1998 Chrysler Concorde Engine Knocking

Hi all! I just got in from an eventful trip with my Concorde! I drove
her about 60 miles from my house to Syracuse, NY. Pulled off for gas,
started driving again and heard a knocking coming from the front end.
Ended up having her towed back to Canandaigua. The tow truck driver
said the knocking was coming from the engine, and that he has seen this
same problem in at least 4 other Concordes like mine in the past few
months. It also had difficulties keeping speed while driving once this
started happening.

Has anyone else had this problem? Right now my car sits at the dealer,
but I know they won't be able to do anything with it before weekend. I
got the car in October with about 62K on her, and she has 72,500 on her
now. There were no clues leading up to this until I got to Syracuse,
then my first clue was the knocking, then the inability to maintain
speed/fighting to get her up to 65.

Thanks!

Carmencita

 

If it's a loud knocking coming from the engine the usual diagnosis is a
"thrown rod" While in some cases this means the connecting rod actually
detaches from the crankshaft and is driven through the side of the engine
(which ruins it) more often what happens is that the rod bearing gets oil
starved and wears out, and I mean extremely rapidly. In a few minutes at
highway speeds, tolerances that are supposed to be in the thousands of an
inch might expand to a quarter of an inch as the bearing is hammered into
smithereens.

Some places will repair these by dropping the oil pan and if the damage
isn't too serious, attempt to extract the piston from the bottom, and put
a new rod in it. Of course, this doesen't address the root cause and
in such a confined area you cannot possibly inspect anything to any degree,
this is pretty much (in my opinion) a hack job that a DIYer does right
before unloading the vehicle on some unsuspecting person.

But if it is a rod, what really needs to be done is the bottom end needs to
be rebuilt. With an engine that only has 75000 miles on it, you might have
a fair chance of having the heads still in good shape, in which case you
can have a rebuilt short block installed, or better yet, pull out yours and
have it rebuilt. I don't know what the book allows for this, if I was doing
it myself at home this is a weekend project to drink some beer, get the
engine out,
drink some more beer, shoot the shit with my buddies, get it separated,
drink
some more beer and shoot some more shit with my buddies, and get the short
block off to a rebuilder, then the following weekend to put it all back
together.
All in all the correct way to look at this if your doing it at home is this
is a
relaxing, pleasurable activity that gives you an excuse to run out and buy
that engine hoist and a bunch of new tools you have always wanted. The
incorrect way of looking at it if your doing this at home is your gonna set
the car up on cinder blocks and yank the puppie out with a rope over a
ceiling beam because you need to have it running by Monday so you can
get to work. And by the way your gonna save a ton of money.

Most short blocks aren't warrantied more than a year or so, though, so
the economics of this get a bit hairy on a 6 year old vehicle. You will
really need to make a judgement call. On the plus side, most rebuilders
do a damn site better job of assembling the short block than the factory
did, and they also will drill out oil passages that the factory made too
small,
and other adjustments to the design that are obvious to anyone with any
kind of background rebuilding engines and half a brain. On the minus side,
if the car's headliner is hanging down like Spanish Moss and the interior
smells like a beach at low tide, this isn't a rebuilder candidate.

You can assume with this car that if you were to sell it now, in the
condition
it's in, if the paint and rest of the vehicle is otherwise immaculate, you
would
get about $200, that is if a DIYer can limp it back to their place. If it's
got
rust, it's worthless.

I would suggest you take this weekend and start shopping for a 2-3 year old
used car. If you can still limp your car into a dealership you might get
them to
"take it in trade" that will relieve you of the cost and aggrevation of
selling it,
they in turn will just sell it off at auction to some engine swapper.
Naturally
you don't buy anything yet, what you want to do is get familiar with the
prices
the stuff is going for, so that when you talk to the mechanic on Monday and
they quote you unpteen bazillion dollars for a new engine, you can make an
informed decision on whether it's smarter to cut your losses and walk away
from
it and take a risk on a used car, or your going to take a risk on doing a
repair.

And just in case, if this is a rod, you really need to re-evaulate how your
maintaining your vehicles. While there are indeed design flaws in engines
that will cause this, IMHO the vast majority of engines that throw rods do
so due
to neglected maintainence. Obviously, changing the oil regularly is the
very
first thing that you should be doing, most people know this. But, another
problem is a coolant leak into the oil, if this happens your oil gets
saturated
with water and nothing gets lubricated. You can go a long time while your
engine is disintegrating before it will start knocking. Do you know what
the
telltale signs of a coolant leak are? Are you changing your dino oil every
3000 miles religiously, or your synthetic oil every 6000? Are you checking
oil
level and coolant level in the recovery container and making a visual check
of tire inflation when you fill your gas tank? Do you look under your hood
every once
in a while and are you familiar with what it is supposed to look like? Do
you
check where you normally park for unusual leaks or oil slicks? Once a
month when you come out in the morning before you start the car do you
take off the radiator cap and check the coolant level? When was the last
time you had someone stand behind the vehicle and tell you if your turn,
brake, and running lights all worked properly?

Years ago they had these full service gas stations that would do this kind
of
thing. Today, the oil change places will usually run your vehicle through a
checklist, but of course, you have to remember to take it in regularly. But
there is still no substitute for learning how to do a 1 minute quick check
at a gas station and doing it every time you fill up. In the time it takes
to get
a full tank you can check at least 4 major things - oil level and
consistency,
tire shape of all 4 tires, coolant level in the recovery container, and an
overall
looksee of the engine compartment, looking for anything unusual (like an oil
spray, coolant spray, broken belt, etc.)

Ted

 

Ted,

Is this an issue with the 2.7 engine? Carmencita had made reference to
hearing about other Concordes having the same engine noise.

Also, who does offer a good rebuilt engine? Are Jasper engines any good?

If this person can't rebuild it on their own, why not recommend doing the
entire engine? Wouldn't they save money on labor since part of the engine is
already disabled?

Last question: What's with those K&N air filters claiming that they offer
5-15 horsepower increase? Is this a case of suckers or does it really make a
difference? If so, how can this be?

 

I see you found that other thread. This is all assuming that you have
the 2.7L engine (which it sounds like you do).

Somewhere in that other thread is a link about swapping to the larger
engine, which is advisable for several reasons - you get the bigger
engine, and because the 2.7L is apparently prone to failure, the laws of
supply and demand being what they are, you can get a lot more bang for
the buck with a used engine going with the larger engine. If the link
is not in that other thread (which I think it is), do a google search on
this newsgroup and you will find it - it's been posted more than once.

If your failure is typical, it is likely due to heavy sludge deposits -
it is probably not advisable to try to build that same engine back up -
if the rod bearing you're hearing got starved for oil, it's a good bet
that other stuff is in bad shape too (as well as massive sludge deposits
that need cleaning out during the complete tear-down and rebuild) -
they're just not to the point of making a racket yet.

I would be curious about you or your dad's maintenance habits (regarding
oil changes) - care to share that info.? The evidence that has been
posted here and elsewhere point to a combination of marginal design and
poor maintenance - apparently neither one by itself is fatal to the
engine, but the two combined (and maybe whether mostly short-trip vs.
highway driving) are fatal to this engine whereas most engines will
survive the same moderately poor maintenance (and driving history). My
2.7 has over 120k miles on it and it's running great, but I drive 80
miles a day of highway driving, and change the oil and filter every
3000-3500 miles.

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

 

I believe the Lexus SUV had this problem several years ago as well.

Ken