[Joshua Kramer]

Hello,

Is there anyone here who can describe the various versions of the 2.7 V6?

I have an '05 Sebring Convertible. I just replaced the water pump and timing chain tensioner. I also added a Stop Block. Unfortunately, the bolts provided with the stop block were not long enough, and I stripped some threads out of my block. Fortunately I was able to correct this by using the correct length bolt and locktite.

The manufacturer of the stop block swears they've sold thousands of those things without issue, and I believe them. I'm pretty sure that when they improved the design of this engine in 2003 or whenever, some key dimensions changed. Does anyone here know details about what is different on the various versions? I'm guessing there are probably a few revisions:

1998-2003 LH
2001-2003 JR
2003-2006 JR
2005-2010 LX

Thanks!

 

[GLHS60]

All 2.7 blocks have the same 4663611 casting number.

The only block difference was from 2001 on, all blocks were slightly relieved, or clearanced at the bell housing area for starter clearance when used in the very rare manual transmission Sebring.

The only time this would be an issue would be when using an earlier block in a later model Sebring and the area could be ground out if necessary.

Not that you asked, but Sebring Engine's have many differences from Intrepid etc. Engines due to North/South vs East/West installations, just not the block.

There were other revisions along the way, including cylinder heads, intake manifolds, tensioners etc.

The main thing that changed was the water pump and gasket, from the troublesome original design with a separator plate with an embedded gasket, to the later style with a conventional style gasket.

The vast majority of 2.7 problems were not from rumored under size oil passages. The early style separator plate gasket very often either slowly leaked coolant into the oil and caused sludge, or quickly failed and filled the crankcase with coolant, that was the main issue. Internet pictures of terribly sludged up 2.7's were mostly the result of coolant slowly leaking into and contaminating the oil, not necessarily lack of oil changes or inadequate PCV system.

Otherwise a jewel of an Engine in my opinion !!

Yours most likely had the newer style, problems arose when newer style water pumps were installed on the older engines without removing the separator plate.

Curious why your original water pump was replaced, and if it for some reason was the separator plate style ??

Can't comment on the Stop Block bolts but it seems you found the solution.

Thanks
Randy

 

[ImperialCrown]

I think that the biggest changes were to the water pump. It caused the most grief.
Machining-wise, I don't think there was that much that had to be changed:
The Chrysler 2.7 liter V6 engines

 

[Christopher]

All 2.7 blocks have the same 4663611 casting number.

The only block difference was from 2001 on, all blocks were slightly relieved, or clearanced at the bell housing area for starter clearance when used in the very rare manual transmission Sebring.

Randy

Guessing that would apply to manual transmission Stratus as well.

 

[Joshua Kramer]

Curious why your original water pump was replaced, and if it for some reason was the separator plate style ??

Thanks, Randy! I'll have to go take a look at the original pump to see if it is a separator plate style, as I haven't thrown it out yet.

Earlier this year I heard what I thought was timing chain noise. I figured I'd install the Stop Block "just in case". Then I found out I'd have to remove the tensioner to install the stop block, so I figured I'd just replace the tensioner as well. As I got under the car to start taking parts off, I noticed that the block was drenched with what looked like coolant; there was also coolant dripping off of the oil pan. The factory service manual said that the water pump usually does leak a little through the weep holes, but if there is a substantial amount of coolant residue on the block the pump needs replaced. I did not know if my water pump was actually leaking. However, the car has about 94,000 miles, and I still owe on it. I did not want to risk having to replace the engine, so I figured I would fix this issue the right way. The right way consisted of a new factory water pump, new factory tensioner, and stop block.

I'll tell you what, replacing the water pump on a 2.7 will definitely teach you patience, especially when it's in a transverse-mount car. When I graduated high school too many years ago, I spent 3 years working in a shop doing mostly electrical and engine work. During that time I did a number of head gaskets, valve jobs, transmission/clutch replacements, things of that nature. This 2.7 water pump job was much more complex than anything I had done before.

 

[GLHS60]

You are obviously very skilled if you performed the job your self!!

Sounds like your water pump was leaking at its seal as it was probably leaking out the weep holes.

The ones that caused all the problems didn't leak past the seal and out the weep holes, instead they leaked internally. Many were bone dry on the outside that were sludged up inside.

Stop block sounds interesting along with a new factory pump and gasket.

You will probably get many more miles and years out of your 2.7 jewel !!

My wife's 2001 Sebring sedan 2.7 never sludged up but at 180K I changed the pump, sparkplugs and thermostat as preventative maintenance. When it reached about 220K she bought a 2011 200 3.6 but kept the Sebring "just in case" as it was so economical and reliable. A couple of months later her nephew crashed his Intrepid so he got the Sebring and its still running perfectly at well over 300K!!

Thanks
Randy

 

[GLHS60]

Guessing that would apply to manual transmission Stratus as well.

Right, I forgot about the Stratus 2.7, 5 sp, some were 3.0L 5 sp. also.

Thanks
Randy

 

[ImperialCrown]

The domestic Sebring/Stratus 4-dr sedans are 2.7L. The DiamondStar Sebring/Stratus 2-dr coupes (and Eclipse) got the 3.0L.
The 2.4L 4-cyl in the DiamondStars is a different engine than the Chrysler 2.4L.
The 2.7L weep hole is out the left (drivers) side of the timing case. It should not weep at all.

 

[Joshua Kramer]

Well, in a previous life (late 1990's) I turned wrenches for a living. I did pretty much of everything with a healthy dose of engine work thrown in... head gaskets, valve jobs, etc. This 2.7 water pump by far is the most complex thing I've done. I was just VERY meticulous about everything, because I knew if I screwed something up I'd hear valves hitting pistons and that'd be the end of it. Every time I remove a part, I put all of its fasteners in an individual baggie and labelled it. I had no left over fasteners.

The stop block is a great idea and it actually saved my tail. It's a plastic part you install under the tensioner; if the tensioner collapses, the plastic part blocks the guide from retracting. I actually went through two of them before getting it right... you have to cut the stop block to size depending on how much your timing chain has stretched. The first two I cut too much off of. I almost said the heck with it and used that one, but then I thought to myself, no, I'm doing this the RIGHT way. It's good I did, too. Before first startup I primed the oil system by pulling the fuel pump relay and cranking for a minute. Then I tried to start for real. It didn't catch until about 2,000 RPM... and catch it did! With the noise it was making I thought for sure I had spun a bearing. But the noise stopped after about 3 seconds. I'm pretty sure that if the stop block had not been in placed and sized properly, I would have heard pistons hitting valves. I've heard of more than one do-it-yourselfer who started his 2.7 after this job only to have it skip a few teeth, and BOOM!

I had a 2001 Sedan with the 2.7 that I had bought brand new. I was kind of lax on the maintenance. When the car had around 48k miles on it, I heard about the sludge issue, and I started changing the oil every 3k on the dot with Mobil 1 full synthetic. What's interesting is that car developed a coolant leak that was not visible- it didn't drip but it consumed coolant. This started at around 60k miles. I drove that car until 170k miles. At that point the 2.7 was still running strong, but the power steering rack blew a gasket somewhere... it wasn't worth it to replace the rack, so I sold the car to a boneyard.

 

[Joshua Kramer]

The 2.7L weep hole is out the left (drivers) side of the timing case. It should not weep at all.

You'd think that, right? But according to the factory service manual, it is supposed to weep a little. If it weeps a lot, i.e. the engine block is coated in coolant (like mine was), then the pump needs replacing.

 

[Joshua Kramer]

You will probably get many more miles and years out of your 2.7 jewel !!

Maybe, and hopefully so. I got everything buttoned up, car ran well for the most part but there was a miss at idle. And to be fair, there has really always been a miss at idle, since I bought this car 2 years ago with 45k miles on it.

In any case, to make a long story short, I have a compression leak somewhere. Cylinders 1,2,4,5,6 all have about 130 pounds of compression. Cylinder 3 only has 60 pounds! I am hoping this is something in the top end, because R&R the cylinder head and having it sent out for a valve job is MUCH easier than pulling the whole engine and replacing with another one.

 

[Joshua Kramer]

Hey GHLS60, here's a question. The FSM states that spark plug holes on the 2.7 cannot be fixed via heli-coil, but others I've talked to say they can. I'd like to keep this car (and this engine lol) for another 100k miles. Do I need a reman head or can I heli-coil the spark plug holes?

 

[GLHS60]

I personally don't have any Experience but know its been successfully done.

Hopefully I.C. will have some input.

Please post results

Good Luck!!

Thanks
Randy

Link: '06 Sebring 2.7L Spark Plug Blew Out of Hole - Chrysler Forum - Chrysler Enthusiast Forums

 

[ImperialCrown]

Is it the #3 spark plug hole that is stripped? Is this the reason for the low compression or is it possible valve damage?
Is the spark plug hole simply cross-threaded (which may be tapped) or are the threads gone? Is the other cylinder bank OK?
Because of the depth of the spark plug cavities, you may want to remove the head for inspection and possible thread service. The service manual may recommend against heli-coiling the spark plug holes for a good reason (usually tight clearances). Have a head/engine machine shop examine the situation and advise you.
If it is something that they recommend a reman head replacement for, that would be the best way to go.

 

[Joshua Kramer]

Hey GLHS60, I have a question (and some results!!) for you. To make a long story short: there is something very, very bizarre wrong with this 2.7 V6. So I sent the head out, it was repaired, and I put everything back together. Started the car, and... the miss was back, and WORSE. Oddly this time it did not throw a Misfire CEL. But it still had the miss. So, I did a compression test again, and... 130 pounds all around except for #3, which was still at 60 pounds. Rats! I was able to do a wet compression test this time. When the cylinder is well oiled it holds 125 pounds. So this means that there's something wrong with the bottom half.

This does not make sense! I bought the car when it was 9 years old, and it had 45,000 miles. I had the oil changed with full synthetic every 3-4,000 miles. It now has 93,000 miles. What would cause one particular cylinder to develop compression leakage both at top and bottom when the other five cylinders are fine? I really don't have a big issue with tearing it back down and this time, replacing the piston and rings in that cylinder. However... I suspect that there are plugged oil passages that are starving the #3 cylinder of oil, which would cause the problem to re-occur down the road. Also, I don't want to spend hours to tear everything down to find out that the #3 cylinder is so out-of-round that it's not fixable. And I don't want to R&R the whole engine to replace with a used engine, though that seems the most time economical option at this point.

 

[GLHS60]

I applaud your tenacity Joshua!!

All I have is a guess as to low compression and agree that would be something with the rings in #3.

Whether the rings are stuck, worn or broken ring lands is purely speculation.

I don't believe you have any plugged oil passages but that's just my opinion.

I hope you find the time to pull the piston and post pictures.

Thanks
Randy

 

[Joshua Kramer]

Randy, if I pull the oil pan and the #3 connecting rod cap, is there enough clearance to get a snap gage in the cylinder? Or would the crank be in the way? If it is possible I would like to be able to spend a couple of hours inspecting the bottom half before I spend a lot more hours dis-assembling everything.

 

[GLHS60]

I can't say, its pretty tight, I'm assuming you want to measure the bore.

Normally not much wear at the bottom but you could examine it for scratches or gouges.

Thanks
Randy

 

[AC TC]

you can try to do a "wd-40 soak" on nr 3. Just fill it with wd-40 or something similar, let it sit over night.
- turn the Engine over a short time befóre putting the sparkplug back and start her up. ( to avoid hydrolock )
Sometimes if piston rings are cooked this will help, its actually standard precidiure on some SAAB models...
You will need to change the oil after this try.

 

[ImperialCrown]

When you had the head off, did you notice any difference in piston top appearance? If #3 looked 'cleaner' than #1 and #5?