Engine rattle

[ronnie]

Hi all , firstly the car been started 4 times since being laid up at the end of the summer . When I start it from cold I'm hearing a light rattle , bit like the pinking noise Roy describes , only on the overun , not on acceleration . Once the engine gets to running temp the noise is nothing like when cold , hardly noticeable . Not looking forward to this diagnosis

[moggiethouable]

BMC and co will no doubt offer the options.
Being an optimistic soul I would hope (if it were my car) for a tappet/valve clearance/wear issue.
In which case it aint too bad

[katy]

Sounds like loose con-rod bearings, and/or weak oil pump.
When cold, remove the spark plugs, crank it over until oil pressure comes up, re-install spark plugs and start it up. Does it still rattle?

[bmcecosse]

It won't be pinking -only happens under load... Just lack of oil to the rockers I suspect.. Don't worry too much at this stage. DO fit an oil pressure gauge !!

[ronnie]

I was hoping that would be the answer Roy ,I was using the word pinking to give an indication of the noise only , hopefully because of the length of time laying the top end would be dry , going to do an oil and filter change and will fit a pressure gauge . The engine was quite before being laid up . Do you think I should flush the engine first although the oil in it is pretty fresh

[bmcecosse]

No! But do have the oil good and hot before draining. Wilko 20W50 is fine.

[JOWETTJAVELIN]

It may be the timing chain and possibly an exhaust leak around the manifold area.