Automotive Basics: Easy Hemi Engine Misfire Diagnosis

It wasn’t the camshaft and lifters? Lol

Okay what if it's p0158 which they also mention that it could be a problem with the O2 sensors or a injector going bad so which one of the cylinders does it mean it's going on plus I also had the po300 come up as well so which cylinder is this injector causing issues

It's the cam and lifters. Sorry

I got 22 codes now after my lifter change out a damn headache 2015 dodge charger 5.7

How about PCM?

great video

I just had a p0306 code pop up on my 2017 challenger 6.4 hemi for the first time. I'll go through all of this and hopefully it's an easy fix. Great videos btw . Hopefully it's not the coil cause they're not cheap. Granatelli

Great video and you got me man.
I misaligned the intake pushrod on cyl 8 while replacing the head a few years ago & the valve would not seat.
I would try to start, backfire and stall …I believe it coded with high manifold pressure but I figured it out.

Any tricks on replacing the dreaded rusty exhaust bolts?

Thanks🇺🇸

If your cam lobe really is rounded, you could just pull the valve cover and fuel pump fuse. Have a buddy crank it over, and see that the rocker is either not moving, or has noticeably less travel

Not true about P0300. I had a broken intake valve spring that threw P0300 and no other code

My engine light came on. Had it diagnosed at O'Riley's it coded miss fire on cylinder 5. Then cleared the codes. Took it to a mechanic and he couldn't find anything wrong. I drove the hemi truck 400 miles and the check engine light never came back on. Is it ok to take it on another long trip??

Awesome. The p300 process would be great. Also, if the cam lobe is wiped, would it cause a loose push rod or rocker? And be visible when removing the valve covers?

My engine misfires under full throttle

Wow didnt even think of switching coil packs, might try that since that only takes a couple minutes

I’m getting cylinder 6 misfires while idle in park. And when they happen you can hear the idle is not running right. And it doesn’t happen while driving.
I’m not getting and codes or check engine lights. But when I noticed the way the engine idles in park I started monitoring misfires with my scan tool. And after my engine warms up , I can get up to 25 misfires in cylinder 6 that stop when I start driving. And again, it’s not enough to throw a code. But I see them while live monitoring and also on mode 6 data.
I’ve already ruled out coils and spark plugs. I have not did a compression test yet.
But doesn’t this sound like early mds lifter failure?
I am currently also keeping mds turned off with my tuner . Is that hurting, helping or probably a non factor in terms of protecting my engine and helping it run better?

Hello got a question about my hemi I changed the head gaskets fixed the throttle control service bull now it starts and runs but turns off

a guy had done the same thing of diagnosis a misfire on a HEMI, he changed the spark plugs everyone was working so he switch up the spark plug that was supposedly misfiring and that spark plug was working so he looked at the coils check those and they were okay, so he checked underneath the covers to see if it was a roller brushing up against the rockers which would make a negative charge those looked good, So he went back to his diagnosis tester looked at all the sparks through each cylinders and those were okay, so he ended up just getting a new PCM with a 50 dollar install for the HEMI with it's VIN connected, then checked the rest of the codes that came up after the install and everything worked like a charm! Pretty cool stuff.

could a warped exhaust manifold cause a misfire too?

I have a 2010 ram 2500 5.7 hemi has a misfire cylinder 1. O psi compression, 135-150 psi in all others. Leak down test it's going past the rings 100%. Looking for advice on budget build for it. I believe there is damage on the cylinder wall. Not sure if I should rebuild it or buy a new for $8300 long block or reman $6000. Any advice would be great thankyou. Engine is about to come out of truck.

I hava a 04 tundra 4.7 v8 misfire on cylinder 8 only at idle, put new sparkplugs, new coil, new fuel injector, new pcv valve, new valve cover gasket camshaft looks fine. Checked compression and the rest are about 150psi and cylinder 8 is 100 psi what do you guys think it could be? It runs fine over 1k rpm. It also started giving 11mpg since this happend

excellent explanation, thanks for sharing your knowledge! don't stop doing this!!!
If the Hemi engine vibrates at idle, could it be a misfire?

I had a sudden event happen - multiple miss fire - changed plugs - 02 sensors and catalytic converters. Barley runs now at all
Any advise

I’m working on my Magnum. Thanks to your videos I’ve had the confidence to do 65% of the rebuild myself. The rest was done by a engine shop. Now my issue is Cylinder 6 connector isn’t giving the meter any reading. I’m getting a code for a misfire. I purchased a new engine wiring harness but it came from a Chrysler. I learned the coil packs are different from dodge and Chrysler. Any suggestions on what I should do? Try Chrysler coil packs or find someone to rewire the harness? Thanks for all you do for the home mechanic like myself.

Just the fact that I can see my engine once it has been removed is worth its weight in gold.
Very informative and likeable channel that definitely deserves more subscriptions.
Greetings from Germany

Thanks ! Excellent topic /tutorial ! Great teaching technique !

2017 ram1500 slt misfire but no check engine light?

I have a question if you or any others may help. I have a 05 300c 5.7 I did a coil pack upgrade went from coil an wire to the just coil packs and about 1yr an half later when I go half to full throttle it starts to brake up could that be the plugs they are about 2 years old an are the e3 plug can anyone help much appreciated

I have. Cyc 3 misfire. I replaced the plugs,ignition coils. Fuel injector. Throttle bottle and camshaft sensor. Still having the issues

Mds solenoids can cause it to on these hemis...but usually a code specific along with p0306 ud have like p1412

You never mentioned the ecm might be shortened out on that cylinder…

2008 Dodge Charger SRT8 6.1L Hemi - 49k miles
Error code P0300 - Last year and replacing the spark plugs fixed the code.
Yesterday i encountered the same code P0300. Couldnt be the spark plugs cause they only have about 5k miles on them. I used Lucas Fuel booster and after a day of driving it fixed the code issue.

Hi I'm watching your channel for awhile and now I actually need your knowledge for my 2014 Ram.
I have a misfire on cylinder 3 (what isn't a MDS ).
I switched plugs and coil and cleared the code with my autel scanner.
Test drive still says misfire cylinder 3.
I checked the injectors (live data with my scanner and they are all in the same range.
The misfire I only get, when I push the truck hard.
Do you think I'm on the point to replace the camshaft and lifters?
I also will replace the oil pump for a hellcat what supposed to fit without modifications.
Btw I have only a 105k on my truck.
What you think ❓
Thank you

AHHHH Man i was hoping you had a video on the P0300 code. My Truck will not stay on. It stalls and is ruff. i Changed the spark plugs already. Nothing! guess i'll check the injectors since you said its usually fuel related.
Thanks for the video

Dam I think I have a lifter problem!! Every time stomp at the peddle I get a really bad misfire!! :,((

wish you do a video on a PCM how to stop the oil from the oil send unit to get up there on a 2013 Dodge Charger cos mechanic said they found oil on my PCM is coming from my oil sending unit somehow thanks

P3439 code with p0300 on 2012 ram 1500 pending in the background not throwing a check engine light, any idea? Also stalled at idle.

A bad PCM could also be the culprit.

Rough idle and random stalling with no code 2007 magnum R/T awd 5.7

Man... I changed plugs just for maintenance and boom... miss on 6. New plugs, new pack. Had no issues beforehand. This is a reman'd engine.

So I had a misfire and could smell gas lik crazy I replaced the cam and lifters! Now it runs but all I can smell is gas gas gas and it’s coming out the exhaust and gray white smoke what can this be?

I don’t know anything about engines but I was able to follow this no problem. Please continue doing these

Any videos featuring those wheels on that car behind you? I think I have the same set of liquid metal 5 spoke wheels that came on my Challenger.

Awesome Tips Sky, I would add one thing right around the time you are checking the fuel injector, I would also check power and ground to the coil, the other thing that can mess you up a bit on these Hemi's that you didn't mention is the MDS solenoid. Great content though and a learned a few tips!

Your presentation on every video is very clear and concise not to mention helpful! Thanks for sharing your HEMI knowledge!!

This is an excellent video. Very educational for a novice like myself. Thank you sir!

Sorry to ask another question... Have you covered the exhaust manifold on the pre eagle 5.7 and doing a 6.1 install? Is it worth it? I can get a set of srt 6.1 for cheap.

Hey i'm getting a po300 code on my ram 1500 5.7 any advice on saving my truck, would great.

I like all of the video’s i like the content and I can understand what you are saying and doing you inspired me to tackle my own cam and intake swap. I was wondering if you could clarify some of the tools you are using. I have already bought the wrong harmonic balancer puller even though it said it worked with my car now I have bought two valve spring removal tools and I’m waiting on my third. I have changed springs before but never had issues finding the right tools.can you tell or recommend the valve spring tool that works best on the eagle heads.

This is a great video Sky, one of your best! Really informative.
On a separate note, your revamped Reignited shirts are really great quality and super comfortable. I wear them all the time!