Two problems

[John 66]

hi so two problems I need to ask about
1.why does the revs on my z4 increase when holding my foot on the brake it will just keep bouncing ( for want of a better word ) 1200 revs only when my foots on the brake take it off and ticks over fine.
2. Have a small clunk when pulling away herd some explanations that it could be the diff also missing some sort of grease somewhere on the drive shaft
Any help on thease would be great

 

[Layor]

hi so two problems I need to ask about
1.why does the revs on my z4 increase when holding my foot on the brake it will just keep bouncing ( for want of a better word ) 1200 revs only when my foots on the brake take it off and ticks over fine.
2. Have a small clunk when pulling away herd some explanations that it could be the diff also missing some sort of grease somewhere on the drive shaft
Any help on thease would be great

The revs going up when you press the brake pedal sounds very much like split air intake rubbers. Had exactly the same problem with my old Zed. I did order a new hose but in the meantime repaired it by taking it off, sealing the split with 'super glue' and binding the hose with amalgamating tape with insulation tape on top. It worked a treat.
Hope this helps, Colin.

 

[John 66]

The revs going up when you press the brake pedal sounds very much like split air intake rubbers. Had exactly the same problem with my old Zed. I did order a new hose but in the meantime repaired it by taking it off, sealing the split with 'super glue' and binding the hose with amalgamating tape with insulation tape on top. It worked a treat.
Hope this helps, Colin.

Hi Colin thanks for the reply so I’m a noob at this where is it located?

 

[John 66]

Have already replaced the air intake boot just after the filter have got an e46 to so know about those already have checked the pipe that runs across the top from the brake assembly near the master cylinder seems to be fine can’t see anything else

 

[Layor]

Hi John,
If you take a look at this article it will show how to replace that part.
https://www.pelicanparts.com/techar...ment/04-FUEL-Intake_Air_Ducts_Replacement.htm

The part you need to look at is shown in pic 7. That was the part I found to have the split. However, check all along that part of the system, the leak could be anywhere. The other cause could be the MAF sensor itself. That is inside the duct where the plug is, just after the air filter housing. The chances of it being that are slight, but always worth a check if nothing else turns up. Once the MAF section has been removed, (it's easy enough to do as long as you are careful) you can spray some brake cleaner fluid on to the sensor or, better still use isopropyl fluid and a soft brush. This is just to remove any build up of dust particles that may stop the sensor from working correctly.
As I said before, it is not likely to be this, as long as the air filter has been replaced regularly.
If anyone else can offer any other suggestions I'm sure they will be along soon.
All the best, Colin.

 

[t-tony]

A way of simplifying leak detection is to use a can of carburettor cleaner and, with the engine idling spray the cleaner around the intake and vacuum pipes while listening for any rise or fall in engine revs.

Tony.

 

[Layor]

Yet another Top-Tip from Tony

 

[John 66]

Thanks tony will give that a go at the weekend do you think it’s still worth giving the maf a clean ?

 

[t-tony]

Thanks tony will give that a go at the weekend do you think it’s still worth giving the maf a clean ?

Can't harm anything John, then it's one possible item ticked off anyway.

Tony.

 

[John 66]

Thanks will let you know