W124 300CE-24 - noise on cold start

[thechasmanblue]

My 1992 300CE-24 makes a rattling, almost a clanking sound on cold start that lasts a few seconds then goes. The car runs sweet thereafter. It's been doing it a little while but was worse than usual this morning.

Any ideas what this might be? It's due an MOT and service in by June where I'll definitely get it looked at but does it sound like it merits a special trip?

The car's done 92k with history showing regular services and I'll probably do no more than 500 miles between now and when the service is due.

 

[television]

This could be timing chain rattle, but 92k miles is a bit on the early side, also the damper on the serpentine belt can do this

 

[5907]

My 300TE-24 used to do this; it could be the hydraulic tappets before they fill with oil, or the timing chain tensioner taking up the slack.

 

[ALFIEBEARD]

My 1992 300CE-24 makes a rattling, almost a clanking sound on cold start that lasts a few seconds then goes. The car runs sweet thereafter. It's been doing it a little while but was worse than usual this morning.

Any ideas what this might be? It's due an MOT and service in by June where I'll definitely get it looked at but does it sound like it merits a special trip?

The car's done 92k with history showing regular services and I'll probably do no more than 500 miles between now and when the service is due.

Could also be the guts of the cat rattling until warm.
Alfie B

 

[S80]

Maybe the air pump - if fitted - though that operates for somewhat more than 'a few seconds' at start-up.

You might try removing the serpentine belt and seeing what happens with a cold engine. The engine can certainly run for 10 seconds or so without coming to grief....

 

[turnipsock]

first guess would be the tappets

it is common if you have the wrong consistancy of oil in in the car.

 

[meanie]

Maybe the air pump - if fitted - though that operates for somewhat more than 'a few seconds' at start-up.

You might try removing the serpentine belt and seeing what happens with a cold engine. The engine can certainly run for 10 seconds or so without coming to grief....

The pump solenoid can also be disconnected at the plug on the inner wing to prove a point.
Might be worth getting the chain tensioner checked if this doesn't stop the noise.