Hemi Tick

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2011 Ram 1500 4x4, 5.7L/545RFE, 131,xxx miles.

*All 16 spark plugs, #3 ignition coil, #3 fuel injector, & Intake manifold seal changed in an attempt to fix DTC P0303.
*Customer complaint.....Misfires randomly/intermittently.
*Requested a Vacuum "check" because he read on the internet that valvetrain issues would result in erratic Manifold Vacuum.

Couldn't really argue with that....Broken valve springs & sticky/stuck valves can certainly cause timed drops in manifold vacuum. Don't usually get caught-up in other peoples diagnostic process because I have my own & adhering to it keeps me focused. Guy was nice enough & gaining new customers is important to my fledgling business, So I decided to oblige him & do the test while he waited.

Engine was actively misfiring at first but slowly cleared up while performing the vacuum test.....Steady 18 inches of vacuum the whole time.
I commented about the noticeably audible valve/lifter tick & the fact these (MDS 5.7L's) are notorious for wiping out camshaft lobes & lifters. Recommended that the valve cover be removed for a visual inspection.

That's when the whole story gets spilled.....He has paid 3 different shops to diagnose & throw parts at this & is understandably reluctant to throw money at yet another misdiagnoses....And stated that the tick has been there for years.
I said....."Tell you what.....I'll pull the valve cover right now while you wait, If I don't find an/the issue, I'll reinstall the valve cover & you don't own me anything"

Took about 10 minutes to pull the driver side/bank 1 cover & Set my scanners bi-directional controls to activate the starter relay. Then I got my flashlight positioned so he could watch the valve action with me.

#3 intake valve was moving @ 0.030" while #5 intake valve was moving over .500"...... He was
shocked2.gif
Also asked a very good question that I honestly didn't have an answer for....."Why is the misfire intermittent"


Video of the vacuum test....Hear the tick?
 
Evidently .030 intake lift is enough to let intake mixture in and let the cylinder fire. But that cylinder would be down on power at higher RPM's.
 
If i understand right, cam lobe 3 is probably wiped out( probably from failed lifter). The misfire would be a lean misfire, until the ecm corrects?
 
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Things got complicated once I pulled the camshaft.....I recommended pulling both heads & replacing all 16 lifters. But he wanted to save as much money as possible. So I said it is possible to replace just the #3 intake lifter & the camshaft thus only pulling the bank 1 cylinder head & the 8 lifters on that side.

Unlike LSx engines.....You have to be VERY cautious & aware that the lifters can drift out of their holders very easily, Some may not hold at all! This one had #1 intake lifter that would not stick in the holder at all. Had to use a pencil magnet....Rubberbanded to the spark plug tube casting to hold it up.
*I use a drill on the camshaft to spin it up & listen for any lifters not sticking in their holders.

Slid the old cam out & immediately slid the new one in.....I thought luck was on my side 'til I inspected the camshaft. One of the cylinder #6 MDS lifters was eating into the cam aswell !!!

Had to pull the bank 2 cylinder head....Replaced 4 lifters in total (2 MDS & 2 standard), 2 were completely failed & 2 had lose rollers. I pleaded to replace them all, But he just couldn't afford it.

Out the door cost....$3,600.

Ready to pull just bank 1 cylinder head.....
[Linked Image from i.imgur.com]
 
Keep these write ups coming!

Curious, how much is a new engine vs $3600 to replace a few worn parts on this one? Understand the guy is going as low cost as possible.
 
Man , a shame to put a new cam in, with the other lifters that may fail too. Did you use factory mopar lifters, or are there better after market ones?
 
Wish I would have gotten more picture of it being assembled....But I had to put my head down & work! I did do a after repair video for you guys....
 
Originally Posted by GMBoy
Keep these write ups coming!

Curious, how much is a new engine vs $3600 to replace a few worn parts on this one? Understand the guy is going as low cost as possible.



Been down that road with Chrysler/FCA....They want to sell a short block for $2000, Then the heads, gasket set, cam, lifters etc for another $4000. God forbid you have a problem down the road. They aren't the only manufacturer that does this piecemeal BS either!
Coming from years at GM dealerships & several more years doing LSx swaps....It's a shock to the system!
 
"What could go wrong?" said the beancounter. "What could go right?" said the metallurgical engineer. We see who won that argument.

What a cluster. Thanks for the pics, my stepson is possibly facing the exact situation, including the money part. cline, just a question- was that the "original" SADI MDS cam or is that an updated one? I see the iron core so I'm not hopeful... I have at least talked my stepson into a billet core and MDS delete if his has eaten any lobes.

Just for a reference... how many hours (not book hours) did this take? Thanks!
 
Surprised no "Class Action"/Lemon law against FDC on these POS hemi engines ??? Its like the most common failure i have EVER seen


I never seen one go past 150K miles without those cam/lifter issues ??


Indiana State police somehow gets their 5.7 Hemi Charger interceptors up to 150-200K miles and still running when auctioned off. Someday when i'm in that area I REALLY want to stop by their maintenance facility and ask whats they're secret lol


Dave
 
Dave, it's easy why they last so long for state troopers. They're either idling (no MDS), or WFO (no MDS here either). Yet if we duplicate their methods for longevity, it will result in brightly colored, one-piece outfits along with an itty-bitty living space for several years.
frown.gif
 
Originally Posted by SubieRubyRoo
"What could go wrong?" said the beancounter. "What could go right?" said the metallurgical engineer. We see who won that argument.

What a cluster. Thanks for the pics, my stepson is possibly facing the exact situation, including the money part. cline, just a question- was that the "original" SADI MDS cam or is that an updated one? I see the iron core so I'm not hopeful... I have at least talked my stepson into a billet core and MDS delete if his has eaten any lobes.

Just for a reference... how many hours (not book hours) did this take? Thanks!


I don't think MDS is to blame, but I agree a billet cam and MDS delete is the way to go. I'd do valve springs as well personally, I read one theory that says the OEM springs aren't strong enough and end up floating a bit hammering the lifters into the cam.
 
That owner is one brave soul not replacing the rest of those lifters. I'll bet had you shown him a dynamic compression test you would have seen very low readings. Especially snap throttle.
 
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