Smokin down hills! (1 Viewer)

[NocalFJ60]

I am in the process of trying to get my cruiser to pass smog. I ran some sea foam in the gas tank and just finished the tank.

I am wondering why when I coast down a hill like 2 miles long in 3rd gear and come to the light and stop my cruiser smokes out the pipe bad. I am not touching the gas going down the hill, but right when I stop, smoke. I am wondering why this happens. Could this be a symptom of my smog problem.

Thanks

 

[lowtideride]

after sea foam? prob. burning carbon out of your engine?

 

[NocalFJ60]

after sea foam? prob. burning carbon out of your engine?

I hope so! I will see if it clears up with this next tank of gas.

 

[humper99]

What color smoke? Blue smoke is oil burning which could come from the valve stem seals. Under high vaccum coasting in gear situation oil can be sucked past a bad seal and into the intake/cylinders. Once stopped at the bottom idling the oil will burn off in combustion and give some blue smoke to the exhaust.

 

[treerootCO]

The hill thing creates more vacuum and could be pulling oil past the valve guides. My 2F does the same thing but it is tired and probably has close to 300,000 miles on it.

 

[fsusteve]

What RPM's are you running when you do this? Sounds like engine braking to me, tough on the motor.

 

[60wag]

I'll third the valve stem seals. I doubt its related to the smog issue. Are you failing on CO, NOx or HC?

 

[NocalFJ60]

The smoke is grey coming out. I am failing on CO and HC only. It is bad on the engine? So when you are going down a steep incline in the mountains and want to stay off the brakes. It just puts more wear on your engine? I will try in the day where I can see the smoke better.


I am probably around 2600 rpms.

 

[NocalFJ60]

What RPM's are you running when you do this? Sounds like engine braking to me, tough on the motor.

Can someone elaborate on engine braking? I understand kinda what it is, but how bad is it for your engine? Do you want to keep the rpms down when going down a steep grade when trying to stay off the brakes?

 

[Stumper]

I have had the white-ish/gray-ish smoke come out of the tail pipe from engine braking down hill. Turned out to be head gasket failure/cracks in the head. Take a look at possible symptoms of that. Antifreeze/gunk on end of dipstick, check for air bubbles in radiator, search on here for head gasket issues. May not be it, but worth looking into.
HTH

Russ

 

[NocalFJ60]

I have had the white-ish/gray-ish smoke come out of the tail pipe from engine braking down hill. Turned out to be head gasket failure/cracks in the head. Take a look at possible symptoms of that. Antifreeze/gunk on end of dipstick, check for air bubbles in radiator, search on here for head gasket issues. May not be it, but worth looking into.
HTH

Russ

I think that might be my problem. I am going to look into it so I can rule it out.

thanks