Fiat Uno Manual
Valve clearances - checking (1116 cc and 1301 cc engines)Engine / Valve clearances - checking (1116 cc and 1301 cc engines)
This should only be required if the valves have been renewed or ground in, or at high mileages when noise or poor engine performance indicates that a check is necessary.
It is important that each valve clearance is set correct otherwise the timing will be wrong and engine performance poor. If there is no clearance at all, the valve and its seat will soon burn. Always set the clearances with the engine cold.
1 Remove the camshaft cover. Jack-up a front wheel and engage top gear so that by turning the wheel, the crankshaft can be rotated.
2 Each valve clearance must be checked when the high point of the cam is pointing directly upward away from the cam follower.
3 Check the clearances in the firing order 1-3-4-2, No. 1 cylinder being at the timing belt end of the engine. This will minimise the amount of crankshaft rotation required.
4 Insert the appropriate feeler blade between the heel of the cam and the cam follower shim of the first valve. If necessary alter the thickness of the feeler blade until it is a stiff, sliding fit. Record the thickness, which will, of course, represent the valve clearance for this particular valve (photo).
25.4 Checking a valve clearance
5 Turn the crankshaft, check the second valve clearance and record it.
6 Repeat the operations on all the remaining valves, recording their respective clearances.
7 Remember that the clearance for inlet and exhaust valves differs - see Specifications.
Counting from the timing cover end of the
engine, the valve sequence is: