Hi there,

My wifes 2002, 1.2 8v Doblo, is experiencing something a little wierd that I hope someone can help with.
When you start it from cold, it tends to tap - EXACTLY like a hydraulic tappet, and then if you turn it off and start it again, 99.9 times it runs smooth as silk, again I though pointing to a tappet.
I have now been told its actually got buckets and shims and not hydraulic tappets at all!!!
I guess I am still looking at the clearances, but before I start, is there possibly something else I should check?

Appreciate any help.
borisb

Hi.
My 1.2 does something similar although it goes away when you up the revs to about 1500, In my case I would say it is a little end as it totally goes under load, it certainly isn't a bottom end fault.
Have you done an oil change recently? and what grade of oil are you using?

Its most likely the clearances, our Seicento (1100 version of the same engine) had really noisy tappets when when bought it at 15000 miles.
After measuring the all clearances and jotting them down you can just about get the bucket and shim out with out removing the cam, the shim will have a measurement written on it. Add or subtract and you will find the one you need. I had a spare head and made do with the selection of shims I had from the two engines and it ran really nice and smoothly after that.

The clearances are all documented on the site somewhere.

Hi there,

Thanks for both replies. From those two, I hope it tappets and not little end! Either way, checking the tappets first is the sensible way to start.

Oil grade, yes interesting, and I wouldn't mind being told what it actually is supposed to be! I changed it fairly recently, and to be honest its low mileage and the oil always looks very good, (not thick black). I used a fully synthetic 10W40 - is that correct?

Again thanks, looks like the weekend is getting booked up!
borisb

if you stop engine then start and its ok (when cold) its probably the valve seat more than the tappet also if it was clearance it would get worse when hot as metal expands (gap decreases) I would assume.

If it was me i'd add a fuel cleaner treatment let it idle until warm then take it for a good blast in case there's a build up on the seat/tappet, worth a try,used to work on the 16v engines.

Is there a slight misfire when the noise is there?

Hi,

Sorry for the very late update.
The valve seat idea does actually sound good. There isn't a misfire though.
Have now moved it forwards...run an engine flush through the oil, and changed the oil, full synth 10W40, and added a Forte Top End Treatment. Still doing it after 100 miles or so. Also run a Forte Specialist Injector Cleaner through it, and still doing it....

So, what I did last weekend was to measure the clearances, and sure enough one does measure .533 on the inlet. (My emanual states it should be .40 +/- .05mm). The interesting thing was this was when cold in morning before starting - so would assume the 'tapping' would have been there on start up, (if I had started it). What I suppose I should now do is start it and run till tapping stops, then let it cool and see if the clearance is the same...if not, valve seat possible. Are the valve seats inserts in the head, could one have come loose???

If still .533, could that be enough to tap, but you would think it would tap all the time if thats the case....

I can see me ending up taking the head of to get to the bottom of it, unless anyone has some ideas please!

Lastly, if I do take the cam out to change shims around, what torque should the cam cap bolts be? The emanaul, (ebay special, recommend stick with Haynes), states 1 daNm. Is that 10 Nm in Italian!