W211 320 CDI Poor Cold Starting

[Made_in_Stuttgart]

Hi

Recently purchased a 56 reg E320 CDI.

Superb car, however even after replacing all six glow plugs it struggles to start in the morning.

When it fails to start a plume of white smoke emits from the exhaust. It starts perfectly the second time round and indeed during the rest of the day.

What could be causing this?

Cheers.

 

[Daeths]

Air in the fuel pipes ? - pull back the protective and have a look while someone cranks it over.

If so, a number of possible areas but from my 1st hand experience, it is one of the o-rings on on one of the fuel lines.

A more technical answer will follow I am sure though.

 

[Made_in_Stuttgart]

Thanks for that.

It's going back to the garage tomorrow, I will mention your suggestion.

 

[_Taz_]

sounds like a leaky injector, perhaps..

 

[Corned]

What does the white smoke smell like? My guess (and that's all it is) would be uncombusted diesel, so either leaky injector(s) or faulty glowplug relay.

Air in the pipes would not produce smoke.

 

[walsi]

My vito puffs out a little cloud of white smoke in the morning if you just jump in and turn the key, if you let the glow plugs run for as little as 10secs it doesn't. Its more noticeable because i have a short straight through exhaust so no silencer to impede its progress.

Martin

 

[Made_in_Stuttgart]

The glow plug light goes out before I attempt to start.

The garage told me they replaced the plugs, maybe it's something to do with them but not actually the plugs themselves?

 

[walsi]

Hi ya, you would know if it was a fault with the glow plugs because either the light would stay on permanently or would go off and come back on again to tell you. Have you tried turning to the glow position and then counting to 15 and then turning the key to see what happens ??

Martin

 

[Made_in_Stuttgart]

No not let it go for 15 seconds, shouldn't need to - I didn't have to in all the previous diesels I've owned.

I did test something this morning - put it into on but didn't start, waited for glow plug light to go off, then did it again. Started first time but really struggled.

 

[walsi]

Hi, the only reason i suggested waiting 15secs is that it might have cured the puff of smoke. I think you have either a leaky injector or a very small air leak in a diesel line, i would guess its losing pressure over night and this is causing the longer cranking time. If it was me i would get a leak off test done, a fuel pressure test and also check the diesel lines before you start first thing and look for air bubbles

Martin

 

[Made_in_Stuttgart]

It's been diagnosed as a problem with the glow plug relay.

Thanks for your inputs, will let you know what it's like once done.

 

[Made_in_Stuttgart]

Update for those interested.

The glow plug control unit/relay (not sure of the official term) was replaced around a week ago and I've not had the problem since (touch wood!)

Thanks for your inputs!

 

[jp]

Just started having problems starting: the engine turns over a few times before "catching".
This morning, first real frost, the engine turned over 10+ times before starting.
Called my local Indy and 20 minutes later the Star thingy said it was a faulty glowplug relay.
Just found this post so am happy that the problem will soon be resolved

 

[6cyl]

How much is the relay?

 

[Mr Filipov]

Around £100-£120 from memory when I did it on my CLS

 

[6cyl]

Good, not too onerous. Hopefully it's the relay and not leaky pipes or leaky hpfp.

It was ok this morning.

 

[LostKiwi]

If its leaky pipes parking uphill/downhill can have an influence.
Parking nose down hill will start better than nose up hill.

 

[6cyl]

Where I park, the front of the car is at a slight downhill angle, approximately 3degrees. From the symptoms described in this and other threads, I suspect an intermittent glow plug relay. All 6 glow plugs were changed last Nov.

 

[andrew056]

Good, not too onerous. Hopefully it's the relay and not leaky pipes or leaky hpfp.

It was ok this morning.

If this is a V6 OM642 engine and it still has the original relay then that is almost certainly your problem , easy fit and you can now get one for about £100 which is a lot less than I paid for mine a couple of years ago.

 

[6cyl]

Car is 8 years old with 62k miles.