Curious engine/cooling issue - any thoughts please?

[Jobsworth]

Seals? Excuse my ignorance but aren't radiator hoses just attached by clips (jubilee in the good old days!). Or is there some super duper new fangled way of connecting a hose?

Yes, there is! They have steel ends crimped on, O rings to seal and stainless steel retaining clips.

Radiator Hose for MERCEDES-BENZ:W203,S203,CL203,C-CLASS,C-CLASS Sedan 5903364314224 | eBay

C-CLASS Coupe (CL203), C-CLASS Coupe Sport (CL203), C-CLASS Sportcoupe (CL203), C-CLASS Sportscoupe (CL203). C-CLASS (W203), C-CLASS Sedan (W203). C-CLASS T-Model (S203). from connecting pipe to engine cooler.

www.ebay.co.uk

 

[DrNick]

You learn something every day!

 

[Gollom]

Despite new pipes as above it would still sometimes loose coolant, especially when being driven hard. Was proving the very devil to pinpoint (my indie is very good and tends not to charge time when diagnosing etc., just parts) so in the end we decided to bite the bullet and replace the radiator despite there being nothing visible with it in situ. I got the radiator myself for £90 and he'll charge £200 for the work. Anyways, think we have found the issue!!!!

 

[Jobsworth]

Yup, that’s it!!