Spamfreedom wrote:

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....

It sounds like you run the engine infrequently, at low loads and it
never really gets hot ... is this close?

If that is the case, you probably have carbon deposits on the valve
stems and lack of lubrication, particularly when starting cold, can
cause the valve stems to stick and bend the pushrods.

You can avoid a lot of this by making sure the engine gets up to
operating temperatures when loaded and then idles for a few moments
before switching off so that oil cannot carbonize on the hot valve stems.

Rick

Good points Rick.

I know the MD series engines have very limited oil lubrication going to the
top end. One of their problems is rusting valve springs. This, according to
Volvo, is due to short run times that doesn't provide enough oil or temp. to
eliminate moisture condensation in the area of the valves, springs and
rocker arms.

I had a valve spring break, due to rust pitting, while in Baja '89, and
found that there had been another boat in the same area that had experienced
the same problem.. My valve dropped into the cylinder and was jammed back
into the valve seat, cracking the passage into the water jacket... Had to
replace one cylinder head.. Also, I was later shown service bulletins
regarding the rust problem in the valve gear area.

The MD17C may suffers from the same rust, condensation problems as the other
MD series engines.

Like Rick says, start it often, run it long enough to get the oil hot and
circulating to all parts (and this should help to eliminate moisture in the
valve area).


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Steve wrote:


The MD17C may suffers from the same rust, condensation problems as the other
MD series engines.

Hadn't considered that aspect but it makes a lot of sense ... rusting
would cause the same symptoms as carbonizing, valve stuck closed, bent
pushrod. Same cure in any event so either bird with the same stone 8-)

Thanks for adding that little piece of info.

Rick

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....

It sounds like you run the engine infrequently, at low loads and it
never really gets hot ... is this close?

If that is the case, you probably have carbon deposits on the valve
stems and lack of lubrication, particularly when starting cold, can
cause the valve stems to stick and bend the pushrods.

well.....I am in the great lakes.....lake michigan actually.....the boat is
hauled in winter....the last few months have been busy and I was not able to
use the boat much unfortunately.....I did go there and start the engine monthly
and I would let it idle for 10 minutes or so then run at 12-1500 rpm for a half
hour.....and even put under load for a few minutes....I thought I was doing
things right, but now I am not sure....maybe wrong oil?...(Rotella T
10W30)....I did put some "power service diesel treatment" in the fuel when I
filled up on monday (and ran the engine for a good hour)...when i started it
wednesday, blam, the problem was there (missing, spitting out intake,= bent
rods)....I took the vavle cover off #2 and all looked fine, no rust or
such,.....I think I must pull the heads (even though I have a whole 6 inches of
clearance in the engine room above the engins...yippee)

So how do I avoid this?.....during the wisconsin winters, I do go down and hand
crank the engine a few spins to move oil.....and I fogged the engine with oil
and ran the oil/dsl mixture thru fuel system etc.....following the manual....I
do need to pull the injectors off this year for cleaning (I didn;t last
year....bad?).....

funny thing is that I do have 2 spare push rods......my last mechanic said he
canl;t get them for one month.....BUT I (and google) was able to find some and
order extras within one day....they were only $20 a piece, cheap spare IMO....

Hey I really appreciate the feedback so I can discuss it with a mechanic (after
I find one that seems to know what is going on....amazing how easy I can stump
some of them with my limited knowledge after reading calder's book).....thanks
again for the great feedback....

As I have mentioned in here, in other posts, I'm on my second boat with the
MD2B. Not an expert but I have experienced some problems with the engines
(no more than you might with other makes) but I have sorted them out myself
with the aid of the manuals and Volvo service bulletins and user articiles.
As a result, I have a higher degree of confidence in the Volvo MD series
than most around this group.

One of the biggest complaints I have had in the past has been the high cost
of simple parts, like gasket, etc. Major parts are expensive as well but now
that there are so many being replaced there are plenty of use parts
available.. I even found a fellow at the boater Swap Meet that had his
cruising spares for sale at a bargin price.

A fellow from Europe contacted me once to let me know that the MD series
engine are still available new in Northern Europe and sell for about $3500
US for a MD2x..

Just one final tip regarding the marginal oil circulation in the valve area
when the engine is cold or shot run... When ever I add oil to my engine, I
do it throught the plugs on the valve cover. These plugs were intended for
adjusting the compression release, but work better for adding oil than the
regular oil fill. Doing this totally floods the valve gear with fresh oil.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Spamfreedom wrote:


So how do I avoid this?.....during the wisconsin winters, I do go down and hand
crank the engine a few spins to move oil.....and I fogged the engine with oil
and ran the oil/dsl mixture thru fuel system etc.....following the manual....I
do need to pull the injectors off this year for cleaning (I didn;t last
year....bad?).....

Leave the poor thing alone in the winter 8-) ... unless you have an
engine preheat system with prelube all you will do by turning it over
will be to introduce cold moist air to the cylinders, wipe what little
cylinder lube remains, and rub dry bearing surfaces against each other.
You will not move any oil except for that which you are far better off
not moving.

If you are going to pull the injectors for testing and calibration then
you can go ahead and squirt some preservation oil in the cylinders. You
don't have to pull the injectors each year unless you have good reason
to suspect problems with them. They can and should go for years with no
attention at all.

If you do not have any signs of rusting under the valve covers or on the
springs as Steve described then your problem with the pushrods is most
likely carbon deposits on the valve stems. They can be the result of
your unloaded runs, people think that is good for an engine and it
simply isn't as you have discovered.

If you find rust on the underside of the top of the valve cover, check
carefully for rust on the valve springs and stems. If you find any, take
an oil can with some diesel and squirt on the springs and stems. Wipe
off what you can and refer to the hammer mentioned in the next paragraph.

It is a credit to the design and construction of diesels that they
survive the best efforts of users to destroy them with kindness. Do not
give it short runs during the layup, do not turn it over unless it is
preheated and prelubed, in the Spring remove the valve cover and check
for condensation on the underside, squirt some light oil on the rockers
and valve stems. If you are really worried about sticking valves, tap
the closed valves with a soft faced hammer to see if they are free ...
they will feel "springy" if they are, solid if they are not and a few
taps and a drop or two of diesel on the stem should free up the stuck
ones. Do the same hammer test on the other valves, some will be partway
open or all the way open, you can rotate the engine to allow the open
valves to close to ensure they are free.

Rick

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....
snip

Only an outside chance but... Have you been using a starter fluid on those
cold weather starts? They have a reputation for bending pushrods on many
deisels. Not seen it happen personally (yes, I've cheated when faced with a
no-start), but many manuals contain the warning.

Some good suggestions on care and feeding in the previous posts. Liked the
hammer diagnostic too!

surfnturf

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On Fri, 31 Oct 2003 03:42:27 GMT,
surfnturf wrote:

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....
snip

Only an outside chance but... Have you been using a starter fluid on those
cold weather starts? They have a reputation for bending pushrods on many
deisels. Not seen it happen personally (yes, I've cheated when faced with a
no-start), but many manuals contain the warning.

Some good suggestions on care and feeding in the previous posts. Liked the
hammer diagnostic too!

surfnturf



I don't use starter fluid (ether) on diesels, it's much better to use
wd-40, or at least, that's what an old and wrinkled diesel mechanic told
me, almost 30 years ago. He must have known what he was doing, he was
old.
Seriously, wd-40 works great, easier on the engine than ether. For
diesels anyway.


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--
Jim Richardson http://www.eskimo.com/~warlock
The reason the Irish are always fighting each other
is they have no other worthy opponents.

BTW, it seems to happen after the engine has sat for awhile
(months) and during cold weather starts....

Does it have hydraulic "lifters" like a US car? I had a couple of the
ones in a V8 Ford bleed down so far that the push rods actually came out
on two exhaust valves - this after a freeway run from LA to SD. When I
started the motor the next AM these cylinders filled and fired but then
the intake pushrods bent trying to open the valve against pressure. Went
back to the 20w40 Ford recommended (vs 5w30 Mobile one) and never
happened again. Of course it hadn't happened in 20,000 mi on the Mobile
1 either so prolly a coincidental set of freak conditions. Anyway, one
more thing to look at ....