UKPOC forums

Good shout....managed to suss it out. Here's the video of the car.....

https://youtu.be/XSGhMY_H0HQ

That does sound strange? It seems to start then stop again, then start, are you making the engine rev faster but just slowly, then back down again?

Isn't it?!

No, its just idling normally until you see me open the door and give the throttle a prod.

My 24v does the same I,ve put it down to the belt tensioner and pulleys

Agree with Kev, sounds like the Belt Tensioner to me.

Thanks for your input all, always appreciated.

I hope this turns out to be just that....its quite a disconcerting noise!

I think you have just offered me some hope - my 24v makes the same noise, although its continuous, not on a cycle like yours. Just before lock down - it had got worse to the point that I decided it wasn't the hydraulic lifters. I haven't driven it in 5 weeks in case something breaks. I've done the same trick with long length of wood to the ear to locate where it's coming from - seems to be loudest if I listen to the left hand end of the rear cam cover, over where the cam sprockets are. I was worried it was a camshaft bearing or something, but maybe its just the tensioner?

Maybe your tensioner has fully failed whereas I think mines about 80% there. Do some YouTube searches for 'failed timing belt tensioner', I couldn't believe my ears at how bad some other cars sounded..... I'd be thinking full engine fail any of them where mine

If like me its at the left of the rear bank, the hydraulic tensioner is right there (see previous diagram) so could be very possibly to blame. Mines going in to be inspected in about 3/4 weeks so will keep the thread updated what the mechanics find.

The 'beat' of that engine note does not compute with anything that 'turns' in the engine.
Not camshaft revs, not belt length, nothing.
Therefore, perhaps it is related to the MAF unit ?
If there is any 'sticky' point where that plug has to move through just maybe that would cause the beat at low revolutions ?
At anything above idle it will not happen.

jrh wrote: ↑

Mon May 04, 2020 11:56 am

The 'beat' of that engine note does not compute with anything that 'turns' in the engine.
Not camshaft revs, not belt length, nothing.
Therefore, perhaps it is related to the MAF unit ?
If there is any 'sticky' point where that plug has to move through just maybe that would cause the beat at low revolutions ?
At anything above idle it will not happen.

Not thought of that but then again, would I not see a non steady idle and movement in the rev counter needle as it 'fluctuated'? Hopefully I'm not missing the point!