I bought a neon brand new in '03... ran 50,000 miles on it N/A and ran 10psi on a stock block for another 30,000 miles. The cold knock was present from the first day i brought it home until the day i sold it. Never caused me any issues.

 

i'll tell you what.

till last year i always used dino oil cuz it was cheap and provided all the protection that i thought my engines needed. i owned many new cars and have put hundreds of thousands of miles on them using dino oil, so i figured it was fine for neons and it is....... BUT if you have the typical engine knocking and valve slap, switch to a full synthetic and most of that noise will go away.

last year i got a 5qt container of wallyworld brand synthetic to try and i was amazed because it was the first time i had put synthetic in any of my neons. the slap went away and never came back. ive been using synthetics in all my vehicles and farm tractors, lawn mowers and gas equipment since.

 

All I can say is based on my own experience and with conventional 5w20 and the MOPAR 409 filter the knocking is MUCH less pronounced than before. I also think that when the car goes to a higher than normal idle in very low temps that the increase in engine speed which would correlate to higher oil pump output lessens the problem.

 

I have a 2002 neon sxt with 149,xxx miles. mine dose it it briefly during first start up in the morning around 10-15* outside it dose it for about 2o seconds or less. it still runs great its nothing to really worry about.