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Sooty exhaust / Petrol smell returns.

Posted: Sun Nov 15, 2015 2:53 am
by simonc
Mornin' all,

The sooty exhaust and strong smell of petrol has returned after an absence of a couple of months. As you can see from the first shot, this is the wall against which I park her, under the shelter of the porch. This is the splatter coming from it.

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And here's my exhaust as of this morning. The car was washed last Tuesday (day off) and the exhaust was cleaned. My only trips have been to the office and back, no motorway work art all.

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Now what is interesting is that last Tuesday I popped down to see Jason about this issue as it's been bugging me for a while. To keep this brief, here's the process he went through while I was there:

1: Took out the plug leads and discovered that the lead to plug number 3 (Looking at the engine and counting from the left) was absolutely covered in oil.
2: He took off the rocker cover and we saw one of the 4 black round seals was wonky in its housing.
3: Obviously he'd taken out the spark plugs and we saw how black they were, not oily but just covered in carbon.
4: He checked the black gasket that goes in the rocker cover, it was replaced 6 or so weeks ago and that was fine.
5: He cleaned up the rocker cover interior which was rather oily and also the top of the engine.
6: He fitted new spark plugs - Bosch genuine ones and Bob's yer uncle.

When I fired her up there were massive amounts of smoke from the exhaust but Jason said that was the oil burning off. Fair enough, after 10 minutes or so it did disappear. Anyway, I drove home and must admit the throttle felt very nice, kind of 'light' which I presumed were the plugs.

However, as you can see, this problem is now back, the smell of petrol is a bit obvious and the soot is pretty manky.

Now, in a world's first, I actually took off the spark plug cover myself this morning and had a look at the leads myself. The plug body on 3 and 4 were a little oily but not to the extent of what I saw last week. I've been to fill her with petrol just now (Shell Premium) and she feels okay but sometimes it just feels a bit sluggish when I put my foot down, not a lot, I hasten to add, but enough to furrow my brow.
Sorry this has dragged on a bit but just wanted to give you the full SP and hope someone can throw some light on it. Thanks as ever, Si.

Posted: Sun Nov 15, 2015 9:28 am
by mercutio
have you had the emissions checked see what its actually doing?

by the way my exhaust always looks like that :lol:

Posted: Sun Nov 15, 2015 9:42 am
by damon
Yep my exhaust looks the same and mine will slatted black jobby up the wall :lol:

Posted: Sun Nov 15, 2015 10:31 am
by wurlycorner
Mine do exactly the same. It's common on short runs, they run rich.

Oil in the spark plug bores is unconnected.
If you found one of the plug bore seals in the cam cover was misaligned, that explains that problem.

Posted: Sun Nov 15, 2015 10:46 am
by simonc
Morning chaps, better deal with this in order:
@mercutio Emissions checks? Matey, we don't need MOTs here (hence the outrageous death tolls on the roads due to the amount of death trap cars running round here) and, to be frank, no one gives a toss about the environment. If I'm honest Merc, I've never seen or heard of a garage with emissions equipment.
@damon But mate, you don't have to face Linda and her volcanic moaning and orders to 'clean it up now' diktats.
@wurlycorner I'm going down to Jason's tomorrow and going to ask him to take off the cover and see if the seal is wonky again.
Thanks gents, appreciate the direction. ;)
Will update tomorrow after I've had a word in Jason's shell-like. ;)

Posted: Sun Nov 15, 2015 11:45 am
by RattyMcClelland
Same as mine.

Re: Sooty exhaust / Petrol smell returns.

Posted: Sun Nov 15, 2015 1:28 pm
by MaccaIRL
Same as mine haha
My 320d wasn't as bad ffs

Posted: Sun Nov 15, 2015 1:31 pm
by chrismc
If the plugs are fouling up in carbon in a big way then it's running rich.

Any issues with leaky spark plug seals will be unrelated...

The new plugs, being nice & clean will have made the car run better temporarily.

Has the car ever had a new Lambda probe??

Posted: Sun Nov 15, 2015 2:49 pm
by simonc
Hi @chrismc. Good point, because a couple of months so we fitted a pretty manky (second-hand ex-scrapper) lambda sensor to try an alleviate a problem that didn't actually exist.

Posted: Sun Nov 15, 2015 4:18 pm
by chrismc
In which case a new lamda won't do any harm ;)