W209 3.2 burning smell from engine bay whats leaking?

[Mickey42]

Hello again guys,
My 2004 CLK 320 has a burning smell coming from under the bonnet. When I looked after a 30 mile run at the weekend there was a small trace of fluid sitting on the bottom plate between the rad and the block, I put my finger in it and I would say is was a reddish colour. Looked at it the next day and it had evaporated. Any ideas please?

Regards Mickey

 

[umblecumbuz]

Except for the fact that it evaporated overnight, that would suggest a possible transmission fluid leak - maybe from one of the pipes connected to the front cooler.
Worth checking the atf level in your gearbox.

 

[LostKiwi]

More info about the smell might be helpful...
Burning oil smell, burning plastic, burning rubber, acrid or pungent?

 

[Mickey42]

Thanks so far. I first thought power steering leak, but no fluid loss. The smell is nowhere near a burning oil smell, more towards hot plastic/rubber smell. It`s not the first time I have seen this slight `leak of sorts` that vanishes, but never had the smell before.

 

[AnthonyUK]

Those engines are very prone to breather cover leaks. Take the engine cover off and check around the coil pack area for leaks onto the exhaust manifold shield.

 

[Mickey42]

 

[Cole@MBS]

Get the top rocker breather covers re sealed, quick and cheap to fix!

 

[AnthonyUK]

Get the top rocker breather covers re sealed, quick and cheap to fix!

Yeah. Order replacement torx bolts along with the high temp silicon sealant as the originals are alloy and are often damaged on removal.

 

[Mickey42]

Love a cheap fix. Thank you

 

[LostKiwi]

While you the breathers off give them a good clean. They have a tendency to block on some cars which will cause high oil consumption and leaks.

 

[Mickey42]

Hi all. All sorted. Resealed the breather cover and all good. Going back to the top of the thread, the mysterious red fluid that evaporates is coolant, the small pipe from the expansion tank had a bodged join in it half way down and not a very good one!

Thanks to all the contributors to my post,

Michael

 

[umblecumbuz]

Phew! Good result.