Smoke billowing from my exhaust manifold?? '98 qx4

[clarosa]

When I drive my suv for a few miles and the engine warms up, smoke will start to billow out from my passenger side manifold. I am wondering if anyone else has has this problem? Could it be the valve cover's leaking because I do see oil residue in that area. The smoke is comming from near where the O2 sensor is conected to the exhaust. Does anyone have any experiences with this that could help me? thanks

[ARKQX33V6]

Smoke from the O2 sensor connection? When cool have a very close look at the exhaust pipe for rusted out pitted material that may be leaking, but with smoke there is something causing it. If the smoke did not manifest itself at the O2 sensor because of no leaking would your tailpipe end be the smoking problem?

If you engine is smoking you may be running too rich and the O2 sensors should pick that up and try to lean the mixture. A smoking engine will start to foul the plugs, run rich, and create all kinds of trouble codes.

Can you determine if that engine is a smoker or is this a new problem?

If a new problem check your air filter for cleanliness, check your throttle plate and horn intake for a black substance, check your EGR for carbon plugging, check your canister for leaks, check your timing and advance and check your fuel delivery for a clean filter, and pressure within the full lines.

The PCV Valve for oily plugged products and when was the last oil change? What is the mileage on this oil producer?

[clarosa]

Thanks for the reply. This suv has 154k miles. i just replaced the valve gasket and i think that was the root of the problem. The oil was leaking from the valves down to the manifold. I think i fixed it, but we will see. it isn't smoking anymore for now.

[ARKQX33V6]

Glad to hear it's fixed. When it is at temp do a quick compression test with 2-3 cylinders at the least better with all 6 find the highest reading and more importantly the evenness of PSIG with all cylinders.

Use a WOT and charged battery while testing.

[carnal_c30]

Completely common! my VG33E had a valve cover gasket leak as well- not as bad though.

Right now, my Y33 Infiniti Q45 and my Infiniti I30 have valve cover leaks. time to get dirty!