350 vortec sounds like a diesel

[Dirtautoguy]

My 1996 chevy k1500 with a 350 vortec in it has 215000 miles burns no oil but it does leak oil a little but I was wondering when it's cold like usually in the negatives it sounds almost exactly like a diesel after it warms up it sounds fine I'm just curious as to whether I should be concerned about it or not?

[00Silverado4x4]

From what I've been taught on the old 350 is, if she's not knocking, leave it alone. Although it could be due a rebuild, 215k miles is pretty good mileage.

[Dirtautoguy]

Well it's still really strong and doesn't burn oil and after it warms up it runs like a champ I was just curious it could be the 85 octane gas I'm running in it too.

[Dirtautoguy]

And if its warm like twenty above its sounds normal on startup it's only when it's in the teens/ below zero but I guess it probably has an excuse with that many miles and in that cold of weather

[00Silverado4x4]

Well it's still really strong and doesn't burn oil and after it warms up it runs like a champ I was just curious it could be the 85 octane gas I'm running in it too.

 

That could be it, for giggles run a few tanks of higher octane in it. See what she does.

[Dirtautoguy]

I had the oil changed, and I put in 87 octane like it recommends and the truck seems to run smoother not that it was running bad, but it also seems to be happier about accelerating not by huge amounts but just slightly.

[Prokopchuk_9]

When's last time you changed fuel filter/spark plugs/plug wires. Like an actual good tune-up??

[Dirtautoguy]

Just over a year ago I replaced those. The cap and rotor have been replaced just a few months ago because they keep going bad.

[Prokopchuk_9]

Why they keep going bad?? Have you replaced the shaft too?

[Dirtautoguy]

I have not replaced the shaft or the coil I'm looking into it now. They keep cross firing or getting the white powdery insulating on them ( which I have just been cleaning)

[Prokopchuk_9]

Ya replace the shaft/coil...I bet it's worn.

[Dirtautoguy]

I just replaced the dist. Shaft today and took it to my cousin to finish timing it and now the motor is alot quieter it seems like and pulls alot harder. I wonder if that was part of the reason it was making these Noises