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Sludgemaster 2000

Old 12-30-2014, 09:49 AM
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Mother-in-law has a 2004 Chrysler Sebring, 2.7L V6, 97,xxx miles

Oil light has always been flaky. Used to flicker on and off, and for the past year or so it's been on steady. Research said the PCV was probably clogged.

Fast forward to a few weeks ago. Told me she started it to go to work and there was a loud tapping noise, so she shut it off and got a ride. Hasn't driven it since.

Well this past week i took some time to tear into the engine a bit. Engine has a definite metallic tapping in the top end, right bank, front of the engine. It's dead silent and purrs like a kitten when it's cold, but after driving a bit or letting it idle for 5 minutes, once it warms up the tapping slowly starts to get louder.




Intake Off


Valves look good


Uh oh


Lots of heat discoloration and oil sludge









And this is what was coming out - hardened (it flaked apart), compressed oil sludge, 1/4" to 3/8" thick at the bottom edge of the valve cover

Last edited by dukie564; 12-30-2014 at 11:01 AM.
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Old 12-30-2014, 10:08 AM
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So i grabbed a shop vac and got to work scraping as much hardened sludge off the head as possible. It was so dried it flaked apart easily and got sucked right up the vacuum hose with ease. Managed to get it to a pretty acceptable level of cleanliness.





So...i did some research. This particular engine has a history of being a sludge monster, particularly in previous years. Supposedly for 2004 they made some improvements to assist with that. The issue is in the construction of the heads - the oil passageways are too small, so they clog easily. Couple this with a hot running top end and unrestricted oil flow into the heads makes a bomb recipe for some impressive oil sludge.

Seeing as the engine is only at 97,000 miles, and purrs like a kitten when cold and prior to this, i'm thinking the bearings are fine. I also don't think there is any issue with the oil pump or pan being sludged up - only the top end.

Additional research now leads me to believe that the timing chain tensioner is to blame to the noise issue - which is either the timing chain digging into the guides (unlikely), or the valves hitting the piston. What i believe is happening is the timing belt tensioner, which is a spring loaded unit at startup and hydraulic beyond that, is failed/failing to keep up with the timing chain slack once it heats up, either because the tensioner is gummed up, or at the limits of it's reach (possibly because the chain is stretched?).

The tensioner is the cylinder to the left






It is NOT easy to get to (back top side of the engine with a power steering pump directly below), and needs to be primed (may come this way from the store), installed, and then activated by prying the guide toward the tensioner. The FSM shows this being done from the back, but it should be able to be accomplished from above with just the valve cover off

[[THIS IS NOT MY ENGINE BELOW]]

Last edited by dukie564; 12-30-2014 at 11:35 AM.
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Old 12-30-2014, 10:26 AM
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So...to the point. I need some educated opinions...


Is it worth fixing?


Things to consider:
Was looking to buy a new car in about a year, doesn't have much money to buy a new one right now
NADA Guide Trade-In value is about $2400 in average condition $1800 poor/fair condition, IF the engine gets repaired. If we scrap it, $300-400. If we fix and sell it, could be worth about 2500-3500 to private seller (but seriously who wants a sebring?)
Needs struts on all 4 corners
Needs a new serpentine belt ASAP (fraying/splitting in the middle of the belt)
Needs a gasket at the upper coolant manifold (minor)
Needs to pass a Delaware state inspection

To fix the timing tensioner issue, I would say the full timing chain job needs done - chain, sprockets, guides, tensioner, and waterpump (which for some ungodly reason is INTERNAL, so if it leaks, it leaks directly into the crankcase). This requires some specialized tools, a lift, and many hours of swearing. I'd leave this up to a shop to do (~$1100-1300 parts and labor).

IF i can replace the tensioner alone, it's about $50. Again, i have no idea if i can even access it until i pull the back valve cover off, or if the timing chain is stretched too far for the tensioner to work anymore (i doubt it with only 97000 mi).

Last edited by dukie564; 12-30-2014 at 10:47 AM.
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Old 12-30-2014, 10:45 AM
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oh, here's a video of the noise once it warms up


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Old 12-30-2014, 10:53 AM
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Best way to fix it would be to pull the engine so you can access everything. New timing chain , tensioners and guides and water pump, just as you've said. Parts are not that expensive, check eBay. Definitely a PITA job. Tough to throw away an otherwise good car over a couple hundred dollars in parts but if you have to pay someone else another grand for labor then maybe it is time to say buh-bye.
The 2.7 is a good motor but definitely sludge prone if running longer oil change intervals. This is one motor that benefits from shorter 3-4K mi. oil changes. And the internal water pump thing was/is a boneheaded design but many engines use that nowadays.
Best of luck on your final decision.
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Old 12-30-2014, 10:56 AM
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pulling the engine myself is out of the question - i do not have an engine hoist or the time to commit, and she lives 1.5 hrs away.
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Old 12-30-2014, 11:04 AM
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May need to just scrap it or drive it till it goes. Do the belt at least. Look for a car in the mean time. Seriously, I feel having a shop take the engine out and work on it, probably cost $800+ I would imagine
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Old 12-30-2014, 11:16 AM
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yea. Timing belt job is 6.5hrs, and about $250-300 in parts
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Old 12-30-2014, 11:23 AM
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So engine work in total would look to be over $1200 possibly. And I know you would do this yourself if given the chance but if money sunk in is going to be half of what a "new" car would be, that just might be the best option.
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Old 12-30-2014, 11:57 AM
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Yikes.
I'd go serpentine belt, a few jugs of cheap oil to run through it at 100-200 mile intervals to try to clear out a decent amount of that crap out and run it till it blows. No use in saving a Sebring unless you have zero budget. Maybe get AAA so you can get it towed to a junk yard when it blows. Did it skip time? Maybe the chain tensioner failed and you're getting some weird valve timing??

Last edited by kgm; 12-30-2014 at 02:32 PM.
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Old 12-30-2014, 05:11 PM
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Originally Posted by kgm View Post
Did it skip time? Maybe the chain tensioner failed and you're getting some weird valve timing??
If it did jump time, depending on how far off time it is there could be serious valve damage since the 2.7L V6 was/is an interference engine. Probably 90%+ of 2.7L V6s end up dieing due to water pump failure which has two ways of killing the engine. Being internal when (not if) the water pump fails it can dump coolant into the crankcase and contaminate the oil destroying the bearings, since it is driven by the timing chain it can also fail catastrophically and cause the timing chain to jump and cause major damage due to the 2.7L being an interference engine.




I'll agree with the others to either do everything (if you do the work yourself, if you pay someone it is getting to the point where it is debatable if it is worth fixing, especially if the vehicle need other work) or just do a quick clean up and run it till it dies, at this point the water pump could fail at any time (most fail somewhere between 80k mi and 100k mi) and likely will lead to engine failure (unless you get really lucky and catch it as soon as it fails).


I had a 2.7L V6 in a 2002 Dodge intrepid, I had to replace the water pump at 86k mi (paid someone to do it since I was in college at the time and didn't have the time or space to work on it and also had the timing chain/tensioner done at the same time). When the transmission started slipping at 150k mi this design was one of the major reasons I got rid of it (I could have fixed the trans for less than I put down on the car that replaced it, but I knew it would likely need a water pump again in the next 10k-20k mi and that ($1,000 - $1,2000) in addition to the cost of the trans rebuild effectively made it not worth it to fix the car. Though never had any sludge issues (changed the oil with full-syn every 5k mi., mostly highway driving at the time), when I sold it with the trans issues, there was not a speck of sludge under the valve covers.


In general those engines are a horrible design and a pain in the *** to work on (with almost everything you need to take 10+ other things apart to get to what you need to fix), I will never buy another vehicle with the Mopar 2.7L V6.

Last edited by dmill89; 12-30-2014 at 05:15 PM.
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Old 12-31-2014, 04:03 AM
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Ahh the 2.7. A coworker of mine has an Intrepid with this engine. Had a wonky oil light when he bought it, than one day it it wouldn't start. He had me look at it and it had the same hollow sound my ZX2 had when the timing belt went out. Not knowing a great deal about this engine, I thought it could be a slipped/broken timing belt. He had it towed to the shop, and it turned out the thing was super slugged up, causing the timing chain to run dry and fail. They ended up rebuilding the engine, after which I suggested religious oil changes with full synthetic.
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Old 12-31-2014, 07:18 AM
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Kill it!
Kill it with FIRE!

I bought a non-running Stratus for $750.

I went through this exact nightmare, same car, same motor.
I dropped the motor, tore it down,
Found a shop that would sell individual rods (Fractured rods have yo be the dumbest idea EVER.) Milled the heads, replaced the timing chain...blah,blah,blah.

Ran fine for a month or two then the new chain snapped and that was the end. Bent valves, gouges in the pistons.....

Why anyone would build an engine with the water pump INSIDE the engine is a complete mystery to me.

So yeah...KILL IT WITH FIRE!!!
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Old 12-31-2014, 08:24 AM
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My first thought was to either fix it yourself which you said you didnt have time.

second thought do you know anybody that works out of their home for half price of mechanics or something I know they are around everywhere....see if theyd want to take a crack at it if you do

but....now that like 3 people have said that they had the same issue with the same motor and same sludge and same repair seems like best idea although not the easiest is to just get what you can put it towards another used car....slap a for sale sign on it for 1000 bucks or whatever you want for it....

Also I know those struts cant be cheap....fix the engine 1200 struts what like 300-400 bucks? idk i dont drive cars but i mean your starting to get up near 2k

Last edited by Scott M; 12-31-2014 at 08:27 AM.
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Old 12-31-2014, 05:02 PM
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Originally Posted by Scott M View Post
second thought do you know anybody that works out of their home for half price of mechanics or something I know they are around everywhere....see if theyd want to take a crack at it if you do
I wouldn't recommend that unless you are really sure that person knows what they are doing (Ideally someone who has successfully worked on these engines before). It is very easy to screw things up on that engine (especially with the timing chain) and if anything isn't done right catastrophic failure is usually the result. In addition there are specialty (often dealer only) tools that are used for many repairs on that engine (including ones that lock the cams in place when the timing chain is removed to be sure they don't move), while it is possible to do many of theses repairs without the specialty tools the risk of messing up and doing damage is much higher.


This is a very sensitive engine (one of the first completely designed by computer) with close tolerances and rarely gives second chances, do something wrong on it and you will likely end up with a 350lb. chunk of scrap aluminum.
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