which cylinder is number 1?

bhawk · #1 (**permalink**) 01-01-2012, 05:11 AM

2003 sentra with 1.8 engine. I'm getting a P0301 code, which is misfire on number 1 cylinder. My question is--- which cylinder is number 1? I presume it is near the front of the engine where the crankshaft pulley and belts are, (which is the passenger side of the car). I presume number 4 is at the drivers side. Am I right?

mpe235 · #2 (**permalink**) 01-01-2012, 05:16 AM

Correct. It is usually a coil. Could also be a head gasket leak. Try swapping #1 and #2 coils to see if the misfire changes to cyl. #2. If it does it's a bad coil.

bhawk · #3 (**permalink**) 01-01-2012, 06:07 AM

thanks for the quick reply. What I did not mention is that the misfire only occurs on a relatively cold start, where the engine misfires for only a few seconds, say 3-6 seconds, then runs fine. Occasionally in the past couple of years, or perhaps frequently, but not always, I found the engine had to be cranked over for quite a few seconds to get it to start. That symptom seems to indicate a weak fuel pump. But it has only been the last few days where I got the code and it stumbles on a cold start. So head gasket is possible too, based on my reading here. When I get time, I will remove spark plugs and check compression. I was thinking I should do a fuel pressure test.
How do I do a fuel pressure test? I have a gauge I once used on my son's ford ranger.
thanks to all for help.

mpe235 · #4 (**permalink**) 01-01-2012, 06:41 AM

Quote:

Originally Posted by bhawk

thanks for the quick reply. What I did not mention is that the misfire only occurs on a relatively cold start, where the engine misfires for only a few seconds, say 3-6 seconds, then runs fine. Occasionally in the past couple of years, or perhaps frequently, but not always, I found the engine had to be cranked over for quite a few seconds to get it to start. That symptom seems to indicate a weak fuel pump. But it has only been the last few days where I got the code and it stumbles on a cold start. So head gasket is possible too, based on my reading here. When I get time, I will remove spark plugs and check compression. I was thinking I should do a fuel pressure test.
How do I do a fuel pressure test? I have a gauge I once used on my son's ford ranger.
thanks to all for help.

The long crank could be caused by a faulty fuel pressure regulator. After the car sits overnight turn the ignition to the on position for about 20 seconds and then try starting it. It should start normally. Unfortunately the regulator is part of the pump assembly. Nissan came out with a repair kit but it is only a few dollars cheaper than the whole assembly.
Before you do the compression test remove the spark plugs and shine a light into the holes. If the top of the piston in any of the cylinders looks clean then the head gasket is leaking coolant into that cylinder.

nissanmaniac · #5 (**permalink**) 05-28-2012, 08:37 AM

the one closest to the crankshaft pulley

bhawk · #6 (**permalink**) 05-28-2012, 10:09 AM

My problem turned out to be antifreeze leaking into number 1 cylinder from a bad head gasket. I changed it out myself. Not really that hard a job. I was impressed with Nissan engineering as the engine is made to take apart easily. thanks for all your help guys.

NissanTech · #7 (**permalink**) 05-28-2012, 11:04 AM

Quote:

Originally Posted by bhawk

My problem turned out to be antifreeze leaking into number 1 cylinder from a bad head gasket. I changed it out myself. Not really that hard a job. I was impressed with Nissan engineering as the engine is made to take apart easily. thanks for all your help guys.

Thanks for letting us know and I'm glad you fix the problem.