240D smoking?? - PeachParts Mercedes-Benz Forum

btrapr · #1 03-15-2010, 08:49 PM

I got a 1982 Mercedes 240 awhile back! It was wedged into a garage full of stuff with old fuel and a dead battery! The seller said that he was told that the bottom end had been gone through...BUT no reverse and the foward gears were a little funny as he called it!

Well the price was right so I bought it!

Work done since then:
1) new fuel filters, air cleaner, new return fuel lines, adjusted the valves, and I ran some diesel purge, ALONG with a good washing...

2) The exhaust pipe was rotted off just below the engine coming off the exhaust manifold- so I had a piece made and pieced it in.

3) I pulled the transmission pan off and found the reverse band strut was in the pan, so I put it back in and adjusted it! GOT REVERSE but the ENGINE HAS CONSIDERABLE BLOWBY AND BLUISH/GREY SMOKE THAT SMELLS LIKE OIL! STILL AHS SOME OLD FUEL 1/4TANK IN THE TANK ALONG WITH ABOUT 5 GALLONS OF FRESH FUEL.

*when I did the purge the exhaust was still rotted so it sounded like a 4cyl tractor! During the pruge I smelled oil and noticed some smoke...Starts great and idles fairly steady...NOW it has a steady stream when you try to put a load on it and a slight steam while idling. I checked the vapor/oil seperator and found it clear so no pressure issues there!

A friend is a Diesel truck mechanic and he offered to loan me a crank case pressure checker along with his compression tester...He said that the crank pressure in inches can be checked to see if its too much...along with a compression check to narrow down the cause...

ANY ideas here?

injection pump, injectors?

I thought about pulling the injectors and letting the cylinder soak in some Marvel oil to see if the rings are gummed up?

Can the valve stem seals be replaced with the head on the motor? IF so how is it done- I will be filling the cylinders with air thru the GP hole...

barry123400 · #2 03-15-2010, 10:10 PM

The marvel oil soak will not work every time but might be worthwhile if vehicle has sat a long time. Marvel oil is best probably for vegatable oil gum ups.

You might be better to try brake fluid to free the rings if they are oxidized in and rusty. I think it is more active on rust. That combined with some miles might get things freed up if they are partially seized and not wear issues.

The repeat heating cycles of daily driving with a little expansion and contraction each time can be helpful as well.

BridelessRacing · #3 03-15-2010, 10:11 PM

Put Jb engine tune up in oil let run 1400 rpm 30 minutes. Let us know results of this

leathermang · #4 03-16-2010, 03:39 PM

Put new valve stem seals in it and let us know if that helps..
some work..but very few dollars to accomplish...
and may be the majority of the oil burning issue....

Diesel911 · #5 03-16-2010, 05:39 PM

X2 on the Marvel M Oil soak. It worked for me. It will work if you have sticking carboned up Rings; assuming none are broke. The main thing is it is available and cheap so if it does not work you are not out much money.
Here is one of the threads:
http://www.peachparts.com/shopforum/showthread.php?t=258757&highlight=Marvel

All the other stuff the other members mentioned is also all good.

I would add a Valve Adjustment to the above. It won't stop Oil burning but could help with compression.

leathermang · #6 03-16-2010, 06:12 PM

We should have a list of cheap possible cures ( to try first) which will do no damage if they do not work.. a 'no harm no foul' list...

After the MM oil soak I do think I would change the oil before running the engine..
I really think the time to do an oil soak is before the engine is turned over if it has been sitting a while... and then turn it over by ' hand'.... I have and have seen some long sitting engines put back into service if this was done first... otherwise there is the possibility of breaking a ring if any rust has formed in the bore... my example was a 312 1957 Mercury engine which had not been turned over in twenty five years....I got it going and gave it to a neighbor who installed it in a pickup truck and drove away in it... a couple of ounces in the spark plug hole overnight, then just before turning with a breaker bar on the crank bolt... only a couple of turns of the engine are necessary to protect the ring from breaking if it is going to work at all... the use of the starter initially is NOT recommended...

vstech · #7 03-16-2010, 08:23 PM

He's concerned the PB BLaster went in, and went right into the pan... oil level went up immediately.
I told him to try gently spraying it in while cranking the motor. it's been run on the road, so any ring damage is already done, spinning the motor over while spraying the injector holes with the blaster should loosen the rings if they are stuck, it's worth a try...

leathermang · #8 03-16-2010, 08:32 PM

In visualizing a ' stuck ring'.... since the bore wears more at its lower portions and a stuck ring is most likely to be one which was sitting in the upper part of the cylinder for a long time.... I think multiple soakings might be needed .... or a couple of cylinders at a time being sure the ones being treated are at the top of their stroke... and I believe PBBlaster may be too thin to be helpful .... you need something which will spread on top of the ring and flow back into the land but be thick enough to stay there a while... Marvel is probably a better choice if this view of the physics is correct.

BridelessRacing · #9 03-17-2010, 12:52 PM

Quote:

Originally Posted by leathermang

In visualizing a ' stuck ring'.... since the bore wears more at its lower portions and a stuck ring is most likely to be one which was sitting in the upper part of the cylinder for a long time.... I think multiple soakings might be needed .... or a couple of cylinders at a time being sure the ones being treated are at the top of their stroke... and I believe PBBlaster may be too thin to be helpful .... you need something which will spread on top of the ring and flow back into the land but be thick enough to stay there a while... Marvel is probably a better choice if this view of the physics is correct.

Jb engine tune up is a acid neutralizer. That contains metal conditioner. It works with the engine heat and vibration to free up rings.

leathermang · #10 03-17-2010, 01:12 PM

Quote:

Originally Posted by BridelessRacing

Jb engine tune up is a acid neutralizer. That contains metal conditioner. It works with the engine heat and vibration to free up rings.

What makes you think that acid is the problem ?

What is the chance that what has stuck the ring/s is a build up of carbon and thus something which will dissolve whatever bonds the burned carbon and residue of diesel fuel additives to the metals involved is needed ?

What is a ' metal conditioner' ? How does that ' work' or ' act' ?

BridelessRacing · #11 03-17-2010, 07:26 PM

Quote:

Originally Posted by leathermang

What makes you think that acid is the problem ?

What is the chance that what has stuck the ring/s is a build up of carbon and thus something which will dissolve whatever bonds the burned carbon and residue of diesel fuel additives to the metals involved is needed ?

What is a ' metal conditioner' ? How does that ' work' or ' act' ?

Prior to ULSD 100 galons of diesel contained 7 pounds of sulfar when combusted this creates sulfuric acid some of which gets on the rings and creates varnish given time. If you can neutralize the acid you can break the varnish. easy demo Go get cereal bowl out of kitchen add diesel to bowl just enough to cover penny add 5 drops of sulfuric acid. stir gently cover with rag wait 6 months and you will have a penny glued to a bowl. Neutralize the acid and the penny will come loose. Metal conditioner penetrates into the metal any where 2 pieces of metal are rubbing together making them slide easier.

leathermang · #12 03-17-2010, 08:11 PM

Quote:

Originally Posted by BridelessRacing

... contained 7 pounds of sulfar when combusted this creates sulfuric acid some of which gets on the rings and creates varnish given time.

Is ' sulfar ' an isotope of ' sulfur' ?

So ' fire and brimstone' in the combustion chamber create varnish ?

vstech · #13 03-16-2010, 08:40 PM

yeah, that makes sense to me.
I called him and left him a message. we'll see what he tries when he calls back.
the car is in a lot right now, so he may need assistance, I offered my trailer to him if needed.

btrapr · #14 03-16-2010, 08:57 PM

Thanks! for all of the advice!

Gonna add some MMO to the mix tomorrow and let it sit until Saturday! I know the nozzles are in pretty poor shape as well...there is only a round NUB when you run your finger acorss the pintle!

I got a set of 265's I took out of a strong/smooth running 300TD from when I put my Monarks in...Gonna try and swtich them out...

CAR is pretty clean overall! Thought about just yanking the trans/motor....hone it check the gap...ring, bearing, and gaskets along with a vavle job...AND put a transmission gasket seal kit in it...

JUST depends on what the guy says when I call him back and bump my buy price for his early 80'2 300D Euro manual car....REALLY want that car! to slap a turbo motor in....

leathermang · #15 03-16-2010, 09:08 PM

Quote:

Originally Posted by btrapr

Can the valve stem seals be replaced with the head on the motor? IF so how is it done- I will be filling the cylinders with air thru the GP hole...

I missed this earlier...

Putting air into the cylinders can be dangerous.... and if you are thinking about its use as with a gasoline engine then I have good news...

You do not need to use air because the piston gets so close to the head you can use it to keep the valve from dropping into the bore..
but you MUST be sure the valves you are working on has the piston UP at that time..

If you ever actually need air in the cylinder....as with a leak down test.. you either need to LOCK the CRANK ...which I do not know of any safe and easy way to do.... OR PUT THE AIR IN WITH THE PISTON AT THE BOTTOM OF THE STROKE...
otherwise you have the potential for a huge amount of torque being created by the air pressure on top of that piston surface... do not take a chance guessing that the piston is absolutely perfectly set at TOP dead center...
If you do not understand this or do not believe it... say so and I will provide the math for the physics...