[Atarian]

Hi all:

Today the SES light came on, code reader shows P0350. 1.8L 5-speed, 186,500 miles. Pulled all 4 coil packs, all read the same - good according to the manual. All are getting battery voltage in and all have good ground. What's odd is the car idles perfectly and accelerates as smoothly and strongly as it ever has.

The only other time this car has had the SES light come on it turned out to be a defective ECM. I found this out after replacing two O2 sensors and the codes remained. Dealer diagnosed defectice ECM - replaced under federal emissions warranty.

With this many miles I'm tempted to just drive it as-is, as there seems to be no degradation in performance.

Any thoughts?

 

[i68k]

have you replaced or rebuilt any of your coilpacks yet? so this has to be either coil, ecu, or electrical wiring. did you clean the connectors that connect to the coils using electronics cleaner, those get hella dirty from everyday driving. make sure the connector clicks onto the coil as well, make sure the coil is bolted down. look at the pins, make sure there isnt one bent or pushed into the connector. if you shake the coil and hear metal stuff inside moving, you need to rebuild the coilpack. you can also bring them to like autozone or something, and have them tested for spark. if your battery terminals are really loose, or the ground has lost connection, then you should start worrying about the ecu. if you lose battery ground when the motor is running, it will ground thru the coils back to the ecu, frying the ecu, hope this didnt happen to you.

 

[Atarian]

I did not replace the coil packs but did check them - per the manual they are all good, and all read almost exactly the same across pins 1-2, 1-3, and 2-3. I did clean the contacts of the connectors and made sure they snapped on tightly. Bolts are secure. By the way the torque value in the book is wrong - it points to the coil securing bolt and gives the torque for the spark plug.

I'm going to get some new plugs (OEM) on the way home and swap them out. That's about all I can do. Battery connection nice and tight - didn't think of that one - thanks. Will also shake the coil packs.

If it's the ECU again I think the car is doomed, depending on the price of a new one. Or something hidden in the wiring harness

Will post results of the spark plug change.

 

[i68k]

please dont use bosch anything on your sentra, except maybe wipers

also, dont use any funny tipped spark plugs, just normal tipped spark plugs. like regular single tipped platinums or iridiums should work fine.

 

[Atarian]

Update:

Picked up new NGK plugs this afternoon - the exact ones listed in the manual. Parked in garage and put a fan on the engine to cool it down quicker. After several hours replaced the Bosch plugs with the NGKs and cleared all codes with my code reader. Drove around for a while until the car was fully warmed up. Parked for several hours. Just got back from driving for about 25 minutes. No SES. Code reader shows no active codes, and no pending codes.

While too early to call this a victory it appears as if the service life of the Bosch Platinum +2 in my engine was exactly 1,520 miles. They did appear to have black (carbon?) deposits already. Not oily. I don't recall the previous NGKs with 60k on them looking this bad.

If the light comes back on I'll be sure to report back here.

Thanks to all who read/replied.

 

[i68k]

anytime, hopefully you problem was those silly multi-tipped spark plugs. not sure the exact reason, but some cars act horribly with them, particularly nissan. also, dont use bosch anything on your sentra, its not german.

when you change your spark plugs, you should only take them out when your motor is cold, which i think you did. never take them out of a hot motor.

 

[Atarian]

Engine was cold - or at least room temperature. I know someone who took one out, or tried to, from a hot engine (w/aluminum head) a while back. Needless to say, it was towed and what was left of the plug was removed by a mechanic. Probably had to re-tap the head, or put a Heli-coil in it, or whatever they do.

Still no codes!

I'm a happy camper.

BTW i86k, I'm only 100,000 miles behind you - watch out. This thing seems like it wants to run forever.