Engine de-coke

[MarkB]

Engine out for stage3 soon... having covered nearly 100K miles is it worth de-coking the heads.

Years ago the backs of valves would be well coked up to the point they had taken on a new shape. Is this likely to be the case on this sort of mileage or has modern EFI got around that?

[s4woody]

i dnt think the term de-coke is the same as it used to be..unless your burning lots of oil then the valves would be gooie..
there is an easier way to clean the back of the valveswithout removing anything..
get the engine hot and remove a vacuum hose..then rev to about 3000rpm and put the end in a cup of cold water..keep the rev's up and as the engine sucks in the water it hits the valves and removes all the puup...
lots and lots of smoke..works well on older engine.s. ..

[ChipHazzard]

I thought red-ex was the best for de-coking an engine, I remember the clouds of smoke it used to produce when i used it on a couple of older cars although they we're n/a rather than injection cars

[MarkB]

These both worry me when running CATS and turbos

[ChipHazzard]

There is that to take into account

[clived]

although they we're n/a rather than injection cars

Surely a car can be n/a and injection?

[grizz]

Mark , send the heads to be acid cleaned when you get them skimmed , I would get them stripped and the valves re seated at the same time.

[MarkB]

Grizz, so you think it's worth doing?

[s4woody]

if you want to keep the car then defo get it chemically cleaned..i'd also get the bore,s done with new piston rings and get the crank checked and a slight regrind with new bearings..you no it makes sense..

[MarkB]

So, complete engine rebuild