Just did an oil change on the car the other day and it was recommended that I use engine flush as hadn't done an oil change for a while. Seems to have worked ok as the tappets aren't knocking now! Anyway, to the point. Has anyone used this in their prized V4 or is it one of those ideas best left alone? Any possible damage it may cause to the engine?

Just to add, I Never go long between oil changes on the NC!

Oooh engine flush can be quite controversial :D

Without going too much into it, what some people find is that in an older engine, carbon and gunk deposits acutally help to seal imperections in gaskets, piston rings, valves etc etc.

After running engine cleaner through their engine it removes a lot of this and as a result the HG goes about a month later :-)

I've never bothered with it myself.. every NC13 Engine i've seen inside, even ones that have done 60k+ have all looked pretty mint.

Unless it's been left standing with oil and water or something I wouldn't bother personally :)

So yes.. it may do some harm.

Good old saying.. if it's not broken, dont' fix it.

So possibly got a head gasket problem looming for the car then! Good job I go cheap and cheerful on the car front! lol
Will keep it well away from the NC.