2003 chevy s-10 4.3 v6
4.3 Vortec v6
Repair work done prior = none I just bought the vehicle a few months ago
Work done to repair this problem = hooked up a scan tool to see if knock sensor was
working. Does not seem to be retarding the timing under a knocking situation.
Checked for 5 volt reference. I have 4.3 volts. Changed the knock sensor. Still have
same problem.
tip/donation yes
question = Hi.
Start up truck. Runs and idles fine until it gets warm. After that when putting a load on
the engine such as going up a hill or accelerating from a light, a spark knock can be
heard at the 1500rpm range. When the engine hits 2000 rpm, it goes away no matter
how much load you put on it. The scan tool indicates the coolant temp to be about
180 deg F, the timing advance will go from 20 deg to 35 deg or so but when the knock
occurs, the timing does not seem to be retarding. I have driven the truck with scan tool
(Actron) connected while driving to check this. I have tried Tecron to clean the
injectors, air cleaner is clean, no trouble codes set, I am and have been running 93
octane to try to keep the knock down.
4.3 Vortec v6
Repair work done prior = none I just bought the vehicle a few months ago
Work done to repair this problem = hooked up a scan tool to see if knock sensor was
working. Does not seem to be retarding the timing under a knocking situation.
Checked for 5 volt reference. I have 4.3 volts. Changed the knock sensor. Still have
same problem.
tip/donation yes
question = Hi.
Start up truck. Runs and idles fine until it gets warm. After that when putting a load on
the engine such as going up a hill or accelerating from a light, a spark knock can be
heard at the 1500rpm range. When the engine hits 2000 rpm, it goes away no matter
how much load you put on it. The scan tool indicates the coolant temp to be about
180 deg F, the timing advance will go from 20 deg to 35 deg or so but when the knock
occurs, the timing does not seem to be retarding. I have driven the truck with scan tool
(Actron) connected while driving to check this. I have tried Tecron to clean the
injectors, air cleaner is clean, no trouble codes set, I am and have been running 93
octane to try to keep the knock down.
JK:
This may be a timing chains or balance shaft noise. Common on this engine. Most
people never complain about it.
A stethoscope would help, but still kind of hard to decide if it is.
Here is the description taken out of a service bulletin...
"Some customers may comment on a rattle-type noise coming from the engine at
approximately 1800 to 2200 RPMs. Spark-type rattle may be caused by torsional
vibration of the balance shaft."
New timing chain kit with tensioner, chain, guide. Noise is not detrimental to chain or
engine performance.
If by chance you have not owned similar vehicles with this engine, a rattle may be a
normal condition. These do have a little rattle noise to the engine. Most people dont
complain about the sound this engine has, since it has it from day 1.
With scanner on, do this procedure at idle and 2200 RPM...
Watch knock signal- voltage or YES- NO. Tap one of the exhaust manifolds with a small
ballpeen hammer. Tap lightly about 4 times per second. Signal should switch, or change
voltage. If not, do it a little harder.
If changes, then the system is functioning.
Things that can cause spark knock on this engine are an EGR with some carbon in it
keeping it open a little bit. Remove valve, blow it out, blow out intake passages.
Low fuel pressure.
Carbon on the valves or pistons. Doing a top engine cleaning may help if a carbon
problem.
This may be a timing chains or balance shaft noise. Common on this engine. Most
people never complain about it.
A stethoscope would help, but still kind of hard to decide if it is.
Here is the description taken out of a service bulletin...
"Some customers may comment on a rattle-type noise coming from the engine at
approximately 1800 to 2200 RPMs. Spark-type rattle may be caused by torsional
vibration of the balance shaft."
New timing chain kit with tensioner, chain, guide. Noise is not detrimental to chain or
engine performance.
If by chance you have not owned similar vehicles with this engine, a rattle may be a
normal condition. These do have a little rattle noise to the engine. Most people dont
complain about the sound this engine has, since it has it from day 1.
With scanner on, do this procedure at idle and 2200 RPM...
Watch knock signal- voltage or YES- NO. Tap one of the exhaust manifolds with a small
ballpeen hammer. Tap lightly about 4 times per second. Signal should switch, or change
voltage. If not, do it a little harder.
If changes, then the system is functioning.
Things that can cause spark knock on this engine are an EGR with some carbon in it
keeping it open a little bit. Remove valve, blow it out, blow out intake passages.
Low fuel pressure.
Carbon on the valves or pistons. Doing a top engine cleaning may help if a carbon
problem.