98 Concorde LXi engines

Accompanying an ad for a used car is an opinion concerning the 2.7 liter
engine that raises some issues. The guy claims the engine is a problem,
collects sludge, and has a high maintenance record. Is there any truth to
this? Here's the website that lists all his arguments:
http://www.datatown.com/chrysler/

 

I personally would opt for the 3.5 (or 3.2 if buying a used one, the 3.2
is no longer available) instead of the 2.7. It does seem to have some
reliability issues that the 3.2 and 3.5 do not, mostly relating to the
fact that its an interference engine with a very long chain-drive to the
overhead cams which is prone to lose tension, jump time, and wreck the
engine. The 3.2 and 3.5 are belt-timed, but they're non-interference
engines. Also there have been lots of reports that the 2.7 tends to run
a higher oil temperature than most engines and as a result tends to
create sludge (which may be responsible for the timing chain problems,
too). I would think that religious oil changes with synthetic oil would
take care of that, but to me that seems like a band-aid.

 

50K repair free and trouble free miles on my 2000 Intrepid with 2.7L
using Mobil 1 5W30, PureOne PL14670 or Wix 51085 filter and 8 ounces
Marvel Mystery Oil with each oil 5K mile change. Add an additional 8
ounces MMO at 100 to 500 miles before oil change. No oil consumption
between changes noted. Have inspected under valve cover with flexible
bore scope. No sludging seen. Everything nice and clean.

Do same with the wife's '96 Intrepid with 3.5L at 98K miles (10W30 Mobil
1). Noted a 1/2 qt oil loss at last 5K miles oil change.

Important thing is to get the engine up to normal operating temp each
time you start it. Boils off moisture caused by internal combustion
process.

 

Thanks Steve. I appreciate the opinion. Question though; what's "an
interference engine"?

 

An engine where the valves and piston occupy the same space during
different parts of the cycle. If the timing chain or belt breaks, the
cams stop rotating and a valve (or valves) will remain open, but the
crank keeps spinning and smashes the heads of the open valves off when
the piston goes up on that cylinder.

A non-interference engine is one where the pistons cannot strike the
valves even if the valves are fully open when the piston comes up to
top-dead-center.

 

Just to add, historically, interference engines would use chains (and
not belts) because chains last a long.long time. Honda is known to
build interference engines with belts. If you don't follow
maintenence interval in changing belt you will lose your engine some
day. Toyota's belt engines historically on non-interference. When
the 2nd generation Chyrlser 3.5 liter engine came out some people
thought it was a belted interference engine unlike its non
interference predessor. I believe poor documentation was the
culprit. According to belt suppliers it is non interference.

 

I'm just over 100k miles on my '99 Concorde with the 2.7. I also use
MMO and Purolator Pure Ones™, but use Castrol GTX (mix 10W-30 and
20W-50). Did have one episode of clogged bend in PCV hose just upstream
of PCV valve, but I think that happened before I bought the car at 58k
miles. Engine runs great, clean inside.

FWIW, I'm of the opinion that, to fight sludge, you only need either MMO
*or* synthetic - not both (Ithough it won't hurt to use both) since
synthetic does a good job of cleaning things up and/or keeping them
clean due ot its inherent properties.

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

 

And (I believe) every Hyundai and Dihatsu engine ever made has a belt
driven cam and has interference. Imagine that - a low end vehicle
bought by consumers who are the least likely to do regular maintenance
or understand the implications of a belt breaking beign the most likely
to self destruct from a scenario inherently designed to void the
warranty.

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

 

Are you sure about this? When I last checked the Gates list, the 2nd gen.
3.2L & 3.5L were both listed as interfererence engines. The service
manual doesn't seem to say one way or another, but I infer that indeed
they are interference. Why do you suspect that they are not? I am
curious.

(Either way I will get the belt replaced before the 105,000 miles are up.
For some reason CA emissions vehicles, which a number of states now
mandate, list a very slightly increased interval between timing belt
changes. Spark plug wire (which are thin and low voltage in the LHs)
replacement intervals are also very slightly longer for CA vehicles..
Anybody know why?)

 

YES!! The 2.7 L is very very hard to work on. For example, to replace
the water pump you must remove the timming chain and guides to replace..
The red coolant is also know to turn into "gel" at times I hear....
(10yrs working at a Chrysler dealer)

 

No I am not sure. Older Gates list said it was non-interference but I
just checked again and like you said, it now says the 2nd generation
3.5 is interference. Perhaps someone who lost a belt can tell us for
sure.

 

Hmmm - according to the *latest* on-line Gates Guide
(http://www.gates.com/brochure.cfm?brochure=981&location_id=540, pdf
link at bottom of page), the 3.2 is ineterference and all the 3.5's are
non-interference. And that's the way I remember it's always been in
their guide.

Replacing spark plug wires in an LH? As you say, they are low voltage
(the primary to the over-the-plug coils). Do they even require routine
replacing? I didn't think they did - never heard of that on various
forums or in the FSM.

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

 

The primary wiring wouldn't need replacement unless it had
suffered some type of physical damage, the boot and spring
connector between the coil and sparkplug will be subject to
carbon tracking just as any other plug boot is, so
replacement of these items would be advisable at the time
the sparkplugs are changed.

 

I'm looking for a Concorde LXi or 300M no older than 2000 with about 40000
to 48000 miles logged. That being the case, can I safely assume any engine
in these cars will be a non-interference engine? (I get the impression
Chrysler responded in '99 - '00 to these issues raised here and made a
change. If not, where can I find a list that will distinguish interference
from non-interference engines between the years 2000 to 2002?

 

Correct. I think some of the confusion also stemmed from the fact that
the 2nd generation 3.5 came out the same year as the interference-type
2.7, and people assumed that the two engines were closely related when
in fact they're not.

 

Yeah, and as much as I defend the American makers, they all 3 built TONS
of v8 engines through the 60s, 70s, and 80s that had a great steel
timing chain.... that ran on a flimsy nylon cam gear There were
exceptions- Chrysler 340 and 440 high-performance engines and the 426
Hemi all recieved steel roller timing sets, but not most others. The
nylon cam gears universally failed before 200,000 miles, and on most of
those engines that had any compression ratio at all it would bend
valves. STUPID! To take engines that otherwise were easily capable of
300,000 to half a million miles with proper oil changes, and then make a
crucial part that failed between 150k and 200k. Not sure about Ford and
GM, but when Chrysler brought out the "Magnum" versions of their
small-block v8s they finally used metal cam gears exclusively.

 

Looks like that Gates guide, Steve referenced only goes to 2000 for
Chrysler.

 

Correction to my earlier post:

Manufacturer's Maintenance Schedule B (severe) lists 100,000 miles for replacing
the ignition cables for Federal Emissions equipped vehicles only and 105,000
miles for replacing the ignition cables for California Emissions equipped
vehicles only. 100,000 miles is the interval for the engine timing belt, with
no distinction on the Emissions equipment.

But this is even weirder:

Maintenance Schedule A (non-severe) lists 100,000 miles for the ignition cables,
regardless of Emisssions equipment. But here the engine timing belt replacement
interval is 100,000 miles for Federal Emissions equipped vehicles and 105,000
miles for California Emissions equipped vehicles.

So, 1.) Why is there a difference between the CA/Federal emissions for these
items, 2.) Why is there a different distinction for schedule A vs B for these
two items, and 3.) Why not just specify 100,000 miles as the interval for both
the cables and the timing belt? Yeesh.

 

I'm just making this up but may CA has a law on how long they have to
last.