Engine knock - video

[oreA]

I've been running the car and listening to it a bit more recently due to one or two things going a bit wrong, and I've picked up a funny knock/tap at lowish revs, and seems more noticeable as the revs drop. I hope it's clear to hear in the video, and for info the engine is running with no aux belt.

I'm at a stage where I'm ready to purchase a new cam belt kit, dephaser, water pump, alternator and aux belt kit, but I need to diagnose this first!

Any ideas? Thanks.....!

 

[bloke]

hard to tell from videos but sounds like it could be little end possibly?

 

[oreA]

:grimacing:

I was hoping it might've been an early symptom of the dephaser failing....

 

[bloke]

it could be but it's hard to tell from the crappy sound you get from phones etc.

 

[oreA]

Thanks for replying :up:. Apart from seeking the advice of an experienced mechanic is there anything I can do to diagnose this myself?

 

[bloke]

pull one lead of the coil pack and rev it and see if it still does it. do them one by one and if it stops when you pull one of them off then there's a pretty good chance that's what it is and on the cylinder that stops the noise.

but it could just be dephaser on it's way, i've had them sound almost like a bottom rattle.

 

[oreA]

Ahh, thank you, I'll give that a go :up:.

 

[oreA]

That was disappointing 😢. With lead no. 4 disconnected the noise seemed to stop, though I was a bit disconcerted by the sparks flying around the coil pack, so I rushed it a bit.

Will check again tomorrow .

 

[Ads29]

Out of interest is it from cold or just when warm @oreA ?

 

[oreA]

I think it's there hot & cold. It was certainly there last night when I pulled the leads from the coil pack, and the car hadn't been started for a day or so. You thinking dephaser noise only when warm?

 

[Ads29]

I don't know to be honest, my spare engine does this when warm, butnisnsilent when cold. I'm planning on a complete rebuild anyway, but may save some hassle and ditch it if it's more serious

 

[oreA]

I really don't know where I'm gonna go with this. I might run it till it breaks. I certainly won't be doing an engine rebuild or dropping a new engine in, I'll probably just get myself another 172 and swap the good bits over.

So I may not be of any help in diagnosing the problem ensive:.