Oil sludge elimination/prevention?

Own a Chrysler Sebring with the V6 2.7L engine. I've read several
complaints about how prone to oil sludge buildup these engines are (and
the not so decent position of Chrysler corp. of not admitting the
problem or solving it). Mine is 58,000 miles and want to prevent and/or
eliminate possible oil sludge in the engine. I can see some of this
gunk like substance inside the oil filler cap. Car is running good, no
noises so far, just a coolant leak near a sensor assy at top left side
of engine that I'm going to have repaired/checked.

Any clues on how to eliminate and prevent oil sludge in these famous
engines.


Beachrunner

 

1)For best protection, use a 5W-30 or 10W-30 full synthetic motor oil
such as Mobil 1, Amsoil, Redline or Pennzoil Platinum Plus. These are
expensive top of the line oils, but worth it compared to the
alternative. You should be able to easily go 5000 miles between oil
changes with these oils; perhaps further depending on your local climate
and driving style. Use a good filter such as Purolator PureOne, WIX,
NAPA Gold, Motorcraft, Amsoil EO, or Fram XG series *only*. Filters are
not all the same quality - stay from the cheap ones.

2) Other good oil choices would be Quaker State Q advanced synthetic
(good for about 4000 miles in my 2.7); Valvoline Synpower or Valvoline
MaxLife Synthetic.

3) For non-synthetic oils, Castrol GTX and Havoline come to mind as
well-proven oils. These should be changed at around 3000 miles in this
engine. These oils will go alot farther in other engines, but the 2.7 is
hard on oil. Theses same oils would easily go 7500 miles in a Honda
Civic. But not in a 2.7.

4) Maintain the cooling system ! This is important to minimize the risk
of water pump failure or failure of the water pump seal(s). Since the
water pump is inside the engine, a coolant leak will leak into the oil
and will create mud-like sludge in no time flat. The water pump and
it's impeller were built around the coolant. Use either Mopar Long Life
coolant (orange stuff - but it is NOT the same as Dexcool which is also
orange), or Zerex G-05 (sames stuff as the Mopar). Do NOT use any other
coolant. If the cooling system has been ignored, have it thoroughly
flushed and re-filled with 50/50 coolant/distilled water.

5) Methods of getting rid of sludge are controversial. Solvent flushes
will definitely clean some of the sludge and varnish. But they are
harsh, and may accelerate wear in the main and rod bearings. And it may
also cause large sized pieces of sludge to dislodge and potentially
block off a narrow oil passage - thus creating a worse problem.

Many of the additives sold in auto parts stores are useless.

I am currently working with a gentle long-term internal engine cleaner
called Auto-Rx. Inside my oil cap and the little bit that I can see down
there looks pretty clean. But my PCV hoses and heat exchanger regularly
produce little bits of coke and tar, which tells me that just a few
inches from my oil filler cap, things may not be quite so rosy. I've
just started it and I don't know how well it work on my engine. I still
have a couple of months to go before I'm finished. I am monitoring it
with oil analysis, dissection of the oil filters and compression
readings. I may pull the valve covers off for inspection.

You can read about Auto-RX here :

http://www.auto-rx.com

Here is a very interesting photo documentation of an Auto-Rx cleaning of
a sludged engine :

http://www.auto-rx.com/rms13/


Phil

 

Use synthetic oil, a good filter and change every 3000 miles.

Coasty

 

If you go to a synth., don't just suddenly switch over. Either put in
1/4 qt. of Marvel Mystery Oil or Sea Foam (or possibly Phil's Auto-Rx
according to its instructions - see below) to do a controlled gradual
cleanout of accumulated sludge over several successive oil changes
(changing filter *every* time). Alternatively you could put 1 qt.
synth./4 qts. dino first oil change with new filter, 2 qts. synth./3
qts. dino with new filter at 1000 miles, 3 qt. synth./2 qts. dino with
new filter at 2000 miles, etc. until you're switched over - or when you
get to 4 qts. synth./1 qt. dino, continue with that ratio forever after
that at your decided-on change interval, new filter each time.

Can also get Ford's Motorcraft branded G-05 at Ford dealers. It's
bright yellow like the Zerex G-05.

My opinion too. Also synthetic oils can do the same thing if switched
over full strength suddenly - not everyone agrees with that - but that
is my opinion - seen it first hand.

Marvel Mystery Oil and Sea Foam, however, work.

OP - you don't say what year your Sebring is. If it's, IIRC, '00 or
earlier, check to see if the PCV hose has a cylindrical metal object
with two small coolant hoses coming out of it - it's a heat exchanger
added to prevent reduce condensation/buildup/clogging by sludge of the
PCV hose. If yours has that, then good. If not, order the replacement
hose with heat exchanger - let us know if you need to know how to plumb
it up (simple).

My '99 Concorde with 2.7 is approaching 170k miles and running great.
Bought it used at 58k miles. Using Castrol GTX with 1/4 qt. MMO and
Pure One™ filter every 3.5k miles on average (changing filter every
time). I do a lot of highway driving (400 miles a week daily commute)
which also helps keep down sludge. I also replaced the PCV hose with
the new one with heat exchanger.

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

 

Yes, use synthetic oil and change at the intervals suggested in your
owner's manual.


Matt

 

Or you can ignore the OWT and just switch over. Make your next change
after a 1,000 miles if you are really worried about the synthetic
magically loosening up existing sludge (very unlikely), but that will
serve only to give you peace of mind, your engine could care less. I've
changed several engines to sythetic with 50K or so on them with nary a
problem.

But this is sort of like saying you should only rotate radial tires
front to back and not swap sides. Some things just die hard...

Matt

 

Just passing on a few things I learned while working in a major's research
lab in my youth with some updates I have learned from the lab guys over the
years.

Assuming one is using a decent detergent motor oil, the number one cause of
sluge is water. This is typically associated with a motor used in cold
weather without getting the oil hot enough to burn off the water. The water
can form acids resulting in direct attacks on rings and bearings and can
speed the formation of sludge.

One wants the oil to neturalize the acid and hold all the solids in
suspension. This is not an easy task, but modern oils can do a very good
job, especially some of the better pure systhetic oils such as Mobil 1.

If I drive in cold wet weather and have lots of short trips and lots of
idling, I would want to change that oil more frequently, even a good
synthetic. If I took mostly longer trips, and knew that my oil got hot
enough to burn off the water, extended oil changes, up to 15,000 miles or
more with Synthetic oil, can be most reasonable.

Those motors that are most prone to sludge formation are typically motors
that have poor designs, usually in the head areas, that run too cool, thus
promote sludge formation even though the block is getting up to running
temperature. Also motor designs that don't promote proper venting of the
water vapor can be a motor with sludge issues.

In this case Synthetic oil and reasonable oil change schedules are called
for. Toyota seems to have gone this way.

Typically, a good detergent oil should remove sludge over time if changed
frequently enough, although I have resorted to a specific solvent detergent
additive to remove solid black formations in the head area of a Ford 6 that
never had the oil changed in 100,000 miles, but don't recommend that for a
motor you have not abussed to the point of needing a rebuild anyhow.

These have been presented to me as general statements based on extensive lab
tests, but I don't mean to suggest that this is all there is to it.

Richard.

 

The sludge is probably coming from condensate and blow-by because the
oil is either too cool or the engine has insufficient crankcase
ventilation. If it were coolant seepage you would be seeing the gel
production which is a different thing. Engine oil will evolve water if
there is a suitable combination of temperature and pressure.

The only cure for heavy sludge is to at least partially dismantle the
engine and use solvent under pressure. You might as well replace all
the seals while at it. If you have to pay $100 an actual hour you
might as well order a reman engine. Light sludge will respond to ATF
in the oil, but while this is good for desludging it's tough on seals.

My family was in the aircraft business when i was young and we had a
mechanic working fo r us that had been in the habit of doing this on
aircraft engines. He'd done it for years on the Continentals in 150s
and the occasional smaller Lycoming and never had a problem-he'd throw
in a quart of Dexron and run it up or fly it around the pattern once
(he had great piloting skills, but we found out later, his license was
from Xerox-he'd never held a legal pilot license or taken dual, he was
self-taught from observation!) and change the oil. That worked well and
fine for the longest time, until Cessna came out with a fixed gear,
constant speed prop airplane that used that same engine. While the
engine seals never protested, the first time he did this on a CS prop
airplane the oil seals in the prop failed a week later. In fact, three
props had three seal failures in two weeks. One was night IFR and
nearly resulted in a dead stick landing. They wound up going into a SAC
base and the couple were "jacked up" by Nazi Air Police on the taxiway.
(Yes I called them Nazis. **** you, Air Police faggots.)

He also used Dexron instead of 5606 in brake cylinders (yes, aircraft
use petroleum fluid in brakes, including antiques with automotive
master cylinders: they change the seals.) but to my knowledge it never
caused a problem.

 

If this story is true, then your mechanic was as poor a mechanic and as
illegal working on airplanes as we was flying them. Putting additives
into an airplane engine that aren't certified is not only stupid, but
illegal. And not much smarter than putting them in car engines.

Matt

 

What did you learn about running a car for 50K or so miles on regular
oil and then switching to synthetic? Have you ever seen this cause a
problem? I haven't, but the old wives tales about this persist. Do you
have any data on this?


Matt

 

You omitted where I said "Also synthetic oils can do the same thing if
switched over full strength suddenly - not everyone agrees with that -
but that is my opinion - seen it first hand."

So your personal experience establishes fact (and I am to ignore when
other people have had problems related to switching over, but you have
never had a problem doing so, therefore...), while my personal
experience constitutes an old wives tale.

The only drug addicts I've ever talked to said they never died from an
overdose, therefore drugs don't cause people to die.

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

 

Matt Whiting wrote:
aren't certified is not only stupid, but

The FAA does not certificate oils, or additives. Oils and other
lubricants along with many other items such as rivets and fasteners are
made to a certain spec, AN or NAS or what have you, and their use is
called for then in the build plans and for maintenance under the
manufacturer's service manual. In other words, you do not need a Type
Certificate or PMA authorization to make rivets or bolts or oil. Most
certificated aircraft engines call for an ashless dispersant aviation
oil in their operating handbooks, but if -as was the case with the
Porsche PFM-it called for a car or motorcycle oil meeting certain
specs, then that would be approved.

Using certain additives is legal. Lots of people with auto gas STCs on
Lycs add Marvel Mystery Oil to the fuel, it appears mildly beneficial,
and the FAA does not object. Using a mix of STP and Vaseline as
assembly lube, and packing oil pumps with Vaseline, is okay as the
stuff is not in the engine in flight-you change the oil once before
flying. You can also use a generic nondetergent oil rather than an
"aircraft" one for this as well saving a little money.

Based on his experience I would say using ATF as an engine cleaner
appears safe on LyCon engines with fixed pitch props, and it is legal
as long as the aircraft is only ground run with the ATF in the oil and
not flown that way. I also know of guys who would drain the oil, and
put in one quart of SAE 30 oil and top off the oil sump with Jet A, and
with the plugs out (and a little oil squirted in the cylinders) pull
the engine through a bunch of times by hand and drain it out.

Smart? Don't know. Legal? Apparently.

 

The rule is that if you are not prepared to change out the seals,
don't change the type of lubricant, and the longer those seals have
been in service the more relevant this is. If you are not a DIYer who
is prepared to change them out (or working with a very high dollar
engine and don't care about the labor bill) save synthetic oil for when
you have a new or reman engine to work with. If you are nursing an old
car with no ACV along out of poverty as I have had to, use whatever oil
the previous owner did, just change it regularly.

I use whatever oil is cheapest in the old cars I drive, except I use
an ashless dispersant oil in air cooled engines like Corvairs and VWs,
and a straight weight diesel oil in Detroits-although I do not own a
Detroit-powered truck, it's important to use single weight oils only in
them. Do you know the reason?

 

I would assume because they do not contain VI's that are relatively
unstable and do not have very good lubricating properties - so they are
diluting the "robustness"/stability/much better lubricating properties
of the base oil.

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

 

Why do you think changing oil type will harm the seals?

No, what is your reasoning?

Matt

 

Don't know about the single weight thing, it is important to use high
detergent package oils in diesels to mitigate acid formation in the
crankcase,
and the high detergent oils I know about (Delo) are all single weight.

you can use high detergent diesel oil in gasoline engines if you use a
larger
oil filter. Natural Gas fired automobile engines do this for the same
reasons (acid formation)

Ted

 

Then why do you need an STC to run autogas in an airplane? If the
engine maker specifies that certain fuels, lubricants, etc. be used then
you have to use those to meet the type certificate, right?

I'm sure it isn't smart. I'm pretty sure it isn't legal, but I'm not
100% sure on the legality as the FAA isn't always easy to figure out.

Matt

 

I have personal experience, but no lab guy information on this issue. Early
versions of Mobil 1 may have caused issues with gaskets, I myself
experienced some oil seepage past a gasket in a car or two back in the 70's
when I switched to 5W-20 Mobil 1. Today, Mobil 1 offers various formulations
and all are very different than the product offered in the 70's and 80's. I
switched our 98 RAV4 to Mobil 1 5W-30 last year with 60,000 miles on the
clock, when I picked it up for my 18 year old, and there has been no seepage
issue at all. It has helped clear out the gel that was starting to build up
from the prior owner's use of the vehicle with conventional oil and too long
oil changes in very cold upstate NY.

Richard.

 

The TCDS on an aircraft is granted for use with a certain powerplant
or powerplants and the fuels acceptable under the ATC on the powerplant
are listed as acceptable on the aircraft TCDS. As it happens after the
late 1930s aviation fuels meeting military specifications were
specified. Engine makers certified their engines for these fuels and
aircraft makers selected those engines in light aircraft for many
reasons, one not mentioned by such industry rectal osculators like
Peter Lert, Budd Davisson, Richard Collins and J Mac Maclellan-the
writers who were as gods then-was that FBOs made it clear they did not
want people being able to use standard gasolines and undercut their
vendor monopoly. Avgas, a extremely leaded low octane base low
volatility fuel, was formulated for the needs of B-17s and B-29s over
Germany and Japan and the DC77's and Connies operating at FL 300-400,
and obviously not for light aircraft never operated over ten thousand
feet. Nonetheless, the true goals of the industry were met under a
pretext. I mean, you never know when a L-1049 Super G Connie is going
to drop in to your 1200 foot pea patch and need fuel.

Now, when the mainstream gasoline providers got away from TEL (and a
good thing, IMO) the supply of avgas was threatened, and Dr. Harry
Zeisloft with financial backing of the EAA- a group designed to make
the Poberezny family, and not FBOs, rich-went to a great deal of
trouble to prove what everyone already knew, that basically low
compression lyCon engines would run fine on car gas. People had been
doing this all along, farmers and ranchers and cropdusters-movie fans
out there will recall Eli Wallach in "The Misfits" bitching as to the
starting properties of "lousy car gas"-but Zeisloft proved it and got
the FAA to issue a STC, with a lot of evidence ad no little political
backpressure.

So, the system worked: the Supplemental Type Certificate modifies the
condition under which the ATCd item may be operated, which is what all
STCs do.

Additives are another story: the FAA does not require Lycoming to
recertify their junk H2AD engines to use their engine oil supplement
(which is GM Engine Oil Supplement, repackaged) and owners are not
required to seek one to use Marvel Mystery oil, Prist, 5606 hydraulic
fluid, or any other popular fuel or oil additive.

 

Two cycle Detroits have holes in the bottom of the cylinder liner for
air intake. Multi viscosity oils don't make it past the holes as well
and the upper bores wear much faster.