My b16 with 132k miles on it makes alot of brown smoke at high rpms. The motor is stock and is well maintained. How can I determine if this smoke is something serious or not?

 

your car is pooping
run seafoam through it.
check your air fuel ratio sumhow.
rich? piston rings?

 

The smoke is a dark brown/black color. What is Seafoam?

 

search seafoam....

 

it cleans out your motor and gas tank

 

it's going to run a little bit rich at high rpms stock, I know I typically didn't get above 5k more than once every 300 miles so it would be a little black for a few seconds after the crossover.

If it's not more than a "few seconds" of carbon build up you probably should at least start with a compression test and inspect the spark plugs.

 

Do a compression/leakdown test.

 

If you're running rich your rear bumper would most likely be covered in black **** above the exhaust

 

Rear bumper is clean. No black stuff on it.....

 

Leaky valve seals.. When your in higher rpm's and your in vtec there is more, higher pressured oil running through. and causes them to leak when they normally wouldnt.. . thats what was wrong with my b16a2. check it out.

 

I thought valve seals only leak if the oil is not changed at correct intervals? Also, aren't leaky valve seals a cause of WHITE smoke? My smoke is black. What is the fix for leaky valve seals? Is it an expensive job laborwise?

 

The seals should be referenced correctly as valve STEM seals. I see too many people calling them just valve seals, which is incorrect. They don't seal the valve, they help to seal the stems.

White smoke is coolant, black smoke is fuel, blue smoke is oil. Valve stem seals will go bad after a while and harden. This will typically first be evident when the car sits for a while and is started. Upon starting it, there will be some blue smoke as it burns the oil that has passed the stem seal and wet the cylinder top.

 

Valve stem seals are notorious to go out in Honda motors. All Hondas burn oil in Vtec, even brand new or freshly rebuilt motors. It's not a huge issue until you start to burn up a lot of oil even during normal driving. I'd advise you to do a compression and leakdown (most important) test.

 

do NOT use seafoam. you will kill your rings at that high mileage

 

Please explain how seafoam will "kill" your rings.. I want to see if this statement has any form of experience/education behind it or if you are making a bandwagon assumption.

 

I pulled my plugs and installed new ones with new wires. The plugs I pulled look to be the factory plugs from Denso. Wires were dated 1999 as well..... I'll get a pic up tomorrow, but the plugs look pretty good in my opinion....

 

Did you replace them with OEM wires? Can't beat OEM or NGK blues. Anyways, I don't know what would cause a brown smoke. You 100% sure its brown? Never heard of brown smoke. You using oil on the stick? Any signs of coolant loss? If not, I wouldn't worry about it.