Hi guys, thought I would share my experience with a smoking exhaust that started and slowly got worse. Similar amount of smoke when you start up a wood fire to grill some steaks, a lot of smoke. This was a rebuilt forged motor with about 1500kms which I had built and I was mentally preparing myself to remove the motor.

 

I started to experience slight smoke after about 20 seconds on first start ups. This after a run would clear up and have no issues through out the day but next morning would smoke again and clear after a run. This eventually got worse over a few weeks which even resulted in oil droplets coming out the passenger tail pipe, the exhaust does not have an X or H pipe so it was a left bank issue.

Isolated the problem to number 6 cylinder as on removing the spark plug I noticed oil on the piston top and the plug was sooty and oily. First thoughts were damaged wiseco piston or valve guide/seals and depression set in bad. Inspection also revealed slight evidence of oil in left and right plenum floor which led me to believe it could be bad PCV valves.

The remedy was to remove the PCV valves and spray carb cleaner into the plenum via the throttle bodies and allow the residue to drain out the PCV holes. I checked the PCV valves and they were working correctly (able to suck on threaded end but not blow).

I decided to do a PCV delete and grabbed a set of used PCV valves and welded up the holes to block them up which I then refitted to the plenum and reconnected the hoses. I then removed the front PCV hoses on the inlet covers and removed the brass restrictors within them to increase the flow as I had deleted the rear ventilation flow and refitted them back into their original postions. I started the car and it smoked a bit but was much less than before and then went for a long run to clear any oil in the pipes. Next morning I started the car and there was no smoke at all which was a tremendous relief. The car does not smoke anymore and I would not have believed that this was the cause of the smoking issue.

So just check your PCV before you go any further.

Good info antman :thumbup1: thanks for sharing.