2.7 Liter w/ 138,000 miles - keeping her in shape

I just purchased a 99 Intrepid (2.7L V6) that has 138,000 miles on it.
I was looking for a high mileage vehicle that I could get cheap. I
thought this car was a steal for $2800. I took it out on the highway
during the test drive and drove it pretty hard. I was impressed. The
engine and transmission felt solid. The body and interior on this car
are are very clean, and I'm a pretty handy guy, so I felt like I would
take my chances with the high mileage. However, after purchasing the
vehicle (I know, I know) I have read some consumer reviews that have
me worried sick about the 2.7L V6. The theme seems to be a sludge
developing in the engine that causes it to sieze. I believe that the
car in question has had regular oil changes. Is there anything I can
do to help prolong the life of the enginge besides changing the oil
every 3,000 miles? Is there a way to tell if the engine in this car
has had any work done on it / been replaced? Also, if it were to go
out, would it be possible / wise for me to put a bigger engine in it?

 

Do a google search on this newsgroup, and you'll find plenty of
discussion on it (BTW - I own a '99 Concorde with the same engine that
now has 125k+ miles on it, and it is running great - no problems).

I think the following will alleviate some of your fears about your
particular engine: I think *without exception*, every post I have seen
here or on www.dodgeintrepid.net forums about a 2.7L sludge failure has
been in the window of 55 to 85k miles. This could be due to one or a
combination of :
(1) Mostly hiway use (i.e., very little short-trip sludge-producing driving)
(2) Good mainenance (routine oil changes at closer to 3000 mile rather
than 10,000 mile intervals.
(3) Luck of the draw on getting good engine (I think this is the least
likely of the three since the root cause IMO is marignal lube system
design issues).

Since I drive my Concorde 80 miles a day and do the oil changes, I think
that is why it is doing so well. I've seen inidications that it was a
sales fleet vehicle in its previous life, so it probably had hiway miles
and decent maintenance then too.

When I bought mine used at 58k, shortly thereafter, when I found out
about the tendency of the engine to sludge up and fail, my solution was
to use 1/4 qt. of Marvel Mystery Oil in the crankcase with every oil
change, target the oil changes for 3000 miles (in reality it probably
has worked out to 3500 miles average), and change the filter with every
change using a good filter (I use Purolator Pure One™, but there are
many other good ones out there).

If you had fewer miles, I would say to switch over to synthetic, but
that would probably be a mistake on your engine *ESPECIALLY* since the
primary concern is sludge accumulation. Synth. will break the sludge
down fairly quickly and could very likely block the small oil return
galleys and valve lifter (AKA lash adjusters)ports and bring about the
exact failure mechanism you are trying to avoid. Using the MMO plus oil
& filter changes like I suggest will do a more controlled, gradual
cleanout. You *could* do a similar thing with synthetic (transitioning
over to it by increasing the proportion of synth to non synth, say 1 qt.
synth to 4 qts. non-synth, then 2 qts. synth to 3 qts. non synth., etc.
until you were at 100%), but that is a personal choice, and there is a
risk no matter what you do (some would say let sleeping dogs lie and
continue with regular oil with changes at 3k miles).

It is common advice in the Intrepid community to switch over to either
the 3.2 or 3.5 engine (I forget which) if you do experience a failure of
the 2.7L. IIRC, it would also involve swapping out the PCM. Again, do
a google search on this newsgroup - it has been discussed before, with a
link to a site for doing the swap (also do a search within
www.dodgeintrepid.net - they have an excellent search engine, and
there's guys there that are intimately familiar with this - one guy
there makes a living rebuilding 2.7's).

Bottom line: I think you're safe since your engine has made it this far.

Be aware that that engine has a timing chain (good), but that it is an
interference engine (not so good), with the implication that if the
chain ever breakes or slips, you could have valve damage. The good news
is that, except for the 55-85k mile sludge-related total failures, in
which case all bets are off, I have never read of the timing chain
letting loose on this engine (i.e., apparently it is good for a couple
of hundred thousand miles).

HTH!

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

If it's gone this far without failing, it has probably been properly
maintained, as in reasonably frequent oil changes. I'd just make sure
to change the oil at least every 4K miles or so to prevent the sludge
problem. If you do a lot of short trips, more frequent oil changes
would be good. Hopefully you engine will keep going for a long time,
but if it does fail, it might be worth replacing it with a 3.2 or 3.5,
though to do so would require swapping the ECM and would, it other ways,
be more complicated than staying with the 2.7. Good luck.

 

Thanks guys! I feel better now, although the car is out of service at
the moment. After three weeks of driving 50 miles a day with no
problems, the battery light came on. Shortly after that my
headlights, dashlights, and radio went out while the car was running.
At first I suspected the alternator, but I checked it on the car with
a voltmeter and it seems ok. I've been putting off testing the
battery (because this happens while the car is running), but I'm going
to give that a shot tomorrow and hope that's the issue. After reading
a few posts it sounds like a bad battery could cause some funky things
to happen while the car is running in these cars. Does anyone know if
the alternator could be giving me intermittent problems, as in it only
works part of the time? I thought when alternators went bad they died
completely.

Thanks again!
-SS

 

Based on my hanging out on Chrysler- and LH-specific forums and
ownership of a Concorde for a over 3 years, I would say that an
alternator failing on these cars is *very* rare (don't know that I've
ever seen a post about a failed LH alternator). When things start
acting screwy on the dash on these cars, it's almost always a battery
problem. They don't act like other cars I've messed with over the years
with charging system issues.

Just to be safe, check your battery connection. There is a direct
connection from the battery to the alternator, so the only places for a
bad connection to the alternator are at the battery and at the alternator.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')