[leomd]

I have a 2003 4.4 with about 98k miles mostly highway. For the last 20k miles I have noticed a valve knock upon acceleration after the car is warmed up - about 15 minutes into driving. Is this just the quality of gas in Miami or is the car telling me it needs a valve job? I don’t notice any loss of power or smoke issues - just this crazy knocking upon harder acceleration. Any thoughts are appreciated.

 

[roverboy]

Mine only knocks on the start up the "Vanos knock". It could be the gas or the viscosity of oil you are using with the heat down there.

 

[leomd]

I beleive I am using a 50 weight oil - could the cause really be oil viscocity and high heat? Using high octane or regular gas seems to make no difference at all with the knocking.

 

[roverboy]

viewtopic.php?f=2&t=31413

In the last comment the user changed the viscosity of his oil and it went away.