Going to try and long story short this. Had timing chain replaced, all new sensors, transmission rebuilt, new plugs, coils, fuel injectors, fuel pump, wiring harness, and other things replaced and still get a misfire on cylinder 5 ONLY when the coolant temp sensor is plugged in, ran a compression test and all was fine, ran a leak down test and it was fine, taking off from a stop sign it feels like it’s shaking starting out then runs fine after gears have changed. Ran a smoke test and no leaks.. I’m stumped. Have no idea what to do next. I don’t believe it’s the head cause it doesn’t smoke or anything else. Any help is appreciated as I done put thousands into this thing and still can’t figure it out

 

check engine light flashes and misfire happens when sensor is plugged in. When sensor isn’t plugged in it doesn’t seem to misfire. It shows both cam sensors and misfire on cylinder 5 when sensor is plugged in

 

Only early 07s had both cam sensors, that was dropped and after that they only monitor the exhaust side.

Post the actual code(s) you are getting. Did you inspect the camshaft actuator solenoid for dirty or missing screens?

Stop throwing parts, instead diagnose your problem.

 

Yes those have also been replaced.
with coolant sensor unhooked I only get code p0118

with sensor connected I get p0340 and p0341 along with p0305. Check engine light flashes then stays solid

 

**correction** p0340 and p0341, p0118 all show up when sensor is disconnected***
the p0340,p0341 shows up after it has ran for 20 minutes or so**
hope I’m not confusing you

 

Does the coolant sensor work properly and read the temp? Do you have a scanner that can read what the coolant temp is when the sensor is connected? Does the coolant heat all the way up to 195F?

What brand coolant sensor do you now have?

 

It does read correctly but I don’t leave it running very long cause the misfire. It is a ac Delco part. I don’t have a obd that reads the actual temp

 

Check/clean connector/contacts @ CMP.

 

It has new camshaft sensors (so I was told). Do they have to be relearned? I was told they don’t because the drive cycle would relearn them. Are you saying check the connections at the ecm? Would this cause a misfire on cylinder 5?

 

Check/clean connector/contacts @ CMP & secured connection.