clat clunk clunk clunk bonk.

I spent some time last evening watching the engine run in the new acquisition 2.25 petrol. It's been laid up for ten years.
It is going clat clunk clunk clunk bonk from the front of the engine at idle. Disappears on revving a bit.

clat clat clunk clunk bonk
clat clunk clunk clat bonk
clat clat clunk clunk bonk

It's quite musical....

Initially I thought it was the water pump, but it sounds lower down than that - is there a damper on the crankshaft end that perishes or anything? The fan belt (or the stringy thing that passes for it) seems to be running true.


ALSO,

I have one noisy tappet. Someone said that this could be a "roller going oval" - is this a common failure mode for these things?


Suggested strategies for the above are welcome!

Thanks

Could be problem with timing chain tensioner.

Could well be timing gear - I had a tensioner sprocket that failed and made some odd noises. I think they're aluminium..
You could check the rollers for ovality but tappets always seem to be noisy on the 2.25.

tottot said:

Could be problem with timing chain tensioner.

Click to expand...

Aaaaaaahhhhhhhhhhhhhhhhhhhh - I hadn't thought of that...... thanks....

If the tensioner has gone it can cause big issues if it then fails totally. My old nissan bluebird had a chain tensioner holding together with bugger all metal. Could have gone any time and nuked the motor. It sounded like a spanish bloke was under the bonnet playing castanets. Fixing it will likely help running too.