Cylinder misfire

This could be caused by a few things. This guide with walk you through the steps


https://www.2carpros.com/articles/engine-misfires-or-runs-rough


Please run down this guide and report back.

I replaced the fuel injector fixed my problem paid $78.00 for the injector.

I just had a check engine light for a #3 Cylinder misfire. Along with the light, the engine started running rough and I can hear a tapping. The check engine light was reset and I replaced the #3 spark plug and the ignition coil. The light is still out, but nothing else has changed so I know the problem is not fixed. Any info would be greatly appreciated.

[quote:2283a6806d="palmer_nicholas"]Engine Mechanical problem
2002 Dodge Ram V8 Two Wheel Drive Automatic 77000 miles

I just had a check engine light for a #3 Cylinder misfire. Along with the light, the engine started running rough and I can hear a tapping. The check engine light was reset and I replaced the #3 spark plug and the ignition coil. The light is still out, but nothing else has changed so I know the problem is not fixed. Any info would be greatly appreciated.[/quote:2283a6806d]

My guess is the hydraulic valve tappet is starting to stick.

my truck is currently running on 7 cylinders due to #4 cylinder bad what should i look for in repair cost including timing change

What is worng with #7? Is it low compression? Is it caused by valves or rings?

[quote:8387070dca="Jacobandnickolas"]What is worng with #7? Is it low compression? Is it caused by valves or rings?[/quote:8387070dca]

its the valve

Hi:
Aprox. est. would be in the area of 5 to 6 hundred. This repair is labor intense. The problem is, if you do a valve job on only one of the cylenders, it may run rough because of the difference in compression. Therefore, both heads should be done unless the other cylenders are still really strong. However, once the heads are off, I recommend having it done.

[quote:8256e59d4d="Jacobandnickolas"]Hi:
Aprox. est. would be in the area of 5 to 6 hundred. This repair is labor intense. The problem is, if you do a valve job on only one of the cylenders, it may run rough because of the difference in compression. Therefore, both heads should be done unless the other cylenders are still really strong. However, once the heads are off, I recommend having it done.[/quote:8256e59d4d]
Thank you, I really appreciate it

My truck its been shaking since I bought it. At the beginning i did a tune up, plugs, wires, cap and rotor. But still the same I check for codes and found 3 misfires on 2,7 and 8. I erased them, ran it and checked again an gave me 4 misfires in cylinders 1,3,5, and 8. I did a compression test but everything is normal. I don't think is the injectors because of the different misfires. I'm starting to think is a sensor problem even though i don't get a check engine light. Can you help me?

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Ram 1500 Van

I have a misfire in cylinders 3 & 4! I changed rotor, cap, wires, and spark plugs and it's till misfiring. My scanner is saying P0300, P0303, P0304. Before I start throwing parts at it I thought I might ask.

Random misfire are caused by vacuum leaks and bad gas.

Wouldn't that make the other cylinders misfire also? I have a constant misfire on the 3 and 4. The 3 and 4 are the center cylinders on the right and left bank that are misfiring. I thought it might be bad injectors but before I got them I did a compression test to make sure and this what I found.
1. 120psi
2. 120psi
3. 90psi
4. 90psi
5. 120psi
6. 140psi

I'm guessing "intake cracked" ?!?

Just by looking at the cylinders arrangement your suspicion could be right -try doing a leakdown test.

Ok here is an update on the Van.

I got to thinking about the low compression in 3 & 4 and I'm NOT a pro by any means but I couldn't see how a cracked intake would result in low compression like I 1st thought. I can see a misfire but not low compression. So I got to thinking ether bad valves or rings. The motor has 130,000 on it so my guess was the valves. With noway to do a leak down test I shot a squirt of oil in the 3 & 4 to see if compression came up but very little changed. Next I hook my air compressor to the 3 & 4 with them at TDC put about 30-50psi in and I had hissing and air coming out of the exhaust pipe.

So I'm thinking bad exhaust valves

ive got a 2002 dodge ram 1500 slt w/4.7L engine. I am getting a misfire on the #6 & #8 cylinder. I have changed the plugs with bosch platinum 4 (all 8) and have also changed all 8 coil packs and am still getting a misfire. I pulled out those 2 plugs again and there is a carbon buildup on both. I also checked the others and they seem to be clean. any ideas on what else to look for

Check the compression and injector for those cylinders

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel

Bad exhaust valves if its coming out of the exhaust end-either way it still has to be open up and find out what's causing the low compression on this 2 cylinders

I am having the same issue as well and nothing seems to work to fix the problem. new Plugs, coils, air filter, clean the throttle body and still the engine revs 400-800 RPMs while in Park and when driving over 50MPH. This is driving me nuts. anyone have suggestions?

Changed 8 plugs, chained coil pack on #4 cylinder ran without throwing dash light for a few days. Lite is back on, also misses. First time it happened was on start up acceleration truck "bucked" then seemed o.k. but was missing, then threw the light. chkd at local auto parts for the code. Replaced plugs cleared light, then few days later came back on, changed coil pack, ran so-so but then light came back on w/same code. what to check next? don't want to throw parts at it, and no significant computer codes???

Misfire at 4

A misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression. check it then report back.

NOTE: Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.