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:

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Reply to
John Gregory
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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.

Reply to
Steve
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.

Steve wrote:

Reply to
Mike Behnke

Reply to
John Gregory

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.

Reply to
Steve

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.

Reply to
Art Begun

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")

Reply to
Bill Putney

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")

Reply to
Bill Putney

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?)

Reply to
Greg Johnson

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)

Reply to
CHRIS WALLACE

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.

service

indeed

vehicles..

Reply to
Art Begun

Hmmm - according to the *latest* on-line Gates Guide

formatting link
pdflink at bottom of page), the 3.2 is ineterference and all the 3.5's arenon-interference. And that's the way I remember it's always been intheir 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")

Reply to
Bill Putney

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.

Reply to
Neil Nelson

Reply to
John Gregory

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.
Reply to
Steve

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 :-p 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.
Reply to
Steve

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

Reply to
John Gregory

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.

Reply to
Greg Johnson

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

miles are up.

vehicles..

3.5's are

various

ignition cables,

interval for both

Reply to
Art Begun

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