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1999 E46 323i Se weird tickover and gutless...

4K views 26 replies 7 participants last post by  steve23002 
#1 ·
M52TUB25 Engine...
:(
Ok, every now and again when i started the car, the tickover would fluctuate between 0 and 3500 rpm, then when you eventually got it to tickover, there would be no bottom end torque. You had to rev it a fair bit to get it off the mark.
Then, it would be fine for a few days.

Thing is, its now doing it all the time.
I've changed the fuel filter, as i thought it might be full o crap, and in fairness, it was, but its still doing it.

I've done some reading and the vanos seals seem to be a recurring theme.
Or the idle speed controller....

The idle speed controller wouldnt make it drive "flat", though would it?
(when i mean flat, its like you have to rev it to 3500 to make it move, then you have to feather the throttle to keep it moving...)

Now the vanos thing doesnt look terribly hard to do, i just dont fancy spending a day in the garage only to find it was the idle speed controller!!

I havent had the codes read, BUT....does the engine light have to come on to lodge a fault in the ecu? cos its not coming on...:(

Any ideas, o fountain of broken bmw knowledge...? :D
 
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#10 · (Edited)
MAF's rarely throw any sort of trouble code at all..

it even says this in the BMW techs fault finding data..

duff MAf symptoms from the tech fault finding sheet

erratic idle
engine stalling
poor starting when hot
poor or sluggish power

MAF's do not exhibit trouble codes in most fault or failure scenario's and can exhibit all or some of the above symptoms..
 
#13 ·
yes limp mode...

vacuum leak or iffy MAF exhibit the same symptoms one is umetered air entering the engine confusing the MAF and ECU the other is the MAF sending duff data to the ECU so it cannot fuel or regulate the engine properly..

same thing from different ends so to speak..
 
#12 ·
Ok, so apart from having to be a gynaecologist to get to the damned idle speed controller, it appears that i have a small split in the hose that goes to it, from the main trunking.
Filled with superglue for the time being until bmw get one....and mine has to be the awkward one, as it looks like theyve superceded it with a different part number...
13541437191 was the original part number, 13541435627 is the new one...wonder if it was a problem, so they made a mod to it... :D
 
#15 ·
Yeah, it got me to work a treat, in fact it felt lovely.
I'm a cynic though (and an engineer, so trust NOTHING!) and have just ordered the two inlet trunks (£9.88 and £8.34 +vat..thats without bmw/oc membership discount!).
I'll believe it when it doesnt happen again..I cleaned the iscv out while i was in there and removed a trumpet looking affair from the top of the inlet side of the airbox (just for curiositys sake!).
I see what you mean, daily. lambda giving ecu funky readings, ecu correcting and thus entering a viscous circle...:D
 
#19 ·
Buggrations....Did it again today. with the new hoses on :(
Might have to get it plugged in and see whats what.

Need some info on the OBD....how many faults will it log? how long does it hold them for?
Part of my head says that the fuel pump may be the root cause, but cannae prove that without changing it....(runs off to see if a walboro fits...:D)
 
#20 ·
afaik the codes are kept til cleared...the MAF still seems a likely cause, as do the cam sensors...maybe even coils.
out of those only the MAF wont store a fault code...have you tried driving with the maf unplugged?
 
#21 ·
Not yet mate, might have a go tomorrow. I'll unplug it and drive to work, see if its any better.
Doesnt feel like a coil, its to intermittent for that, usually they die and thats that, it feels like a subaru sort of thing, doesnt it?
I did wonder about the cam/crank sensors as it feels like its being retarded, like its running rich (anyone remember carbs? like the chokes on, on a hot engine) :D
Just had the father in law on the phone who knows who's who in the dartford areas, he's given me a number of a guy to read my codes. I'll clear them and drive it around till it does it again, then get them read again..:hihi
 
#23 · (Edited)
Right, its not the MAF. It did it again so i disconnected it and reduced my car to a metro... :D

so it aint that....whats this breather i keep hearing about? if i remove the oil filler, its pulling a vacuum, so that seems ok...

EDIT: looked it up on google. Found that this ccv/pcv/crank vent valve jobbie is a poxy job and can take 3+hours to do...as long as you have the £100 worth of hoses too!
 
#24 ·
GOTCHA!!

Hah!


After hours of interweb searches and a truckload of forums and threads about hesitancy and powerless 2.5's i found this...


"Take the decorative trim off that covers the fuel rail. There is a crankcase hose that runs parallel to the fuel rail. It connects via a worm clamp to a hard line going to the crankcase vent valve between cylinders 1 and 2's intake runners. The other end is a quick-clip connector between the intake runners of cylinders 5-6. You don't need to remove it to inspect it........the early E46's had a mostly rubber hose. Look at the 45 degree bend that is close to the connection between the runners of 1 and 2.......see if it is cracked. We call it a "buttcrack hose".......since it looks like a butt when it is cracked. "

From E46fanatics (sorry to namedrop!)
http://forum.e46fanatics.com/showthread.php?t=296238&highlight=cyclone&page=2
Post #22.
Buttcrack....oh yes indeed...

Pipe is located by the first inlet valley...


Looks like its time for a visit to my favourite dealers for a new pipe... :)




#7 i think....
 
#26 ·
Right, thats better. Running like a turbine now. Yay!
Camshaft sensor changed, once you've got the airbox out and the vanos solenoid off (that took a quick net search, incase i hacked it up!!) its one bolt and an electrical plug to swap.

Lets hope thats nailed it..:D
 
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