What can this cause?

RichP · Post by **RichP** » Tue 12 Mar, 2013 18:22

Could this be the cause of:

A) poor idle
B) misfire under acceleration between 1700-2000 revs in all gears.

I'm doing this on my phone, so I hope it works...

Mod Edit: Image link fixed.

Post by **Robert T** » Tue 12 Mar, 2013 18:25

The split is after the MAF, so any air that leaks in will not be being metered, so yes, it could potentially cause both. I'd remove it and see if the split goes right the way through. Even if it doesn't I'd consider replacing it anyway.

Cheers R.

RichP · Post by **RichP** » Tue 12 Mar, 2013 18:32

. Any idea how much this boot costs? And should I replace the other vacuum (?) hoses attached?

Post by **Robert T** » Tue 12 Mar, 2013 18:37

Mass air flow sensor/ASC - BMW parts catalog

Parts #3 - Coopers are currently showing it at £20.81.

Double-check part numbers for your car.

Have a look at the prices of the other hoses, and if they're not too expensive, I'd replace while you've got it apart.

Cheers R.

RichP · Post by **RichP** » Tue 12 Mar, 2013 18:43

Thanks!

Del · Post by **Del** » Tue 12 Mar, 2013 19:33

On the M44 (1.9 16V) engine there is a lot of vacuum pipework under the top half of the inlet manifold. The MAF bellows you have photographed is connected to:-

Part 13 41 1 247 782 (BMW part cost me £2.81 1/2012) and this part feeds to a “little tree” of four pipes (distributor piece 13 53 1 739 618 cost me £24.11 at BMW 1/2012) which is connected to the four M44 injectors to aid the fuel atomisation process. You could use generic vacuum pipe of the same internal size which would probably cost a couple of quid.

As Robert suggests, it may be worth doing the lot. I found that two pipes in my distributor piece had also aged and split. My car ran smoother and had more power after renewing it all.

The little bit of pipe at the front of the engine, connected to the fuel rail pressure regulator? also cracks and splits – I used a generic bit of left-over vacuum pipe to fix that - cost £0.00.

Vic-Z3 · Post by **Vic-Z3** » Tue 12 Mar, 2013 23:11

Temp fix it with some black silicon sealent worked for me and still does to be completly honest .........

RichP · Post by **RichP** » Wed 13 Mar, 2013 00:45

Thanks everyone!

I'll dismantle it and see if i can find any further deterioration. I presume i will need to remove the intake manifold?

I've just spent a fortune on other problems so could do with spending as little as possible (at least before next payday!) , but if its a big job, the pipes are obviously perished, or it works out pretty cheap i'll change the lot.

if it is localised and minimal damage i might go for the silicone approach and hopefully it will last until my finances have recovered a bit!

I'll let you know how i get on, and whether it fixes my problems (or improves performance

)

Just an additional point, is the oem maf sensor made by bosch? i.e. has mine, which is bosch, been replaced at some point? I got less service history than i would have liked when i bought the car.

Del · Post by **Del** » Wed 13 Mar, 2013 08:49

The M44 OE MAF is made by Bosch. That looks like a BMW OE MAF on your car as it has both the BMW part number 1736224 and the Bosch part number.

Mike Fishwick · Post by **Mike Fishwick** » Wed 13 Mar, 2013 16:12

It maybe worth seeing if the engine mounts are allowing excessive movement under torque - lift the bonnet, and while someone engages the clutch against the handbrake see if the engine moves much.

The engine mounts are filled with water and antifreeze as a damping medium, which allows a soft mount to be used without excessive movement, but if the some of the fluid has leaked excessive movement can take place.

RichP · Post by **RichP** » Wed 13 Mar, 2013 19:14

i took the intake block off, (why does it always need a tool you don't have?!

had to go and buy an 11mm spanner as i couldn't get a socket over the back nut), the hoses all seemed pretty decent, except the boot and the pipe joined to the boot, so i cleaned them up and sealed them with silicone. But once the car was warm, it was exactly the same

I have just read your post zedonist, and i'll try it tomorrow now the silicone has set, but i cant imagine the o2/silicone issue would present the exact same problem as the crack, so its back to the drawing board.

I'm thinking of taking it to a local garage that specialise in electrics, i've been there before and they are very helpful in explaining and demonstrating exactly the issue. They said it would be £50 approx to run diagnostics/test drive/inspect etc and hopefully find the problem.

With my level of mechanics experience

i need to know whats wrong before i start changing things!

Good plan?

RichP · Post by **RichP** » Wed 13 Mar, 2013 22:13

i would have got a new boot & hoses, but it involves the mersey tunnel and navigating liverpool, so i went for sealing to see if it had effect, with a plan to get the parts in the not too distant future.

i'll let you know what the car GP diagnoses.

cheers.

BladeRunner919 · Post by **BladeRunner919** » Thu 14 Mar, 2013 08:21

RichP wrote:i would have got a new boot & hoses, but it involves the mersey tunnel and navigating liverpool, so i went for sealing to see if it had effect, with a plan to get the parts in the not too distant future.

i'll let you know what the car GP diagnoses.

cheers.

Don't forget that we have forum members with diagnostics too:

http://www.zroadster.net/forum/viewtopi ... =5&t=36055

zroadster.net

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