few have suggested other stuff, but my (2001 330i Manual Touring) was a cam position sensor when it exhibited those symptoms (Actually, it was both sensors, but hey ho...) - Good luck getting it sorted though!

Wouldn't a cam position sensor trigger the EML light and cause the car to idle horribly and cause the whole cabin to vibrate?

[j44esd]

Gaygle said:

Wouldn't a cam position sensor trigger the EML light and cause the car to idle horribly and cause the whole cabin to vibrate?

Mine didn't, so outside of that I can't comment. It just felt r-e-a-l-l-y lethargic, so I ran it up to my friends garage, fired up the diagnostic kit and low and behold two CPS faults. Cleared both, ran it up the road, one came back. Replaced that (The easy one to get to), then a week later it still felt ropey, took it back - sure enough the other code had returned - replaced that one - right as rain!

Yes, I should have just replaced them both in the first place, I know that...
Although, ref. your EML lights, I did have one moment as it was running wrong where all the lights came on, then went off - so that may have been related - but it only happened once, and it didn't return and it was 12mths+ ago

EDITED TO ADD: Although the idle was lumpy, it wasn't that bad, so I could understand how someone who has not owned the car long may not notice it!

[Martyn D]

Maybe a good idea to get a code read, sounding like the cam sensor but this usually causes it to turn over more than usual on starting and stalling problems on idle, (won't throw any warning lights) also check for air leaks causing unmetered air to enter after the maf sensor, lastly disconnect the maf and it will run on default settings if it improves it could well be a maf fault, although other things can effect how the maf reads.

[ChasW]

I had similar problems on a 2000 Z3 3.0 I test drove over the weekend. It felt like a 2.0 litre not a 3 litre. Also did not feel that smooth above 3000rpm. I used to have a 2008 130i M Sport which was like a sewing machine. Would the symptons highlighted above aplly here. The engine has done less than 40k and has been regularly serviced.

[philmots]

I used to get 27 mpg from my 330 auto driving carefully. It went too.

[Romanymagic]

My 330 goes really well but I have naff MPG - currently at 20.8mpg - perhaps it goes too well!