Blown Engine in '99 300M

That's right, I don't believe it. If Chrysler designed a PVC system so
poorly that it can pull liquid oil into the intake, then my opinion of
Chrysler engineering will drop dramatically. And you couldn't pull
enough vaporized oil through a hose the size of a typical PVC hose fast
enough to pull 2-3 quarts of oil out of the engine "within minutes."
Are you claiming that you can pull a couple of quarts through the PVC
system "within minutes?" Can you provide even a single reference from a
credible industry source (person, technical article, etc.) that
describes this phenomenon?

Why would lose of oil pressure due to aeration cause a stall due to
lifter collapse when lose of oil pressure due to no oil at all in the
sump not cause this?


Matt

 

Only if you have a special engine designed for inverted flight. Most
aircraft engines will stall very quickly in 0 or negative G flight.

Unless the tube is in liquid oil, how can it pull oil from valve cover?
I can see it pulling air with atomized oil in it, but you'd have to
pull a LOT of such air to get even a quart of liquid oil. And most cars
will run at least one quart low and probably 2-3 low before seizure.


Matt

 

Only if it the engine is an aerobatic engine and is certified for aerobatic use.
Besides carburetor issues, the big change here is dual (or more) oil inlet, so that
the oil pump can suck oil whether it is at the top or bottom of the pan, and a simple
valve to prevent air from being sucked in from the inlet currently not in use. A
second breather is also needed. The details are more complicated, but you get the
idea. The carburetor problem is eliminated by only using fuel injected engines for
aerobatic applications.

 

But you are contrasting about apples and sewing machines here. Airplane engines are
designed to operate at 75%-80% continuous power, something that normal auto engines
are not designed to come close to.

 

Matthew S. Whiting wrote:

The 3.5L engine has a windage tray, I doubt that it was an oiling issue.

If I had to theorize, I'd say that sitting virtually un-loaded at
redline for 10-15 minutes straight caused something like connecting rod
cap walk or maybe a flaw in a connecting rod bolt to allow that bolt to
fail. Running at WOT and full load is less abusive of connecting rod
caps and bolts than running at redline and no load. Another possibility
is valve float allowing the pistons to just "kiss" the valves, bending
them slightly as they rotate and finally flexing a valve head off,
causing the engine to swallow the valve head and the ensuing
destruction. But its all guesswork without actually looking at the engine.

 

Just for fun, I asked a colleague at work today about his experience
with oil consumption at high RPM. He's an active member of a couple of
local sports car clubs, one that runs at WGI and another that ice races
in the winter. He runs a BMW M3 at WGI in the summmer and a Nissan
Sentra on the ice in the winter. Both are basically street cars with
the addition of roll cage and safety harnesses and different brake pads
and tires for the track. Both are driven on the street and have stock
engines. There are many other brands of cars that run at WGI in both
races and on open track days. I was up there recently and saw
everything from Minis, Mustangs, Camaros, Vettes, and BMWs to a Porsches
and a Ferrari. Most were stock other than tires, brakes and safety
equipment and they were running for an hour at a time during this open
track day. I rode along in the BMW in two different sessions and the
only time the RPM fell much below 5,000 was entering the corners. We
ran near redline a fair bit of the time, even though we were running in
the rain and really couldn't open it up at the top end.

His reply:

"The general answer is no, an M3 engine does not consume significant
extra oil at high RPM. Nor do most engines that I've seen in action at
the track. Purpose built race engines many times do use significant oil
during a race, and it is held in a pressurized reserve I believe.
As aside note, my personal M3 however, does put out some oil. I
originally thought it was engine oil, but I now think it is differential
fluid -- a leaky seal as shown on my garage floor. It coats the back of
the car during a track session."


Matt

 

We're not talking about an M3 engine here. We're talking about a Chrysler
3.2 or 3.5L engine (which I don't think has been clarified), which, as I
have stated twice, besides the PCV line, also have a plain, absolutely
non-restricted tube (no PCV valve) going straight from one of the valve
covers to the intake pipe between the air filter and the throttle body.

I've even seen discussions on certain Chrysler news groups about (plugging
the original hole and making a new hole and) re-connecting the intake end of
that tube into the air filter box upstream of the air filter (i.e., less
negative pressure relative to the crankcase) for the dual purposes of
cutting down on oil consumption and providing some free oiling of wet-type
filter elements.

I guess just one set of questions remain: If you were Chrysler or a Chrysler
dealer, and a customer told you that just before their otherwise
under-warranty engine locked up, it was run for several minutes at 6300 to
6600 rpm, would you honor the warranty? Why or why not?

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my address
with "x")

 

Here's another piece-o-information: Several months ago, a co-worker was
behind me (I was in my '99 Concorde) on the way home on a two-lane
road. I passed two cars. The next morning when I got to work, he told
me that both times when I punched it to pass that a puff of black smoke
came out of the exhaust.

I poked around and discovered that a bend in the hose going to the PCV
valve was clogged slam shut with carbonized gunk even though the PCV
valve was clean. I also had noticed higher-than-normal oil consumption
lately. I replaced the PCV hose, and the puffs of smoke and the high
oil usage stopped.

I'm thinking that, with WOT and sudden downshift (jump in rpm) the puffs
of smoke came from oil that got sucked thru that un-restricted hose that
I talked about (going into the intake hose upstream of the throttle
body) - and I was probably in the 5k to 5500 range on the tach - just
high intake hose vacuum and moderately high revs with a disfunctional
PCV system.

I'm thinking that even with a funtioning PCV valve at over 6 grand, that
hose would be seeing a relatively high pressure differential = oil flow
(goes along with the mod that people talk about of re-connecting that
hose to the ambient side of the air filter box in my previous post).

Perhaps the OP's PCV was also not functioning, which would have greatly
aggravated the problem. His *is* the same age as my car and almost as
many miles.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

I understand that Chrysler isn't BMW, but you missed the part about many
other types of cars running for an hour or so at a time around WGI. I
don't recall seeing any Chryslers or many Fords (I think there were a
couple of Mustangs), mostly GM and imports.

However, I still haven't heard a good explanation as to how enough oil
can get into the valve cover to allow the PCV line to suck it out. I
did some searching last night and the only think I found even close to
this was in regards to longitudinal V-8 engines that were kept in a
nearly 1-G turn for a fair amount of time (must be during skid-pad
tests). The article said that in this case, the oil could accumulate in
the valve cover to a sufficient degree that it could be sucked into the
PCV line. I doubt the 300M was kept in a constant turn during this
high-speed operation, and even then, depending on the location of the
drainback holes, it would be hard to pool oil in the valve cover(s).

I don't dispute that high-speed operation will increase oil consumption
as you are sucking more vapor from the crankcase/valve train areas, but
you'd need to suck LIQUID oil in order to deplete enough to kill the
engine "wihin minutes." This would be an oil consumption rate of a
quart or more in 10 miles or so. That is several orders of magnitude
more than "normal" consumption. Several hours of high-speed operation
might do this, but I still don't believe it can happen in minutes.
And I wasn't able to find even a single reference in my search that
suggested this being possible. If you know of one, I'd love to read it.

It depends on the red-line of the engine and what is written in the
owners manual. If 6600 RPM is below the redline (I don't know what it
is for the 3.2/3.5 family), and if the owners manual didn't prohibit
high-speed operation below redline, then, yes, I'd honor the warranty.
There would be absolutely no basis for not honoring it.

If 6300 or 6600 is above the redline, then I'd deny the claim.
Likewise, if the owners manual says something like don't exceed the
redline under any circumstances nor exceed xxxx RPM for more than 5
continuous minutes, then I'd deny the claim assuming that xxxx RPM had
been exceeded for more than 5 minutes.

I hope the OP posts the actual failure mode here once the engine is torn
down ... assuming the dealer even bothers to diagnose the failure.

Given the other posts about the automatic override of the 300M tranny, I
suspect the details of the story aren't accurate in any event. Could
well be the car was low on oil to begin with or developed a bad leak
that was ignored and driving in 1st just exacerbated things.


Matt

 

Last I knew, black smoke was a rich mixture and blue smoke was oil. It
isn't uncommon for a puff of black smoke to be emitted when you punch
the throttle quickly to WOT. I can't speak for the Concorde
specifically as I don't have a service manual for it, but most of the
cars I've owned in the last 10 years go into open loop mode at WOT where
a richer and less controlled (I think certain sensors like the 02 sensor
are ignored in open loop mode) fuel/air mixture is used. This will
cause black smoke, especially if the throttle is punched at relatively
low RPM.

I think it was a temporarily over rich fuel mixture during the
transient. I don't doubt that a defective PCV can increase oil
consumption, but it won't increase by 10 to the 3rd power.


Matt

 

FYI... this is a 3.5L with around 65,000 miles. Oil was changed regularly
at 3000 mile intervals, with no significant consumption between changes, and
the level was checked at each refueling. As of the last refueling, the
crankcase was full to slightly overfull. When I got to the vehicle where it
stopped I checked the fluids (oil and transmission) before trying to restart
and both appeared normal. (By which I mean there was fluid of the right
color on both sticks. Couldn't tell for sure about level, as the car had
been pulled off the side of the road and was leaning to the right.)

If anyone's interested, I'll post any information I get on the damage once
the tear-down starts. I talked to the shop today (not a dealer), and
they've located a used engine from a source they trust for about $2000.

 

I'm curious as to the cause. Feel free to email if nobody else here is
interested.

Matt

 

I would not be surprised if that were the case (35 mph normal driving at
under 2000 rpm vs. >6 grand - there are at least square, if not higher
order, laws involved).

Me too.

I, too, would not be surprised if there was a second anomaly besides the
driver contributing to the failure. On the other hand, it would not
surprise me that you couldn't maintain over 6000 rpm without some
serious damage in an otherwise good engine - oil related in some way.
Just think of the huge forces on the soft bearing inserts (I didn't know
how to spell "babbitt") - which are in fact several orders of magnitude
above low rpm operation.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

How are the forces several orders of magnitude higher? They should be
linear (f=ma) or a squared relationship for rotary motion (f=mv^2/r).
If 1,600 is normal cruise, then 6,400 would be only 16 times higher,
still barely one order of magnitude. Please explain how you calculate
"several" (which I take to mean at least three) orders of magnitude
higher forces.

Again, I don't know the redline published for the 3.2/3.5 engine, but up
to redline, the engineers should have taken the forces, heat rejection
requirements, etc., into account at that RPM. If there are limitations
on duration of operation at just below redline, then they should be
noted in the owners manual. Since I don't have a 300M, I can't check
this out.


Matt

 

I think its common sense that you don't hold any engine at something
like 80% of redline and no load for an extended period. But in legal
terms, it might take something more quantitative.

 

Well as a dealer or crysler or any one, ford gm what have of course I
would do everything I could to not honour it.
But look at it this way if that RPM is under the redline on the tach
then it is within reason that it can be driven in that range. Also with
all these computer controlled engines does crysler not put a cutout on
the engine? I once had a little GM rental that once it tried to go over
redline it would start to slow down, the rev limiter would kick in and
that would slow it down. So either the rev limiter was faulty or there
is something wrong with the engine if it seized up after being run at
that speed, could be it ran out of oil or it was in such a sharp turn
that the pickup ran dry and at that speed sure it would seize up.

 

I didn't recall the OP saying anything about no load, but even so, I
don't consider this common sense at all. If an engine can't be run
continuously at the published/indicated redline, then it was set too high.

It's been a while since I read this and I'm not able now to find a
reference, but I'm pretty sure the myth about "no load" being harder on
an engine then "under load", is largely a myth. Kind of like the myth
that running an engine at full throttle at low RPM being harder on it
than running higher RPM at part throttle to draw the same power. This
is commonly called "lugging" the engine in the automotive world and
running "under square" in the aviation world.

Matt

 

Myth? try it on a roller crank Porsche and report back, please.

I'd recommend "high RPM at part throttle" first, just because the other
option may cause your test to abort early.

nate

 

It was already established earlier in the thread that the computer would
have forced an upshift at 6600 rpm. Apparently this was a worst-case
screw up in that the vehicle speed was just below what would have forced
an upshift.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Perhaps I mis-spoke. What are the straight-line piston acceleration vs.
rpm relationships for a sine wave motion and acceleration at TDC and
BDC?

You mean if you had a 300M, you'd cruise it at 53mph in first gear for
20 minutes or until it locked up just to satisfy your and our
curiosity? What a guy! 8^)

Certainly the engine life would be a fraction of what it would be for
the normal range of driving conditions. IOW, I'm pretty sure that an
engine is not designed to last 100k vehicle miles with the tranny locked
in first gear at 53 mph. You do not design or warranty something for
worst-worst-case abuse in a competitive market - excess weight and costs
would make you non-competitive. No engine would be designed or
warrantied for such conditions, which is what your last paragraph is
implying.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")