Quick answer: A Ram 1500 misfire commonly stores P0300 or a cylinder-specific code, and on the 5.7L HEMI the leading causes are worn spark plugs (the HEMI uses two per cylinder), failed ignition coils, and on higher-mileage trucks a collapsed lifter from the cylinder deactivation system. A repeating single-cylinder misfire with a tick usually means the lifter, not the ignition.
The Ram 1500 is one of the most searched trucks for misfire codes, largely because the HEMI has a few well-known wear points. This guide separates the cheap ignition fixes from the expensive internal one so you know what you are dealing with.
Why the HEMI Misfires
The 5.7L HEMI runs 16 spark plugs – two per cylinder – so ignition maintenance is double the usual job and often gets deferred. It also uses cylinder deactivation (MDS), and the lifters that ride on the deactivating cylinders are a documented failure point. A collapsed lifter or worn camshaft lobe produces a persistent misfire on one cylinder that no amount of new coils will fix.
For the general misfire breakdown, see our main guide: P0300 – Random/Multiple Cylinder Misfire Explained.
Most Affected Ram Years
- 2009-2018 (5.7L HEMI with MDS): Lifter and camshaft wear are widely reported past 100,000 miles.
- 2013-2019: Coil and plug wear are the routine cause.
- 3.6L Pentastar trucks: Coil failure is the usual culprit rather than lifters.
Symptoms on the Ram 1500
- Flashing check engine light during an active misfire.
- Rough idle, shaking at a stop, hesitation under load or when towing.
- A ticking noise from the top of the engine – a strong lifter clue.
- Misfire that stays on the same cylinder after new ignition parts.
Common Causes (Cheapest First)
- Worn spark plugs – remember there are 16; replace all together.
- Failed ignition coil – swap to a neighbouring cylinder to confirm.
- Fuel injector fault – less common but possible.
- Collapsed MDS lifter / camshaft lobe wear – the expensive one, indicated by a tick plus a fixed-cylinder misfire.
Check These Yourself First
- Note whether the code is P0300 or cylinder-specific – a fixed cylinder points internal.
- Listen for a tick at idle with the hood open.
- Check plug service history; overdue plugs are extremely common on HEMI trucks.
Estimated Costs (2026)
| Job | Parts ($) | Labor ($) |
|---|---|---|
| Spark plugs (all 16) | $80 – $200 | $180 – $400 |
| Ignition coil (one) | $40 – $110 | $60 – $130 |
| Lifter and camshaft repair | $700 – $1,800 | $1,500 – $3,000 |
Note: 2026 US estimates. Confirming whether the misfire is ignition or lifter related before ordering parts is the single biggest money saver on this engine.
Frequently Asked Questions
How do I know if my HEMI misfire is a lifter?
A lifter problem typically produces a ticking noise plus a misfire that stays on the same cylinder even after new plug and coil. An ignition problem moves or clears when you swap parts between cylinders.
Does the Ram 1500 really have 16 spark plugs?
Yes – the 5.7L HEMI uses two plugs per cylinder. This makes a plug change more expensive than on a typical V8 and is a common reason owners delay it, which then causes misfires.
Can I disable MDS to prevent lifter failure?
Some owners choose that route, but it does not repair existing wear and may affect emissions compliance depending on your region. Address a failed lifter mechanically rather than masking it.
Related: P0300 full guide · P0301 cylinder 1 · P0420 catalyst