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-   -   "Thar She Blows!!". W115 blow-by video. (http://www.peachparts.com/shopforum/diesel-discussion/299393-thar-she-blows-w115-blow-video.html)

tomscat1 05-25-2011 09:04 PM

"Thar She Blows!!". W115 blow-by video.
 
http://www.youtube.com/watch?v=BnXaMkyA0hw&feature=youtube_gdata_player

The above link should be a YouTube video I did over the weekend, showing the blow-by in my W115 300D. How much blow-by is too much blow-by?

I am thinking, after this experience, that I may have to rethink the Marlene Diederich name that i have given to the car.... Keeping the same initials, and simply changing it to "Moby Dick!!!".

"Thar she blows! "

:)

Please let me know if the video fails to load. Thanks.

strelnik 05-25-2011 09:41 PM

Quote:

Originally Posted by tomscat1 (Post 2724339)
http://www.youtube.com/watch?v=BnXaMkyA0hw&feature=youtube_gdata_player



I am thinking, after this experience, that I may have to rethink the Marlene Diederich name that i have given to the car.... Keeping the same initials, and simply changing it to "Moby Dick!!!".

.

It would still be MB, as in " Mercedes Benz"

Biodiesel300TD 05-25-2011 09:44 PM

If it still runs and isn't running away then it's not too much blowby!:P
Is the engine cold or running at operating temp? If it's cold then try it again when it's warm. Also how long ago was the valve adjustment? If it was just was the day you took the video, try it again after you run the car for a couple days. The valves may reseat a little and reduce the blow by.
Other than a rebuild, unfortunately not much can be done about blowby. One thing you can try is pouring a little bit of Marvel Mystery Oil or brake fluid into the cylinders and let it sit for a while. This will break any gummed up piston rings. You'll have to remove the injectors to do this. Change the oil post soak, to remove any fluid that drained down.
You can use thicker oil to help reduce the oil loss to blowby, I've also seen people put filters in the bypass hose to filter out the oil so they don't burn it.

tomscat1 05-25-2011 10:24 PM

Quote:

Originally Posted by Biodiesel300TD (Post 2724357)
If it still runs and isn't running away then it's not too much blowby!:P
Is the engine cold or running at operating temp? If it's cold then try it again when it's warm. Also how long ago was the valve adjustment? If it was just was the day you took the video, try it again after you run the car for a couple days. The valves may reseat a little and reduce the blow by.
Other than a rebuild, unfortunately not much can be done about blowby. One thing you can try is pouring a little bit of Marvel Mystery Oil or brake fluid into the cylinders and let it sit for a while. This will break any gummed up piston rings. You'll have to remove the injectors to do this. Change the oil post soak, to remove any fluid that drained down.
You can use thicker oil to help reduce the oil loss to blowby, I've also seen people put filters in the bypass hose to filter out the oil so they don't burn it.

That blow-by video was done with the engine cold, about 15 minutes after I adjusted the valves. Don't forget, I was working under considerable pressure that day, what with the end of the world fast approaching, and all that. I wanted to get that video in the can, so to speak, before the Rapture. :)

Thanks for those suggestions... I plan to do a leak down test shortly, and proceed from there based on what I find. I may take that suggestion about the Marvel Mystery Oil after I do the leak down.... Then do another leak down to see if it made a difference. If the problem seems to be limited to the cylinder head, e.g., valve stem guides and seals, I will probably have the head redone. If there are significant issues in the bottom end also, I may opt to just swap in a good used engine. Assuming that is something that can be found. :)

Anyway, thanks for your input.

Skippy 05-25-2011 10:36 PM

So why are thinking about changing your head? Does the car exhibit any symptoms? Your blowby doesn't look that bad. It would probably pass the "tea kettle test".

tomscat1 05-25-2011 10:47 PM

Quote:

Originally Posted by Skippy (Post 2724386)
So why are thinking about changing your head? Does the car exhibit any symptoms? Your blowby doesn't look that bad. It would probably pass the "tea kettle test".


Yes, it uses a quart of oil in 150-200 miles. I have been told it need guides seals, and rings.... But I want to delve into that a little more to see if it really needs 'all of the above', or perhaps... Just some of the above.


What is the 'tea kettle test'? I can see the visual connection... But I haven't heard that term before.

Thanks.

1980sd 05-25-2011 10:51 PM

I'm new to diesels but that looks like a DISASTER :eek: Please tell me I'm wrong...

kerry 05-25-2011 11:06 PM

I've seen considerably worse in a well running 617.

tomscat1 05-25-2011 11:37 PM

Quote:

Originally Posted by kerry (Post 2724402)
I've seen considerably worse in a well running 617.

I really don't know how to evaluate the blow-by.... That is more of a sideshow.... I have heard from others that it is not that big of a deal...

My concern is the 1 quart every 150 miles, or so, of oil consumption. For the amount that I drive the car, frankly, even that isn't a big deal.... But I would like to determine the cause, and then decide what's to be done about it.

It is really a neat car, I like the style, and, as an OM617 W115, it is an historic and increasingly rare model.... So I would like to preserve it. Historic in the sense that the 1975 300D was the first time Mercedes put a 5 cylinder diesel in a sedan.... And it was only in the W115 for those two years, in 1975 and 1976. Then the W123 was introduced.

My son loves it, and I plan to give it to him at some point. I would like to give it to him in better shape than it is now.

Oh, and did I mention... It was also built the year I got married... So a bit of Romantic Nostalgia there also. It is more than just nuts and bolts, and dollars and cents.

All of the above enters into my decision as to what ultimately needs to be done to the car. More than you wanted to know, I am sure. :)

katja 05-26-2011 01:11 AM

Mine isn't quite that steamy, but not too far off. Despite a new oil cap gasket, it still makes that oily mess on the valve cover gasket and oil works its way onto the top of the air cleaner too.

I'm not sure if it's the way the camera's picking up the audio and the belt or pulley noise, but the idle of that engine doesn't sound right to me...it sounds slow and a bit rough. Though mine does that too when it's completely cold and the idle control is all the way down.

Anyway, Mr. Camping said the end of the world is really October 21, so you have a few more months to improve the blowby before everything blows up.

Skippy 05-26-2011 01:11 AM

Yeah, a quart in 150 miles is pretty bad. You're probably right about the head, but right to do a leakdown test first.

Some of your reasons for liking your 300D sound similar to my reasons for wanting a '78 300SD: First turbodiesel passenger car ever, only available in the 116 chassis two years, and built the year I was born.

mach0415 05-26-2011 06:32 AM

Quote:

Originally Posted by Biodiesel300TD (Post 2724357)
If it still runs and isn't running away then it's not too much blowby!:P
Is the engine cold or running at operating temp? If it's cold then try it again when it's warm. Also how long ago was the valve adjustment? If it was just was the day you took the video, try it again after you run the car for a couple days. The valves may reseat a little and reduce the blow by.
Other than a rebuild, unfortunately not much can be done about blowby. One thing you can try is pouring a little bit of Marvel Mystery Oil or brake fluid into the cylinders and let it sit for a while. This will break any gummed up piston rings. You'll have to remove the injectors to do this. Change the oil post soak, to remove any fluid that drained down.
You can use thicker oil to help reduce the oil loss to blowby, I've also seen people put filters in the bypass hose to filter out the oil so they don't burn it.

My understanding is that blowby indicates ring wear or a hole in a piston - some kind of lower end issue. Valve adjustment would not allow compression to leak into the sump. It would only leak through the exhaust or intake. This is the purpose of doing a cylinder leak-down test as the result of low compression numbers - to find where compression is being lost.

kerry 05-26-2011 10:13 AM

The vent line for the vacuum pump visible in the video seemed somewhat dirty. It's possible you have a hole in the diaphragm and are feeding oil directly into the intake via the vent line.

Biodiesel300TD 05-26-2011 01:19 PM

Quote:

Originally Posted by mach0415 (Post 2724523)
My understanding is that blowby indicates ring wear or a hole in a piston - some kind of lower end issue. Valve adjustment would not allow compression to leak into the sump. It would only leak through the exhaust or intake. This is the purpose of doing a cylinder leak-down test as the result of low compression numbers - to find where compression is being lost.

Yes you are right but I also think that if the valves aren't closing all the way due to tight clearances then oil will have a chance to slip past the valve stem seals up into the head, assuming the stem seals are worn. While this may not be the largest portion of oil in the blowby it's not helping at all, and it's something easy to fix and is preventative maintenance.

Biodiesel300TD 05-26-2011 01:20 PM

Quote:

Originally Posted by kerry (Post 2724573)
The vent line for the vacuum pump visible in the video seemed somewhat dirty. It's possible you have a hole in the diaphragm and are feeding oil directly into the intake via the vent line.

That dumps oil directly into the air intake, which adds to smoking but not blow by. I've had that problem on my 240D. Put a new diaphragm in the pump and the smoking went away.


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