E46 3.18i MAF Problems

Post Sun Aug 29, 2010 5:37 pm

Hi All,

I have been suffering from power loss for a while - i put my foot down and its like driving a slug and expecting acceleration... I have been reading a lot on this problem as many 3.18i owners seem to have it. One of my major suspects is the MAF after trying/replacing some other things.. so within the last hour i have just done the following:

1. Tried disconnecting the MAF while the engine is running expecting it to stay running (according to what i have read) but it cut out - this isn't right for starters is it?

2. restarted the car without the MAF connected and is started fine so i went for a drive. IMMEDIATELY, i noticed the power difference it was all a little jerky at first but i put my foot down and the car flew through the first couple of gears... to the point where your stomach turns not expecting to go that fast (if you know what i mean).

3. Drove for about half a mile like that then i noticed that the auto changing was getting rather heavy and it would THUMP going down into first gear. I didn't like that, it was actually a bit worrying so i stopped the car and plugged the MAF back in. (Why would the gear shifting change like that without the MAF? ) - With the MAF back in the car went straight back to normal, sluggish but absolutely no thump in the gear change... phew!!

4. Got back home and cleaned the MAF with contact cleaner put it back on but it made NO noticeable difference.

5. While the engine was running i unplugged the MAF again but this time NO cutting out, the engine just seemed to adjust a little.

6. I left it unplugged and drove it like this one last time and sure enough the power was back again!... not smooth but definitely back. The clunky gear changing wasn't there but i only went around the block a couple of times.

One las thing;

7. just remembered is it normal to unplug the MAF and have the dash light turn on next to the 'P' (park) that looks like an orange cog with an exclamation mark in it? according to the manual its an Automatic Transmission fault light causing the transmission to switch to the emergency-run program??

After all my research on the net and this result makes me confident that part of my problem is definitely a faulty MAF. Some of what happened i didn't expect buy you guys have much more experience I'm sure, so please give me your thoughts?

Much Appreciated

Jason

Post Sun Aug 29, 2010 5:42 pm

Is it ticking over ok? I take it you've checked vacuum hoses?

Post Sun Aug 29, 2010 5:52 pm

Thanks John, As far as i can tell yeah the idle is generally okay.... sometimes a bit low but it has never cut out on me. Touch wood!

I had a look at the hoses and again they seem okay, when you say vacuum hoses which do you mean? I have checked the obvious ones...

Post Sun Aug 29, 2010 9:35 pm

I know that on mine the engine management light came on and i suffered loss of power and rough idling (bit low and high when cold) and apparently the crank case vacuum hoses and fuel pressure regulator hoses are really bad for going on them - mines was split v.badly - goes from the rocker cover down the back - you can get your hand in to feel if it is split, renewal involves the removal of the pollen filter at the bulkhead - easy enough to do.

Managed to find a pic of an engine bay to illustrate - hope this helps it did my tits in for donkeys

Post Sun Aug 29, 2010 9:57 pm

Hmm I've definitely changed the CCV and hoses... that was the first thing i did but it didn't make a difference. I'll have to check the fuel pressure hose asap... thank you for taking the time to find the pic!

Post Sun Aug 29, 2010 10:08 pm

No problem Jay - i feel your pain - your right a lot of problems when you start searching - you buy the fuel pressure regulator hose in a metre roll im sure.

It should be soft and supple mines was quite hard and cracked when you bent it.

Thats what I get for buying a stupid 4pot

Post Sun Aug 29, 2010 11:00 pm

haha! - I just went out and took it for a drive... usually when the car is cold i have to start it then wait until it's warms before i can pull away (crazy i know). This time i started it, unplugged the MAF and its stalled. Had to start it up a few times before it held idle. Then i just put my foot down and pulled away as you should be able to do and sure enough no problem the power was there like i've never felt this car do! Made me feel all boy racer again - Joy!

Side note: i just saw your thread on the work you have done on your cabby - well done mate it looks stunning! Your perseverance definitely paid off!

Post Tue Aug 31, 2010 9:24 pm

I definitely have an MAF issue...

A new one form the dealer is £280 vat incl - I found this one on the net

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 4159wt_904

Would you buy with confidence??

Post Fri Sep 03, 2010 11:10 pm

Update!! Problem Solved ... well at least one! Woohoo!

I ended up buying a new MAF from:

http://www.emissioncontrols.co.uk/

The website doesn't look like much but the price was £159.00 inc next day delivery for an original Bosch MAF (dealer £280.00) - replaced it straight away and i couldn't believe the difference, my little 1.9 engine did me proud and put a big smile on my face! The power was there like never before... Fantastic!

However, my EML light is still on, i'll plug in the pc tomorrow and see what's happening... Then it'll be on to the next problems... getting rid of the EML light once and for all and the Airbag Light! Last but not least, find out why I'm losing coolant.

For now I'm happy!