After washing dax rush today running 2wd cosworth after getting back in to take home only running on three cylinders sounds like an old pig. Thought it would have dryed out after 10 mile drive but still only running on three was fine before washing. Will this just cure its self after drying and how long will that take did not see any water near engine or electrics?? Or could have some thing else gone wrong??????

Also just had oil change and new filter castrol rs 10w/60 and sounds like a bag of nails when first started up very light tap on cam area for a couple of seconds but also some other kind of very light tap thats intermitant once warm sounds lovley and no smoke or rattles of any kind. Do I need to try a different oil????

Another thing is that i have a workshop manual that states that it should be running either 10w/30 or 20w/50 should i use theses vicosity`s???

 

mmm, a dax rush with a cossie engine - yummy

Castrol 10/60 is what many people use, certainly for older engines, anything thinner will just go out in smoke through your exhaust.

Could just be a coincidence that it ran on three after a wash to be honest. I had a similar problem on mine (running on three), turned out to be a plug which had a hairline crack on the ceramic insulator.
There are many other things that could be the reason it's running on three. I assume you know what to look for.

The intermittent tap could be a sticky follower, they get gunked up with time and short or replacing or cleaning them, there isn't much you can do.

 

would what petrol im using make any difference to the running do you have to use 98ron petrol???

 

you must run at least 97 ron[super unleaded] otherwise you will be doing some damage!

castrol RS 10/60 worked for me but you could try out a number of oils.

valvoline 15/50or 20/50 sorry cant remember which one
mobil motorsport 15/50 is what a lot of people use