Guess that noise...

[bogbeast]

Hello All,

Would like you opinion of a knock that I am getting from the griff.

Started about a week ago, I noticed when I gave it a sharpish blip of the throttle (out of gear at lights) I could hear a knock coming from what seems to be the bottom of engine bay..). Just one knock per blip. Seems to happen in gear (clutch in or out) or in neutral (again clutch in or out)

At idle it there is no noise, press the throttle normally and no knock. Don't hear it during normal driving (constant revs), only when 'pressing' on..

Blip it when its cold and there is is no knock, wait 2 mins for some heat to get in the engine and then blip it, you get a knock.

I am thinking timing chain rather than ends or cam but I could be wrong. 37000 miles and on cam number 2 so not expecting it... (mind you a 404 sounds intresting...)

Any suggestions gratefully recieved!

Ta

edit: P.s Oil pressure is completely normal...

>>> Edited by bogbeast on Thursday 3rd July 12:56

[IPAddis]

Loose engine or exhaust mount? Worn wishbone bushes? Failing shock absorber? Not sure from your descrption that it is definately engine-based.

Ian A.

[GreenV8S]

I would look to see if the exhaust is catching something when the engine rocks. Maybe the exhaust itself has shifted, or worn/loose engine mounts allowing it to rock more than normal.

[bogbeast]

Thanks guys.

The knock sounds more 'solid', more like someone tapping a vice with a hammer.... (what am I on about..)

I certainly will be jacking it up for a thorough investigation this weekend..



>> Edited by bogbeast on Thursday 3rd July 13:11

[Stig]

Broken engine mount.

[tig]

I'd second (or third ?) the engine mount idea. Dave Batty replaced mine a couple of months ago (at 32000 miles) and the difference was brilliant.

I also had the knocking - caused by exhaust manifolds dancing around but could normally reproduce it by just gently going on/off throttle at a steady speed.

[BogBeast]

Well, Steve Howard has had a good look and it seems it was the front pulley coming loose enough to allow it to move (hence the 'clonk')

Seemingly a common problem...

Thnaks again for the advice.