Knocking

[Mark Watson]

Hi Experts,

                     I have a worrying knock on my 2010 E93 Convertible.  On start up I get a knocking sound for only a second then it disappears. The car runs and sounds fine..if I stop and start there is no sign of the knock. But if I leave the car for a few hours the knock re appears..

 

any suggestions or have you heared of the same problem..

 

thanks

[X5smw]

Water pump? Thermostat related or oil flow?

im guessing it’s when the engine is cold, so could be oil distribution ? 
 

 

[Greydog]

More information about the car, what engine? how many miles? what service history?

Stu has probably nailed it as an oil distribution issue, when the engine is off oil is draining back to the sump so no pressure in the chain tensioner or lifters or both. Try turning the engine 2 or 3 times but not letting it fire to build pressure see if that helps.

If it does then you could try 5-40 grade oil that may help short term, but the only real cure is an engine out job to fit a new oil pump and pressure switch plus chain tensioners

Dave