I posted a few weeks ago about my 98 454 making what sounds like lifter noise all of a sudden. I changed the oil and filter even though both only had about 800 miles on them without having any effect on the noise. The oil I drained out looked normal and it looked normal on the dipstick before the drain. Truck just turned over 113,000 miles on it.
My fiancee's father listened to it while I revved the engine up and he said the noise sounded like it was coming from the valve cover on the driver's side. I had him get in the truck and do the same thing while I listened to it and it does sound like lifter noise. It is not a loud tap or tick but sounds like generally loud valve train noise. At idle it sounds almost normal but only gets kind of loud as the RPM's increase.
Last week I changed the thermostat because I had been running a 180 degree one and my gauge was staying pretty low so I decided for the winter I would put a factory 195 degree one back in. I used an AC-Delco one. I have been keeping an eye on the coolant overflow tank and it has gone below the cold mark on the tank twice but I don't know if this is because I had air trapped in the system or because I have an intake coolant leak. The oil does not look like it has coolant in it so if it's leaking, it's not a very big one. I don't know if an internal coolant leak would cause this lifter noise. My 98 5.7L truck had slow intake coolant leaks four times over the years without any lifter noise so I don't know if this would be a cause.
There are no CEL or misfires according to my OBD II scanner. Truck seems to run normally otherwise with plenty of power. I just don't want to ruin the engine by continuing to run it.
So my question is, what are some of the reasons why an engine all of a sudden would develop lifter noise? Thanks,
Wayne
My fiancee's father listened to it while I revved the engine up and he said the noise sounded like it was coming from the valve cover on the driver's side. I had him get in the truck and do the same thing while I listened to it and it does sound like lifter noise. It is not a loud tap or tick but sounds like generally loud valve train noise. At idle it sounds almost normal but only gets kind of loud as the RPM's increase.
Last week I changed the thermostat because I had been running a 180 degree one and my gauge was staying pretty low so I decided for the winter I would put a factory 195 degree one back in. I used an AC-Delco one. I have been keeping an eye on the coolant overflow tank and it has gone below the cold mark on the tank twice but I don't know if this is because I had air trapped in the system or because I have an intake coolant leak. The oil does not look like it has coolant in it so if it's leaking, it's not a very big one. I don't know if an internal coolant leak would cause this lifter noise. My 98 5.7L truck had slow intake coolant leaks four times over the years without any lifter noise so I don't know if this would be a cause.
There are no CEL or misfires according to my OBD II scanner. Truck seems to run normally otherwise with plenty of power. I just don't want to ruin the engine by continuing to run it.
So my question is, what are some of the reasons why an engine all of a sudden would develop lifter noise? Thanks,
Wayne