It's alot to due with heat. The engine cooks the oil is what I've heard, turns it into sludge. And also the waterpump leaking coolant into the oil. It's not really limited to Intrepids and Concords either, I've heard of cases of Strati and Sebrings taking a turn because of it. IIRC Chrysler specs a different oil now for the 05 and up 2.7L. If mounting was an issue on the motor then the LX's are doomed right from the start.

 

You are right those are all things that contribute to the forming of the sluge. I agree there may be a few cases of it in the stat and sebring but you here far more cases of it in the intrepid. Does the 2.7 in the intrepid run hotter then the stratus? My feelings on it are the poor flow in the intrepid and concorde allow the oil to pool a bit more and allow the oil to heat more thus raising the chances of sludge to be formed in the treps and concordes. synthetic is a bit thinner and flows a bit easier and suspends the particles of combustion better also reducing the affects and possibility of sludge.

 

My temp. gauge doesn't come up to half...I wouldn't think that the 2.7s run hotter in the Intrepids.

 

Not really coolant temperature, more of oil temp. Adding an external oil cooler won't be a bad idea either.

As far as the flow goes, the 01 and up 2.7's seem to have less problems in the LH's. (Also same year when the cloud cars came out as a new model). Does anyone know other than engine blocks is there a massive difference between the two motors (ie: different specs?)

 

Needless to say, I'm kinda paranoid with this motor, even though mine has never given me any trouble. Now that I know what I know about these motors, my guard is up...WAY UP. Since I hate idiot lights [they come on when it's too late], would it be wise to install an oil pressure gauge as well as an oil temp. gauge?

 

They switched to newer oil to achieve better gas milage and emissions. AKA 5W-20 a semi synthetic blend that comes from the factory. Aftermarket it's either semi-synthetic or full blown sythetic. My Explorer calls for 5w-30 but when i'm towing i put in as heavy as 10w-40 and in the winter as low as 0w-20 (Mobile One). Gas milage GREATLY improves with 0W-20 due to less resistance, but just for protection I buy a quart of the Lucas Synthetic Oil Stabilizer!

 

My wife's '01 4.6L Expedition calls for 5W-20. How much difference (if any) would there be using a 5W-20 in the 2.7L Intrepid as opposed to a 5W-30? Better flowing in cold(er) temps, obviously.

 

I hjad a 2000 intrepid 2.7. Great car untill the water pump went out at 40K. $1,100.00 repair at the dealer. Dallas Dodge (don't ever go to this dealership) screwed it up so bad I had to get rid of it. The cooling fans ran all the time after the new pump. I think they may have put the wrong thermostat in. Contrary to what people think they come with a 180 thermostat.
The dumbass mechanic said it had a 195. I checked with parts and they said 180.
I replaced the fan relays the coolant temp sensor, vented the system, no good. it never ran hot, just a little warmer, and I was afraid because of all the hype about sludge it would burn up.
i only owed about 7 grand on the car but a new engine is about 8K. No brainer, I got rid of it. I wish I had tried a different thermostat. The car had 3k mile oil changes from new with mobil 1 5-w 30, there was no reason for any problems.

 

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.

 

I have a 99 intrepid, I ran a quart of atf with 2 oil changes to clean the sludge out. Then I only run petroleum based oil instead of wax. The guy from Mobile said Mobile Clean 5000 is their petroleum based oil. I run 10-30 so the oil doesn't get to thin. I change the oil every 3000 or 3 months which ever comes first.