Chrysler Hemi 5.7 6.4 class action re lifter failure.

[bjm]

A class action in US has been instigated re ongoing lifter ,camshaft failure in these Gen 3 hemi engines ,as fitted in numerous Chrysler ,Jeep, Dodge vehicles since 2010.What makes it interesting is that it is noted by the plaintiffs that FCA have Known about these failures plus issued a TSB to dealers re this problem which had been kept secret ! It is estimated that 20% of hemis will have these failures with no known fix.I might add GM have and are still having the same problem.Basically failure of rollers in the lifters.
Info Google Car Complaints.com hemi lifter failure class action

[bjm]

Originally Posted by Farwest

When I first read that on the US forums I decided to 'look into it'....it (failure) appears to be brought about by the 'fuel saving gizmo' that disables cylinders at times in operation to 'save fuel'....mechanics stated the 'closed down' cylinders(valve train)failed to lube sufficiently and bingo failure...another engineering feat of mastery...not....and our brand, as you stated, is most certainly not the only badge suffering the same fate

Actually happening in all hemi lifters ie non mds as well . From 60000 ks up One Mopar workshop in Melbourne is rebuilding around 50 of these failed motors per year! At around$7000.00 each .Conservative estimate at least 100 plus engine failures in Aust per year.

[bjm]

Originally Posted by Farwest

When I first read that on the US forums I decided to 'look into it'....it (failure) appears to be brought about by the 'fuel saving gizmo' that disables cylinders at times in operation to 'save fuel'....mechanics stated the 'closed down' cylinders(valve train)failed to lube sufficiently and bingo failure...another engineering feat of mastery...not....and our brand, as you stated, is most certainly not the only badge suffering the same fate

Happening in all eight lifters ,not just the MDS ones.Roller bearing failure,
then roller locks or rotates ,goodby cam as well

[drover]

Maybe from the great idea to use the lightest weight oil possible to get the best economy stars, seems to be a trend thats coming back to bite many manufacturers.... Had always wanted one myself..............

[bjm]

In my 2015 JGC SRT 6.4 hemi I use Penrite 10 Tenths 0w40 syn no slump oil ,basically a race oil.Plus Penrite rep alsosaid put in their zinc additive as well.He said major problem in the last few years is the Govt mandatedlowering of available zinc they can put in oil to combat wear.

[Mace1]

Originally Posted by bjm

In my 2015 JGC SRT 6.4 hemi I use Penrite 10 Tenths 0w40 syn no slump oil ,basically a race oil.Plus Penrite rep alsosaid put in their zinc additive as well.He said major problem in the last few years is the Govt mandatedlowering of available zinc they can put in oil to combat wear.

This one:

https://www.sparesbox.com.au/part/pe...saAi0UEALw_wcB

My local Jeep specialist likes it as well.

[Jeeper6]

The ole "Hemi ticK' as a lifter or two fails.

My previous WH Overland had the 5.7 Hemi engine, it had 194,000 kms on it when I sold it, that Hemi just purred.

I only sold it and moved to the diesel as the standard 75 litre tank meant cruising from servo to servo much of the time, and when going away with the camper I always had to carry additional 40 litres of petrol so as to be able get back from where I went! Petrol ain't the best to be carrying a round in jerry cans!

I always used Nulon 5w 20 in that engine as recommended. It just ran better on the Nulon stuff than any of the other oils I tried. If I used higher spec such as 5w 30 the MDS wouldn't operate properly and the OBD read would come up with an "incorrect oil viscosity" fault code. The MDS needed a thinner oil to operate effectively...a thicker oil and the MDS wouldn't kick in reliably.

The MDS could have had some effect on the failures, but I read an article some time back by an engineer who reckoned the MDS really made no difference to the roller cam follower failing.

The rollers would starve for oil and could in some cases seize and begin to wear the cam lobe down. Hence the tick as that cam follower got it's turn to open a valve. usually the tick would disappear at revs....but ultimately the engine would develop a miss.

He maintained that the main reason the followers failed, was due to the engine design by Chrysler to shorten the valve train push rods so as to achieve better valve opening with less push rod bend...all assisting fuel economy allegedly.

To do this they set the camshaft higher in the block which was further away from the crankshaft. The cam followers largely rely on oil spray from the crank for lubrication. They also had a new oil gallery running under the camshaft. On top of that due to the higher camshaft the flatter angle of the lifters in the block needed to work with the shorter push rods also hindered oil running down the lifters to oil the rollers.

These modifications to the original Hemi motor layout he claimed contributed to much less oil spray reaching the cam lobes and followers...especially at low revs such as crawling in traffic where oil spray was virtually non existent....and at idle.

His answer was to ensure the engine doesn't lug too long at low revs, to use a lower gear to keep engine revs up, or make sure to run the engine up to at least 1000rpm from time to time in traffic to get the oil spray lubrication up to the camshaft roller followers. Never idle that engine longer than absolutely necessary.

I followed that advice and wouldn't idle the engine if I could avoid it, and would make sure especially at start up when things were a bit dry, once oil pressure was up to warm it up at around 1000rpm...not a 500rpm idle.