oil sludge

[juggalojesus87]

i have been looking around on the internet and found that the 2.7 has a problem with oil sludge and causing the engine to lock up or die. i also read this is due mostly because The oil galley is too small and that causes the oil to gum up. is this true and could this be help by using synthetic oil and a higher flow filter like k&n? has anyone had problems with this?

[wafrederick]

It is true about changing the oil to synthetic and you can use any brand oil filter.The recomended synthetic oil is Mobil 1

[juggalojesus87]

what is the reccomended oil type to use... i got a extra 5 quarts of 10w30 laying around...

[wafrederick]

Read the owners manual and it should say in there.

[juggalojesus87]

im going to use mobile one full synthetic oil and a kand n filter wnd doing a engine flush before hand to remove what sludge is in there.

[juggalojesus87]

is it true that they fixed the sludge problem in the 2001 znd newer models or is it still the same? there is a lot of debates on this engine...

[wafrederick]

I believe they fixed the problems in 2002.Jasper has never sold a 2002 and up 2.7 engine yet.

[juggalojesus87]

just my luck lol i got a 2001. i still owe on the car but i might go for the 3.5 after a pay it off i see them as low as 800 around here and i know a shop that will swap it for 1000 just hope it lasts that long for me to pay it off

[BLISTK]

I have seen of a few extreem ways to fix sludge in a car.

1. Drain your oil, fill it up with diesel and run it for 5 mins.

2. 50/50 mix of diesel and fresh cheap oil and run for 10 - 15 mins

3. Sames as above but use 50/50 mix of Kerosene and Fresh Oil. Kerosene is also one of the main active ingredients used in oil fush products.

4. Run Diesel Engine Oil in your car for a few thousand K's. Castrol RX Super, or Shell Rimula X are suppose to have the highest detegent levels and are suitable for Petrol engines as well.

I have learnt of these methods while i was working in South Australia Mommba Gas Filed for 3 months. This is what the Mechanics up there did to clean a sludged engine. Be it petrol or diesel. Cos its very dry, dusty and hot up there slug is more of a problem and its a regular thing they did to clean an engine.

The first time i saw it preformed is when i went to pick up my landcruiser that i used up there after it had a service. I saw this mechanic pouring a liquid (diesel when he told me) in the crankcase of another landcruiser. I though that he was joking, but sure enough he shoved me the container and yep that smelled like diesel. I stayed there till he finished running it just to fully witness it.

Anyways thats how you fix sludge the extreem way i guess, i never tried it. But useing Castrol RX or the Shell Rimula X are less nerve racking options to clean an engine thats sludge build up.

[stlrj]

Originally Posted by va3ux View Post

"...Plus, the chain and sprockets expose the oil to significant additional aeration, which leads to more rapid oxidation. Oxidation of the oil is the pathway to sludge formation, which is further accelerated in this engine because of the higher than normal internal temperatures found in the 2.7.

These are the reasons the 2.7 is so sludge prone. But proper use of synthetic oil and maintaining the PCV valve/hoses/heat exchanger will pretty much negate all of it.

The 2.7L is not the only engine in production that suffers from sludge. There are others too."


Phil


*******



This got me thinking about my other car, an 86 Porsche 911 with a 3.2 engine, that also has two large double row timing chains on a single overhead cam, intermediate shaft and tensioner sprockets that also exposes the oil to significant aeration, shear and high temperature ( remember, these are air cooled and run much hotter than water cooled engines) but these engines have never had an oil sludging problem. Why?

I think it has to do with the oxidation issue. Early 911's do not have a PCV valve, only an outdated crankcase vent sysem, so the blowby gases inside the 911 crankcase are oxygen depleted since they are products of combustion that have made it passed the rings or valve guides.

The Intrepid 2.7, on the other hand, has it's crankcase bathed in an oxygen rich environment created by an extremely effective PCV valve system that is constantly drawing fresh air through the vent hose on the passenger side valve cover which, I believe, is a receipe for disaster that may be at the root of all oil sludging problems.

Therefore, in order to create the same oxygen depleted environment inside a 2.7 crankcase to effectively eliminate oil sludging, we need to plug up or cap the PCV valve to allow only 02 depleted blowby gases to enter and escape the crankcase without introducing any oxygen rich fresh air, just like a 911 system.



Make sense?


Cheers,

Joe

http://www.dodgeintrepid.net/forums/t70556/

[Spectria, L1 MT]

Sorry Joe,
Yes, it makes sense, and Don't do it!

I hope you will accept my advice on this without taking offense.

The 911 engines have always had very free flowing breathers and oil drain back.

"I think it has to do with the oxidation issue. Early 911's do not have a PCV valve, only an outdated crankcase vent sysem, so the blowby gases inside the 911 crankcase are oxygen depleted since they are products of combustion that have made it passed the rings or valve guides."

Early 911's do have a free flowing crakcase vent system that brings in clean air to the crankcase and would contribute to the oxidation problem theory.

It's the fact that 911 owners Always have their oil changed on time. Nobody can afford to replace those engines...

There is no comparison.

Also, the 911 does not run hotter than the water cooled motors. The temps are just measured in a different way. Head temp sensors give a direct temp reading of the head, whereas the coolant temp sensors on water cooled basically give an average temp of the coolant, not of an exact spot.

I haven't the experience of most on the Intrepid, but apparently keeping the oil clean and changing the oil and filter on time is the most important thing.

I have a friend who took his '04 Intrepid to an oil changer place and they charged him 39.99 for the oil change, but after beginning the work mentioned it's an extra $40 bucks to change the oil filter???

Anybody ever heard of this???

He passed on the filter change. He has an oil light that comes on after 20 minutes driving at a stop, brake pedal applied.

Goes off at speed, back on at stop.

When cool, no light.

[stlrj]

Here's the best explanation I have found so far relating to oil sludge in another forum:

http://www.dodgeintrepid.net/forums/...d.php?t=171698