5.7 hemi issues

[Leroy Sanchez]

I have a 2012 ram 1500 Laramie with a 5.7 hemi. I recently had my cams and lifters changed along with the oil pump heads, water pump, timing, chain, spark, plugs, coils, injectors, you name it. Well, I have had to take it back to the shop three times due to the fact it was throwing several codes and still had low oil pressure 12psi. Along with a very ruff idle and a very pronounced tick on the passenger side during start up that goes away almost immediately. However, I am still throwing a misfire for cylinder eight and can’t for the life of me. Figure out what the hell it is. I pulled my valve covers checked the lifters ran a borescope in the cylinders to make sure there was no damage. I took it into a different shop. He suggested Unloyal change and to add Lucas after doing this. I am still having the issues. I would appreciate any help on what could be causing this.

 

[jws123]

Check the pushrods on cylinder 8 make sure they are clicked in all the way very common when re installing for it to not seat all the way i do it almost every time lol. as dor the oil psi i would verify it with a mechanic guage and then change the sensor.

 

[Leroy Sanchez]

I change the oil pressure sensor already. Still having that issue. I will definitely double check the oil pressure with a gauge and thank you for your help. I didn’t even think about the push rods.

 

[jws123]

I change the oil pressure sensor already. Still having that issue. I will definitely double check the oil pressure with a gauge and thank you for your help. I didn’t even think about the push rods.

If the oil pressure is still low with manual guage change the oil filter could be messed up not uncommon.

 

[Leroy Sanchez]

So I did another oil change added Lucas to the mix and it seems to have helped my oil pressure is staying around 20-22 psi at idle. However, I cannot for the life of me figure out what is causing the misfire in cylinder eight. I pulled the valve cover and check the push rod. Made sure it was clicked into position. Everything looks good. But I it is still throwing the code.

 

[indept]

It could be a bad injector or coil (Even though they're new), each could be swapped with another cylinder & see if the code follows. With all of that work, have you checked compression since the rebuild? Did you use quality parts or did you go for cheapest?

 

[Leroy Sanchez]

Swapping everything was the first step that I took. Checked the compression 160 to 165 on all cylinders. All Mopar parts. Check the cylinders with the borescope. No damage to the cylinder walls. Everything looks great. But I continue to get a misfire in cylinder eight.

 

[indept]

Swapping everything was the first step that I took. Checked the compression 160 to 165 on all cylinders. All Mopar parts. Check the cylinders with the borescope. No damage to the cylinder walls. Everything looks great. But I continue to get a misfire in cylinder eight.

Have you verified the injector & coil are getting their signals, it's possible the wiring may have been damaged during the rebuild.

 

[Dusty]

Swapping everything was the first step that I took. Checked the compression 160 to 165 on all cylinders. All Mopar parts. Check the cylinders with the borescope. No damage to the cylinder walls. Everything looks great. But I continue to get a misfire in cylinder eight.

Have you connected a scan tool and recorded all codes? If so, what are they?

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 83966 miles

 

[Rob Friend]

What do you mean by heads being done? I had a #5 misfire for a long time, thought I did everything until I remembered to do a leak down test and had a bad intake valve. I pried up on the valve and it sealed up. I replaced the head and all good. Good for thought