Timing chain

[Liam7755]

Why would my car give what sounds a lot like a chain rattle but ONLY when it’s started after it’s warm? Stone cold for 2 days no start you don’t hear the slightest of noise! But if I drive it for an hour or so then start it a little while later it will rattle slightly for about 3 seconds.

 

[whitenemesis]

Engine is still warm, so tolerances are greater. Oil is still warm so slightly less viscous.

 

[m80]

As a 1st step you might consider changing your cam chain tensioner.
If it isn't totally cured by that it gets more involved.

 

[Liam7755]

Engine is still warm, so tolerances are greater. Oil is still warm so slightly less viscous.

I see! Its strange as it never done it the first 2 weeks I had the car .. then I changed the oil for shell helix 5w30 and noticed it afterwards. I do wonder if it was running different spec oil before hand that somehow made it quieter

 

[Liam7755]

As a 1st step you might consider changing your cam chain tensioner.
If it isn't totally cured by that it gets more involved.

Id love to, but i cant seem to find where my tensioner is! Its the om651 4 cylinder engine

 

[m80]

top of block, o/s rear.

119 here,

M 651.940 - CAMSHAFT AND CHAIN DRIVE > Mercedes EPC Online > nemigaparts.com

Parts catalogs. Spare parts catalog Mercedes EPC Online. Mercedes. Van. Engine - Power Systems CAMSHAFT AND CHAIN DRIVE.

nemigaparts.com

 

[RichardF]

I see! Its strange as it never done it the first 2 weeks I had the car .. then I changed the oil for shell helix 5w30 and noticed it afterwards. I do wonder if it was running different spec oil before hand that somehow made it quieter

I changed oil from Mobil one to another brand but still within spec tappets became noisy on a cold start, and the car started using oil between services. I then went to Petronas and back to quiet tappets and no oil use.

Start with the simple things 1st.