Been reading a lot about the "shaking at idle" problem with the VG engines. I can see easily that my car has a lot of carbon building up just by looking at my dual tipped monza muffler...and touching it...and observing the dark black dust on my finger (lol...)
anyhow, i have read that some people add ATF to their engines for short periods of time (a quart per 4 quarts of oil) and since ATF is corrosive, it will clean out the buildup, but you have to be careful and not leave it in too long or the seals will eventually get eaten through. anyone ever heard of this?

 

I'd use Marvel Mystery Oil over ATF, and I'd also Seafoam the combustion chamber as well (one at a time of course). Good luck.

 

I've done it on my 93 Chevy S10 and 96 Civic, both came through with flying colors no problem. The S10 had a blown intake manifold gasket which put water in the oil. I fix the gasket and substitute one qt of motor oil for 1 qt of ATF, ran the truck for it's usuall oil change interval, drain and fill, no problem so far. This was over 18-19 months ago.

Right around the time when I moved from FL to NC the Civic went EXTREMELY long without an oil change. Since I had good results with the ATF in the S10 I figured why not. Again I did the same substitution the ran it for it's normal oil change interval. Drain and fill, and no problem. This was over a year ago.

Granted, there are many engine flush additives you can buy at your local parts store but I wanted something that could be used long term and that's why I used the ATF.

Regardless of what you might hear it can be done

 

the black soot on your exhaust is from the engine running rich

 

All cars have some soot build up in the exhaust pipe....

 

that's because by default cars are programmed to run rich.

 

Teh more powah!!!

 

Not all the time. Only during warm up and WOT. But some cars at WOT have been known to run a bit lean.

 

even during regular use, it's safer for the OE

but yeah, some have been known to go lean at WOT

 

ACtually anytime other than my two examples will have the car running as close to 14.1 : 1 as possible. Especially nowdays.

Old maximas might run rich because 99.99999999999999999999999% of them ignore the 02 sensor that slowly degrades into a rich condition.

I suspect our friend with his 222hp VG is probably the same way

 

Who is this??????
222hp!!!

 

I thought stock our maximas were running like 12:1

 

warming up and WOT yea. But the narrow band O2 sensors are for making sure our cars stay near 14:1.

~Alex

 

Yeah, I kinda jump the gun with my post. If you're looking to remove the black soot in your tailpipe, AFT in the crank case will not fix your problem. As stated, all internal gasoline combustion engines will have some sort of soot in the tailpipe. You have a under laying problem somewhere else in the system if you're trying to resolve a idle vibration problem.

 

I would say injectors. I replaced mine and my tailpipe is clean. I would check them. Like Candiman says, you have an underlying problem causing this. Especially if you have the "shaking at idle".

 

haha, yes...

 

o2 sensor sounds right and its a cheap, easy fix...cheaper than going injectors first.

ive almost got a brand new car here, if any of you have been following my tuning/repairing for the last 8 months or so...

 

Although I wouldn't have a problem using Seafoam (in the combustion chamber and gas tank) while there is MMO in the crank. If I am going to use MMO I empty ~ a quart of oil 1000 miles before the change and add a quart of MMO. Don't use seafoam in the crank, the MMO is doing the job for it.


You can also use MMO in the gas tank. It's popular for rotary guys to use MMO in the combustion chamber (pull the spark plugs and "pour" some in) to help unseize a motor or to help condition it. While you can do it with piston motors I wouldn't bother unless you know what you are doing.

 

being new to a newer nissan motor< had 2 datsun 76 280 Z cars> how do you lean out a ve max

 

SAFC][ is one way