I have a kind of tapping noise coming from the engine. Its a 2.0 DOHC Sierra Sapphire......any ideas?

Ive just done an oil and filter change, not helped the tapping

 

If it's coming from the top it is likely to be tappets.
You could try a ENGINE FLUSH like WYNNS, I use these to excellent effect on my cars including my cossie, then there is a HYDRAULIC valve lubricant that is also very good from wynns.
tabetha

 

deffinatelly sounds like tappets mate. my dads dohc does it he uses a slightly thicker oil than the recommended as its done over 120,000. seems to qieten them down abit

 

TABETHA is that right about you using a flush to help the tappets on a cossie. Mine tap a bit when its cold and then it is ok. I just didnt dare try anything since the engine has a turbo on it. Just in case it damages the turbo in any way.

 

most tap when cold but it should go after a min or 2. thats normal

 

A lot of tappy noises on a cossie are normal when first started, but should(mostly) settle within 10 seconds or so, though there will always be one lazy one.
Some people have used pattern lifters, as some PUG/VW/SEAT and other ones physically fit, but operate on a different pressure so will never work well and cuase noise after a few hundred miles that won't go away, not worth it when the cossie ones are only around Ł75 a set, and easy to do as well.
I personally use a flush before every oil change, I only use WYNNS, as found it to be ace, it is not crude like the old flushes and disolves the carbon rather than causes it to flake away and block oil galleries.
It will not affect the turbo in any way, quite the opposite as it will clean the oilways there too.
If it only taps when it is cold but ok when warm, I would not worry, mine has chronic piston slap when cold, and people mistake it for a MASSEY FERGUSSON, though at 170,000 miles without rebuild it is entitled to a protest now and again!!
I use flush in new engines as well, the insides of other engines I have taken apart which have been flushed regularly show NO carbon deposits, not a trace anywhere, turbo engines are by thier nature going to suffer far more blow by than non turbo so causing more carbon wash into the oil.
Just use a good oil like SILKOLENE PRO S, or similar to help keep it clean as the detergent package is great with this oil, and get it nice and hot once a month or so as this also helps to rid the oil of crap.
tabetha

 

But this isn't a Cossie is it? I think the guy has a 2.0 DOHC 8v I4.

Are you getting a clattering from multiple valves at the same time or a persistant tapping from one tappet? If its a clattering they have always been a bit prone to this, particularly on starting. My Dad had one and it did it from new for the first 5-10 seconds when it had been left for a a day or two.

Have you fitted a proper Motorcraft oil filter? It always seemed a lot worse with a pattern filter in it. Probably because the non return valve in it was not up to the standard of the Ford one...

 

Something else worth thinking about...

Don't these have a timing chain instead of a belt which can be a bit 'rattly' sounding like the top-end?!

 

Interesting you say that mate. It had a Motorcraft oil filter on her, I put a Halfords one on when I did the oil change using 10/40 Castrol. Its worse now that I have done the oil change, the old oil was very black, maybe thick enough to keep things quiet!!??

 

I bit of a daft question but its not the injectors is it cause i know my old sierra 2.0 the injectors were a bit noisey. I used 5/30motor oil in mine and it was ok not noisey.

 

Missed the bit about not a cossie!!
A quality FORD oil fiulter is a myth, they do not exist and are cheap shit.
I cut open a EFL298 filter(2wd cossie) and it had extensive rust inside, though was only bought a week before, AND stored in a snap lock freezer bag as there is a lot of dust in my garage.
It was certainly nothing special inside, and having since cut open a few more, I now use FRAM, had a MUCH larger filter area.
As for the non return valve, it does not do that well, after my cos had been stood 2 months it would not produce pressure as it had drained back the oil, until I spun the oil pump shaft by drill, for around 1 minute prior to starting.
I have just had to replace the GENUINE FORD OIL FILTER on my dads mondy, this was fitted in APRIL this year,(got all old receipts), but had rusted through and was leaking at the corner of it, when removed the paint was all lifted, upon opening up it was rusty as hell inside.
Not my place to tell you what make to use, make your own mind up, but remember, FORD DO NOT MAKE OIL FILTERS, they are made by someone else with FORD stamped on them, FORD are in the car game to make MONEY, the cheaper they get them the more PROFIT they make!!
tabetha