Revving when braking?!

[ripp]

I'm a bit scared not to damage the poor guy's stuff now if they're so sensitive. guess there isn't a certain way to get them out safely

 

[Mike@Rentech]

I recon the plenum gasket is leaking, remove plenum and check.
Had a couple in for the very same fault, usually the wrong bolts are fitted to the plenem which wont tighten correctly due to being to long and hitting up against the fuel rail protector.

 

[sideways danny]

i've seen that done. Normally revs up though

 

[ripp]

I recon the plenum gasket is leaking, remove plenum and check.
Had a couple in for the very same fault, usually the wrong bolts are fitted to the plenem which wont tighten correctly due to being to long and hitting up against the fuel rail protector.

I have a missing bolt there, but it's been like that for about one year. It had been over-tightened and the thread was gone. I guess that means a new lower inlet if I wanna screw another bolt in right?

 

[Soot1e]

You can remedy it by fitting a longer bolt and a nut underneath. It's fiddly holding the nut underneath to fit the bolt but depends which bolt thread is stripped.

 

[ripp]

it's one of those two closer to the engine (from the total of five which hold the plenum to the lower inlet, three towards the grille and two towards the engine)

 

[Soot1e]

If you cant get a nut on it you could drill it out and re-thread with the next size up, 8mm, tap a new thread and Bobs yer uncle.

 

[Andyman]

Buy a helicoil kit. Not too expensive

 

[ripp]

got rid of the problem today
I used some high temp silicone on the plenum-lower inlet area (below and above the gasket-about 1-1,5mm thick squeezed out of the tube, surrounding each inlet), and bought the missing bolt holding the plenum.
the noise is gone, and the "revvin' when braking" initial problem also solved.
however, the idle got down a few times to about 600rpm (when coming off the throttle) for the first 10-15 mins of driving but now seems fine, although it drops to idle a bit quicker than before.. I hope this won't become a problem when the engine is cold
I guess when messing with the TB and inlets weird stuff happens :S

 

[jinjur]

RESULT!

well done

Jj

 

[franx]

good going. Nice reactions from people too here , great.

 

[ripp]

back on this problem again.. It looks like the revvin thing is not entirely gone as I thought. It still does it when the engine is cold and while on the move (standing still in neutral with engine on and pressing the brake pedal nothing happens). let's say driving at 30 mph in 3rd, then going in neutral and immediately hitting the brake the revs go up a bit (from 1200 -engine being cold- to about 1500) kinda like blippin the throttle. checked the brake vacuum pipe and it looks ok and tight.

 

[Tigger]

lol @ the video too :rasp:

Your tea is ready

 

[franx]

Go a total different way , i would be checking the first lambda sensor.. the up+down revving is why i draw this conclusion. Had this too and was lambda. Nothing to do with the earlier whistle or brake pedal though. I can imagine the brakepedal being hit , drawing power from the circuit and having influance on the lambda reading ? Your battery is allright ?

 

[ripp]

battery is ok, changed it 2 years ago. up and down revving only happens when pressing the brake pedal 2-3 times when in neutral. it's like pressing both brake and accel pedal at once. not having a messy idle to be clear.
first lambda will be changed soon though as I'm having some mpg issues