Who runs with their MDS off?

[Burla]

For the first seven years or so I drove with MDS off to cure transmission shudders I was having in low rpm's, th fixed shudder no issues no MDS 7 years. Once I went to c+ in rfe no more shudder I don't bother shutting it off now 8 years no problems.

 

[Dave2015Hemi]

The wrist pin / piston squirters they use in the 6.1's / 6.2's and 6.4's could easily be reconfigured to spray oil onto the cam lobes

So why has nobody done it?

 

[Wild one]

So why has nobody done it?

Probably because the majority of the racing world removes them,but they also go through the engine a couple times a season,and alot of those guys have made the necessary mods to successfully run the Johnson lifters
The Mopar world is probably about 10 years behind the GM and Ford world when it comes to development of racing parts
There's probably not a big market for them either,as the average owner isn't going to pull the engine and take it apart and machine in the holes required to adapt a squirter to spray oil onto the cam

 

[Dave2015Hemi]

Probably because the majority of the racing world removes them,but they also go through the engine a couple times a season,lol.
The Mopar world is probably about 10 years behind the GM and Ford world when it comes to development of racing parts

You would think someone would have had a awesome fix for the lifter issue after all this time. Sadly many dealers and repair shops don't even know some of the things I've learned here like the flattening of the exhaust manifolds. They keep replacing them with new ones and they warp again and again.

 

[Wild one]

You would think someone would have had a awesome fix for the lifter issue after all this time. Sadly many dealers and repair shops don't even know some of the things I've learned here like the flattening of the exhaust manifolds. They keep replacing them with new ones and they warp again and again.

There's always the Johnson lifters,but to run them you'll want a high volumn pump,custom length pushrods etc,and that's usually beyond the scope of what the average owner wants to do,or spend.
Realistically the amount of hemi cam failures is only a drop in the bucket compared to the amount of hemi engines that are on the road.It might seem like alot on the forums and facebook pages,but in reality it isn't,when you look at how many of the engines that are on the road with no issues.
You only hear of the owners with cam issues,you never hear from the millions of owners that don't have any issues

 

[Wild one]

Well ain't that co!nd!nkyd!nk i just mentioned Rogers block off plugs earlier,and i go onto facebook,and the first thing that pops up is Rogers ad,lol

hemi performance talk​

Roger Stanke · 8h ·

Billet Reusable Gen 3 MDS Plugs 4/pk $99.00 www.stankemotorsports.com (651)481-9612

 

[Fnjoey]

Reading a lot about pros/cons of the MDS. I honestly don't see that it gives you THAT much of a MPG boost, and it just seems like it could be one more thing that could go wrong. The idea of all of your cylinders not firing and aging together seems sort of . . . . . potentially bad.

Also, I'm finding where I don't even like having the auto on/off ignition running, either.

I usually run mine on all tge time only because I forget to turn it off.. I did at one point drive a month with it off just to compare and I didn't really gain any mpg. Now once in a while I drive like a grandpa for too long and my truck memorizes that driving so I kick it off for a couple of days to bring it back to my normal driving style.

 

[greywolf2112]

Thanks, guys - I'm going to leave well enough alone for now and stop obsessing and worrying so much about these things - I never used to, but one blown transmission in my Expedition (72,500 miles) has me paranoid about . . . . well, everything when it comes to my vehicles now, LOL.

 

[Tulecreeper]

I disengage the MDS when driving around town because I don't like the feel of the throttle when it kicks on and off every couple minutes. When I'm at 50 MPH or above and know I'll be staying there for a couple miles or more, I'll go ahead and let it do it's thing.

 

[Dave2015Hemi]

So how do you turn the idle up to 900rpm? I'm going to look at a 2016 Sport Express Saturday with 96,000 on it and it looks perfect and has good records but I'm hoping when I hear it start cold there is no tick. Exhaust bolts have been replaced it said but no mention of new ones or which side. If I end up getting it I'd like to turn the idle up to 900rpm to help out. I'm also curious if I will hear the MDS kick in or not.

 

[Wild one]

So how do you turn the idle up to 900rpm? I'm going to look at a 2016 Sport Express Saturday with 96,000 on it and it looks perfect and has good records but I'm hoping when I hear it start cold there is no tick. Exhaust bolts have been replaced it said but no mention of new ones or which side. If I end up getting it I'd like to turn the idle up to 900rpm to help out. I'm also curious if I will hear the MDS kick in or not.

900 might be a bit high,as it'll want to push through the brakes at a light, about 800 would be as high as i'd go.The only way to up the idle rpm is to use a tuner to increase the idle rpm

 

[WSix]

I shut mine off as the drone it creates bothers me.

 

[stevieb92]

900 might be a bit high,as it'll want to push through the brakes at a light, about 800 would be as high as i'd go.The only way to up the idle rpm is to use a tuner to increase the idle rpm

Which tuner?

 

[JF19Longhorn]

Mine never goes into MDS mode at Hwy speeds.. I'd need a strong tail wind and a long down hill slope to get it to kick on. Under 50mph it'll kick on sometimes and I let it do it's thing.

Only time I disable it (+/- buttons on the steering wheel) is when the truck is cold. I'll wait till she's has some heat in the motor before I'll reenable it.

 

[mikeru]

Mine never goes into MDS mode at Hwy speeds.. I'd need a strong tail wind and a long down hill slope to get it to kick on. Under 50mph it'll kick on sometimes and I let it do it's thing.

Only time I disable it (+/- buttons on the steering wheel) is when the truck is cold. I'll wait till she's has some heat in the motor before I'll reenable it.

If you're fine with MDS letting it "do it's thing", you really don't need to disable it when the truck is cold. Oil and coolant temperature are two of the parameters that must be met before MDS will enable. Coolant temp needs to be at least 158 degrees and oil temp needs to be at least 120 degrees before MDS will enable.

 

[NCRaineman]

When driving around town, hauling or towing I use the minus button on the wheel to manually select 8th gear, which keeps MDS off. Here in the foothills of Appalachia there isn't a lot of flat ground, so MDS constantly kicks on and off... annoying. If I'm doing a highway run I'll set the cruise to 72 and let the MDS do it's thing. Most of the semis around here are governed at 70 so if you cruise just a hair faster than that they won't pass you. Gets pretty good mileage like that.

 

[GTyankee]

GreyWolf2112

I had a friend that owned an Expedition
He kept going through transmissions

Ford replaced the First transmission & would not do it a 2nd time.

So he went to one of the larger chain type transmission stores to get it rebuilt.
They rebuilt it once & less than a year later, it was going out again.

That chain type shop said that they would not touch it a second time.

He asked what could possibly be causing that particular vehicle to go through transmissions that often.

He rode motorcycle, so his wife & 2 children were the only occupants.
The Transmission mechanic told him that FORD put a piece of crap Mustang 2 transmission in a extra heavy gas guzzler & they would continue to do that, until they went through all those transmissions that they had in Inventory

 

[greywolf2112]

GreyWolf2112

I had a friend that owned an Expedition
He kept going through transmissions

Ford replaced the First transmission & would not do it a 2nd time.

So he went to one of the larger chain type transmission stores to get it rebuilt.
They rebuilt it once & less than a year later, it was going out again.

That chain type shop said that they would not touch it a second time.

He asked what could possibly be causing that particular vehicle to go through transmissions that often.

He rode motorcycle, so his wife & 2 children were the only occupants.
The Transmission mechanic told him that FORD put a piece of crap Mustang 2 transmission in a extra heavy gas guzzler & they would continue to do that, until they went through all those transmissions that they had in Inventory

Yikes - I hope that's not the case for my Expedition!

 

[DanAR]

Mine never goes into MDS mode at Hwy speeds.. I'd need a strong tail wind and a long down hill slope to get it to kick on. Under 50mph it'll kick on sometimes and I let it do it's thing.

Only time I disable it (+/- buttons on the steering wheel) is when the truck is cold. I'll wait till she's has some heat in the motor before I'll reenable it.

That’s how my 23 seems to behave. To be honest I have never perceived any motion, jerk, noise, change in exhaust note, drone - nothing other than the ECO light appearing on mine. It’s completely transparent to me. I didn’t understand the truck even had it for the first few months after I bought it - and the I realized from the forum it did.

 

[ffeschjeff]

You nailed it Rick. On 4th gens, the eco light comes on any time the truck sees that you're driving economically, and is not directly tied to MDS. On 5th gens the eco light is directly tied to MDS.
The fact that Dan's eco light does come on tells me that the system is working. There are very specific conditions that all must be met for MDS to activate. It's likely that at least one of the following are not met when you're at 70/75 mph:

The PCM will activate the 4-cylinder mode when the following conditions are met:

* Low engine load

* 1200 to 3000 rpm

* Vehicle speed between 12 mph and 90 mph

* Battery voltage from 9 volts to 15 volts

* Oil pressure from 15 psi to 147 psi

* Oil temperature greater than 120 F

* Engine coolant temperature from 158 to 248 F

* Ambient temperature from 14 F to 248 F

* No throttle position sensor or MDS faults


Since "Low engine load" isn't really defined and is not easily measured by the driver, it's difficult to determine if that's why yours doesn't activate on the interstate.

So is it possible to change the speed at which MDS is allowed to turn on? say 35mph?