Smoke problems 1982 diesel merc

[saxonrider]

Hey,just got onto site, a hello to you all.I Have white/grey smoke (under acceleration) coming out of a 1982 Mercedes diesel estate that I have, it's a 240diesel engine. The engine seems to tick over fine, done a 4hr drive recently, but the clouds of smoke under acceleration is a pain. Have been told it's maybe the EGR,told to block it, but all could find on engine is a small metal bottle?, or maybe it's the injector timing that's out of sync & the smokes unburnt fuel, but the smokes greyish white not black under acceleration????????????? or maybe a head gasket or tired engine?
I'm based in Tarporley, Cheshire area, is there anyone in the area that knows about old diesel engines, sure could do with some help with this; thanks.

[skirk]

Is it auto or manual?... if its an auto it could be the modulating pressure valve in the gearbox. When they go, you can get copious clouds of white smoke.
Steve

[saxonrider]

Hi, it's manual. I had someone look at it yesterday, they reckon the piston rings need replacing as there is excessive pressure in engine & from oil cap & oil spits out as pressure is escaping...the engine runs fine but blowing smoke under acceleration? they reckon it's a large job on the engine..£700 quote to repair....mmmmm? so much for a cheap runabout.

[Old Merc]

Before you consider having the engine pulled apart try and find an "Old School" Merc`specialist,someone who knows these engines and will give you a proper diagnosis.How many miles has she done? I`ve been led to believe these old engines are bullet proof and never need pulling apart.
I bet its something else??

[skirk]

The 240d engine is usually good for well in excess of 500,000 miles but if not maintained will wear out....a set of rings is about £80 and a good quality headset will be around £60 Add a set of bigend shells at £45 and you are a ta couple of hundred for parts. not a complicated engine well within the capabilities of a competent DIYer.

[tr7v8]

White smoke would be unburnt fuel so would be over fueling. Never worked on Mercs but is the cold start stuck on & over fueling it? If it is grey smoke then it is over fueling & getting burnt even partially. It isn't rings or pistons/bores as that would be black smoke.
I'd look at a basic healthcheck, compression test & then injector test & service. Not sure what pump is on these so that would be a line of attack.
A possibility would be head gasket but I'd expect it to be down on performance. Won't be EGR as it won't have one, they are recent emissions crap.
Worth going to an old school diesel specialist & getting them to have a look.

[cptsideways]

White smoke is usually unburnt fuel, maybe a dodgy injector/timing. White smoke is NOT rings.

[saxonrider]

Thanks to you all for your input it's very appreciated. The mechanic who looked at the engine the other day basically said there was a lot of back pressure in engine & this was pushing the oil out into the weakest points of escape, i.e the exhaust was taking oil & burning it off after car is accelerated; the engine ticks over smoothly & has power & it cruises nicely at 70-80 miles per hour, I done a 4 hour drive recently, but the grey/white smoke pours out under heavy acceleration.
Maybe will have a go at fixing the engine myself, just bought the manual?. It's a lovely old Mercedes which has been looked after,for an 82 it's in good condition. It has only a couple of rust spots, the interior is all original and had it on the ramp lift and underneath is all good. I suppose it was a nostalgic purchase as my dad used to have one of these and it brought back good memories seeing one again....as a kid bouncing around on the springy boingy seats driving through the countryside sat in the passenger seat was definitely a memory factor, and it's still lovely to drive today, although in comparison to today's vehicles it's like driving a tank...a Mercedes tank lol.

[saxonrider]

The smoke under acceleration or high revs is not black but grey/white, it stings the eyes. The mechanic who had a look thinks there is too much back pressure in engine therefore the rings he says need replacing; he placed the oil cap over the hole loosely after taking it off and pressed firmly without locking it in & pressure was squeezing out spitting bits of oil, there he said..that's your rings that need replacing..too much back pressure??????????
Anyway will try what your posts advise..injectors service & clean, air & fuel filter clean, fuel mixture adjuster, will try these before start playing around with engine parts. I just hope it's not piston rings as the engine ticks over nicely, doesn't overheat...just want it to pass it's mot & get it on the road; I'm on a search for an old school diesel mechanic who can have a look at the engine & can give me a second opinion

[Hooli]

Get a compression test done, wet & dry. If it's lacking compression & a bit of oil down the bores restores it then it is the rings/bores.

[saxonrider]

Job done...took car to old school diesel mechanics in winsford (SP Diesels,Stan & Tony). They put in a engine cleaner in the engine oil, ran it for three days, returned car there & they changed engine oil, fuel filter, air filter & oil filter,...bingo...problem solved,...no more clouds of grey acrid smoke..just a little

Thanks to you who took the time to reply...cheers

[Old Merc]

Find out what cleaner they put in? I bet it was FORTE engine flush ?