Smoking and confused - 84' 300TD - PeachParts Mercedes-Benz Forum

billy_witort · #1 09-09-2003, 12:13 PM

****Please see message #7 (titled "the plot thickens") for updated smoking issue description****

I have read up on a lot of smoking issues on this forum but felt this one is quite unique. The smoke is a whitish smoke combined with some black making for a gray. I know that blue/white = oil, white = water, and black = gas. Here is the sequence of events that led to the smoking:

--> Drove the car for 1 hour (no sign of smoke)
--> Stopped the car and pumped the priming pump a few times, gas leaked out of the priming pump and the pumping felt firm like there was fluid being pushed. I did this to test the pumping mechanism for the first time, mostly out of curiousity.
--> Started the car again and now a significant amount of white/black smoke is coming out of the tailpipe (especially during loading).
--> I drove the car around for 5 minutes and the smoking is still very significant.

Can someone please provide some insight here? It doesn't make sense to me that the car should smoke so badly after it has been a few minutes. Is this normal? Please let me know.

Thanks,
Billy

Wasuchi · #2 09-09-2003, 02:23 PM

I would take the car on a long hard drive. Sounds like maybe you broke sum crud loose when you pumped the primer pump.... I can't imagine what else it could be other than maybe a bad spray pattern from the crud (that should have been filtered out). Maybe some fuel additive/injector cleaner would help too. Also if the pump leaked you should get a new one (new style) and replace it, I think they are around $15 and it takes about 2 minutes to replace it.

billy_witort · #3 09-09-2003, 04:44 PM

Thanks for the advise Wasuchi, I have been meaning to clean out the injectors soon anyways...

The problem still persists after starting it up 4 hours later, heavy white smoke upon loading (rev up to 2000 Rpm's and punch it up to 4000 or so does a nice big cloud). I inspected the fuel lines and the line going from the second filter (big cylindrical one) to the Ignition pump has some evidence of small air bubbles at higher RPM's.
* Is it OK to get some air in the fuel system? I think that is what might have happened when the priming pump leaked when I was pumping it.
* Is it required to manually bleed out the air from the fuel system or does it automatically purge out the air after a few seconds? Someone please advise.

Thanks,
Billy

Wasuchi · #4 09-09-2003, 09:53 PM

I'm really surprised nobody else has answered you yet.

I assume the air you are seeing is in the clear plastic filter right before the injection pump? If that's it a little air is normal in it, just a few bubbles. If the car starts it should be able to purge any air that shouldn't be there by itself unless air is constantly being reintroduced. I would think air would make it run really rough if that's the problem too. Have you been able to determine if the primer pump is leaking still (other than when you pump it)? Also if it's the old style primer pump (white plastic top)you have to screw it back in to lock it closed I think and unscrew to pump, the new style (black top) you just push to prime.

All of that said it does sound like raw diesel in the exhaust or water getting into the engine (have you looked at the oil and the coolant level?) What does the smoke smell like? I really don't have any other thoughts, there are a lot of guys that know 100X more than I do about these cars maybe one of them will jump in soon. Good luck.

kerry · #5 09-09-2003, 10:19 PM

I can't resist--sorry. If you had gas coming out of your fuel lines, you found the problem. Try substituting diesel.

madmic · #6 09-09-2003, 10:59 PM

My 116 was doing this and I purged the system with lubromoly dieselpurgeand it solved the problem sopund like a leaky gumrd up injector. On my vw I took out the injrctors had them cleaned ( one rebuilt by DIS) no more prpblem with smoke.

Pat

billy_witort · #7 09-10-2003, 03:47 PM

Hi All, Thanks for the help so far it is much appreciated. It may be worth starting a new thread here but I think I am going to just spit it out and hope for some good feedback...Please read on:

I drove the car home (~40 miles) and the smoking (white/blue and very thick cloud) continued the whole way. I am sure that some of this smoke is attributed to oil burning (read below for more on this) since I lost about 2 quarts of oil in 40 miles. When I got home I parked on a inclined surface (~5 degrees), popped the hood and took a look around. With the car idling I noticed:

--> The first fuel injector is leaking fuel. I can see bubbles that are gurgling near the distal end of the injector.

--> The fuel filter has some evidence of Algae in the fuel system. I can see black deposits on the filter.

--> The rear of the car was covered in small oil spots.

--> The tail-pipe was rich with wet oil (stuck my finger in there and it was covered)

--> The car was not generating any white smoke while idling...

***** I rev (2000 rpm's to 4000 rpm's, quick burst) the engine a few times and notice the following******

--> A large amount of white/blue smoke from the exhaust

--> Oil in it's liquid form dripping from the tailpipe!!! When I rev the engine the oil literally spray's out of the tailpipe!!! total amount dispensed while watching was about 5 Tablespoons.

Some background information that might help in providing advise:

--> Car has 135K miles on it. The engine has recently been tested to have good compression (350,325,300,350,350)

--> I changed the timing chain and adjusted the valves 2 weeks ago. Felt the Turbo shaft at this time and it did not have any play in it as well.

--> Vaccum pump tested to have 20in.hg. at idle and 25 at higher Rpm's

Oil is somehow getting into the combustion chamber and exiting the exhaust in it's liquid and gas phase. Any ideas on how this is happenging???

Some ideas of mine (remember I am a newbie here):

1. Fuel Injector : Could a very leaky fuel injector somehow cause this? Sort of a long shot but I am crossing my fingers for a simple fix : )

2. Valves: If oil were excessively leaking into the top of the cylinder through the valve's would it be able to somehow escape without getting burned up? Would this be caused by the valve guide seals?

3. Piston rings: The car has good compression but the oil scraper ring could still be damaged.

4. Vaccum pump : I have read that some excessive oil smoking may be caused by a bad vaccum pump or a bad bladder in the vaccum system. Is there a vaccum hose that I could check that might be spilling a ton of oil into the exhaust?

Please advise on the best next step towards finding the root cause of the problem. This car has been a big handful for me in my first month of owning it and this forum has been priceless. Thanks in advance for reading such a long thread. Please post any questions that might lead towards solving this.

Thanks,
Billy

kerry · #8 09-10-2003, 04:10 PM

None of the above?? Turbo seals are bad?

I don't think a bad vacuum pump would put oil into the combustion process.

billy_witort · #9 09-10-2003, 04:45 PM

Thanks for the input. It seems the liquid oil leaking out the exhaust pipe is a big signal here...Does this reduce it down to the Turbo or a bad valve guide seals on an exhaust valve? Is there a way to check if it is the turbo without removing the whole thing?

kerry · #10 09-10-2003, 05:02 PM

Way too much oil for valve guide seals. Got to be a catastrophic induction of oil into the system to get liquid oil out of the exhaust. I can't imagine anything it could be apart from the turbo? Can anyone else?

Wasuchi · #11 09-10-2003, 06:08 PM

Sounds exactly like what my powerstroke did when it blew a turbo seal... the smoke was a lot more blue than white if I remember correctly. At least this is probably one of the easier things to fix of all that have been mentioned..... just need a good turbo shop and some $$$.

billy_witort · #12 09-10-2003, 07:17 PM

I was really careful while replacing the timing chain but leave open the possibility that something might have gotten introduced into the valve guide area. If there were something introduced could it cause excessive liquid oil to leak into the exhaust and all the way out the tailpipe?

Another thing worth mentioning here is the car seems to run just fine...

How can I check the turbo to determine if it is causing the problem? If I remove it and take it to a shop, are there some simple diagnostic checks they will do?

Thanks!
Billy

Wasuchi · #13 09-10-2003, 09:20 PM

I guess you could look around the turbo housing to see if there was any oil leaking out, I kind of doubt it though. The turbo most likely will work just fine with a blown oil seal so with that much oil loss I would agree with kerry.

Take the turbo off yourself or have a shop do it but make sure it's rebuilt by a place that specializes in turbos or you'll be dealing with it again sometime, there is a lot of balancing to do that needs to be done by a pro to be done right.

billy_witort · #14 09-11-2003, 03:26 PM

I just spoke with a person from "Majestic Turbo", they rebuild turbos for these cars ($325-$495 depending on problem) and we discussed how so much oil (about 1 tablespoon per minute) could be leaking out the tailpipe. One thing he mentioned was that if there were a enough crankcase pressure caused from Blow-By, the pressure could cause the oil from the Turbo oil return line to get blown back into the turbo and then blown out the exhaust.

Does this seem likely?

If I disconnect the hose that connects the valve cover to the air filter, should this eliminate the crank case pressure enough to eliminate this from happening?

Please let me know.

kerry · #15 09-11-2003, 03:43 PM

Doesn't seem likely but pull the breather tube and see what happens. Many people have reported extensive blow by on this board, but no one has ever mentioned that it is blowing back into the turbo and out the exhaust. I don't even understand how it could get back into the turbo and out the exhaust unless the oil seals were bad. It might get into the intake but then it would burn before it got out the exhuast.
You could also check for a turbo at a junkyard or on Ebay. My local pick and pull would sell one for less than $50.