240D smoking?? - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 03-17-2010, 02:03 PM

I had not seen that flywheel lock .... clearly the proper safe way to do that..
Do not try to use the emergency brake and trans to try to keep the engine from turning... the ft lbs of torque which would be applied to the clutch would be several times the amount the car diesel engine is able to apply ..thus may not be available to keep it clamped..

How is it determined that the test procedure is ' well under 100 lbs ( PSI ) ' ?

BridelessRacing · #17 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 · #18 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 ?

moon161 · #19 03-18-2010, 01:57 AM

Quote:

Originally Posted by leathermang

How is it determined that the test procedure is ' well under 100 lbs ( PSI ) ' ?

Test Pressure- determined by the guage on the air tank.

I broke my first HF leakdown tester b/c the regulator was adjusted wide open out of the box and I hit it w/ 100 psi from the tank. It would never adjust to a zero read after that.

Next one, I backed the regulator off all the way and blew most of the air out of the tank. It adjusted to a zero read just fine with the reduced tank pressure and regulator setting.

It had a lot to do with reading the instructions in the box after the first adverse outcome.

BridelessRacing · #20 03-18-2010, 10:38 AM

Quote:

Originally Posted by leathermang

Is ' sulfar ' an isotope of ' sulfur' ?

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

You may be a chemist so I may be in over my head chemically. I know Im correct in that combustion creates sulfuric acid.
Internal combustion engines such as reciprocating internal combustion engines produce air pollution emissions, due to incomplete combustion of carbonaceous fuel. The main derivatives of the process are carbon dioxide CO2, water and some soot—also called particulate matter (PM). The effects of inhaling particulate matter have been studied in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death. There are however some additional products of the combustion process that include nitrogen oxides and sulfur and some uncombusted hydrocarbons, depending on the operating conditions and the fuel-air ratio.
Not all of the fuel will be completely consumed by the combustion process; a small amount of fuel will be present after combustion, some of which can react to form oxygenates, such as formaldehyde or acetaldehyde, or hydrocarbons not initially present in the fuel mixture. The primary causes of this is the need to operate near the stoichiometric ratio for gasoline engines in order to achieve combustion and the resulting "quench" of the flame by the relatively cool cylinder walls, otherwise the fuel would burn more completely in excess air. When running at lower speeds, quenching is commonly observed in diesel (compression ignition) engines that run on natural gas. It reduces the efficiency and increases knocking, sometimes causing the engine to stall. Increasing the amount of air in the engine reduces the amount of the first two pollutants, but tends to encourage the oxygen and nitrogen in the air to combine to produce nitrogen oxides (NOx) that has been demonstrated to be hazardous to both plant and animal health. Further chemicals released are benzene and 1,3-butadiene that are also particularly harmful; and not all of the fuel burns up completely, so carbon monoxide (CO) is also produced.
Carbon fuels contain sulfur and impurities that eventually lead to producing sulfur oxides (SO) and sulfur dioxide (SO2) in the exhaust which promotes acid rain. One final element in exhaust pollution is ozone (O3). This is not emitted directly but made in the air by the action of sunlight on other pollutants to form "ground level ozone", which, unlike the "ozone layer" in the high atmosphere, is regarded as a bad thing if the levels are too high. Ozone is broken down by nitrogen oxides, so one tends to be lower where the other is higher.
For the pollutants described above (nitrogen oxides, carbon monoxide, sulphur dioxide, and ozone) there are accepted levels that are set by legislation to which no harmful effects are observed—even in sensitive population groups. For the other three: benzene, 1,3-butadiene, and particulates, there is no way of proving they are safe at any level so the experts set standards where the risk to health is, "exceedingly small".
Finally, significant contributions to noise pollution are made by internal combustion engines. Automobile and truck traffic operating on highways and street systems produce noise, as do aircraft flights due to jet noise, particularly supersonic-capable aircraft. Rocket engines create the most intense noise.
Sulfuric acid reacts with most metals via a single displacement reaction to produce hydrogen gas and the metal sulfate. Dilute H2SO4 attacks iron, aluminium, zinc, manganese, magnesium and nickel, but reactions with tin and copper require the acid to be hot and concentrated. Lead and tungsten, however, are resistant to sulfuric acid. The reaction with iron shown below is typical for most of these metals, but the reaction with tin produces sulfur dioxide rather than hydrogen.
Fe(s) + H2SO4(aq) → H2(g) + FeSO4(aq) Sn(s) + 2 H2SO4(aq) → SnSO4(aq) + 2 H2O(l) + SO2(g)
the reaction with sulfuric acid to metal given time creates varnish. I love wikipedia.

leathermang · #21 03-18-2010, 11:03 AM

I am not a chemist at all. I am just asking questions and trying to understand whether the remedies suggested fit the physics of the situation...which I am not sure of either.
That was interesting and a lot of work it seems to me... and will be fun to read the references.

What is your chemical description of ' varnish ' ?
Are the suggested fluids capable of dissolving that ' varnish ' ?
Is the varnish which builds up in an auto transmission valve body ( which Trans-X is able to dissolve ) the same as what you believe gets between the lands of the pistons and causes a ring to ' get stuck' ?
Would you say that ' sulfate' ( or ?) is a better word for what we assume is capable of ' sticking' a diesel ring to the aluminum piston land ?
For whatever you call this substance you feel is made in the bore and capable of sticking a diesel piston ring what is capable of ' dissolving ' it ?
Thanks,Greg

BridelessRacing · #22 03-18-2010, 11:22 AM

Quote:

Originally Posted by leathermang

I am not a chemist at all. I am just asking questions and trying to understand whether the remedies suggested fit the physics of the situation...which I am not sure of either.
That was interesting and a lot of work it seems to me... and will be fun to read the references.

What is your chemical description of ' varnish ' ?
Are the suggested fluids capable of dissolving that ' varnish ' ?
Is the varnish which builds up in an auto transmission valve body ( which Trans-X is able to dissolve ) the same as what you believe gets between the lands of the pistons and causes a ring to ' get stuck' ?
Would you say that ' sulfate' ( or ?) is a better word for what we assume is capable of ' sticking' a diesel ring to the aluminum piston land ?
For whatever you call this substance you feel is made in the bore and capable of sticking a diesel piston ring what is capable of ' dissolving ' it ?
Thanks,Greg

Yes the same thing Transx is a acid neutralizer. Transmission fluid also contains sulfar and with time and heat creates sulfuric acid. If you then park the car for a while (ESP Ford AODs) the acid turns to varnish and sticks trans valves and balls. In the case of this 240 that has been siting up. This same acid can stick piston rings by creating varnish between the groves and rings of the piston. Having used JB ETU4 on lots of atvs and boats and a few cars I know this cheap trick works.

leathermang · #23 03-18-2010, 11:36 AM

Quote:

Originally Posted by moon161

Test Pressure- determined by the guage on the air tank. I broke my first HF leakdown tester b/c the regulator was adjusted wide open out of the box and I hit it w/ 100 psi from the tank. It would never adjust to a zero read after that....It had a lot to do with reading the instructions in the box after the first adverse outcome.

My question is whether it is legit to frame the parameters of the test based on things like how much air is available from your air compressor, whether you are using the proper gauge.. as perhaps it needed to be a glycerin protected mechanism ... or unfortunate procedural mistakes due to reading the instructions after rather than before, ...
OR should the test be designed by looking at the working ( or failing to work ) pressures in the bore/gasket/head/valves and saying ' we need 'x' amount of pressure to give us reliable feedback ? Feedback includes sound production which is used as a complimentary feature of this test.
When we discussed this in the past I suggested 100 lbs as the starting pressure because most people who have compressors can reach that figure..and then the math is simple for the leakdown times.
So , what are the working pressures in a diesel engine... and what pressure do we need for a leakdown test to be legit/helpful ?

leathermang · #24 03-18-2010, 11:54 AM

Quote:

Originally Posted by BridelessRacing

Yes the same thing Transx is a acid neutralizer. Transmission fluid also contains sulfar and with time and heat creates sulfuric acid. If you then park the car for a while (ESP Ford AODs) the acid turns to varnish and sticks trans valves and balls. In the case of this 240 that has been siting up. This same acid can stick piston rings by creating varnish between the groves and rings of the piston. Having used JB ETU4 on lots of atvs and boats and a few cars I know this cheap trick works.

I guess my visualization of this process is clouded by the fact that the auto trans is IMMERSED in this trans fluid from which the varnish is produced by oxidation and heat compared to the relatively dry nature of the piston rings at the time the engine is stored. To me a build up of much dryer... even baked .... carbon residue seems more probable.
Another question is whether ' ring sticking' happens at the top of the piston more often than the bottom.. Or perhaps ring sticking is usually THE OIL ring... which might mean that the amount of soot in the oil could be the culprit more than the chemical residues coming from the bore and combustion....
So you have regularly encountered stuck rings on your vehicles engines ?
I was under the impression this was a very uncommon situation... does this happen to you over a short period of ' non use' ... like a winter ?

BridelessRacing · #25 03-18-2010, 08:35 PM

Rarely will rings stick in 12 months. but when someone has a brain fart and pulls a perfect running skiboat up a boatramp with the out drive down this repair can easly cost $5000 to repair outdrive. 3 to 4 years later when i buy this boat it isnt at all uncommon to have stuck rings or lifters. To fix this i remove all spark plugs spray JB80 in the holes. Roll engine over by hand. Remove and clean carb reinstall. Hook up to water hose. I now automatically add engine tune up (etu4). Heres why On a engine that has been sitting rings and lifters stick. I have had motors crank and run with a dead miss and no smoke stuck lifter. or run ok with smoke. Stuck rings. The etu4 will usually fix the problem in under 5 minutes at 1200 -1500 RPM. Some times it will take 20 minutes. Yes i realize I am compareing a gas to a diesel but the design is the same. As for the rings not being submerged in oil. a crankshaft spinning at 1200+ RPM will sling plenty of oil up to the rings.

leathermang · #26 03-18-2010, 09:11 PM

Quote:

Originally Posted by BridelessRacing

a crankshaft spinning at 1200+ RPM will sling plenty of oil up to the rings.

Are you familiar with our turbo engine's annular ring pistons and the oil squirters matched to them ?

Your stuck engine examples fit my impression of the type of situation which might regularly produce stuck rings or lifters. I suspect on our diesel engines stuck rings are reported more often than they actually exist.

btrapr · #27 03-18-2010, 11:31 PM

Great info! thanks

I was a little scared about the PB Blaster seeping past the rings overnight...THEN I thought about it...This stuff is made to squeeze into parts that are FUSED together with rust, so getting past the rings should not be that hard! I am still hopefull! I have gone by the car the last two days and dumped Marvel into the holes and sliped the paper towels back into the hole...The engine does start great and actually idles nice!

The JB engine tune sounds like another option...

I am going to change the nozzles out tomorrow and I have new heat shields ready to go!

*I also got a set of vavle stem seals...I heard that I can set the pistons on their perspective compression stroke and sneak the vavle springs off without taking the camshaft loose??? $9 for the seals so if I can get them in place without further disassembly I am going to go for it as well.

Can anyone varify that the adjusters/locks and springs come off from udner the cam so I can replace the valve stem seals?

vstech · #28 03-18-2010, 11:36 PM

Quote:

Originally Posted by btrapr

Great info! thanks

I was a little scared about the PB Blaster seeping past the rings overnight...THEN I thought about it...This stuff is made to squeeze into parts that are FUSED together with rust, so getting past the rings should not be that hard! I am still hopefull! I have gone by the car the last two days and dumped Marvel into the holes and sliped the paper towels back into the hole...The engine does start great and actually idles nice!

The JB engine tune sounds like another option...

I am going to change the nozzles out tomorrow and I have new heat shields ready to go!

*I also got a set of vavle stem seals...I heard that I can set the pistons on their perspective compression stroke and sneak the vavle springs off without taking the camshaft loose??? $9 for the seals so if I can get them in place without further disassembly I am going to go for it as well.

Can anyone varify that the adjusters/locks and springs come off from udner the cam so I can replace the valve stem seals?

after I got off the phone with you, I took a look at my 240 with the bad cam, and it looks like you can get the rockers out once you loosen the valve retainers. cam should not need to come out.
I can take a pic and text it to you, or you can come look at mine before you attempt it.
your call.
oh, and you don't have to go to the compression stroke, it's actually easier to figure tdc on the pots by going to the exhaust stroke... watch the cam release the exhaust valve and you're there.

leathermang · #29 03-18-2010, 11:42 PM

Quote:

Originally Posted by vstech

oh, and you don't have to go to the compression stroke, it's actually easier to figure tdc on the pots by going to the exhaust stroke... watch the cam release the exhaust valve and you're there.

Perhaps it is too late at night for me to be thinking straight...but I think the reason it is done at tdc on the compression stroke is that the valves are not being compressed by the springs at that time... whereas the exhaust stroke and intake are next to each other in the cycle and clearly have one of the valves open...

vstech · #30 03-18-2010, 11:57 PM

true, but on the compression stroke, both valves are closed the entire travel of the stroke... kinda hard to find tdc except on #1 right? and I think at the tdc of the exhaust stroke, both valves close... true the intake is gonna be close to opening, but I would think it to be easier to figure.