HEMI Start-Up Tick

[The Critic]

I noticed a new bit of info in the 2021 Ram owners manuals about the HEMI start-up tick:

"Hemi engines (5.7L) at times can tick right after startup and then quiet down after approxi- mately 30 seconds. This is normal and will not harm the engine. This characteristic can be caused by short drive cycles. For example, if the vehicle is started then shut off after driving a short distance. Upon restarting, you may experi- ence a ticking sound. Other causes could be if the vehicle is unused for an extended period of time, incorrect oil, extended oil changes or extended idling. If the engine continues to tick or if the Malfunction Indicator Light (MIL) comes on, see the nearest authorized dealer."

Anyone want to explain why short trips may exacerbate the start-up tick?

 

[mbacfp]

Never heard short drive cycles being responsible. Subscribed.

 

[AutoMechanic]

Wonder if the oil drains down fast so it has to come back up and just takes a few seconds longer or something.

 

[tiger862]

I noticed a new bit of info in the 2021 Ram owners manuals about the HEMI start-up tick:


Anyone want to explain why short trips may exacerbate the start-up tick?

Short trips are hard on oil as not getting fully up to temp. Then you have carbon build up that can cause a tick but also on extreme cases a knock. I run lots of short trips as well as idling I.E. my Caravan has 67 hrs in 1200 miles. Last vehicle was worse and had tick when cold but the minute I took it on Interstate I ran it hard then tick disappeared for awhile. Oil takes longer than coolant to get hot.

 

[clinebarger]

Probably from the way the Hydraulic Lash Adjuster mechanism inside the Lifter gets it's oil .....They oil from the top down, Through the Pushrod from the Rocker Arms via the Rocker Arm Shafts.

When I put new lifters in a Hemi which is often....They tick like mad 'til they get pumped up/fully primed. Usually have to raise the RPM a little to accomplish this. Soaking the Lifters in oil before install has little to no effect.

GM LSx engines are very similar in architecture, But the Hydraulics are fed from the bottom up through a feed hole in the Lifter Body. They quiet down within a seconds of initial start after replacement.

 

[AutoMechanic]

Didn’t realize something this new would have hydraulic lash adjusters.

 

[OilUzer]

It says short cycles ... then in the example sound like even one "short distance" driving can cause the issue. No?
Therefore it must not have anything to do with fuel dilution.

What is an "incorrect oil"? Oil with no moly?

 

[DemoFly]

Me thinks this is in the owners manual for the same reason Chrysler has 1 quart per 1000 miles of oil consumption as normal for most of their vehicles in the owners manual. So they don't have to warranty anything.

 

[demarpaint]

Me thinks this is in the owners manual for the same reason Chrysler has 1 quart per 1000 miles of oil consumption as normal for most of their vehicles in the owners manual. So they don't have to warranty anything.

Over the years I have seen many owners manuals address oil consumption to cover the mfgs. a$$, not just Chrysler.

 

[dlundblad]

I noticed a new bit of info in the 2021 Ram owners manuals about the HEMI start-up tick:


Anyone want to explain why short trips may exacerbate the start-up tick?

A co worker of mine had a 2014 that saw nothing but highway miles for the 6 years she owned it. Bought it new and had the dealer service it. She complained about the tick as well as something in the upper end needing replaced.. Would have cost 4ut she traded it in.

Just with this example, I don’t think short trips have anything to do with it.

Some say a 5w30 oil, but it doesn’t seem to be oil related either.

 

[dlundblad]

Me thinks this is in the owners manual for the same reason Chrysler has 1 quart per 1000 miles of oil consumption as normal for most of their vehicles in the owners manual. So they don't have to warranty anything.

I think it was the 3.8 that started that. It’s known to use oil. Overall good reliable engine, just uses oil even at low miles.

The 3.6 in my brothers Jeep doesn’t have noticeable consumption.

 

[Trav]

Didn’t realize something this new would have hydraulic lash adjusters.

I would be even more surprised if it didn't have them.

 

[demarpaint]

I think it was the 3.8 that started that. It’s known to use oil. Overall good reliable engine, just uses oil even at low miles.

The 3.6 in my brothers Jeep doesn’t have noticeable consumption.

Same here, my 3.6 L 2016 Rubicon doesn't use a drop in a 5K OCI.

 

[aquariuscsm]

They warn against extended oil changes.

 

[OVERKILL]

Probably from the way the Hydraulic Lash Adjuster mechanism inside the Lifter gets it's oil .....They oil from the top down, Through the Pushrod from the Rocker Arms via the Rocker Arm Shafts.

When I put new lifters in a Hemi which is often....They tick like mad 'til they get pumped up/fully primed. Usually have to raise the RPM a little to accomplish this. Soaking the Lifters in oil before install has little to no effect.

GM LSx engines are very similar in architecture, But the Hydraulics are fed from the bottom up through a feed hole in the Lifter Body. They quiet down within a seconds of initial start after replacement.

Yup, this.

 

[OVERKILL]

Didn’t realize something this new would have hydraulic lash adjusters.

?

Why?

It's typically only the Asian OEM's (like Honda) that have used shims and buckets to adjust lash (though there are a couple of Ford examples too).

 

[Astro14]

Didn’t realize something this new would have hydraulic lash adjusters.

What would they have instead? Mechanical lash adjusters? AKA Solid lifters like a high performance 50s Chevy?

Edit: how many OHV V-8 engines, like the Hemi, have you worked on?

 

[pantygnome]

Ive narrowed down a loud knock/tick on my 2017 Hemi RAM...it happens like this:

If the truck sat, say overnight, then I start it just to move it a short distance (think: to the other side of my driveway), then shut it down....if I start it again within an hour or two, it will make a fairly loud knocking noise for 3 seconds at startup. Not a lifter tick, IMHO....its a deeper tone.

If I: drive it longer before shutting down (as simple as driving through the roundabout at the end of our street) OR I let it sit for an extended period again, the loud knock does not occur at startup.

I have no idea WHY it does it, but over on RAMForum it seems to be a common thing in this exact scenario. Im not sure if that is what the manual is referring to or not as a "short distance". There are theories as to what it is but I dont think anyone knows for sure (probably not even Mopar).

 

[Blinker]

Oh, Chrysler.

 

[AutoMechanic]

?

Why?

It's typically only the Asian OEM's (like Honda) that have used shims and buckets to adjust lash (though there are a couple of Ford examples too).

Oh. I thought these were done away with in the 1990s maybe early 2000s.