Smog Pump, Good or Bad? Q & A

[MikeR351w]

I am trying to figure out if my smog pump is good or bad and should bypass it. There is a noise comming from one of my pullies and all appear to be fine upon inspection, except for the smog pump. When I spin it by hand, with the belf off, it stops right away and makes a scraping noise.'

Is this normal? I would like to remove it and bypass it with a shorter belt, as I do not have catalytic converters anyways. Will the removal of the smog pump effect drivability? Thanks!!

 

[mob]

hmm, id remove it, you dont have cats so you should be fine. If you have the smog pump tube from your exhaust cap it off, and cap the holes behind each head. Just take off the smog pump, take out the hoses and buy a shorter belt, the pump shouldnt stop like that, im pretty sure the smog pump is a free spinning pulley. I rememeber when my alternator blew up the pulley wouldnt even turn, and the belt was just running over the pulley burning the belt as it went over it, and made a horrible screeching sound, just ger ride of it before it causes more problems. If you had cats id say other wise, but since you have o.r pipe just get ride of it, should free up alittle weight up front too.

 

[HISSIN50]

If you have no cats anyhow (for off-road use, o' course ), I'd also ditch it.


Should you decide to open the pump up and fix it:
The vanes inside the pump travel on an elliptical path. The two major ways you get scraping is that the bearings on the mainshaft take a crap, which leads to screeching and the vanes hitting the walls because of the additional run-out. Or the leaf bushings begin to fail, which keeps the vanes from travelling into the drum with ease. This allows the vanes to hit the wall and side load the leaf bushings, snowballing the issue.

Some pumps do tend to make noise, but there should not be resistance to make the internals spin. Even some reman'd pumps have instructions saying that they can be noisy and drag a little (when spun by hand) for some miles.

All that said, an AIR pump delete pulley sounds like a nice alternative.

Good luck.

 

[niklid05]

I would delete it. I deleted mine a month or so ago. I ran a shorter belt. I also took the canister and bracket off. I can see the ground through there now lol.

 

[MikeR351w]

Sure,

Will do. I will run a shorter belt tomorrow and see if that stops the screeching noise. Also, I have another question about my pulleys. I went throught 2 alternators in one summer. Both had the same problem. The pulley on the alternator started to wobble. When you spun it, it looked like a a bent bike rim on a bicycle. I figured the belt was too tight, so I re routed a pulley with a a/c eliminator kit and a shorter belt. That seemed ok w/my new 130 amp alternator, but now I heard the same screeching noise I heard with the old setup. So i was wondering if the Smog Pump was causing the belt to hang and bend the alternator pulley. Is this possible?

 

[stangbear427]

I don't know about that, the only time I've seen anyone go through alternators that fast was when they bought them from one of those "Mcdonalds Auto Parts" type places. I've never heard of this particular problem.

But along the original line of questioning: I agree with everyone else that deleting the smog pump is a good idea that shouldn't cause any problems. One less thing to crap out and ground you, IMO. My 266,000 mile GT flew through emissions without it no problem, and for that one week out of every two years that the catted oem pipe is in the car, there were no drivability issues whatsoever. Technically I wouldn't think running cats full time without the air pump working would be a good idea, but I have no personnal evidence to back this up.

 

[rd]

If it is noisy, change it. If it fails, it drags the fanbelt with it.

If I had it connected, etc, I would just replace it. Removing it will require a belt change, etc. This costs almost as much as the pump.

My 79 still has one on it's 5.0. No clue if it works, but it and all of it's little pipes and vacuum hose buddies are still there.....

 

[MikeR351w]

I fixed the screeching with an adjustment of the tensioner pulley. However, I would still like to get rid of the smog pump. How much HP would I gain from that? Just curious.

 

[stangbear427]

Not much. Nothing, really. However, everything you can do to make the crank spin up easier makes the process more efficient and can only be a step in the right direction. Now removing the smog pump, the power steering, and adding underdrive pulleys- there's something you may feel. Direct benifits of just removing the smog are simpler though: you'll remove weight from the heavy end of the car, remove the possibility of that pulley ever freezing up and throwing the belt leaving you stranded (had it happen), clean up the cluttered engine bay, and make it easier for the engine to do it's job. All good things.