MOTORTREND: Hemi Engine Autopsy: 235,000-Mile 5.7L Out of a 2011 Challenger

[OVERKILL]

Also, the first time I've ever seen anyone comment with authority that a simple oil viscosity difference could cause a serious issue in an engine.

"A common problem is for the locking pin in an MDS lifter to not engage or disengage from the plunger, often the result of using an oil viscosity heavier than the specified 5W30 synthetic. When this happens, the loose roller tappet hammers and bounces on the cam lobe at high speed when it's supposed to be solidly engaged. The initial failure cascades until the needle bearings in the lifter cause the roller to lock up, at which time the affected cam lobe wears away. The valve seats and valves also pay a price when this happens."

And that whole statement is a load of nonsense.

1. The 0w-40 and 5w-20 lifters are identical as are the rest of the valvetrain components.
2. Lifter failure of the same variety has happened on engines without MDS... shocking!
3. The camshaft doesn't magically change when MDS is engaged, the inside of the lifter unlocks from the outside, the outside continues to follow the lobe profile, but the inside compresses and decompresses the spring that's inside the unit. The lifter is never "loose", there is always spring pressure, either from the pushrod and valvespring or from the internal spring. It is the removal of oil pressure that results in the pins re-engaging on the next cycle, locking the inside and outside together.

I'm not sure what they think happens, that the lifter takes a break from riding the cam when MDS is on but if you use 5w-40, it flails away on the cam lobe while maintaining contact with nothing?

Man, the number of bad takes on this is incredible!

 

[OVERKILL]

I believe the 0W-40 specced Hemis don't have the MDS system, however.

Yes they do, I've owned four of them.

 

[Scuder]

Yes they do, I've owned four of them.

You're right. My cousin's SRT Challenger and my son in law's truck both have manual transmissions. Both spec 0W-40, and neither have MDS. Not realizing it could be manual/automatic dependant, I wrongly assumed none did.

 

[Jetronic]

Meh, Dodge themselves is being praised for their well-wearing engine. The dealer, well, I'm sure whatever tech did that lousy work 169K miles ago has moved on.

All that said, I'm pretty sure that the article is wrong and this vehicle calls for 5W-20, not that it matters. I'm guessing 5W-30 is better for this engine and since similar Hemis call for 0W-40, that would be fine too - so thicker oil isn't the problem here IMO - although I'm sure there's someone out there putting conventional 20W-50 in their Hemi and I definitely wouldn't wanna be the next owner of that one!

How thick is the 5W-20 or 5W-340 at -25F? Is that damaging? It should be...

How thick is 20W-50 at 10F?

If higher viscosity oil is damaging these engines, they should come with a pre-heater as even 5w-20 gets as thick as syrup when it's cold enough.

 

[Jetronic]

The bent dowel likely happened when the timing chain guide broke & took the chain out... Not much of a way for the "Technician" to do that. Of coarse it should have been caught when the cam gear was off replacing the timing components.

Using abrasive disc's is a BIG no no.....But some mechanics can't break the habit even though every auto/engine manufacturer warns against it.

I've seen them use this and wire brushes on transmission halves... and afterwards they leaked. Tried to explain the wire brush was harder than the aluminium cover asnd so a dangerous practice but no avail. I scraped old gasket off and never had one leak afterwards.

 

[OVERKILL]

You're right. My cousin's SRT Challenger and my son in law's truck both have manual transmissions. Both spec 0W-40, and neither have MDS. Not realizing it could be manual/automatic dependant, I wrongly assumed none did.

Yup, the manual trans 6.4L SRT's didn't get MDS, nor did anything with the supercharged 6.2L (Hellkitty and derivatives).

 

[kschachn]

How thick is the 5W-20 or 5W-340 at -25F? Is that damaging? It should be...

How thick is 20W-50 at 10F?

If higher viscosity oil is damaging these engines, they should come with a pre-heater as even 5w-20 gets as thick as syrup when it's cold enough.

Actually no it should not be. That temperature is within the pumping limit for an oil with a 5W winter rating.

 

[JustinH]

Do most manufacturer's have dealer techs service headgaskets in this manner? Or do they just ship a longblock and do the work off site?

I remember talking to a Hyundai tech, and he said they mostly get a refurbished motor and drop it in.

I don't think a dealer tech is equipped to do the headgasket, when parts need to go to a machine shop and milled with precision, not a rotary pad.

 

[The Critic]

Do most manufacturer's have dealer techs service headgaskets in this manner? Or do they just ship a longblock and do the work off site?

I remember talking to a Hyundai tech, and he said they mostly get a refurbished motor and drop it in.

I don't think a dealer tech is equipped to do the headgasket, when parts need to go to a machine shop and milled with precision, not a rotary pad.

Most OEM's do not approve of machine shop work for warranty repairs. It is either reuse (if serviceable), or replace with a bare head and assemble on-site.

Dealer techs regularly perform major engine repairs. For example, Toyota does not sell any complete or long block engines; it is short block only and you must build your own.

 

[ls1mike]

Yup, having a daily driver that turns 13 second 1/4 miles is simply joyful.

13 get out of here with that.

 

[Scuder]

13 get out of here with that.

Yeah, 40 years ago, in my early twenties, my only car was a 440 6-pack Super Bee.
I've had 13 second cars since, including my Barracuda presently (13.99 still counts!). But, no daily driver. To own one today would require giving up the Barracuda to maintain domestic tranquility.

 

[jhs914]

You're right. My cousin's SRT Challenger and my son in law's truck both have manual transmissions. Both spec 0W-40, and neither have MDS. Not realizing it could be manual/automatic dependant, I wrongly assumed none did.

Manual 392 SRT Hemi's did not have MDS. Automatics did. I had a 2012 SRT8 392 Challenger six-speed manual----no MDS.

 

[Silver]

Somebody should tell Johnny Bumpkins he can save money by doing his own oil changes. One might think an automotive journalist would know this. Since his tech articles often consisted of taking parts supplied by advertisers to a shop and documenting their installation, an argument could be made he doesn't have the skills required to change his wife's oil.

I wouldn't do my own oil changes to save money. As long as I'm ok financially, it's not worth the trouble and I'm going to assume this guy had a decent salary.

I would, and do, change my own oil because I don't trust anyone else.

 

[Jarlaxle]

Meh, Dodge themselves is being praised for their well-wearing engine. The dealer, well, I'm sure whatever tech did that lousy work 169K miles ago has moved on.

All that said, I'm pretty sure that the article is wrong and this vehicle calls for 5W-20, not that it matters. I'm guessing 5W-30 is better for this engine and since similar Hemis call for 0W-40, that would be fine too - so thicker oil isn't the problem here IMO - although I'm sure there's someone out there putting conventional 20W-50 in their Hemi and I definitely wouldn't wanna be the next owner of that one!

Pretty sure that the ones calling for 0w-40 do not use the MDS. (Mine doesn't have it.)

 

[Jarlaxle]

How thick is the 5W-20 or 5W-340 at -25F? Is that damaging? It should be...

How thick is 20W-50 at 10F?

If higher viscosity oil is damaging these engines, they should come with a pre-heater as even 5w-20 gets as thick as syrup when it's cold enough.

MDS doesn't activate when cold.

 

[The Critic]

Pretty sure that the ones calling for 0w-40 do not use the MDS. (Mine doesn't have it.)

My friend's 21 Ram 2500 6.4 calls for 0W-40 and has MDS.

 

[Jarlaxle]

I didn't realize the HD trucks got MDS. That had to be recent.

 

[The Critic]

I didn't realize the HD trucks got MDS. That had to be recent.

GEN III HEMI® Engine Quick Reference Guide Part IV

MORE CUBES AND MORE POWER: 2011 – 2021 6.4L/392 HEMI® V8 ENGINE So far in this series, we have covered the beginning of the great HEMI® engin...

www.dodgegarage.com

I think the truck 6.4 motors have always had MDS.

 

[The Critic]

MDS doesn't activate when cold.

The one in my truck activates within 1 mile of startup. Usually by that time, coolant temps are not past 130F.

 

[Jarlaxle]

The one in my truck activates within 1 mile of startup. Usually by that time, coolant temps are not past 130F.

You are in California. You don't have actual cold.