Under bonnet exhaust fumes CLS320cdi

[johnnyb]

For the last couple of days I've noticed a slight whiff of exhaust fumes when ever I stop at red lights or junctions etc. This is with the windows closed and the interior fans running. Tonight I decided to have a look under the bonnet as I suspected an exhaust or manifold leak and I can definitely smell exhaust fumes under there. I can't be 100% certain but I think the engine may be sounding a little louder too once the engine cover was removed, more like a loud ticking which if I'm not mistaken can be the sound of a blowing manifold.

I've read about the manifolds breaking up internally and damaging the turbo although this also seems to cause rough running and my car is running perfectly. Does this fault allow fumes to escape when this happens or is all the damage internal? The car is a 2008 cls320 with 64000 miles.

 

[Dieselman]

Leaking injector seal.

 

[jaymanek]

The ticking is most likely normal.

What can happen is the exhaust manifold to downpipe bolts can snap when doing the routine inlet port motor job.. Could be that this has been done in the past and not sealed correctly?

Also maybe a leaking injector? Have seen a few of these leaky now..

 

[johnnyb]

Would a leaking injector cause exhaust type smells?

I'm not sure if the inlet port motor has been replaced in the past but I've owned the car for eight months and the smell has only just started.

 

[johnnyb]

After having a good read about this it is possibly pointing towards a leaking injector seal. I'll have a proper look over weekend in the daylight.

Thanks for the pointers both of you.

 

[johnnyb]

Right, I've just had a look and on the v6 it's pretty difficult to even see the injectors. I've definitely got smoke coming from the driver's side of the engine though and possibly from the injector closest to the bulkhead. It's difficult to be certain though with the intake pipes and associated gubbins in the way.

Next question, any recommendations for a garage who can fix this in the South Yorkshire or North Derbyshire area? I've used Europa Mercedes (official Mercedes garage) in Sheffield for servicing but I'm guessing that they might be expensive?

 

[E270 Owner]

Mobile injector guy will be a better solution and probably cheaper.

 

[Vinylhead]

I thought the same as you when I had this problem.It was a leaking injector seal.

 

[johnnyb]

I dropped the car off at the garage yesterday and got a call today to say it was indeed an injector seal. All sorted and ready to pick up tomorrow morning. A much less expensive fix than I had been dreading.