Question Wobbly Smog Pump

Shrav

Shrav

I'm New Here
Completionist Award C4
Mar 1, 2021
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VetteCoins
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1987 Corvette vert
Province
ON
Hi all,

At Timmy yesterday I head a weird noise (sounded like a squeaky idler pulley) in drive at idle. When I put it in Park the noise changed (quieter).
When I got home I popped the hood and could see that the smog pump puller had a wobble to it. That is my likely culprit (though it was quiet). I suspect it is on the way out.
What are my options? Where can I get a reasonable rebuilt unit (I don't want to gamble on a used 35+ year old one)?
I know there are delete bracket/hubs and I'm not against that BUT I know that the MOE did blitzes years ago (when I was living near Barrie) and now that I'm near Ottawa, are they still doing those?
I have looked at replacing the bearings but I don't have a press and I see no real good Youtube vids that would help.
Suggestions please!
Thanks in advance!
 
Shrav said:
Hi all,

At Timmy yesterday I head a weird noise (sounded like a squeaky idler pulley) in drive at idle. When I put it in Park the noise changed (quieter).
When I got home I popped the hood and could see that the smog pump puller had a wobble to it. That is my likely culprit (though it was quiet). I suspect it is on the way out.
What are my options? Where can I get a reasonable rebuilt unit (I don't want to gamble on a used 35+ year old one)?
I know there are delete bracket/hubs and I'm not against that BUT I know that the MOE did blitzes years ago (when I was living near Barrie) and now that I'm near Ottawa, are they still doing those?
I have looked at replacing the bearings but I don't have a press and I see no real good Youtube vids that would help.
Suggestions please!
Thanks in advance!
Click to expand...
Does the C4 run the pump off a common serpentine belt, or a separate fan belt? My 78 C3 had the latter...I simply removed the belt so that the pump was still there in case anyone checked it, but the belt was gone. Could always argue that it just broke that day.
 
rfh928 said:
Does the C4 run the pump off a common serpentine belt, or a separate fan belt? My 78 C3 had the latter...I simply removed the belt so that the pump was still there in case anyone checked it, but the belt was gone. Could always argue that it just broke that day.
Click to expand...
Unfortunately it is all one belt.
 
Found one state side that I have to drive 2 hours to get this weekend. $226 after conversion (not including what I’ll get dinged at the boarder).
I’m going to pull the old one and bring it with me to a) match up and b) for the core charge so I’ll get about $20 back after conversion.
Still not bad considering I couldn’t find anything in Canada and used would cost more than that after shipping.
Bonus points because I used my credit card that doubled my warranty!
 
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VikingTrad3r said:
was the replacement u drve to get a new smog pump?

what year? 85’s is diferent that 86-89
Click to expand...
Yes, picked one up at O’Reilly’s (a US parts chain) last Friday night.
My car is a 1987.
New pump was a little different (I had to use washers as spacers where the pump connected to the hose because the holes were not as deep as my original pump so they bottomed out before before actually pulling tight) and the 2 holes at the back of the pump were smaller so I had to buy smaller bolts.
But aside from that, it fits fine and no more wobbly hub.
Car actually runs quieter so I guess the old pump was worse than I thought.
Glad I realized it before it became a gernade under the hood!
 
Shrav said:
Hi all,

At Timmy yesterday I head a weird noise (sounded like a squeaky idler pulley) in drive at idle. When I put it in Park the noise changed (quieter).
When I got home I popped the hood and could see that the smog pump puller had a wobble to it. That is my likely culprit (though it was quiet). I suspect it is on the way out.
What are my options? Where can I get a reasonable rebuilt unit (I don't want to gamble on a used 35+ year old one)?
I know there are delete bracket/hubs and I'm not against that BUT I know that the MOE did blitzes years ago (when I was living near Barrie) and now that I'm near Ottawa, are they still doing those?
I have looked at replacing the bearings but I don't have a press and I see no real good Youtube vids that would help.
Suggestions please!
Thanks in advance!
Click to expand...
There is supposed to be an extra pulley on the smog pump for balance. A lot of C4 owners just remove it. This can be done without even loosening the serpentine belt. I left mine stock. There are other mods that have more effect than this one. If your smog pump only has one pulley with no outer ring, someone already removed the disc. In Conn. this is referred to as the C4 Frisbee Mod. I recently added the following mods:
1) Throttle Body Coolant Bypass. 2) Throttle Body Booster. 3) K and N air filter with custom plate that has all fins removed. These were tough to perform correctly being as anal as I am and using all mechanical ability from my father who drove a C1. This black beauty with a Doug Nash 4plus 3 really has a lot more torque now. (The coolant throttle body bypass is supposed to create a hotter spark because the throttle body has no warm coolant running through it now). This ultimately makes the car run cooler.
 
Try those 3 Mods on your C4 and it's a lot of bang for the buck. 1) Throttle Body Coolant Bypass 2) Throttle Body Booster 3) K and N kit.
The throttle body kit is an L shaped rubber hose that connects directly to the heater pipe on the passenger side. There are 2 rubber plugs for the now vacant ports on the throttle body and 2new hose clamps. This kit was about 30.00. The booster kit is an aluminum piece that looks like a butterfly. It attaches to the dual openings and is held in with a special nut that drops in through the throttle body plate.( 30.00) I always had a K and N air filter so I bought the new air filter plate for 60.00 from an online source.
 
sharkface said:
Try those 3 Mods on your C4 and it's a lot of bang for the buck. 1) Throttle Body Coolant Bypass 2) Throttle Body Booster 3) K and N kit.
The throttle body kit is an L shaped rubber hose that connects directly to the heater pipe on the passenger side. There are 2 rubber plugs for the now vacant ports on the throttle body and 2new hose clamps. This kit was about 30.00. The booster kit is an aluminum piece that looks like a butterfly. It attaches to the dual openings and is held in with a special nut that drops in through the throttle body plate.( 30.00) I always had a K and N air filter so I bought the new air filter plate for 60.00 from an online source.
Click to expand...

these are a waste of time for hp.
 
sharkface said:
There is supposed to be an extra pulley on the smog pump for balance. A lot of C4 owners just remove it. This can be done without even loosening the serpentine belt. I left mine stock. There are other mods that have more effect than this one. If your smog pump only has one pulley with no outer ring, someone already removed the disc. In Conn. this is referred to as the C4 Frisbee Mod. I recently added the following mods:
1) Throttle Body Coolant Bypass. 2) Throttle Body Booster. 3) K and N air filter with custom plate that has all fins removed. These were tough to perform correctly being as anal as I am and using all mechanical ability from my father who drove a C1. This black beauty with a Doug Nash 4plus 3 really has a lot more torque now. (The coolant throttle body bypass is supposed to create a hotter spark because the throttle body has no warm coolant running through it now). This ultimately makes the car run cooler.
Click to expand...
this is not correct. the smog pump has no frisbee. its the crank pulley that has the frisbee. and removing the frisbee does actually gain you some hp (low single digit so nothing to get excited about) as removes weight from the rotating assembly!

hope that helps.
 
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