my daughter has a 2006 Altima 2.5, the car runs fine when driving or sitting in idle. A couple of weeks ago when you start it up the engine sounds like it's missing and literally sounds like a rod or loud knocking but after the car starts it runs rough for 2-3 seconds then it's fine. Sometimes it starts with no issues. I talked to two different Nissan techs and one said it was the catalytic converter so he gutted it out. Still no help. Then he said it was the #4 coil. Changed that out, no change so I changed the other 3 coils out, no help. The other tech told me to change out the crank position sensor so I changed it and the cam position sensor. Still no change. I just pulled the spark plugs
and put a pressure test on the radiator. Within 45 minutes 3 of the 4 cylinders I can see water on top of the pistons. #4 looks brown. I taped a qtip to a straw and it appears to have mainly water, possibly small amount of oil but the other 2 cylinders has water for sure. So I'm thinking this is what seems to be causing the car to misfire on start. Does this sound correct? I'm tired of getting the run around from these guys and spending money on it. Could this be a seal or more than likely a head leaking??? Any advice would be greatly appreciated, thanks, Clyde
JA: Does the vehicle stall at low speeds? Does it sputter?
JA: Are you fixing your Altima yourself? What have you tried so far?
Customer: Please read my comment
JA: Anything else you want the mechanic to know before I connect you?
Customer: no thank you, ***** ***** in my first comments