In desperate need of help diagnosing! - Page 2 - PeachParts Mercedes-Benz Forum

Lucas · #16 02-16-2015, 12:13 PM

I remember this thread. I copied your valve cover paint job. Couldn't scratch of the logo though.

I would say take a step back. Look at it as a new motor to you and diagnose.

I just did my head. Had a moment of panic. But then I stepped back and diagnosed it. I had a crack delivery valve. To find this i loosened the injector lines with it running. When I loosened #1 it didn't run any worse. I swapped the injectors and rechecked. Still #1. So I removed the line and watched the fuel coming out. Looked fine. I sprayed some diesel on and watched it suck it around the delivery valve holder. Problem found.

Did you check to make sure you had the right head gasket? Laying it on and matching up all the holes?

It has to be something simple. If they did a bad job on the machine work it won't last, but it should work.

White smoke is water. Usually. Like they said. Compression and leak down.

If I have a problem for more than a few days I ask for help. Sometimes it's worth it to have someone take a look. I'm a good mechanic, but these motors are complex.

moon161 · #17 02-16-2015, 12:25 PM

What was the break-in like?

Stretch · #18 02-16-2015, 01:34 PM

Quote:

Originally Posted by Mersadie

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The timing is absolutely perfect, unless the marker is wrong. was very careful with that.
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I'd still perform the 2mm lift test to check.

PeachPartsWiki: Measuring Timing Chain Stretch

It is a good exercise that makes absolutely sure the camshaft timing is correct

Quote:

Originally Posted by Mersadie

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How would air get in the fuel?
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You need to bleed all the air out of the system once you have broken a connection (or connections)

Quote:

Originally Posted by Mersadie

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-I was very suspicous of ip timing, but drove it for months dailyat exactly 24* BTDC(carefully drip timed). When the new pump went on, I timed it at 26*BTDC to try and reduce some cold start coughing. That solved that issue, and seems a tad more responsive.
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Has your IP got the cover on the governor for the use of the A-B timing lights?

Quote:

Originally Posted by Mersadie

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Heres another question though. the other day when we were in checking the valves, we found large traces of oil in the air cleaner flex tube, and into the turbo. Now while i know this is coming from the top of the valvecover into the oil seperator, and while im posotive the oil seperator isn't doing its job, do you think that it is just the fact that the excessive blow by is shoving more oil up there than the seperator was ever meant to handle?

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Could be too much blow-by causing this. But if the engine has been rebuilt properly you should not be getting this trouble.

barry12345 · #19 02-16-2015, 02:00 PM

Quote:

Originally Posted by Mersadie

Thank you guys so much for the quick responses! I will just go ahead and answer our questions in chronilogical order.

1.vstech: The camshaft was not spec'd, but looks very very healthy, no scoring or scratches or rounded lobes.
The timing is absolutely perfect, unless the marker is wrong. was very careful with that.
How would air get in the fuel?
-I was very suspicous of ip timing, but drove it for months dailyat exactly 24* BTDC(carefully drip timed). When the new pump went on, I timed it at 26*BTDC to try and reduce some cold start coughing. That solved that issue, and seems a tad more responsive.

-Compression Tester is going on order very very soon. Not a fan of Harbor Freight.

-The engine has run for months on a dailybasis, so I think its out of the break-in period... And the IP is drip timed.

-The money is being spent on things that would get replaced anyway. Every compenent before I started had 250k+ miles on it. It may seem crazy, but the goal of this project is to get the car back to its original glory to experience exactly what the person who drove it off the lot in 1982 felt.

-Like I said earlier, as far as I can see the engine reads perfectly timed, but that is a very good idea for checking if the markers are right. Do you mean just stick a straw in the prechamber and tape the base of it? How do you seal it in?

Once again, thank you guys. Already lots of useful info and things I need to try now.

Heres another question though. the other day when we were in checking the valves, we found large traces of oil in the air cleaner flex tube, and into the turbo. Now while i know this is coming from the top of the valvecover into the oil seperator, and while im posotive the oil seperator isn't doing its job, do you think that it is just the fact that the excessive blow by is shoving more oil up there than the seperator was ever meant to handle?

Thanks!
- Matthew.

Something like a rubber with a hole drilled through for a straw or whatever you can think up. There is no pressure to deal with. Yes I would expect the blow by to be responsible for the oil being present.

For others members information. When I was casting septic tanks in situ. I would deal with my form ties by putting them through 1/2 in pipe. These pieces of plastic pipe also controlled the forms separation. I used 3/8 threaded rod for form ties.

The plastic pipes where easily driven out of the concrete later. I had noticed years before that when drilling out rubber with deep hole saws the result was a tapered rubber plug. Drilling two inch rubber surplus disks was done with a 3/4 hole saw and resulted in a well tapered very tight fitting plug.

Driving them into the pipe holes gave the tanks an absolute seal. No reason they will not last the life of the tank anyways. That is the way I personally would make up a shallow plug for the injector hole with a passage drilled through for a straw. There are probably easier ways though.

Some of my behaviours unfortunately get undesired side effects. The regulations at the time stated the builder of the septic tanks where responsible for the tanks integrity. I guess they had never considered guys like myself exist.

I could form and pour a 2000 gallon tank in 5000 pound grade concrete in less than half a day top and all for three hundred dollars back then. So the scoundrels changed the provincial regulations to allow only csa/ual approved septic tanks.

Departments like the environment here dislike people slipping out of their excessive controls. First they tried getting engineers to inspect and find my tanks lacking in comparison to commercial preformed tanks.That did not fly at all well for them.

The tanks I made where vastly superior. Todays approved concrete pre cast tanks sold locally and certified have what are to me serious shortcomings.

The engineers did drive some of my plugs out for inspection and where surprised they where tapered. When asked where I acquired them I told them I just fabricated them myself. I sensed they wanted to ask how but that might show their limitations. Hard rubber plugs with a nice taper are easy and fast to produce.

TnBob · #20 02-16-2015, 03:33 PM

No one here can see, hear, smell or feel your motor.
Have you considered going to a performance shop and having them
diagnose the motor ?

automch · #21 02-18-2015, 06:59 AM

Quote:

Originally Posted by Mersadie

Hi! My name is Matthew and I daily drive a 1982 300d, some of you may have seen my rebuild thread. The motor is completely gone through, thousands invested and,unfortunately, everything is not perfect. Ive been trying to diagnose my problems for about 6 months now and no luck. So I decided that it would be smart to get some outside opinions and help because many people are smarter than one. Let it be known I have done my hw, probably cumulative hours spent on this forum would add up to days, and I've tried all the simple obvious things. Anyway, I will list out the problems, symptoms, and what ive tried as follows, any help or pointers or even ideas would be incredibly helpful!!

1. The Vibration, the Smoking, the Blow By.
As I said earlier the engine is completely gone through. New cylinder sleeves bored to spec of the pistons. Pistons measured and weighed all in spec of each other. Head was completely redone, new exhaust valves, vacuum tested, valve stem seals, valves adjusted (and frequently checked!). Brand new injectors. All of the things that I would think could possibly contribute to this fairly brutal idle vibration, the constant WHITE smoke out the tail pipe, and some pretty substantial blow by. EXCEPT, the injection pump. Well, months later, I now have the injection pump rebuilt. New delivery valves, internals, and calibrated. I was expecting this to cure the majority, if not all of my problems. Granted, all of the problems(except blow by), were noticeably reduced, I still dont consider it a complete win. At this point im starting to believe that all of these problems are connected. Perhaps the machine shop botched the head, im getting blow by from leaky valves, which is also causing it to run rough and smoke..?...? I have no idea, my next test will be the compression. Hopefully that will tell us something interesting. Feel free to ask questions, and any thoughts are helpful! Really need to get this guy fixed as I cant have it consume my life, and bank account, forever..

2. Oil Cooler lines.
Yes, kind of off topic, but scary to say the least. I have brand new oil cooler lines, replaced during the rebuild about 6 months ago, and what do you know?! Leaking like a siv above the ac compressor.... I want a more reliable, more permanent fix, that wont leave me wondering if ill ever be stranded on the side of the road with a seized engine. #1 fix in my head is practicing brazing on the old lines, braze on some an fittings, and run short braided an flex line. #2 is tapping the oil cooler for an npt fitting? Then converting to an, then running an line straight from cooler to filter housing and getting metric to an fittings for the housing? Any thoughts on which would be better? Or possibly even better ideas?

I know you guys will be helpful, always are, so thank you in advanced! Hopefully we can solve these problems together.
Have a blessed day!

Hi Matthew, I am a Retired ASE Master Technician and am willing to look at your engine for you. I am 2 hours from Atlanta in Anderson SC.

First though a couple questions:
1. What brand and type of piston rings did you use?
2. How much piston skirt clearance is there?
3. Were the cylinders selectively honed to match the piston that would fit each cylinder?
4. How about the turbo, is there any side movement in the shaft. A badly worn turbo or damaged shaft seal can cause what appears to be blow-by because it blows pressure into the crankcase. I have seen it in other diesels.

If you want me to look at it for you send me a PM and I will give you my phone and address.