Hi,


My s2000 (87k miles) recently started making a tapping noise when idling. The noise only appears once the engine is hot. The noise does not follow a frequency and often taps a few times and is quiet for a few seconds.

The noise stops when revved. As well as this when the spark plug in cylinder 2 is disconnected the noise stops. (it seems to be coming from this area as well)


I have already replaced the TCT and adjusted the valves. (Before I suspected the wrist pin could be the cause)



The noise is identical to this:
https://www.youtube.com/watch?v=eClujheWaKQ


(I can post a video if required but it sounds just like this)



From the information I can find this seems like it could be a wrist pin. What do you lot think?


IF this is the case what are the consequences of running the engine like this?

Also what repair is required to fix it? Roughly how much would this cost?

Thanks for your time people!


EDIT -
Videos uploaded of it now:

https://youtu.be/mpE9xROUy9g

https://youtu.be/Rov0aOCw9cg

 

Have you checked the pulleys, tensioner, drive belt etc? Maybe you forgot to tighten one or more of the jam nuts when you checked your valves, it happens more often than you think.

 

Thanks for the response. I really appreciate it

I haven't checked the jam nuts yet but after I did the VA I went over them all to double check so I am fairly confident it is not this. Also the sound was there before adjusting the valves.

The tensioner moves smoothly and I did have a quick look at the pulleys. If it were the pulleys the sound shouldn't stop once the spark plug is disconnected in cylinder 2? (the belt is brand new).

 

" The sound shouldn't stop once the spark plug is disconnected in cylinder 2? "


Sounds like rod knock. Big or little end.

 

Thanks for the reply again!

If this were the case (as I am beginning to believe is the case) would the frequency / noise still be there at higher RPM? Currently it is only on idle.

 

Video Links below:

https://youtu.be/mpE9xROUy9g

https://youtu.be/Rov0aOCw9cg

The one outside the car is after the engine has heated up a little more.
Both were taken before VA and TCT were done.

 

Sometimes I wonder if it's better to just replace rod bearings every year just to avoid the headaches of them possibly jacking up the crank if they do go out. To my understanding you can change bearings from under the car without taking out head.

 

Replacing rod bearings is something you do on a 200k refresh. Or at least it should be.

 

is it possible to replace from under car without taking off head?

 

Bottom end, yes. Wrist pin, no.