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Discussion Starter #1
hey guys

I read somewhere that they changed the 2.7 after 01 and it cut the sludge problem down. what i wanna know is How safe is it to buy a 02 or newer 2.7 engine?? i found a few low milage 04 2.7 SEs that cought my eye but im scared after my 99 2.7 problems. anyone hear of the sludge problems on 01 and newer engines?
 

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I heard they changed the oil pickup tube and timing tensioners. But I still get emails frequently from people that want to swap their dead 2002 + 2.7 to the 3.5. My opinion is they are better, but not much than the 98-01. They still seem to have the timing chain and water pump issues.
 

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From what I've read the 02 to 04 2.7s are more reliable than the previous years but the sludge problem was never completely resolved. I would buy it just because of the new pickup tube and the PCV heat exchanger setup alone. If you use a good synthetic oil in there you should be good to go.
As with any purchase, I recommend you ask LOTS of questions first ... even better use the W word (Warranty that is ):grinyes:
 

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The 2001's also have the heat exchanger in the pcv. Thing is, if its pretty low miles then its a good time to buy. Figure its a 2004 so its only a couple years old, not a lot of time to beat it to death. Unless, it was a previous rental or fleet car that wasn't maintained.

As far as fixing the sudge issue, its kinda hard for DC to fix a problem that they won't acknowledge even exists! the heat exchanger is good to keep the vapors nice and hot so water vapor doesn't condense back into liquid. The older 2.7's can easily be retrofitted with them. Peva (who I haven't seen on here in a long time) retrofitted one to his '99 Corde. The water pump/timing chain issue, well not a whole hell of a lot can be done there. If they went with a timing BELT instead of CHAIN (like on the 3.2/3.5L) then there wouldn't be any issue. No matter what if the water pump starts to fail by either shaft seal or pump gasket, its gonna leak into the timing cavity and mix with oil. No matter how good they make the pumps, seals and gaskets, eventually they wear out and leak.

My '01 has a few clicks shy of 82K miles. I bought it 2 years ago May 14th with a tad over 48K miles on it. This last oil change I tried synthetic and I'm noticing a little bit of seepage at the back of the oil pan. To date the only issues my 2.7 has had were the oil light flicker, and I hear a sqeak from the belt area when I shut the motor off (I think the A/C idler is going), and the previous mentioned seepage. Its all about taking care of it. There's no substitute for good maintanence.
 

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I got 130k on my 2.7 im shooting for 200k give them a little love and attention and they are ok so ive found
 

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2000 es 2.7 autostick. 156,00 here. But that's KM's for me.
No problems, runnin' fine.
The autostick cars came with an engine oil cooler so it may help alleviate the high oil temp issue for me.
I wouldn't use the fact that there are less complaints about the later 2.7's than the earlier ones be a deciding factor as to engine design robustness. It could simply be that the newer engines haven't gotten enough time on them yet to expose thier weaknesses. If my 2.7 ever goes, I'll probably replace it with the same and enjoy the few extra mpg's the "smaller" engine gets (although the 3.2/5 sounds attractive from a power standpoint too.)

There's nothing wrong with a timing chain vice a belt. If you think back a little, pretty much every detroit engine cam with a chain. Belts are a relatively new thing. The problem with the 2.7 chain is it's length and DCX's method of controlling the chain slack. Oh yeah, zero clearance engine design makes a simple timing chain (or belt) failure a catestrophic event. I've had belts break on zero clearance engines and the end result is the same- junked engine. Long chains or belts are a nessesity of DOHC engines, the long chain/belt runs become a weak point as the slack and stretch is difficult to manange properly.

Cheers

BJ

Just some stuff for thought.

Cheers

BJ:anon:
 

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Discussion Starter #8
well coool i may see whats out there was lookin for a ES but my insurance would go upalso kinda like doing stuff to it so i would hate to get a fully loaded car and have nothing to do to it jsut scared of the 2.7 as that is the reason i need a new oen is Because of a 2.7
 

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Great White said:
It could simply be that the newer engines haven't gotten enough time on them yet to expose thier weaknesses
I was thinking along those lines as well. The "only time will tell" thoughts.

Great White said:
There's nothing wrong with a timing chain vice a belt. If you think back a little, pretty much every detroit engine cam with a chain. Belts are a relatively new thing. The problem with the 2.7 chain is it's length and DCX's method of controlling the chain slack. Oh yeah, zero clearance engine design makes a simple timing chain (or belt) failure a catestrophic event. I've had belts break on zero clearance engines and the end result is the same- junked engine. Long chains or belts are a nessesity of DOHC engines, the long chain/belt runs become a weak point as the slack and stretch is difficult to manange properly.
Just to clarify, I didn't mean there was anything wrong with using a timing chain. But agreed it is a long-ass chain! The issue I was pointing out with using a chain instead of a belt on an engine designed like this one, is the fact that the chain needs to be oiled and a belt doesn't. So in the case of using a timing belt, there is no oil in the timing case so if the water pump starts to leak, its not directly dumping into the oil supply. On the 2.7 however, since it uses a chain that has to be oiled and the pump is inside the timing case, well I think you can figure the rest.

Timing belts have been around for quite a number of years. The Ford 2.3L 4 cylinder that was in the 1980 Mustang I used to have had a timing belt. I'm sure there are more applications prior to 1980 that used a belt. But yeah, the 2.7 chain is practically long enough to jump rope with!
 

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Yup.
The main issue I see with the chain and the 2.7 is the length. Timing chains on the old v8's and such were relatively short and as such chain stretch was essentially a non issue (the nylon gears ususally went first). With the long chain on the 2.7 the "stretch" (actually it's the clearances opening up on each individual roller) becomes significant to the point where elaborate methods of compensating for it become nessesary. And it's not easily managed like a belt, sliders, guides and hydraulic/spring contraptions have all been tried in various combinations to varying degrees of success. The main advantage of a belt is that they have a comparitively low amount of stretch compared to a chain of the same length. And that stretch is easily managed with a pulley and tensioner. Belts also have a shock absorber effect between the irregular pulses of the crank and the drivetrain (an added bonus for valvetrain life).
I am in agreeance that coolant in the crankcase is a bad thing, roaches plain bearings post haste! I used to see this all the time when someone did a cam change on a 305 (cam eating monsters!) or changed an intake and didn't change the oil before sending the car out of the shop. Sure as shoot, it's was back within the month with either low oil pressure or rod knock.
So sure, putting the water pump where they put it didn't show alot of thought towards longevity. But of course, they were just concerned with getting it into a very small form factor and having it last beyond the warantee period. Sorry folks, they don't care about you, just your money.

Could a belt have solved these issues?
Maybe, but I don't really think so. Chrysler probably still would have put the pump were it is (see comments above) leaving at least one seal in the crankcase and people would still overdrive the recommended change interval on the belts. A non interference design engine is the best way to.........ahem.........idiot proof an engine against this type of abuse.

Bottom line:

do the maintenance, spend the big buck to change the parts at the recommended interval, or pay bigger bucks for an engine rebuild/replacement.

People may not want to accept it, but the 2.7 is a high performance engine. As such, it is pretty highly stressed and operating at the outer edge of it's design parameters.
Think about it: aluminum heads and block, DOHC, 4 valves per cylinder, combination windage tray/mains brace, 6 bolt mains, fuel injection, composite intake manifold, 200 hp from only 164 cid (if you think about it, if doubling displacement doubled hp, that would be 400hp from a 328cid. Getting into serious hp range there). All factory delivered, tuned to work, AND GET 28-35 MPG!!!!!!!
20 years ago this was big dollar race engine stuff!
You'd easily pay 30-60,000 just to build a small block with those features. If you could get it at all.
Stressed engines require alot of care and maintenance, not the best choice for a family vehicle, which are by their very nature, abused. People with family cars want to load up the fam and head out without the hassle of an engine that is very intolerant of lack of service. Power and technology extract a price, and it is maintenance.

I think the 2.7 is an awsome little engine, stuck in an application and platform (transverse front drive chryslers included) that is not complimentary for it. Has it got some issues? Sure. all cars and powertrains do. No matter what banner you want ot wave or how much people may espouse how great thier "brand x" or "brand y" car is/was.
Family cars should be built with proven "stone axe" reliable mechanicals, they are not the place to put leading edge technology.
That's why the Crown vics, Caprices, and slant six cars were such successes in thier days. Contemporary, but not ground breaking.

Anywho, I'm ranting now so I'll sign off.

Cheers

BJ:anon:
 

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Actually, DC has a few engines that have the water pump run off the timing belt. The 2.4L 4's (and I imagine the 2.0's since they are basically the same as the 2.4) are inside the timing case and run on the timing belt. Also, the 2.5L found in my wife's old Sebring had the water pump running on the timing belt. The 2.5L is actually a Mitsu motor (scaled down version of the 3.0L). So the design of running the water pump off the timing belt/chain isn't a new concept for the 2.7L.

BTW, good post, Great White.
 

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True, it is not a new configuration, as running a timing belt vice chain/gears is not new either. But if you look at the overall evolution of the internal combustion engine these designs are relatively new. Timing chains and external belt driven pumps were far more common even as these "newer designs" and configurations are now the norm.
Don't get me wrong, I think timing belts are far superior to chains for todays designs.
I do remember the I4 2.2/5 running the water pump off the timing belt also (I'm sure there were others but it's late and memory fails me at the monment). However, the I4 2.2/5 did not have a seal seperating coolant from the engine oil. The pump was in the water jacket on a housing mounted to the block. The achilles heel of the 2.7 water pump design is, as you mentioned, the shaft seal on the water pump (two on the 2.7 if I remember, double the chance for failure) which is the first and last defense against crankcase coolant contamination and the side loading of the shaft induced by the chain tensioning mechanism.

Cheers

BJ:anon:
 

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Even though we've seemed to hijack this thread, its a good conversation.

I talked about this in another thread awhile back. I haven't seen how the 2.7 pump is designed but my thoughts on the double seal are this. We know that there is a weep hole on the drivers side of the block, to let it be known the water pump is starting to leak. My thoughts are that this weep hole passage is located between the inner and outer shaft seals. When the inner starts to leak, it leaks out the weep hole. but hope that the inner starts leaking first, because if the outer seal is already shot when the inner seal starts leaking, you're pretty much f**ked.

Yes, using a timing belt/chain drive on a water pump puts lots of stress on it. Think of the rigors that the timing components go thru, especially if its really raced around. Hopefully, in the future, they could find an alternative setup, like an electric motor-belt driven water pump, or even a direct gear drive. However, the gear drive still poses some of the same issues as a timing chain, it needs to be oiled, and the thus the possibility for oil/coolant contamination in the event of failure.

Look back at a lot of Chevy motors, the 350 CI for instance. The timing chain on that is maybe big enough to fit your head thru. And where is the water pump? Externally located on the front of the block, driven off the accessory belt for the alternator and whatever else. And just like any water pump, it has weep holes on both top and bottom of the shaft, so when it starts to fail, it leaks out. But since the pump is externally mounted to the front of the block, there is no contamination issues. Maybe that design is one of the reasons why Chevy engines seem to last a lifetime? I used to have an '89 C1500 with a 4.3L V-6, which is very similar to a 350 in design, and actually shares the same bore and stroke as the 350, just 2 less cylinders. That motor had 174K miles on it when I bought it from the 2nd owner, and 221K miles on it when I traded it 4 years later. I did a timing chain on it, and the only other major work it needed in 4 years was a clutch. Like a typical Chevy, it blue smoked a little upon start up, but beyond that a good solid running motor. I'd like to see that kind of mileage out of my trep.
 

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froggy81500 said:
I was thinking along those lines as well. The "only time will tell" thoughts.



Just to clarify, I didn't mean there was anything wrong with using a timing chain. But agreed it is a long-ass chain! The issue I was pointing out with using a chain instead of a belt on an engine designed like this one, is the fact that the chain needs to be oiled and a belt doesn't. So in the case of using a timing belt, there is no oil in the timing case so if the water pump starts to leak, its not directly dumping into the oil supply. On the 2.7 however, since it uses a chain that has to be oiled and the pump is inside the timing case, well I think you can figure the rest.

Timing belts have been around for quite a number of years. The Ford 2.3L 4 cylinder that was in the 1980 Mustang I used to have had a timing belt. I'm sure there are more applications prior to 1980 that used a belt. But yeah, the 2.7 chain is practically long enough to jump rope with!
I agree with all of the above. But there is one more item to consider as well. The big timing chain plus the extra sprocket for the internal water pump adds an incredible amount of mechanical shear stress to the oil - additional shear that is not seen in an engine with a dry belt. This shear pulverizes the viscosity index polymers, making the oil thinner and thinner with increasing mileage on the oil. This can put the rod bearings at risk if the oil isn't changed soon enough. The oil in my 2.7 is sheared down to a 20 weight by 3000 miles when using dino (Castrol GTX) , and down to a 20 weight in about 4000 miles on synthetic (Group III oil, not Group IV PAO). The failed rod bearing sort of leads to the double whammy that is not experienced in other designs : severely thinned oil leads to eventual rod bearing failure; rod bearing failure leads to dramatic drop in oil pressure; drop in oil pressure causes the main timing chain tensioner to back off; main timing chain loses tension, skips a few teeth on the sprockets and the valves smack the pistons. Result : trashed engine.

Plus, the chain and sprockets expose the oil to significant additional aeration, which leads to more rapid oxidation. Oxidation of the oil is the pathway to sludge formation, which is further accelerated in this engine because of the higher than normal internal temperatures found in the 2.7. All of this makes a strong case for using Group IV or Group V full synthetic oil in this engine. Also note that the thermostat on this engine is at the INLET to water pump, while on most cars it is on the outlet from the engine. Typical exit water temperatures (to the rad) on the 2.7 are around 110 deg C (230F) even though the thermostat is 82C (180 F). Other engines with 190 F thermostats have exit water temps (to the rad) controlled to around 190F - damn near 40 F degrees cooler than a 2.7. If the bulk water leaving the engine is 230 F, imagine the temperature on the surface of the heads that the oil sees !

These are the reasons the 2.7 is so sludge prone. But proper use of synthetic oil and maintaining the PCV valve/hoses/heat exchanger will pretty much negate all of it.

The 2.7L is not the only engine in production that suffers from sludge. There are others too.

Phil
 

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I
Plus, the chain and sprockets expose the oil to significant additional aeration, which leads to more rapid oxidation. Oxidation of the oil is the pathway to sludge formation, which is further accelerated in this engine because of the higher than normal internal temperatures found in the 2.7.

These are the reasons the 2.7 is so sludge prone. But proper use of synthetic oil and maintaining the PCV valve/hoses/heat exchanger will pretty much negate all of it.

The 2.7L is not the only engine in production that suffers from sludge. There are others too.
Phil
This got me thinking about my other car, an 86 Porsche 911 with a 3.2 engine, that also has two large double row timing chains on cam, intermediate shaft and tensioner sprockets that also exposes the oil to significant aeration, shear and high temperature ( remember, these are air cooled and run much hotter than water cooled engines) but these engines have never had an oil sludging problem. Why?

I think it has to do with the oxidation issue. 911's do not have a PCV valve, only an outdated crankcase vent sysem and the blowby gases inside the 911 crankcase are oxygen depleted since they are products of combustion that have made it passed the rings or valve guides.

The Intrepid 2.7, on the other hand, has it's crankcase bathed in an oxygen rich environment created by a PCV valve system that is constantly drawing fresh air through the vent hose on the passenger side valve cover which, I believe, is a receipe for disaster that may be at the root of the sludging problem.

Therefore, if you wanted to create the same oxygen depleted environment inside a 2.7 crankcase to eliminate oil sludging, all you need to do is plug up the PCV valve and allow the blowby gases to escape through the crankcase vent hose without introducing any oxygen rich fresh air, just like a 911 system.

Make sense?


Cheers,

Joe
 

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DOnt matter which year, Dont drive it liike you stole it, and keep up with maintainance and you shud be good, they dont like to be driven ruff, keep that in mind and u will be Ok
 

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Holy Old Post Batman!!!


That oil aeration issue is very interesting.

Next question, is the 2.7 in the LX platforms any better? I saw one at my local yard, and they pretty much reconfigured everything in the engine bay. The other thing that got me wondering was that whole "Lifetime Warranty" thing they had going on.
 
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