111 replies to this topic

[Jay6spdRT]

http://www.challenge...ht=timing chain

read thru the topic, and embrace the BS from the dealer

No loaners available. Wrong! One of the members gives him the special number to call Chrysler about that.

No one has looked at the car yet.... but the owner goes to the bay to get some items from the car and finds the engine dismantled.

No damage to the pistons or rods... but the valves are bent to shit. So I assume the pistons hit them... hard. Hmmm, I think I would be worried about pistons and rods.

Apparently, the cars this has happened to are almost entirely autos with MDS enabled. Seems like it's happened in a few cars when they're driving at 70-75 mph on expressways. Some are theorizing it's related to the MDS cycling on and off.

Interesting.


BTW, what's with the archived topics? Is that something new? I wanted to add this to a topic already started about clearance, and it says the topic is "archived" and can't be updated, even though it's only a month or so old.

[StevoHemi]

I saw that thing about the archive too. I think that if there is no activity within a thread for 30 days, it will get locked up? Just thinking out loud here. I may be wrong.

Alan... Alan... Alan...

If it is the MDS causing the breakage, I got a remedy for that!

Install a Maggie! Maggies and MDS don't get along at all! In order to run with a Maggie, you gotta turn off the MDS. Driving back from Kentucky a few weeks ago, while cruising at 73 mph, my Maggie RT averaged 24.4 mpg!!!!

Stevo

[sharkcohen]

http://www.challenge...ht=timing chain

read thru the topic, and embrace the BS from the dealer

No loaners available. Wrong! One of the members gives him the special number to call Chrysler about that.

No one has looked at the car yet.... but the owner goes to the bay to get some items from the car and finds the engine dismantled.

No damage to the pistons or rods... but the valves are bent to shit. So I assume the pistons hit them... hard. Hmmm, I think I would be worried about pistons and rods.

Apparently, the cars this has happened to are almost entirely autos with MDS enabled. Seems like it's happened in a few cars when they're driving at 70-75 mph on expressways. Some are theorizing it's related to the MDS cycling on and off.

Interesting.


BTW, what's with the archived topics? Is that something new? I wanted to add this to a topic already started about clearance, and it says the topic is "archived" and can't be updated, even though it's only a month or so old.

I believe the 2010 in my neighborhood that had its timing chain break is a manual.

[Dale]

Well shit...I need to turn MDS off again with my predator, I just hit 7000 miles and still under warranty.

[70Barracuda]

I turned mine off with the predator as I prefer driving it as a V8 all the time. You can get rid of MDS permenantly by pulling the cylinder deactivation solenoids and replacing them with blockoff plugs, although it would of course require a good bit more work.

[stevert]

I will let you know if I fucking blow up driving down to pettys and arringtons on saturday. my MSD is de-activated with my maggie, I am just praying I dont end up on a highway in Ohio at 4am,,,,

[BACNBLK]

I read that earlier over there.
My MDS has been off for 2.5 years. So if that's what's causing it 'm good to go.




Joe

[Jay6spdRT]

How many miles do you have on your car, Joe?

[chris1992]

I've never disabled MDS and I have over 76k on my R/T.. But now that I've seen so many people have the problem, I may turn it off once I buy a trinity

[Dookie]

I cant see how MDS would be causing this, from my understanding, the only thing MDS solenoids do is trigger a the PCM to cut off injectors at a given parameter, to given cylinders (4 of them). Hows is the timing chain effected here?

[BillsRT]

It also cuts oil pressure to the valves on those cylinders .

[BlackVoodoo]

I've talked to Chris about my concerns if MDS engaging/disabling put a sudden shock on the timing chain. Tonight when I get home I'm disabling my MDS. Screw saving 2mpg I wanna save my engine.

[BillsRT]

Wish i could on mine

[chris1992]

I personally believe, if it is the MDS, that it is when you begin to go up a steep hill. MDS struggles to stay on, but will eventually turn off, causing a big shock to the timing chain

[Jay6spdRT]

I don't know.... some are considering it to be an auto problem... but.... Shark said he knew of a six-speed with the timing chain issue.

I would like to know if the timing chain part number changed for 2011 or 2012. That would indicate that Dodge was aware of a deficiency.

Also, whether or not the timing chain is the same part number for the MDS engine vs the non-MDS.

Who knows? maybe there was just a bad-batch of timing chains that made it to the factory. I'd like to know the build-dates on the cars involved too.

[BACNBLK]

How many miles do you have on your car, Joe?

You really want to know Jim? ..... a little over 19,000 in three years

I have had only 1 timing chain ever break in my life on any car. My 1970 W-31.


The chain guides are some sort of plastic on our rides. There has been talk of that also may be a problem. Who knows....

Some one posted pics up on the Z a while ago of the 5.7 chain compared to the 6.1. If I remember right a big difference.



Joe

[Speedy]

I've not heard of a single 6 speed having the problem. Shark needs to confirm the one he thinks he saw.

That leaves the common denominator the MDS. I've not looked over the actual mechanics behind how it's setup, but if half the cylinders are not firing, then the one bank that is carries the load of the side that isn't. From a timing of the engine perspective, I can see how that could put stress on the timing chain as the pistons and valves still have to be kept in unison, even though it's an unbalanced firing of the cylinders.

[AFDoc]

As I understand MDS, or any cylinder deactivation, the cylinders are deactivated is a set order so that 1) all the cylinders are deactivated equally and 2) there is no side to side imbalance. On a V-8, this sequence naturally keeps the engine "balanced." On my V-6 Honda pilot, since 3 are deactivated in sequence, there is a back and forth imbalance that is not supposed to be harmful to the engine but does set up a harmonic. They've tuned the subwoofer to put out the same frequency, 180 degrees out of sync (even when the radio is off) to cancel out the sound.

[Jay6spdRT]

Somebody should ask MC88 about this over at CT..... since he's such 'insider support'. lmfao