I have a shot to buy two former police cars. A good friend of mine is one of the officers that drove them and I know what problems to expect from each car. One is a crown vic, the other a 2010 Hemi Charger with MDS. AKA cylinder deactivation. Plenty of horror stories of lifters eating cams but I can't figure out how common this is or what exactly causes it, seems that these cars are very sensitive to oil and need 5w20 to engage MDS smoothly. This car circled a 1 square mile town for 8 years and likely never really got into MDS much as there is no where to even get above 35-40 in it's turf. Maybe this is a good thing for the car, maybe not. I'm expecting it will go cheap because it has some issues that will turn off buyers. The Charger is the one I want, and my cop buddy seems pretty sure that I would like it because it was a very strong runner.
Hemi MDS issues are how common?
- Thread starter Gasbuggy
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I had 105k on mine with no real issues beyond the broken manifold stud problem. But my other buddy had his eat a cam lobe at about 150k, and another on the page had one fail at around 80k. My buddies is driven hard, the 80k one idled a lot.
It happens, but not very common considering how many of these engines are in use. The MSDS in the Hemi Charger will work with oils other than 5W20 too.
Oh another thing... everyone (I may have a Mopar obsession and follow/am a part of more FB groups and pages than I care to admit) has said it started out as a misfire under heavy or wide open throttle acceleration.
Zee09
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I had a 09 RT and to me the MDS ruined the driving experience.
Loved the car but it felt like a real bad case of turbo lag.
That killed it for me.
Loved the car but it felt like a real bad case of turbo lag.
That killed it for me.
I have been a mod in a popular hemi forum for over 10 years. IME the Hemi enjoys fabulous reliability, especially since it is in so many different types of vehicles.
FWIW our 14 at 80k miles runs fantastic and if it didn't have a light on the dash you would never know about eco mode!
FWIW our 14 at 80k miles runs fantastic and if it didn't have a light on the dash you would never know about eco mode!
My Hemi Ram 1500 has 205k on it now with MDS. No problems no oit use. GREAT truck.
OVERKILL
$100 Site Donor 2021
Originally Posted by Gasbuggy
I have a shot to buy two former police cars. A good friend of mine is one of the officers that drove them and I know what problems to expect from each car. One is a crown vic, the other a 2010 Hemi Charger with MDS. AKA cylinder deactivation. Plenty of horror stories of lifters eating cams but I can't figure out how common this is or what exactly causes it, seems that these cars are very sensitive to oil and need 5w20 to engage MDS smoothly.
The Charger is going to run circles around the Crown Vic and the Vic is just as likely to eat its timing chain guides as the HEMI is to munch a lifter.
Regarding MDS, the same MDS system is used in the SRT's that spec 0w-40, so no, they don't need 5w-20 to engage the MDS smoothly. Former user Clevy ran 0w-40 in his Charger R/T and was successfully able to get a CEL when it was like -35C for viscosity being out of spec, but otherwise the ECM didn't seem to know the difference. Lots of folks running 5w-30 too.
Originally Posted by Gasbuggy
This car circled a 1 square mile town for 8 years and likely never really got into MDS much as there is no where to even get above 35-40 in it's turf. Maybe this is a good thing for the car, maybe not. I'm expecting it will go cheap because it has some issues that will turn off buyers. The Charger is the one I want, and my cop buddy seems pretty sure that I would like it because it was a very strong runner.
The MDS doesn't require significant speed to engage, simply a light touch on the pedal. We've owned three HEMI's now and all of them would readily engage in-town whenever you were light enough on the gas (driving normally). Drive with enthusiasm and it stays out of your way.
I have a shot to buy two former police cars. A good friend of mine is one of the officers that drove them and I know what problems to expect from each car. One is a crown vic, the other a 2010 Hemi Charger with MDS. AKA cylinder deactivation. Plenty of horror stories of lifters eating cams but I can't figure out how common this is or what exactly causes it, seems that these cars are very sensitive to oil and need 5w20 to engage MDS smoothly.
The Charger is going to run circles around the Crown Vic and the Vic is just as likely to eat its timing chain guides as the HEMI is to munch a lifter.
Regarding MDS, the same MDS system is used in the SRT's that spec 0w-40, so no, they don't need 5w-20 to engage the MDS smoothly. Former user Clevy ran 0w-40 in his Charger R/T and was successfully able to get a CEL when it was like -35C for viscosity being out of spec, but otherwise the ECM didn't seem to know the difference. Lots of folks running 5w-30 too.
Originally Posted by Gasbuggy
This car circled a 1 square mile town for 8 years and likely never really got into MDS much as there is no where to even get above 35-40 in it's turf. Maybe this is a good thing for the car, maybe not. I'm expecting it will go cheap because it has some issues that will turn off buyers. The Charger is the one I want, and my cop buddy seems pretty sure that I would like it because it was a very strong runner.
The MDS doesn't require significant speed to engage, simply a light touch on the pedal. We've owned three HEMI's now and all of them would readily engage in-town whenever you were light enough on the gas (driving normally). Drive with enthusiasm and it stays out of your way.
for those that have had the exhaust manifold bolts replaced, what kind of cost out of pocket did you incur?
Dad has a 2013 Grand Cherokee Hemi with 130,000 miles. MDS works flawlessly, I can't even notice it besides the "ECO" dash light. I've run 5w30 synthetic in it since it was new, and it gets driven hard.
I've had two Hemi's, a 2005 Magnum RT with MDS and a 2012 Challenger SRT8 manual trans (no MDS). On the Magnum I ran headers, Borla exhaust, intake, and a tune. I put over 100,000 trouble free miles on the engine. The non-MDS SRT8 was trouble free as well. I know a lot people like to bad mouth Chrysler products, but both of mine were great cars.
I just had the one Hemi in my old 2011 1500. We never had any MDS related issues up until the point we traded it in. Approx. 150,000km or less. It was fed 5w20 and run hard. We had one warped exhaust manifold changed and gasket on the other bank done under warranty. I have a buddy that runs a 2010 1500 that did the exhaust manifolds himself outside warranty. It was not fun but he managed. Another friend of mine, who is a mechanic bad mouths the Hemi as he apparently sees quite a few with the cams self destructing.
LE cars are usually run hard and if they are still kicking when taken out of service, its a good indicator that the car is just fine.
LE cars are usually run hard and if they are still kicking when taken out of service, its a good indicator that the car is just fine.
My 300C has 175k and no issues here. It has the hemi tick but that's another topic. I do agree the MDS in the first gen motors doesn't engage as smoothly as the later ones. It's not noticeable at low speeds but cruising when I floor it theres just a ever so slight hesitation. With the MDS off it's a rocket. Just buy the Charger, you won't be disappointed!
While the MDS system gets the wrap for the whole seized-lifter-eats-a-cam-lobe thing, there is some evidence that it is not a causation relationship. There have been non-MDS engines that had a lifter seize and chew up the cam, and there have been MDS engines that had one of the non-MDS lifters in it seize up and bork the camshaft. I think the fact that so many of the Hemi engines have MDS makes it look like there is more of a connection between it and the problem than there really is.
From what I have been able to gather, there is no real sure-fire way to avoid it. It's truly luck of the draw. However, if desired, the MDS function can be disabled, but you will need to purchase a tuner to be able to do it. That is what I have done with mine. I leave it off because I dislike how it engages at slow speeds, not to mention how it sounds when it is engaged. But if I ever take another trip to Atlanta, I will use my tuner to enable it again to get the gas mileage it affords.
From what I have been able to gather, there is no real sure-fire way to avoid it. It's truly luck of the draw. However, if desired, the MDS function can be disabled, but you will need to purchase a tuner to be able to do it. That is what I have done with mine. I leave it off because I dislike how it engages at slow speeds, not to mention how it sounds when it is engaged. But if I ever take another trip to Atlanta, I will use my tuner to enable it again to get the gas mileage it affords.
The Crown Vic 4.6L will last another hundred years without any real issues, other than electric fans and the normal cracking plastic intake manifold. My last 2011 CV was retired at a tick under 150k miles and went through 4 fans, an intake manifold and some a/c stuff, and that was it. Zero issues.
You can buy a cheap used tuner and program the Hemi and disable the MDS. You'll get 15-20 more HP, a more sensitive throttle and often times, better mileage. The 5.7 will eat that 4.6 alive all day long and twice on sundays.
Good luck with either choice.
You can buy a cheap used tuner and program the Hemi and disable the MDS. You'll get 15-20 more HP, a more sensitive throttle and often times, better mileage. The 5.7 will eat that 4.6 alive all day long and twice on sundays.
Good luck with either choice.
Hemi camshaft lobe/lifter failures are not exclusive to MDS equipped engines....Just like LSx camshaft lobe/lifter failures are not exclusive to AFM equipped engines.
Chrysler started using SADI (Selectively Austempered Ductile Iron) camshafts in the Hemi right about the time MDS came out. I believe this surface hardened soft material is the root cause of Hemi Cam/Lifter failures.
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
Chrysler started using SADI (Selectively Austempered Ductile Iron) camshafts in the Hemi right about the time MDS came out. I believe this surface hardened soft material is the root cause of Hemi Cam/Lifter failures.
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
OVERKILL
$100 Site Donor 2021
Originally Posted by clinebarger
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
Sounds like the Ford Modular camshafts, which are produced in this manner.
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
Sounds like the Ford Modular camshafts, which are produced in this manner.
Originally Posted by OVERKILL
Originally Posted by clinebarger
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
Sounds like the Ford Modular camshafts, which are produced in this manner.
Ford can get away with it, their cams barely lift those valves
Originally Posted by clinebarger
Before that they used 5150 steel lobes which is the industry standard for roller camshafts & even then they used a cost cutting measure while manufacturing them.....The Lobes & Journals where pressed on a 5150 steel tube. I've seen a few isolated instances of a Lobe coming loose.
Sounds like the Ford Modular camshafts, which are produced in this manner.
Ford can get away with it, their cams barely lift those valves
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