Tonight I am some combination of befuddled, encouraged, surprised, delighted, and cautiously optimistic. Let me 'splain. I came up with an idea to either prove or eliminate from consideration the possibility of a head gasket leak or a cracked head. Such a malady would not only add unwanted water into the combustion chamber at certain times in the cycle, but it would also force gas bubbles into the cooling jacket which would then find their way to the radiator. Seeing them is sometimes difficult so i came up with the device shown in the picture. This way any bubbles would rise through a relatively quite column of water and could more easily be seen. After an hour of idling the engine was up to temperature and had been for 30 minutes. Absolutely no sign of that steady stream of bubbles that would indicate a leak. But it was also not running rough either. Hmmmmm. This is a good thing to be sure and I think I know why. Last night I added a cup of Marvel Mystery Oil to both the crank case and the fuel. I have seen this stuff free up stuck valve lifters and return an engine that sounded like it had 3 loose rods to quiet smoothe runnings. Well it ran for a half hour or so last night and then I shut down. That got it circulated through both the oil and fuel systems where it could reside while dissolving sludge and varnish. And I think that is what must have happened. Since there was no leak into the cooling jacket that left rings, and valves. And as of this morning it occurred to me that it might also be an injection pump failure in that cylinders outlet. So I may have cured it by the use of the MMO. I will do this all again tomorrow and see if these results repeat. If it rins good for tomorrow's test I Will consider the issue closed. I won't ever know what was ultimately wrong. But I guess I will just have to live with that. I will let you know what happens. Peace.
--------------------------------------------
On Mon, 6/27/16, Bogy Wan Kenobi polespearbogy@yahoo.com [diesel_mercedes] <diesel_mercedes@yahoogroups.com> wrote:
Subject: Re: [diesel_mercedes] 240d engine in Jeep acting up
To: "diesel_mercedes@yahoogroups.com" <diesel_mercedes@yahoogroups.com>
Date: Monday, June 27, 2016, 7:52 PM
I swapped the injectors
(1 and 4) and the problem stayed with #4.
I also tested checked the
clearances hot and they were intake 0.005" intake an
0.014 exhaust. I left them alone.
I couldn't do a hot compression test
because my comp tester has a leak at the quick disconnect
that has to be fixed. I will repair it in such a way that
I can use it to blow air into the cylinder to see where it
goes - exhaust, intake, water jacket, crank case.
I began to wonder if there
might be a piece of foreign matter above the valve (where
the stem goes into the casting) that is holding it open when
it gets hot. If warranted, or maybe if not, I will pull the
manifolds before I pull the head to check for such
abominations.
Getting
closer,
Bogy, "Hardware eventually
fails. Software eventually works"
- Michael Hartung
From: "Bogy Wan
Kenobi polespearbogy@yahoo.com
[diesel_mercedes]" <diesel_mercedes@yahoogroups.com>
To: "diesel_mercedes@yahoogroups.com"
<diesel_mercedes@yahoogroups.com>
Sent: Sunday, June 26, 2016 10:43 PM
Subject: Re: [diesel_mercedes] 240d engine in
Jeep acting up
#yiv9573442433 #yiv9573442433 -- #yiv9573442433
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I hadn't considered a
sticky valve. But it would not be that bad all things
considered. And it may be fixable with some MMO if it is
just some sludge. Much better than a cracked head or piston
to be sure. I like this engine and if the head comes off
then so do all the rings. Plus cylinder dressing and a
complete head job and timing chain.
What do you think about advancing the timing a
bit, just 'cause, for that better performance you talked
about? I have lower diff's (3.54:1) than the 240Ds came
with, but the oversized tires more than compensate and I am
in 15% overdrive now. A little extra power would certainly
help, but not at the expense of the rest of the drive train.
Actually 4.10 or 4.11 diff's would give me a very
accurate odometer/speedometer and the engine would see the
same load as if it were in the original 240D. But until then
a little extra power would be desirable sans adverse side
effects.
Bogy. "Hardware eventually fails.
Software eventually works"
- Michael Hartung
From: "'Mark
in Lakewood, CO' beeser750@q.com
[diesel_mercedes]" <diesel_mercedes@yahoogroups.com>
To: diesel mercedes <diesel_mercedes@yahoogroups.com>
Sent: Sunday, June 26, 2016 9:04 PM
Subject: Re: [diesel_mercedes] 240d engine in
Jeep acting up
#yiv9573442433 --
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The valves on these engines
(and all other MB Single OHC engines) get LOOSER as the
engine gets hotter. So, if they're set correctly when
cold, then they are most surly completely closed when hot.
Unless, they get sticky when they get hot....
Maybe a broken valve spring? Other out-there
ideas: A bizarre crack in the piston that opens up when it
warms up. (Should cause more blow-by.) Bent valve.
Some tiny bit of debris/dirt in the IP, injection line or
injector.
The IP being 5 degrees retarded
shouldn't make that big of difference, and besides, that
would affect all cylinders the same.
By-the-way, you can advance the cam about
10-degrees by moving the sprocket one tooth to the right
relative to the timing chain. That would have your cam
advanced 5-degrees, if it's now 5-degrees retarded,
which would give a noticeable improvement in performance.
If the IP timing can't be corrected by rotating the IP
on the block (it's mounted with slotted holes), it will
need to be removed and reset onto the splines on the
auxiliary shaft.
Mark in Centennial, CO
From: "Bogy Wan Kenobi polespearbogy@yahoo.com
[diesel_mercedes]" <diesel_mercedes@yahoogroups.com>
To: "diesel mercedes" <diesel_mercedes@yahoogroups.com>
Sent: Sunday, June 26, 2016 2:15:40 PM
Subject: Re: [diesel_mercedes] 240d engine in
Jeep acting up
Once
it is warmed up the miss happens at all speeds.
I forgot to say that I had the
pump off and discovered that the check valves in the lift
pump were not sealing. So I corrected that.
I also determined that the #1
outlet is exporting only about 70% of the fuel that the
others are. Yet when I crack the #1 injector line the engine
almost stalls. Not so with #4. Cracking #4 makes almost no
difference once it starts to miss. I will deal with that
once the #4 problem is solved.
Also, there was a lot of air problems that I
only discovered when I replaced all the hoses with clear
lines. That made a LOT of difference. But I highly recommend
clear flexible hoses if you possibly can.
Also there is a check valve on the IP fuel
return outlet that I did not know about previously. That was
stuck and freeing that up also made a lot of difference in
the ability to bleed out the air and get it to start.
As for the chain stretch, the crank was about 5
degrees ahead of the cam so the cam, and hence the IP, was
retarded. Is that a significant problem? Even if so I
can't see that being responsible for a miss when things
warm up.
I plan to warm it
up and pull the valve cover and check the valve clearances
when they are hot to see if they are closing and thus
affecting compression. But I am going into uncharted
territory after that.
The
only thing else that I can think of, and I just thought of
it, would be a cracked head that opens up when hot. And THAT
is not a happy thought. But I do not notice any pressure
build up in the cooling system, nor a loss of coolant. But I
will look closer tomorrow when I resume the
investigation.
Thanks for
replying,
Bogy.
"Hardware eventually fails. Software
eventually works" -
Michael Hartung
From: "'Mark in Lakewood, CO' beeser750@q.com
[diesel_mercedes]" <diesel_mercedes@yahoogroups.com>
To: diesel mercedes <diesel_mercedes@yahoogroups.com>
Sent: Sunday, June 26, 2016 8:47 AM
Subject: Re: [diesel_mercedes] 240d engine in
Jeep acting up
Is the miss when warmed up
present only at idle, or at all engine speeds?
It's very doubtful that the compression
will change in one cylinder more than the others after being
warmed up. Perhaps the efficiency of the injector could
change with temperature, but this is also unlikely.
If the miss is exhibited at or near idle
speeds, then this is usually due to air in the fuel line,
or/and a weak lift pump. From my experience, this will
initially show up once the engine is warmed up, moreso than
when cold.
If your crank is five degrees
retarted relative to the cam (assuming the marks on the
dampner/pulley are accurate), then your cam is 5-degrees
advanced. This would indicate little or no chain stretch,
and would help performance, fuel mileage, etc.
Mark in Centennial, CO
From: "Bogy Wan Kenobi polespearbogy@yahoo.com
[diesel_mercedes]" <diesel_mercedes@yahoogroups.com>
To: "yahoogroups" <diesel_mercedes@yahoogroups.com>
Sent: Sunday, June 26, 2016 8:29:17 AM
Subject: [diesel_mercedes] 240d engine in Jeep
acting up
Guys and
gal:
I have successfully installed a 240D
and manual transmission in my Jeep CJ7. After some grief
caused by a bad injector in the #4 hole the idle stabilized
to the point that you could "balance a nickel on its
edge". The aforementioned grief was due in part to
replacing the injector with another that was also
malfunctioning. A third injector from the old 5 banger
suddenly stabilized the idle and I have since pressure
tested and spray-pattern tested all of my spare injectors.
(At least all of them that I could find.) I had 6 bad
injectors out of some 20 spares. I now have a complete set
of known good replacements for both my jeep and my daily
driver, a 300td. But I digress.
Although the
idle is now stable cold, when the engine warms up it has a
pronounced miss. Cracking the lines reveals it is the #4
cylinder again. I adjusted the valves with the engine cold
(not sure if that was the right temperature) and ran a
compression test. All 4 holes are within 8% of each other
cold - hence the decent idle when cold.
My question is - what might be the reason for
it to start missing when it warms up. And since it is a
diesel the obvious cause is a drop in compression to the
point that it cannot get the intake air hot enough to ignite
the fuel. Basic physics. There is no evidence of a head
gasket leak that I can detect and that leaves rings and
valves, and/or possibly an injector that malfunctions when
it gets hot. And a change of injectors with one from another
cylinder would prove/disprove the injector possibility.
Oh yeah - I measured my chain stretch and when
the cam marks line up, the crankshaft indicator is about 5
degrees after tdc. I know this will affect the timing to
some degree or another and since the IP is closer to the
crank it should be somewhat less than 5 degrees. Your
thoughts here are appreciated. I have not compensated for
this at the IP, yet. Could this be part of the failure?
I am willing to accept that
the rings fail when they warm up. I have never seen that and
I certainly don't like the thought of doing a ring job
even though I will if it is necessary. I am more inclined to
believe it is valves expanding when hot beyond the clearance
limits. But when the engine cools down it again idles fine.
Any and all comments and
flames and . . . are welcome.
Color me perplexed.Bogy.
"Hardware eventually fails. Software
eventually works" -
Michael Hartung
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