tappet rattle

[Nik_Codling]

Hi All,

I seem to have a persistent tappet rattle on cold start-up. Once the oil pressure is up it's fine (this takes a second or so from starting), but I'm wondering whether I am either using oil that is too thin (and draining away overnight), or my hydraulic whatsits are worn. The car (300CE) is on 115,000 miles now, and gets oil changes every 6k, so I'd hope it's not premature wear....

The oil has just been changed, and it's better, but it's still doing it a bit - should I try a thicker oil?


Thank you for any advice.

Nik

 

[kiwi_bloke]

nothing to worry about

its nothing to worry all of our mercs do it.... theyve done about 130000 km... untill your oil pressure comes up there is little oil circulating about the engine......untill there is oil circulating the engine will be a tad noisy

josh

 

[Mike Buley]

?sticking valve.
:idea:

 

[dieselman]

Try flushing the engine with flushing oil. It will remove the gum from the hydraulic tappets.

 

[barrie_davis]

I have the same problem on my 300SL (134K miles). Easily cured by turning up the radio volume :lol:

Rgds

 

[dave elcome]

Try flushing the engine with flushing oil. It will remove the gum from the hydraulic tappets.

No offence Dieselman, but i wouldn't recomend this action Barrie.

Mine follows The symptoms you describe with 123k on the clock, i can only imagine that it's telling me that it needs a set of new hydraulic tappets, not a major job.

I replaced these on my previous Merc, and it made a vast difference.

All the best

 

[dieselman]

Dave

I appreciate your comment re flushing, but this isn't a 1960s MG run on sludge for oil.
I have flushed a number of cars after they have been run on poor oil for many years and have never suffered a problem.
A friend flushed his "new" 1960s Perkins engine last weekend, with no problems.

Don't forget any oil put into this engine in the last ten years has greater detergent properties than older oils.

I would be surprised if there is significant black death in the engine as it is. A flush will remove the gum from the tappets and allow oil in faster.

Nuff-said. AMEN!

 

[Nik_Codling]

Thanks guys.

Funnily enough, upon changing the oil it's now settled down, so I think a flsuh might be the order of the day.

I noticed prior to changing the oil that even after the initial rattle on start-up there was a very feint rattle from just one of the tappets, so I guess this might have been sticking a bit - it would go away after a little while, and doesn't happen now the oil's been changed.

I'll probably do another oil change in a week or two and see about flushing it then.

Thanks chaps.

Nik