VT V6 knock in engine

[graham7773]

I have had about 6 different mechanics(??) look and listen to my VT V6 and none of them can offer an explanation for the knock in my motor. Lifters have been replaced with new ones. The knock is loudest when the motor is cold. As it warms up the sound becomes almost inaudible but comes back if the motor is revved but not as loud. One suggested cam or cam bearings but would'nt the mechanic who did the lifters have noticed any lobe damage? And there is no apparent loss of power which could be expected if valves were not opening correctly. Anyone with similar problems? Any ideas?

[])R@G()N]

So its running normal no missing or anything ?
My moneys on a big end bearing is rooted, but a mechanic should of picked that up. what sort of oil are you running in it?

[Killr6]

does it make the noise when your driving? or just idle?

[graham7773]

The car just went for a 2000k round trip (110+Kph)without any dramas, just the noise there when I start it. It's still there when I'm driving but harder to hear with all the other normal noises like tyre noise etc. 41psi in the tyres transmits road noise very well! I just upgraded engine oil to Penrite 20w50 from 10w40. Not much if any difference. Next oil change will be Penrite 20w60. Then I think I will be looking for another motor, VX or VY low k's. The engine does not miss but does have a very slight uneveness at idle. One thing that all of the mechanics aree on is that apart from the tick/knock, it is one of the best ecotec motors they have heard especially at 230000Ks

[FATMOE]

230k....expect noises it's a fact

[graham7773]

mzak89, I agree that the higher the Ks are, the more noises. I would just like to find out what this particular noise is and fix it if possible. Other than that, a low Ks VX or VY motor is on the horizon. Just an extra note, I just saw a VT motor for sale that had been rebuilt and run for about 2000Ks. $2500??? Nah!

[])R@G()N]

can you tell where the noise is coming from ? is it a tick or a knock?

How long ago did you get the Lifters done, was the noise there before getting them done?

If its the a big end bearing the thicker the oil you use the quieter it should be when cold, No one should use 10/40 in these motors its just to thin especially when there getting up in K's.
I have always used 20/50 and changed it every 10,000k's and My engine hasn't got any knocks ticks or anything, it got 240,000 on the clock now.