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Head noise?!

309 Views 10 Replies 6 Participants Last post by  joes01bullitt
buddy of mine has a 1999 GT changed the oil yesterday has 110xxx has been using castrol GTX 5W-30 since he bought it at around 60k....

well he switched to 10W-30 yesterday and a bottle of lucas because of the high mileage and being that its a daily driver and weekend racer. Well now his heads seem to be ticking or the timing chains cant really tell...

I told him to go back to the 5-30 and see what happens from there...

any input or help will be greatly appreciated.


1 - 11 of 11 Posts
use 5w20 or 5w30...those motors dont like thicker oils
use 5w20 or 5w30...those motors dont like thicker oils
really what gives?
I could use some head....:banana:
I could use some head....:banana:
sounds great right about now.....:cool:
really what gives?
tolerances are tighter, and something about getting oil to the top of the motors faster is why I think. What Ive always thought about MOD motors.
Don't need anything thicker than 5w30.
really what gives?
tight tolerances. ive heard of thicker oils causing issues in more than one instance...
It's called cold start pump ability. Eventually the cold start knock rubs more clearance into the bearings and you end up with an engine that is down on oil pressure, among other things. You may also consider the switch to a Wix brand oil filter if not already using.

As for the heavier oil for the higher mile engines...I currently have and also have had several 300K+mile "service industry" oriented vehicles that I've ran 5W30 oil in and even with these high miles on them, they do not smoke or consume any oil whatsoever. The most I have had to do is replace rear main seals a time or two. I recently did a leak down and cranking compression test on one cylinder just because I was very curious. I had 180PSI and less than 5% leak down on an ice cold cylinder. This for me is just further testament of something I already have long known: Royal Purple and sometimes Mobil 1.

You also need a quality oil as the microscopic amount of it left on the cylinder wall by the oil ring leaves very little to keep the rings and surface finish lubed. Therefore, you need a very good oil so they will live for many of miles.
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thanks for the input guys.

told my buddy,he switched back and no more noise!
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