smokey when vtec.

[cheapdouchebag]

when i hit vtec, roars nice for a sohc, i like it but im leaving a trail of smoke at the back. why? engine runs fine n smooth. someone told me to use a heavier motor oil, im using honda's oem motor oil which has FEO premium motor oil written on it and a yellow themed label. got from a honda wrecker.
10w or something is written at the back

[pieee]

I was going to write a post like this as well but you seem to have asked the exact same question I'm trying to find out the cause of this also because it is currently happening to a friend.

[IEVAQ8]

first a couple of question u need to answer,
what colour smoke is it blowing???
how many km's on engine??
is the car modified???

[vtecster]

white smoke alot? if it is maybe leaking head gasket

[cheapdouchebag]

not sure what smoke, hard to tell.
230xxx kms on engine
not modified

[pieee]

Mates engine

Black Smoke
170,XXX KMS on engine im pretty sure

Not modified.

[czy_sol87]

its normal, alot of hondas do this, they tend to burn through oil as well

check ur compression a little smoke isnt bad, alot of smoke and smoke on idle, smoke on take off, and general crusing is when u have to be worried

white smoke means headgasket
if u can smell alot of burnt oil could be ur piston rings

but if its pretty stock and ur blowing a little smoke not too bad

also could be carbon build up in the exhaust, ie if u havent thrashed it in a while first time u do usually blows heaps of smoke out the exhaust

i know mine did that..

[EK1.6LCIV]

smelling oil could be present if you have a gasket leak say from the sump, crank seal, rear main seal, etc going onto the hot exhaust line under the sump

[~Sp33~]

Mates engine

Black Smoke
170,XXX KMS on engine im pretty sure

Not modified.


Does it lack power? Black smoke = running rich. If it's OBD0, check the map sensor on the fire wall, it runs a vacuum line to the intake manifold, and if the line is bad (leaking) it will tell the ECU that you're pressing the throttle harder than you actually are which makes your engine dump more fuel in than you need.

[blastnpast]

i owned an integra vti-r which blew the black smoke heavvvy black smoke :D so i traded that thing in and got my moneys worth hehehehe im on a project ek1 now :)

[pieee]

I'm pretty sure there is no lack in power, the vtec pulls pretty hard (when the panzy actually puts his foot down)

I will forward it to him about the map sensor.

Thanks for your help :)


Does it lack power? Black smoke = running rich. If it's OBD0, check the map sensor on the fire wall, it runs a vacuum line to the intake manifold, and if the line is bad (leaking) it will tell the ECU that you're pressing the throttle harder than you actually are which makes your engine dump more fuel in than you need.

[slimx]

what abot white smoke on a cold startup? after its warmed up though its fine??

is that bad??

[~Sp33~]

what abot white smoke on a cold startup? after its warmed up though its fine??

is that bad??

White smoke on a cold start usually due to condensation burning out of the exhaust.

[Jay-Jay]

i got kinda the same problem. .i got a b16a and when i hit vtec it blows black smoke out the exhaust and leaves oil shit on my rear bumper. .wat could it be?

[slimx]

black smoke is healtthy.. from wat i know??

u seen VL turbo's? fkn black smoke as it does a burnout lol.
white smoke is the baddd thing..

So is white smoke on cold really bad?? or just .. happens ..

as for .. oil n shit going on your bumper, get a plain exhaust tip just extend it out.. thats wat they usually do.

[dwn_boi]

I wouldnt worry about it, mine and alot of friends with Honda's have the same issue, my guess is similar as mentioned before, vtec allows more fuel/air mixture into the combustion chamber so its going to run richer which will cause the black smoke. If you were really concerned about it, try getting a tune up?

[dwn_boi]

i got kinda the same problem. .i got a b16a and when i hit vtec it blows black smoke out the exhaust and leaves oil shit on my rear bumper. .wat could it be?

as mentioned before would be a carbon build up in your exhaust, I get a similar thing happeneing, if you feel inside your exhaust it'll feel black and kinda greasy.

[EK1.6LCIV]

due to it running overly rich

[~Sp33~]

black smoke is healtthy.. from wat i know??

No smoke is healthy. If the engine isn't burning clean, it needs a tune.

[EK1.6LCIV]

black smoke for a diesel isnt too bad lol

wonder how old the cat is on that car

[~Sp33~]

http://images.ibsrv.net/ibsrv/res/src:honda-tech.com/get//images/smilies/ugh.gif

[Jay-Jay]

im loosing oil aswell guys. .and by how much smoke comes out the exhaust when i hit vtec doesnt look healthy

[IEVAQ8]

if ur also loosing oil, go and price up a rebuild, coz ur rings are fuked.........

[tmy]

Black smoke when vtec engages is pretty normal. VTEC Runs rich = smoke.

[~Sp33~]

Black smoke when vtec engages is pretty normal. VTEC Runs rich = smoke.

I'd like to see proof of VTEC running rich. The whole point of VTEC is to tightly manage a consistent A/F ratio through the whole rev range. It doesn't get to 5500~ rpm then dump your fuel tank in the engine.

[jks24]

ive asked several ppl now including a few Honda mechanics and they have also told me its normal for a bit of black smoke out of the exhaust when using VTEC....

[EK1.6LCIV]

I wouldn't worry unless it's going on for more than 10secs and a by stander might call the dot with details for a random epa check lol

[tmy]

I'd like to see proof of VTEC running rich. The whole point of VTEC is to tightly manage a consistent A/F ratio through the whole rev range. It doesn't get to 5500~ rpm then dump your fuel tank in the engine.
Proof, that i do not have.

Just relaying what my mechanic told me.

[dwn_boi]

I'd like to see proof of VTEC running rich. The whole point of VTEC is to tightly manage a consistent A/F ratio through the whole rev range. It doesn't get to 5500~ rpm then dump your fuel tank in the engine.

So what causes the black smoke then?

[dwn_boi]

Like I understand where your coming from as to consistancy, the Higher RPM Cam opens the valve for longer allowing more A/F into the chamber, not just extra fuel (afaik).

I just figured that maybe there is a slight possibility that more fuel may enter? But I guess you'd need proof to prove that theory...

[czy_sol87]

what abot white smoke on a cold startup? after its warmed up though its fine??

is that bad??

sounds like one of ur injectors might have a slight leak, so theres a build up of petrol in the cyclinder and when u start it up the white smoke appears

either that or head gasket is gone

[czy_sol87]

I'd like to see proof of VTEC running rich. The whole point of VTEC is to tightly manage a consistent A/F ratio through the whole rev range. It doesn't get to 5500~ rpm then dump your fuel tank in the engine.

maybe on a completly stock motor, dude, but what happens when u change something...like higher flow air filter, or bigger exhaust system, which most of the ppl on here would have done...

ecu reads more air, so it dumps more fuel in, most of the time, dumps more than needed, thats why its good to tune ur car after mods....

[Neesmo31]

Stoich! Is it running a standard computer?

[~Sp33~]

maybe on a completly stock motor, dude, but what happens when u change something...

An intake filter or an exhaust isn't going to really make much of a difference to the air fuel ratio. Obviously though, if you're going to start altering compression or advancing/retarding the timing it's going to alter how effective the engines burn is.


Like I understand where your coming from as to consistancy, the Higher RPM Cam opens the valve for longer allowing more A/F into the chamber, not just extra fuel (afaik).

This isn't my POV. The aim of a VTEC engine is to remain efficient, while maintaining an accurate air/fuel ratio throughout the RPM range. Like i said earlier, it doesn't get to crossover and pour as much fuel in as possible causing black smoke.

[dwn_boi]

This isn't my POV. The aim of a VTEC engine is to remain efficient, while maintaining an accurate air/fuel ratio throughout the RPM range. Like i said earlier, it doesn't get to crossover and pour as much fuel in as possible causing black smoke.

I didn't say it was your point of view and you basically just repeated what you said before, still doubting everyone else idea yet don't seem to have your own thought on what the excess black smoke is caused by.

The aim of vtec is to maximise higher RPM power output, if anything what your saying about efficency would be more relevant to the lower RPM ranges...

[~Sp33~]

I didn't say it was your point of view and you basically just repeated what you said before, still doubting everyone else idea

What's everyone elses idea? From what i read everyone else is just commenting on how 'vtec runs rich'. Which is wrong.



The aim of vtec is to maximise higher RPM power output,

By being efficient. Did you miss this? Let me quote it again:


while maintaining an accurate air/fuel ratio throughout the RPM range.

An efficient engine doesn't just mean fuel economic, it means (in brief) to makes power with minimal waste.

You stand to gain no power from running rich you also risk engine damage from un controlled ignition, so why would Honda produce an inefficient engine? Have you ever seen a new Honda blow black smoke during VTEC? (even back when EK's were new?) No.

Black smoke can be attributed to a fouled/old ignition system (spark plugs, leads, distributor, or 02 sensor) or a leaking map sensor, leaking injector... This isn't the point that seems to be discussed though. Your point being that VTEC causes black smoke, in which is wrong.

[2ds]

Every B16a I've ever seen has let out a small puff of black smoke on hitting vtec

It doesn't keep coming out after the changeover but there is always a little at the start.

And this is black smoke (being fuel) not blue smoke (oil)

[migoreng]

I'd like to see proof of VTEC running rich. The whole point of VTEC is to tightly manage a consistent A/F ratio through the whole rev range. It doesn't get to 5500~ rpm then dump your fuel tank in the engine.

according to my last dyno my stock h22a4 stays around 12.6 AFR til vtec..then goes towards ~11.8AFR at redline...

i don't really notice much smoke during the day but at night with headlights behind a grey/black smoke trail is really noticable...

[~Sp33~]

according to my last dyno my stock h22a4 stays around 12.6 AFR til vtec..then goes towards ~11.8AFR at redline...

i don't really notice much smoke during the day but at night with headlights behind a grey/black smoke trail is really noticable...

It's pretty common to drop slightly to dissipate cylinder heat and prevent pre ignition...

Not going to cause:


a trail of smoke at the back.

I'm just saying that Honda isn't going to tune their cars to smoke. (or any car manufacturer for that matter). I've already mentioned that anyway and made my point.

Good luck to the OP, make sure you post up what fixes the problem.

[cheapdouchebag]

yeah thanks but i cant be bothered fixing it
it doesit all the time when i floor it at the first sign of green light bahaha ima p plater hoon. if i ease it on and then pull through each rev then its fine.

got some news
5.3k for full b18c conversion inc transmission swap :D
and they giving me free dc2 vti-r brakes woo :D
drive in drive out beauty!

[Jay-Jay]

i've been told that it could be my valve stem seals. the thing is it only smokes after 7000rpm under that she is perfect. anyone had a problem like this and found out what it is?