Hello everybody. Longtime reader of the site. Have gotten tons of useful information and questions answered all without ever needing to post just by reading through the archives. I do have a couple of questions that have been danced around before, but never really to my exact situation. Forgive me if anyone feels the answers have already been given. If they were, I simply missed them.
Anyways…
2001 Silverado Extended cab with a 4.8 with 149,000 miles. Had an event to attend this weekend. Drove from central PA to Cincinnati, OH. Roughly about 450 miles one way/900 round trip.
Question 1: On way out, cruising between 65-75MPH check engine light would flash and then quit (from what I understand this means a misfire was detected). It did this 3 or 4 times (not consecutively- there was some time between each time it did it), and eventually just stayed lit. We stopped for a restroom break or two and once for gas and light stayed on each time engine was restarted. When we got to Cincy and drove around there at city traffic speed the light went off. Was off the next day-again just city driving. Left there Monday morning and on the way home, same thing as before. When I got home, I read the code and it was P0300. From reading here, I gather it could be plugs, wires, coil packs or more severe causes like compression issues, leaking intake manifold, bad injectors. I got 19.7MPG on the highway with three full size adults and luggage, so I don't think it's possible that it's one of the more severe issues or it would show up in the mileage, right? I'm going to put new plugs (Delco Platinum 41-962) and wires (Delco 9748HH) on this weekend. I replaced both about 6 or 7 years ago. I think when I bought the wires, I got the shorter 9748GG because that's what the sales clerk gave me and they're stretched pretty tight. I didn't know at that time that there were two different wire sets that only varied in length at that time. Could this be an issue (or the issue)? In you guys' opinion, it this a worthwhile thing to try?
Question 2: When driving, when the engine gets to the 2000RPM area, I get an extremely loud tapping sound. From the cab, or even standing outside of the truck it sounds almost like an exhaust leak- that tell tell ticking sound. Thing is, it only does it from around 1800-2200 or 2300RPM. Above that or below that RPM range, the engine just purrs like a kitten. When you open the hood and rev the engine, you can tell that it's not an exhaust leak. It almost sounds like something in the top end. If it was a valve or lifter or something else in the top end, it wouldn't quiet down at the higher RPM would it? Also, if it was something in the top end of the engine, I wouldn't be getting almost 20MPG highway would I? Let me add that this isn't the piston slap issue that occurs when the engine is cold that I've read so many posts here about. It does that too, but that goes away when the engine warms up- this tapping occurs when engine is at normal operating range.
Question 3: Could Question 2 be related to the issue in Question 1????
Any help or comments would be greatly appreciated!!!
Anyways…
2001 Silverado Extended cab with a 4.8 with 149,000 miles. Had an event to attend this weekend. Drove from central PA to Cincinnati, OH. Roughly about 450 miles one way/900 round trip.
Question 1: On way out, cruising between 65-75MPH check engine light would flash and then quit (from what I understand this means a misfire was detected). It did this 3 or 4 times (not consecutively- there was some time between each time it did it), and eventually just stayed lit. We stopped for a restroom break or two and once for gas and light stayed on each time engine was restarted. When we got to Cincy and drove around there at city traffic speed the light went off. Was off the next day-again just city driving. Left there Monday morning and on the way home, same thing as before. When I got home, I read the code and it was P0300. From reading here, I gather it could be plugs, wires, coil packs or more severe causes like compression issues, leaking intake manifold, bad injectors. I got 19.7MPG on the highway with three full size adults and luggage, so I don't think it's possible that it's one of the more severe issues or it would show up in the mileage, right? I'm going to put new plugs (Delco Platinum 41-962) and wires (Delco 9748HH) on this weekend. I replaced both about 6 or 7 years ago. I think when I bought the wires, I got the shorter 9748GG because that's what the sales clerk gave me and they're stretched pretty tight. I didn't know at that time that there were two different wire sets that only varied in length at that time. Could this be an issue (or the issue)? In you guys' opinion, it this a worthwhile thing to try?
Question 2: When driving, when the engine gets to the 2000RPM area, I get an extremely loud tapping sound. From the cab, or even standing outside of the truck it sounds almost like an exhaust leak- that tell tell ticking sound. Thing is, it only does it from around 1800-2200 or 2300RPM. Above that or below that RPM range, the engine just purrs like a kitten. When you open the hood and rev the engine, you can tell that it's not an exhaust leak. It almost sounds like something in the top end. If it was a valve or lifter or something else in the top end, it wouldn't quiet down at the higher RPM would it? Also, if it was something in the top end of the engine, I wouldn't be getting almost 20MPG highway would I? Let me add that this isn't the piston slap issue that occurs when the engine is cold that I've read so many posts here about. It does that too, but that goes away when the engine warms up- this tapping occurs when engine is at normal operating range.
Question 3: Could Question 2 be related to the issue in Question 1????
Any help or comments would be greatly appreciated!!!