2.7 Oil Sludge Problem

I've read a lot of the numerous posts concerning the sludge problem in
the 2.7's. I've noticed that many of the complaints Chrysler addressed
were "up to the 2002" model year. Was the situation corrected/improved
in the 02?
TIA
Bill.

 

Yes, especially when the oil is changed every 3k or 3 months and use
synthetic with the proper weight.
Coasty

 

See recent posts on this Bill. There apparently were some modifications
made that reduce the sludging tendency and that also make it less
sensitive to the presence of sludge. Rumor is that the biggest changes
began in the 2003 model year. The main changes are reported to be
significantly reduced operating temperature and larger diameter oil
gallery passages.

As Coasty mentioned, using synthetic oil in this engine should
essentially eliminate the high-temperature sludge/varnish problem. At
the very least make sure that any oil you use meets Chrysler Material
Spec MS-6395, whether it's synthetic or non-synthetic.

Depending on which brand/type of synthetic is used, you definitely could
extend the oil drain interval well past 3000 miles to help offset the
additional cost of the synthetic, especially in the more recent model years.

I have a 2001 2.7 that will reach the 150K mile mark in another couple
of days. Until recently it has had 3000 mile oil/filter changes with
good quality non-synthetic oil (mainly Castrol GTX and Valvoline Maxlife
High Mileage). I did two experimental 4000 mile runs this year with 2
different synthetics and had the oil analayzed at the end of each run.
One synthetic, made by Shell, was pretty much at the end of it's life
by 4000 miles. The other synthetic was Quaker State Q Advanced and it
definitely had some life left in it at 4000 miles; I would say it could
have gone another 1000 miles but that would have been it. In different
engines (like the Chrysler 3.5L or nearly any other non-turbo engine),
both of these oils would have gone a lot farther than 4000 miles before
reaching the point they did in my 2.7.

My next move will be to move up a *true* synthetic like Mobil 1,
Amsoil, Redline or Pennzoil Platinum and repeat the tests. These should
go alot farther than the Shell or Quaker State synthetics did before
they need changing, and should not leave any deposits if changed in time.

The 2.7L is hard on oil, no question about it. The newer ones are
apparently less harsh than the older ones.

Phil

 

The one that I know first hand about is the addition of an in-line heat
exchanger added to the PCV hose - steals heat from the coolant system to
keep blow-by gases from condensing out and clogging up and dissolving
the walls of the PCV hose, which they were prone to do. I think that
change was made to productuon cars starting in either '00 or '01. It
can be added to earlier ones (I added it to my '99 Concorde).

I have also read that the oil pump was upsized to provide better
lubrication to the rear mains - that was also an early change - maybe '00.

Certainly there have been other changes that I don't know about that
others can discuss.

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

 

Thanks for all the info. I'll start a gradual switch-over to synth.
next oil change (I have GTX in it now.) This car has what might be the
worst life - short drives in town and most of the time it barely
reaches op. temp.
Thanks,
Bill

 

That's a bit of different situation then Bill. In your case, if you
want, you could stick with straight non-synthetic and just change it
frequently. Moisture and fuel dilution - both from short trips and low
operating temps - contribute to low temperature sludging and loss of
viscosity (thinning of the oil). The best remedy for this is frequent
oil changes. You can minimize this to some degree by taking it out on
the highway once or twice a week for a 10 - 20 mile spin. The type of
driving you describe is classified as "Severe" service in the owner's
manual, hence the more frequent oil change schedule.

In your case you aren't wearing out oil due to prolonged highway driving
or prolonged stop and go driving in high outside temps - both of which
shear the oil and lead to high temperature deposits (high temperature
sludge/varnish). Those situations are where synthetic really has the
most benefit.

Phil

 

Good poit. It's also the ideal situation for an additive like MMO or Sea
Foam. I know some people are dead set against any additives. However,
I look at it this way: I think it's bad practice in general to put a
torniquette on your arm or leg, but there are certain situations in
which it might just save your freakin' life!

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