Do you personally have any bad experience with this car or motor type, or are you just talking BS? I've read a dozen of these "the sludge will kill the 2.7 before you know it", and it all seems to be based on what people have read, heard about etc. Few of these reviewers and commenters seem to have any first hand experience about this engine type. I have personally experience with the 2.7 as my current car is a Sebring v6, no problems with sludge or any other problems related to this car. The engine has even been internally inspected using an endoscope and it was totally clean.
There are so many people talking BS out there!
Take that endoscope and shove it you know where. The reason you're not having trouble with your 2.7L is because you have A SEBRING NOT AN INTREPID. Most of the 2.7 problems are with the Intrepids. Its because Chrysler put in a small engine in a big car. So the car is very underpowered and can't handle the load. As in the Sebring's case it's a smaller car, and is designed perfectly to fit the weight to power ratio.
The Sebring V6 Conv is only about 100 pounds lighter than the Intrepid. The exact number is of course depending on model year and equipment, but this is correct as an average. The reason is a heavy sub-frame that has been added to the Sebring Conv (like on most other convertibles) to ensure proper rigidity.
Also the drag coefficient for the Sebring Conv is somewhat higher than that of the Intrepid, meaning that the engine works slightly harder when cruising. Further, the same sludge claims are made for 2.7 equipped Sebrings as well.
I don't get it. Here in Europe synthetic oil has been specified for most cars at least for the last 10 years. Why don't just use synthetic in the first place? Sludging was a problem of the eighties for many car manufacturers, but I have never seen a single instance of sludge where synthetic oil has been used. And remember here in Europe we use high reving 1.6/1.8/2.0L engines, and there is practically speaking no speed limits on the motorways so the engines get a good thrashing. Synthetic oil IS much more expensive, but will typically last for 3 times the mileage. So in the end synthetic oil is cheaper, especially considering longer engine life.
The problem with sludge build up in certain engines is from:
1. Too many short trips, where the engine doesn't get full heated up to burn off the water in the crankcase (water from condensation).
2. When they started adding ethanol to gasoline, the sludge problems became worse.
3. Besides running too cold, overheating can cause the oil to break down and turn to sludge (I've pulled valve covers and oil pans on overheated engines, to find sludge and carbon build up). The Chrysler 2.7 has a problem where the water pump leaks inside the engine and contaminates the oil.
4. Using cheap oil or not changing it often enough can cause sludge build up (using synthetic oil can help prevent sludge build up).
5. If there's signs of sludge build up, don't just try using engine flush treatments or switching to synthetic oil, instead of dropping the oil pan and cleaning out the sludge. If you just loosen up the sludge and carbon deposits, and they get circulated into small oil passages, the oil passages can become blocked up and you'll end up with engine damage due to oil starvation.
The Toyota 3L V6, Chrysler 2.7L V6, SAAB 2.0 and 2.3L 4 cylinder, and VW Audi 1.8L turbo 4 cylinder engines are known for oil sludge problems. As you may have gathered from reading reviews on this site.
Maintain your cars by following the maintenance schedule in your owners manual or even changing oil and filters more often. Don't forget to check the PCV valve. Avoid too many short trips. If your Chrysler 2.7L V6 is losing coolant, have the water pump inspected and replaced if necessary. It's probably a good idea to replace the water pump when you have the timing chain inspected.