JMOrem

Hello all,

car: 2002 C5 Z06. All stock except for intake. No exhaust mods or cam.

The other day I was cruising down my neighborhood street when I noticed my car started making an odd noise and the check engine light started flashing.

Based on the CEL flashing, I assumed random misfire and parked the car. Since I am was not sure if the plugs have been done before. I replaced all plugs with pre-gapped TR6's, all new MSD wires and all new AC Delco ignition coil packs thinking this would solve the problem.

I started it up and it still sounds choppy and feels like it wants to die, no power.

Any thoughts what next step could be? Injector? Did it jump the timing? Cam sensor? Exhaust leak? I'm at a loss.

feeder82

broken valve spring? pull the covers and check

JMOrem

Thank you, my build date falls in late 2001 so its less likely to be the case, however I will remove them and check on that.

Any other possibilities if that's not the case?

JMOrem

I just pulled off the valve covers and all springs look good. My mechanic buddy came by and took a look and said it sounded like a rod knocking..... Any input here? Can a rod knock cause a misfire? The oil spout also smells like gas

JMOrem

Can someone offer any advise?

Engine misfire after driving 30mph down my neighborhood street. Felt a miss and sounded like the engine was misfiring. Replaced, coils, plugs, wires and popped off valve covers to look at springs, they look in great shape.

Not sure what else could be the issue. Engine runs strong, but has a missfire still and one of my buddies says he can hear a slight knock. Could a rod knocking cause a misfire? Cant really hear it unless you listen from under the car.

Not sure what else this could be!!

Smoken1

Have you pulled the codes?

killian96ss

Have you done any maintenance or cleaning engine lately?

Steve

JMOrem

Just normal oil changes. i don't ever put water on the motor

JMOrem

Here are the current codes:

P1571 HC
2285 H
U1040 HC
P1689 H C
B2264 H
B2265 H
1064 H

** Some of those may be because the ABS module is currently out, being rebuilt.

JMOrem

Anyone have any thoughts? Kind of at a loss right now. Have a giant paper weight

El original

Had a friend with a misfire issue (not on a Corvette but) could not figure out until a mechanic got a spray bottle with water and sprayed over engine when running. It closed a spark short on a wire that solved/found the problem. Maybe something silly like a wire short, I know you changed them out but hey...Good luck I truly hope it is something as silly as I mentioned. Rob

killian96ss

Have you tried a spark checker on all 8 plugs just to make sure each cylinder is getting spark and firing?

Steve

Mace

I don't know but a rod knock sounds like someone pounding metal against metal, not a miss. RK are a very distinctive sound

mace

pjdbm

choppy, low power, could you have jumped the timing chain?

JMOrem

now thinking its a vacuum leak from under the intake area

JRat84

Fuel filter?

Chicago1

Post a vid cause we are all guessing at this point..

P1571 HC-Traction control system (TCS), torque request signal -malfunction

2285 H- APP Sensor 3 Circuit(Accelerator Pedal Position) Sensor 3 Circuit Performance.Read more: https://www.corvetteforum.com/forums...rformance.html Post 3..


U1040 HC- Loss of Communications with TCS

P1689 H C-Traction control system (TCS), delivered torque signal -malfunction

B2264 H-Vertical Position Sensor Fault ( Left Door Control Module )

B2265 H- Horizontal Position Sensor Fault (Right Door Control Module )

1064 H- Loss of Communications with BCM ..from Bill Curlee- Body Control Module It controls or interfaces with ALL the body functions and communicates with ALL the other modules. Without it,,,your car will not function.


The BCM and APP Sensor 3 Circuit would be my first start but again post a vid please

JMOrem

UPDATE: Still at a loss with this car right now.

Last week, took off the intake manifold for what I thought was a vacuum leak. Replaced all intake gaskets, oil sending unit replaced since I was already in there and it was leaking for awhile.

On top of already replaced all coils, plugs, wires. Car still shows intermittent misfire. Will not tell us which cylinder. Checked valve springs as well and all look great.

Sounds like an exhaust leak, but its a running issue. I'm at a complete loss, been without this car for 2 months. Anyone have any further ideas?

JMOrem

help?

pjdbm

You changed many parts all at once, sometimes that prolongs the troubleshooting.

I will throw something out to you, it is a long shot but have you made sure all voltages to this car is good? I know this vehicle will act and perform wacky with voltages that are too low.

long shot but at this point...........