i have a 95 Nis pickup 4cyl and the engine idles and runs smooth but during startup and acceleration i get a little puff of smoke and if i rev the engine. are there any additives that i can use or does this sound like a mechanic problem???? Also what could be causing this to happen?

 

Try seafoam. It is awesome.

 

There are two questions you need to ask:

- Is the engine burning motor oil (do I need to add oil between oil changes)? If so, you may be seeing the results of this oil burning.

- Do I see this "smoke" after the engine has completely warmed up and I then accelerate? If the engine is still cold you are probably seeing the "steam" from the evaporation of the condensation of water that has occurred in your exhaust system. Remember, burning a gallon of gasoline produces almost a gallon of water as a part of the combustion process. I suspect that this is what you are seeing, particularly if the "smoke" is white like steam.

Good luck.

 

No this smoke is bluish white ,mainly when you accelerate, at idle its not smoking, the engine has about 126,000 miles on it now.It drives fine but im curious as to what could be causing it!

 

You did not say if the engine burns oil between oil changes. But based on your description, I'd say it is a mixture of burned motor oil (the blue) and steam (the white) from the combustion process. The bluer the smoke, the more oil you're likely burning.

 

I think your fine. Sounds like a bit of blow by to me. I have a 92' Nissan pick up truck, 5spd with 67,000 miles. If I drive it hard a bit, I get a bit of smoke but I think its just unburned gas exiting the tail pipe. I rarely rev the Truck past 3500. Thats what I have my Car for Other than that, its drive perfectly.

Just check the oil every few weeks and make sure it at the right level. I use MObil 1 Fully Synthetic Oil on my car and truck and I burn Zero between changes.

-matt

 

The cat converter will take care of unburned gasoline so that it does not come out of the tail pipe as unburned gasoline. It will be water vapor.

 

are there any additives or engine flushes i may be able to try or should i take to a mechanic?

 

well my gut is saying just old age-worn piston rings... does it happen worse after long (lets say downhill) in-gear decelerations? (extended and gear assisted slow down = strong vac to pull oil and/or fuelpast the rings or seals)

another possibility is less than perfect valve seals...

either way, its a costly mechanic bill. you can try a slightly thicker oil (but that can play havoc with your lifters, if they are hydraulic)

this is one of those situations where a flush might exacerbate the problem... if crud buildup is helping keep the blowby at bay lol.

i would try a thicker oil, or a full dosing of marvel mystery oil. its very mild, and won't dislodge chunks of varnish... downside is you might need to try it through 2-3 change cycles. i've never used seafoam personally, but have heard nothing but good things about it... however it IS a more aggressive product. (both will condition old seals and rings, helping them swell, and hopefully seal better. both will also act as a detergent, breaking down sludge or varnish... but not to the extent a kerosene based flush would.. definitely a safer choice, in your case, than a flush in my opinion.

there are also a gamut of "stop smoke" products out there.. personally, i don't trust any of them that don't have a chevron logo attached its spendy, but the chevron additives (be it injector cleaner, ring and seal conditioner, or many of the other petroleum based additives out there) have always worked the best for me. Lucas, and other such additives have done absolutely squat in many situations.. and a wquick look at bobistheoilguy.com will show you some interesting things about lucas oils.. blech.

is the smoke bad?

 

You could always try AutoRX. A lotta people swear by it.

 

Your motor is aging normally... ungracefully. I had a truck that did the same. It was the valves seats. Just ride it till the wheels fall off!
Happy early St. Paddy's!! ( I am starting early-Green beer bender!!!)

 

I know the motor has some age on it but at 126,000 should it be smoking and how would i correct the valve seats?

 

This really depends on how the vehicle is driven the majority of the time.
If it's hammered on constantly and abused, it'll show. The same is true on the flip side if you baby it.