Blown Engine in '99 300M

It's been my experience that when a car won't turn over most people suspect a dead battery, DOA computer etc..... is there something else you're forgetting to tell us? Like maybe you forgot to have the oil changed for the past 40k miles, or were drag racing when the engine died?

If you were just a normal driver doing routine maintenance, I would call the Chrysler 800 number and talk to them. They might help cover at least some of the costs. What have you got to lose?

Good luck;

SRG

Not enough info. What does "died hard" mean? Please describe the sequence of events. Have you owned this car since it was new? What kind of maintenance do you practice?

Yeah, of course.

, doesn't look like you should have a tough time finding a low-miles used engine assembly for $2500 or less.

DS

You're right, I should have been more complete. A driver who shall remain nameless did not know how to use the autostick, pulled it into low, and drove at 55mph for awhile. After about 10 minutes the engine complained loudly and smokily. Now the starter motor engages when you turn the key, but the engine won't rotate.

Oil changes, by the way, were at regular 3000 mile intervals. Thanks for asking. ;-)

I'd look for a low-mileage junkyard engine, as Dan Stern (I believe) suggested.

And don't let nameless drivers hold the engine at no-load redline for 10 minutes anymore, OK? :-)

David Vanc> You're right, I should have been more complete. A driver who shall remain

Whoof. Yeah, that'll do it, especially if "awhile" was actually a *long* while, and if "55mph" is kind of a guess that might be just a smidge on the low side.

So the engine didn't *die*, exactly. It was *killed*. I'm not certain why you're "disappointed"; machines tend to die when they are severely abused. That's just...what happens!

DS

She won't.

cheapest engine for 99 300M is $250 located at NE, accourding to

it looks like you will get a used one for less than

1000. good luck.

PS: there might be some other sides sellimg much cheaper parts.

It's people like you who contribute to Americans' impression that people who cannot speak English are stupid.

DS

I suspect a troll here. The autostick will force an upshift if you redline the engine. The

3.5 in the 300m will do 6000rpm all day long if it's well maintained.

Just for fun, I tried to force my 99 300m to do what the original poster claimed. At about 6500rpm it shifts into 2nd.

That aside, Dan is right. You can't protect a machine from complete idiocy. If someone drives a *street* car along for 10 minutes at 6000-7000rpm and then has the audacity to complain, ummmm.....f*ok 'em. They're not designed for that purpose.

C

According to the '99 FSM, the overall drive train ratio in 1st gear is

2.84 (tranny) x 3.66 (final drive) = 10.3944 engine revs/tire rev.

Factory size tires are 83.7" circumference.

Forced 1-2 shift is at 6300 rpm for 3.2L, 6600 rpm for 3.5L.

If you do the math (forced shift speed in mph = 1mi/5280ft x 1 ft/12" x engine speed at forced shift in rev/min. x 83.7" vehicle travel/1 tire rev x 60 min./hr. x 1 tire rev/10.3944 engine revs), the shift would be forced at 50.33 mph for the 3.5L, or 48.04 mph for the 3.2L.

Conclusion #1: 55 mph in 1st gear is not possible - perhaps OP exaggerated the speed - 50 mph could be done with 3.5L, but not 55 mph.

Draw your own conclusions about whether the engine could survive 6600 rpm indefinitely (questions: What was it's condition? How much oil was in the sump?)

Conclusion #2: I have too much time on my hands. 8^)

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

This doesn't make sense. Autostick will upshift before the engine crosses the redline.

True. It can, however, be held at close to red line at 50 mph (see my other post). Sustained high engine speed can cause much higher than normal oil consumption (thru rings, valve seals, or the crankcase vent system - for example, there's a vent tube *not* connected to the PCV tube that ports right into the intake tube between the air filter and the throttle body - oil gets sucked thru that tube at high speed open throttle situations because the ability of the PCV system is exceeded). You may have noticed a sudden drop in oil level when checking the level after a WOT high speed passing situation even in an engine in good shape

- this is not unusual on many engines - and that's just for a few seconds of abuse.

I can believe that the oil would be steadily depleted at sustained high speed operation, say at 6000-6500 rpm operation. The oil level could drop to dangerously low levels within minutes - especially if the oil level was towards the low side at the start of the episode.

Just a theory - but I think oil starvation is a possible or likely failure mechanism even for a good engine in this sustained very high speed operation.

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

I doubt a stock engine of any make (except maybe a VTEC which is built fly-weight to start with, and I'll slap the first person that says "Wankel :-) could handle it for 10 full minutes.

Can I borrow some?

I don't think I actually complained, Chris. I did ask solicit ideas from folks who probably know more about this stuff than I do. If you're one of them, I thank you for your time.

Best regards,

DJV

Yours sounds like as good a theory as I've heard so far, Bill. Thanks for taking the time.

I too was curious as to why the computer didn't force an upshift. As I wasn't in the vehicle at the time I can't say with certainty what the speed or duration was, but the estimates I gave were based on the road traveled and distance from the origin. It could easily have been running 5-10 mph below the posted, 55mph speed limit.

The engine had plenty of oil in it to start, but the depletion scenario you described matches up with the likely conditions at time of death. I'm learning a lot...tuition's been expensive though.

Again, thanks for your time.

Best regards,

DJV

I've never seen this before.

I can't believe this. Airplane engines run at WOT pulling 70-80% of full power for hour on end. And they are air cooled with looser tolerances than modern cars by far. They typically burn only a quart every 5-10 hours. I can't imagine a scenario where an auto engine would consume oil at the rate of multiple quarts per hour (the rate required to consume enough in a few minutes to trash the engine). I just don't believe this is possible.

I agree that oil starvation might be the cause, but not oil exhaustion. One of the biggest problems with high rpm operation is aeration of the oil causing the oil pump to "lose prime" and be unable to maintain sufficient flow and thus pressure. Racing engines typically take steps to prevent this, things such as windage trays (I think that is the right terminology) or dry sump oil systems. I'd sooner think this as a likely cause.

Matt

That's, um, nice, MW, but we're not talking about airplane engines here, and "looser tolerances" have nothing to do with the elements of the PCV system accurately described in a passage you apparently don't believe.

If that were the mechanism in this case, the engine would probably have stalled for lack of oil pressure to the hydraulic lifters long before it seized.

It seized.

DS

You can also run an airp[lane engine inverted. I doubt you could do that with a Chrysler LH engine. There are differences in the crankcase venting, as I pointed out. Believe it or not, oil does get pulled thru the intake thru a valve cover vent tube when the PCV gets overloaded.

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