Can i drop it without taking the exhaust out. Please say yes, my cat looks like its on its last legs and if that buggers up it turns a cheap job into an expensive one.

Inside the sump, as well as the crankshaft, is an oil pick-up pipe that extends to the bottom of the sump. This is easily damaged when replacing the sump. It also means that the sump needs to drop its full height before it clears this pick-up. Unlikely to be possible unless the exhaust is dropped the same distance.

Soak all the fittings with plus gas or similar penetrating oil, not WD40, it is too weak. Soak the bolts for a day or so, reapplying, to give it plenty of time. Then should come apart.

Ach, cheers Bill. Its the pick up i want to look at. Im thinking (hoping) its partly blocked. I had a post about tapping cold tappets. Oil filter change did nothing so kind of hopeing that is part blocked and not enough oil is getting to the lifters causing the cold start chatter.

I assume Stilo 1.2 is the 16v engine. Presumably this has hydraulic tappets. If they are fixed like the 8v, oil pressure is not the issue.

Only way for oil pick-up strainer to be blocked is really heavy wear to the engine, or lots of goo from missed oil changes. What is the history?

Could try a flushing oil, then change filter and oil, flush again. Have you removed the cam cover to check for condition and oil supply to the top end?

Yeah 1.2 16v. 2002 with 47k on the clock. Full service history until i got my hands on it 12-13 month ago. Runs like a dream until teh chatter started, say around end of October. All i did was an oil dump and fill with Tesco cheap crap for under 100 miles then an oil filter change with whatever national tyres use.

So yes i kind of have missed oil changes as the car wanted a service since the day i bought it and god knows how long before. Must look at last stamp.

The problem is more likely to be gummed tappets than a blocked pick-up. The pick-up is a coarse strainer, only really catching larger bits, leaving the filter to collect finer particles. The top end has smaller oilways, so more susceptible to contaminants.

Oil grade is more important than where you bought it. Tesco will source from a reasonable source, but if you've used 20/50 instead of 10/40, the thicker oil will not go through the oilways properly until hot.

Get some flushing oil and change the oil for this. Run it as directed, then change for the correct grade (check the handbook, but probably 10/40) with a filter change. If lucky this will sort it. If not, you may be into new tappets, or removal for thorough cleaning.

Moral: Good oil, and regular changes are expensive, but cheaper than engine repairs.