Bought the car in November of 2009 with 72,000 miles and documentation of maintenance for the first owner's entire span of ownership including everything from tire rotations and oil changes every 3.5k to an engine replacement at 50k miles with a brand new factory engine. After a year of driving it and oil changes every 3k, the car developed a low-pitched "grumble" at idle. This progressed in a week to a full-on engine knock due to sludge and lack of oil pressure. Vehicle is undriveable. I still owe $4k on it. No warning lights on the dash of any kind.

About 1 month ago I was forced to replace the water pump. After that, upon start up the engine made some noise for a few minutes until it warmed up, though I blame it more on the cold weather. I purchased the car in 2005 and have never driven it in Michigan during the winter months.

Just the other day, I pulled up to a stop sign after a 10 mile drive and heard a terrible knocking noise. It sounded like diesel!

I do not have the funds to take my poor Sebring to a mechanic so I decided to self medicate her. I purchased three 5qt jugs of oil, 3 oil filters, 3qts engine cleaner, and 1 quart of Lucas oil treatment. I basically did 3 oil changes today. The first two changes I added engine cleaner to the oil and followed directions on the bottle. After each oil change the engine got a little quieter, never silent like it was last week but quieter. With the last oil change I added the Lucas treatment and followed the directions on the bottle. After running the car for about 10 minutes it quieted right down and the knock was gone!

I am pretty sure this knock was from the timing chain tensioner losing prime, causing timing chain slop. It was coming from the back of the engine where the timing chain gears are.

After researching this 2.7 engine I will definitely now add oil treatment for every oil change. So far I seem to be a lucky one without sludge. When I changed the waterpump everything looked pretty clean. I am now coming to grips with what seems to be the fact that when the waterpump fails the engine will shortly follow. I just hope that by adding the oil treatment I will prolong this a little longer.

Car was bought in 2003, started leaking transmission fluid, heater motor resistor went bad, replaced resistor fixed leak, paid car off in 2008, tie rods went bad, ball joints went bad, replaced in summer 2008, then oil light started blinking, thought it was sensor light would stay off sometimes for a whole day, started losing coolant but never overheated, replaced water valve top of engine, started making noise from engine, did research found out engine would build sludge due to poor design, removed intake, valve covers, timing cover, oil pan engine was completely plugged oil drains blocked a complete mess. Replaced timing chains, gears, oil pump, water pump, tensioner, parts alone over $600 labor in time 6hrs. Repair lasted maybe 7 months problem reoccurring need to replace engine. Car is a money pit do not purchase no matter how attractive the price. No help from dealer, car was out of warranty.