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I own a 02 Intrepid SE, 2.7 with 164,000 miles. Oil light came on for the first time a couple of weeks ago. Dropped the oil pan, which was a simple job. Just as I suspected, sludge and carbon had blocked the pick-up screen. What I hadn't expected was so much of it. The inside wall's of the oil pan were coated with a good 1/4 inch of the stuff. So I cleaned the pan and the windage tray and the pick-up tube and screen and re-installed all parts. Replaced the oil using Castrol High Mileage Oil and a PH16 Fram Oil filter. I will run the engine for 500 miles and replace the filter and oil as described above. Now for the " FIX "! If you will look at the way the cranckcase is ventilated on this engine you will notice that both valve cover vent hoses are connected to the suction side of the engine. Pass side is connected to the air intake hose, creating a vacuum to pull air from the crankase. The driver side is connected to the throttle body, also pulling a vacuum on the crankcase, this set-up puts the crankcase under a sealed vacuum. There is no place for the engine to pull outside air, to let the engine breath. My solution is to remove the pass. side hose and block the opening at the intake hose and install a breather cap at the valve cover the way the older engines had it. This should let the engine breath the way it was done for many years. Only time will tell if this plan will fix the problem with sludge build-up. The way I see it, we got to try something and this idea might just do it.
 

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The system you just defeated is called a PCV system, it is present on many cars, including the non sludge prone 3.5/3.3/3.2L engines. It is an important emission control device. If the oil carbonized, that's due to heat and an oil that can't take the heat.

The problem is probably not solved..... keep an eye on it!
 

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Discussion Starter #3
Hello Hardwareguy, by doing what I described above, the PCV procedure has not been eliminated, the PCV valve is located on the drivers side and will function as it should. The modification will allow the engine to pull air into the crankcase more easily, producing a free-flow ventilation of the repeated ( vacuum/pressure) created within the crankcase. I believe the vent hose located on the pass side, designed to allow air into the crankcase when the pistons are causing a vacuum within the crankcase, is located to close to the throttle body which is under a positive vacuum, creating the same pull on the crankcase as is the PCV side of the system, so where is the crankcase able to pull air into it and release the vacuum created within. Older engine designes pulled from the air cleaner housing before the filter where vacuum was not present. Even older designes used a filtered breather cap for this purpose. This modification doesn't remove the PCV Valve or it's purpose. It allows a less restricted release of the vacuum created within the crankcase. This will also allow more air to flow thru the crankcase and cool the inside of the engine and condense the oil particles floating around inside the engine. I'm sure Chryslers theory for restricting this process was to prevent the amount of these air born oil particles from entering the combustion chamber via the PCV Valve, which increases the emmissions reading--however so slightly. The down side is, they created a closed system within the crankcase and the lack of proper ventilation creates an oven effect which cooks the oil particles that would otherwise not be present in such volume. In summary--- The old PCV design worked for years, and sludge was not an issue.
 

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In a word:

No.

There's so much incorrect and misinformed with what you're attempting, I don't know where to start. There's a good two pages of writing in just your last post alone. I don't feel like typing for a hour to point out the issues and you seem pretty determined to do this.

So I'll just throw in my .02 and let's just leave it at this:

Changing to the system you propose will cause more harm than good. It may not kill the engine, but it will do nothing for the "sludge problem" (*edit: actually, upon further consideration, it may make it worse *) and it will increase the amount of unburned hydrocarbons your car produces.

Take from that what you will.

I will give you pos rep for the thought though!

Cheers

BJ
 

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Discussion Starter #5
givin the alternative--4,000.00 for a replacement engine--a few extra hydro's, so what. As for the mis-info, you really need to explain in detail where the mis-info is. Please, re-educate me.
 

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TAURUS said:
givin the alternative--4,000.00 for a replacement engine--a few extra hydro's, so what.
My 4 year old and every other child thank you for your concern for their future and that of every generation to follow......
And what you are proposing won't save your engine or any money. In fact, it'll probably cost more you in the long run.
TAURUS said:
As for the mis-info, you really need to explain in detail where the mis-info is. Please, re-educate me.
There is no way I'm typing out that much information. Do a google on crankcase, pcv, pumping losses, windage, etc.
You'll have to educate yourself. I'm not typing 29 years of automotive experience when the information you need is already on the web somewhere. You just need to seek the knowledge.

Just FYI:
PCV= positive crankcase ventilation. Just that title alone should clue you in a bit. If not, better keep reading :)
The crankcase does not operate in a "sealed vacuum". But engines would be a lot more efficient if they did. We'd sure as heck have to come up with a better sealing solution than piston rings if this were to come to pass.

If you want to make your engine last, the key is religious and fastidious maintenance. If the engine oiling paths are already blocked there's not alot you can do.
Use an engine flushing product and follow the directions to the letter. You'll never get it completly clean, but it sure is a good start. Then use a good quality oil (I'm one of the mobil one supersyn users myself for a reasonable price/quality trade-off) that is well reputed for the detergents and additives it contains. These are what keeps the crankcase "clean" along with a very thermally stable oil.

Start Google-ing!

Cheers

BJ
 

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TAURUS said:
Now for the " FIX "! If you will look at the way the cranckcase is ventilated on this engine you will notice that both valve cover vent hoses are connected to the suction side of the engine. Pass side is connected to the air intake hose, creating a vacuum to pull air from the crankase. The driver side is connected to the throttle body, also pulling a vacuum on the crankcase, this set-up puts the crankcase under a sealed vacuum. There is no place for the engine to pull outside air, to let the engine breath. My solution is to remove the pass. side hose and block the opening at the intake hose and install a breather cap at the valve cover the way the older engines had it. This should let the engine breath the way it was done for many years. Only time will tell if this plan will fix the problem with sludge build-up. The way I see it, we got to try something and this idea might just do it.
I have yet to see any car made in the last 20+ years that didn't have their pcv system set up in the exact same way, sludge or no sludge. Instead of using a breather filter, like some older cars used to do, the clean filtered air flows thru the breather side via the air intake tube, which is cleaned by the air filter. As far as suction on both sides, you are right and wrong. Yes, both sides have a suction or vacuum, but not at the same time.

Under low or no throttle, manifold vacuum is greater than the intake air flow, so crankcase vapors are flowing into the breather hose and back out the pcv valve. Under hard throttle, manifold vacuum is lower because of the wide open throttle. Under those conditions, its possible for the pcv system to flow backwards, as evidenced by some oil in the intake duct. Your solution by adding a breather is not bad except for a few things. #1 is the smell. You will start to notice an oil smell. That is another reason why the pcv system has been designed the way they are, so they don't emit those emissions into the atmosphere. #2 is the possibility of the breather becoming oil soaked and leaking onto the hot exhaust below. I'm sure I don't have to remind you of the flamability of oil.

In any event, using a breather filter isn't going to cure any sludge. It all depends on whether its burnt up deposits or moisture contamination. Burnt up oil indicates that either the engine has been running too hot and/or the motor oil that's been used hasn't been up to the task and breaks down fairly easily. the other type of sludge has to do with moisture contamination. that can be caused by a faulty pcv system, not venting moisture properly. My 2001 has factory installed what is called a heat exchanger inline with the pcv valve. It scavenges heat off one of the heater hoses to keep the crankcase vapors nice and hot and keeps water vapor in vapor form. Some seem to think that the sludge issue seemed to decline once they started using the heat exchangers on the motors. I have pics in other threads. another source of moisture is the water pump, being that its inside the timing cavity soaked in oil. But if yours were leaking, you'd notice you'd be losing coolant from the recovery tank on the driver's fender.
 

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There is nothing wrong with the factory PCV setup on this engine....Fresh, clean, filtered air is drawn into the right side valve cover-- it travels from there through the holes in the right head accross the crankcase (where it picks up excess fumes, vapor, gasses, etc.) -- then it is up through the holes in the left side head where it exits the crankcase and is drawn through the PCV valve at a metered rate and enters the intake airstream (behind the throttle plate) where it mixes with the incoming air and goes into the cylinders to be burned and exhausted...This is the way it works in all cars since the '60's when they eliminated the road draft tube that simply dumped the excess crankcase gases under the car.... There is no problem with this system.. You might check the valve, hoses and passages to make suse they are not clogged or restricted...

I can see where your thinking originated , but what you are proposing will not help..unless your air filter is really clogged the air box where the PCV intake hose connects is not under engine "vaccum" it is just in the incomming airstream.. The "sealed" nature of the PCV system actually helps it eliminate more vapor from the engine, which helps fight "sludge"... This engine builds up sludge because of lack of regular maintenance, just like any other engine...It is a bit more intolerable of bad maintenance than most engines, mainly because the engine metal parts runs hotter than most engines. The heat is generated by the 2 cat converters sitting paralell to and right next to the heads, this adds a lot of extra heat to the block and heads, and all of the plastic composite upper engine parts and valve covers do not do very well in helping to dissipate the excess heat..Plus it is a small engine in a pretty big car so it works hard... The oil tends to bake on the sides of the block, pan and heads.. Dirty oil mixed with a little water vapor bakes on as "sludge"

Just my 2.7cents worth..
 

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I thought the fix was to use sythetic oil. Am I wrong? Is what I tell anyone that has a 2.7 around my area. Also tell them to make sure they maintain it well.
 

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Ya the OP should check his water pump..bet its weeping into his crankcase which is causing the sludge in the 1st place..
 

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Sludge is caused by water getting into the oil. On the 2.7, that's the water pump failing.

Manually scraping sludge out of a crankcase and then 'doing something' unrelated to the root problem is NOT a fix.
 

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[QUOTE='98-ESer]Sludge is caused by water getting into the oil. On the 2.7, that's the water pump failing.
[/QUOTE]

Yes and no. Water can come from other sources besides the water pump. Engines that don't get warmed up fully very often will suffer the same fate if the oil is not changed frequently. Short trips where the oil doesn't get hot enough, moisture will build up in the oil. In engines that do get warmed up often, the moisture will become water vapor and be removed thru the pcv system, which is yet another reason to make sure the pcv system is operating properly. So sludge isn't isolated to a few engines, it could happen to any engine, that isn't serviced properly. You could take a 3.5, which doesn't have the same opportunity as the 2.7 for the water pump to contaminate the oil, and still end up with sludge just by doing short trips and not changing the oil often enough.
 

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Discussion Starter #13
Hey all, I didn't create this post to start a battle of wit's. Only to share what I fell will help a situation that is far from random. From what I have found about the 2.7, there is a critical engineering flaw in it's design. After reading all the horror stories about this engine posted by every type of car owner, from the documented service type to the owner with as low of mileage as 24,000, these engines fail due to sludge build-up. Enough so that a class action law suit is being considered as we speak. Frequent oil changes, all types of oil, nothing seem's to be a sure remedy. Other manufactures of all alum. engines dont seem to have this prob. So why not try to open our minds to find a solution rather than do nothing and hope we get spared the horror of the 2.7. I myself will try to swim to shore, rather than wait for a boat. Thank's for your opinions and good luck .
 

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Discussion Starter #14
PS--- If it were a water pump leak bad enough to cause the amount of sludge that was removed from my engine's oil pan, not just loose sludge but hard carbon build-up on the sides of the oil pan, there should be a drop in the amount of anti-freeze in the radiator system--there is none.
 

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TAURUS said:
PS--- If it were a water pump leak bad enough to cause the amount of sludge that was removed from my engine's oil pan, not just loose sludge but hard carbon build-up on the sides of the oil pan, there should be a drop in the amount of anti-freeze in the radiator system--there is none.
See, what you're describing sounds moore like carmelized oil rather than a moisture contaminated oil sludge. Carmelized oil is also common in engines to some degree or another. Thick, caked on like you are finding it says that your engine has seen a lot of miles between oil changes at high temperatures. Sludge is typically characterized by a milkshake look, a whitish or creamy color to it, like snot. Burnt up or camelized oil looks much darker and is no better for your engine than sludge is. If indeed your engine has a build up of baked oil, modifying your pcv system isn't the answer. Regular oil changes are. Of course, you have no way of knowing the history of the maintenance on this vehicle prior to your ownership, but based on your descriptions, it sounds like they definately went quite a bit longer than 3000 miles between.
 

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"Sludge" seems to have become a catch all as of late for enything out of the ordinary that happens to engine oil.

"sludge" is nothing new.

Water in oil makes it milky in appearance and the real danger is in the water replacing the oil as the lubricant at the bearing susrfaces. It also takes away the oil additives "anti foaming" properties. Foam is air, air is a poor lubricant.

Coking is also another thing that seems to have fallen under the evils of the word "sludge". Coking occurs when oil exceeds it operating temperature. It becomes carbonized for lack of a better word. Extremely poor lubrication properties.

Poor maintenance also causes "sludge". This was also evident in the old V8's and engines that supposedly didn't have this problem. I've rebuilt more than one small block that was "sludged" to death.

I've also seen "sludge" in engines run without thermostat's. And before you go "aha, too cold! Water in the oil!" froggy, no thermostat makes an engine run hot, not cold. The coolant doesn't stay in the engine long enough to do it's job of removing heat.

So, "sludge" is not new. It's been with us forever. What has happened lately is that engines have become smaller, more compact, and produce more HP per cube than before (Read-heat).

Chrysler (and the 2.7) is not the only one dealing with these issues. Every manufacturer is (toyota and mercedes comes to mind). So yes, other manufacturers of aluminum engines (which has nothing to do with it) have these problems too.
A class action law suit? That's been going on for years. Good luck if you plan to hitch your wagon to that horse, you won't get very far.
Critical engineering flaw in it's design?
Horror stories about this engine posted by every type of car owner?
Don't believe everything you read on the net my friend. Did it ever occur to you that satisfied people are often the silent mass and those that feel they've been wronged scream to high heaven to anyone hat will listen? I've got a high mileage 2.7 with no issues whatsoever. NONE. But I know how to take care of a vehicle.
Look at it this way:
How many 2.7's did (and does) chrysler produce? Now remember, these came in other models too. I'm only guessing, but I'd say in the hundreds of thousands.
Now go out and count every on eof those complaints. I'm guessing you'll get in the thousands of complaints (even if you allow all the reposts of every bitter individual who posts everywhere they can find).
Just for arguments sake, lets say DCX made 100,000 2.7's and there are 1000 dead engines. that's 1% of total production. If you account for double complaints and those who actually did kill thier own engines (it happens no matter what people think) it drops below that even. Lets say 10, 000 cmplaints. 10%. Still a low number, assuming premature engine failure was not the owners fault.

I'm not saying I don't feel sorry for those who have to bear the brunt of a hefty repair bill, but very often it is (no matter how much people don't want to hear/admit it) the owners fault.

here's the thing;
people have come to think of cars as appliances. Drive it and it should never break. Just isn't so. Oil changes are recommended at certain intervals for a reason. Those trips to the corner store 3 blocks away for some cigs is what kills your engine. They nessesitate a severe maintenance schedule. Most people don't think this and do the schedule maintenance thinking they don't operate in severe duty conditions. Truth is, everyday driving is actually severe use!
Maintenace. It's how you make the engine live. Plain, simple, effective. Truth.

Cheers

BJ
 

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Great White said:
Maintenace. It's how you make the engine live. Plain, simple, effective. Truth.

Cheers

BJ
As an owner of another higher mileage 2.7 (and many other high mileage cars/trucks of various makes) I'll have to agree... You also have to remember to maintain it when it needs it , not just when it suits you to do it...
 

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Discussion Starter #18
This is true Froggy, I don't have a water in the oil prob. I would also agree that poor maintanance will cause the prob. But, what about the 2.7 owners that have serviced their engines properly and have sludge issues? So far I have cleaned the carbon and sludge from the oil pan and routed the right side pcv hose to the front of the air cleaner box( in front of the air filter) and installed the old style, thru the breather housing filter, as the older GM air cleaners had it. Decided to not use the breather cap. I've also installed a manual oil pressure gauge which will allow me to monitor the actual oil pressure---engine has 168,000 miles on it and at idle with engine at operating temp. oil pressure is at 11 psi. When running at 2100 rpm pressure is at 42 psi. At cold start up the idle pressure is at 56 psi and 80 psi at 2100 rpm. I think it's safe to say those pressures are ok for an engine with that amount of mileage. My next modification, if I can find it, is to install a oil cooler. Maybe you Guys know where I can find one. Thank's
 

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Discussion Starter #19
RE: 99 Intrepid 2.7L - what is the solution to Sludge? - 4/2/2006 3:13:09 PM


notallhere
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Status: offline Just had to jump in here, i got my 99 intrepid for $400.00 had 108k on it and the engine was shot. I bought the new short block and put it in, from what the part guy at the dealership told me the oil journels in the block were to small on the original blocks causing the overheat temp mostly for the main and crank bearings.
The sludge problem is from a poor venting design alowing the engine to use recycled air from the intake which is mixed with exhaust fumes from the egr. That is why the sludge was bulding up the exhaust gasses cause the oil to break down and build up as sludge.
The solution i chose was to block the intake vent off the intake manifold and draw clean cold air in to the vent of the valve cover, just put a small vent filter on it and that takes care of the emitions entering the engine thus prolonging the life of the oil.
With regular oil changes and a good grade of oil i have had 0 sludge build up in the last three years.


Hummmmmm-just found this post, thought I should share it--FYI
 

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TAURUS said:
Status: offline Just had to jump in here, i got my 99 intrepid for $400.00 had 108k on it and the engine was shot. I bought the new short block and put it in, from what the part guy at the dealership told me the oil journels in the block were to small on the original blocks causing the overheat temp mostly for the main and crank bearings.
The sludge problem is from a poor venting design alowing the engine to use recycled air from the intake which is mixed with exhaust fumes from the egr. That is why the sludge was bulding up the exhaust gasses cause the oil to break down and build up as sludge.
The solution i chose was to block the intake vent off the intake manifold and draw clean cold air in to the vent of the valve cover, just put a small vent filter on it and that takes care of the emitions entering the engine thus prolonging the life of the oil.
With regular oil changes and a good grade of oil i have had 0 sludge build up in the last three years.


Hummmmmm-just found this post, thought I should share it--FYI
some of what is in that post is full of ****. Where does "recycled" air come from? Another thing also is that the egr system feeds into the plenum after the throttle plate, and because the plenum is under a vacuum and air is moving in instead of out, its impossible for EGR fumes to go back out past the throttle plate and into the breather hose, or even back out thru the pcv valve. So any notion of egr fumes breaking down the oil is completely untrue and goes against the laws of physics. Whoever posted that shouldn't be under the hood of a car.
 
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