W203 - Oil leak around filler cap

[dwm]

Hi,

I have a W203 C Class Sports Coupe 220CDI (2004, facelifted edn). Took it for a long journey today, after about 1 1/2 hours I smelled burning oil, pulled over and lifted the bonnet. All around the filler cap area, and splashed over the engine cover and up onto the 'lining' of the bonnet was a fair quantity of fresh oil. Inevitably, some oil had splashed down onto the engine.

Luckily, this happened about 100yds from a small local garage (albeit an agricultural specialist!). Mechanic was fairly old school and admitted to not being used to more modern cars but was good enough to check it over. He lifted it on the ramp, took off the cover on the underside and couldn't see any obvious leak, so concluded that the filler cap was probably loose/had a poor seal. We cleaned up obvious oil (leaving a fair amount on the engine) and checked levels which the on-board test said were fine.

Mechanic reckoned I was good to drive the 80 miles home. I did so, fine for first 60 mins, last 20 mins had the familiar oil smell and finally smoke.

I checked again and this time there's no obvious oil around the filler cap, but there was a lot of smoke coming off the engine generally.

Any ideas whether this is likely to be residue from the earlier spill burning off once the engine got hot, or whether its likely there is a leak which we missed earlier? Do you think its likely to be safe to drive it the 50 mins or so to my nearest specialist from cold?

Any help much appreciated!

 

[BlackC55]

Have you topped the oil up recently and not put the cap on properly?

 

[dwm]

No, though I opened the cap a couple of weeks ago to try to check the oil level visually (it's due a service in Jan).

Driven about 40-50 miles on short runs between then and today so surprised the problem only occurred today. Stupidly I removed the cap today upon seeing oil all around it and can't for the life of me remember if it felt loose.

There was no fresh oil splashed anywhere after driving back this evening.

 

[BlackC55]

Ok,

Why did you remove the cap to check the oil level?

My guess it was not put on properly and the oil has run down the channels on the rocker cover and eventually on the exhaust. It may have taken a while to do this.

Get the engine cleaned asap and the leak re-checked to be sure

 

[dwm]

Thanks for your helpful reply.

Stupid question, but where/what type of garage would you reccommend that I use to get the engine cleaned? Is it the type of thing a local garage can do or should I be looking for a specialist? I live in North London (not the best place for decent garages) and am conscious that it's probably best not to drive far with oil on the engine block.

Re: opening the cap to check, it's not a mistake I will repeat! New to this car - had not realised there is no way to check the oil other than use the on board computer (was used to a slightly aging polo where you could visually check oil was towards max as well as use a dipstick).


***edit***
The other thing that I meant to add is that the smoke appears worst when in stop-start traffic (ie. in D on the auto, foot on the footbrake) - if I slip it into Neutral the smoke seems to slow down. Not sure if this could be symptomatic of anything?