Hi all, I was fiddling with the Uly's timing to try and stop the pinking I'm getting, which is better on high octane fuel, but still does it when hot. After googling 'pinging' etc, I find that advanced timing will cause overheating, something I'm still getting, like after 10 miles at a constant 70mph on a dual carrageway, the fan comes on while I'm still doing 70?!.
Now I had already retarded the ignition before, while trying to find the poor running stutter, because it was set advanced from the factory. It didn't 'ping' before and it's been spot on now for ages.
Anyway, it was also suggested that an intake leak can cause 'pinging', so I tested for it and found one. So I have removed the TB today and found that the front intake port is covered with a layer of flakey carbon buildup, but the rear one is spotless and shiney, like new. There is nothing in the manifold 'Y' piece.
So is this a normal thing to happen if the seals are leaking??
Or is there something else wrong?

Valve guide oil seals ?

_________________
Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

At 10,000 miles I shouldn't think so.
Have you seen this before, Maz?
Why does the carbon stop at the end of the port and not even stain the end of the manifold?

Yes, reversion and deferential in manifold/head temps.
Standard guide seals are dogshit.

_________________
Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

O.K. so which, head is the hot one? presumably the rear which means fan on, and able to burn the carbon out?