Coolant / Temp Query 1.8Tdci Mk2

[SmithyJ]

OK so I've been cleaning and tidying up the basic stuff on the Focus. After boiling the brake fluid one night I had the brake fluid changed,when they did the boil test it was boiling at 150 degrees c! Something tells me it's never been done, although the discs and pads look new ish.

Anyway while I had the scuttle covers of I've blanked the Egr and sealed with gasket seal, cleaned all the bits you can't normally see. And I've changed the 90 degree pipe at the top of the engine due to a hole appearing.

Runs sweet as a nut now, well after a few combined cycle miles to reset the ecu and very smooth delivery.

What I did notice today on a high speed run is whenever I take it up to the maximum and then while off throttle to decelerate, the temp needle seems to spike and then return to middle. I've never noticed this before so can anyone tell me if it's normal. Gonna change the coolant as a precaution anyway.

Also, is it common for the intercooler to fill with cack? Noticed alot of black cack in the pipes

[SmithyJ]

Forgot to add it's running a stage 1 remap now with upgraded panel filter.