Recently we have been seeing more and more 996 and 997 engines that have a tapping sound and smoke from one of the tail pipes at start up.
In the past this tapping noise was lifters or timing chain tensioners that failed but recently we have seen several cars with a worn out piston and cylinder.
The top shirt of the piston wears out allowing the piston to rock up and down and as the piston comes over top dead center the top edge of the piston hits the cylinder head causing the tap or knocking noise.
If you take the spark plugs out on the side that is smoking the plug that is becoming fouled is the bad cylinder. Typically this happens on the 4,5,6 bank which smokes out the drivers side tail pipe.
When can fix these engine with a replacement case half and three new pistons for around $10,000.
We have also put in used engines which can save you approx $2000 but you never know what you are getting with a used engine. You could be spending $7500 on a motor with the same problems you already have.
Call (267) 279-9477
Doylestown Auto Repair
241 Harvey Ave
Doylestown, Pa 18901