My smog is rattling and banging louder at startup than ever before. The 1987-1990 CC calls for part number 7849159 but I can't find a rebuild available anymore and only one NOS one on ebay. Problem is the one on ebay in the pictures has the correct part number on its box but a different part number (26013993) on the back of the case. That part number matches a 1990-1992 V12 Jaguar XJS. I can't find any cross-reference so I'm kind of leary of it. The parts book shows 7838575 for pre-1987 W A/C 307's. If it was just a part number change that would broaden the search. I know they don't generally do arbitrary number changes but does anyone know if they are interchangeable. I know everyone will say take out the emissions stuff, but it is a part-time daily driver and I don't have time to do all of that work and I would like to keep it all stock. Thanks.

 

If you type 7849159 into the ebay search box, three come up for sale.

 

That number on the back correlates to the Jaguar because that is the same pump your car uses. It's really just a casting number and not the catalog part number.

Aftermarket- Cardone 32-257.

The two pump GM part numbers WILL interchange physically. If there's any difference internally, I don't know what that is, although I do believe there are some internal differences and some slight casting shape differences but still should bolt up and fit. Works the same, though. The diverter valve bolts on to the back of either in the same place and uses the same p/n gasket, GM p/n 14015367. The main differences I've seen is the 87 pump has a tri-lobed spacer/stiffener that longer bolts would go through for the pulley. The plastic fan is the same p/n 7835231. If you look at your pulley on your car, you'll see where the bolts are an aluminum spacer of sorts for the 3 bolts holding the pulley on. The pulley itself is different as well somehow, IIRC, but you should be able to swap your pulley and spacer/bolts to the "new" one. Your pulley on your car should be stamped "LJ", which is GM p/n 22531890. Pre-87 pumps did not use the spacer or the longer bolts.

FWIW, I temporarily used an 87 159 pump off an 87 Cutlass Salon on an 84 Cutlass V8 for a while until I replaced it with the correct 575 one. Same exact part number you're looking for. No issues.

 

Use this website to find that part in a salvage yard if you don't want a DIRTY Jaguar part corrupting your Olds and making it unclean.

https://www.car-part.com/

 

You're sure it's the pump itself rattling and not the check valves on the air injector manifolds?

I'd install new check valves as a matter of course, since if one fails exhaust gas will cook the pump in short order. Good lord does that plastic pump stink when that happens.

Hint- use an impact wrench to remove the check valves. Might save twisting the injector manifold into oblivion.

 

22534540 and 22534541 are the pipes that connect to the heads and have the check valves on them. They're pipe threads for the tubing and check valve. When they go, they'll sound bad, but I've hardly ever heard them rattle. Rattling like ball bearings with a mad badger in a sh*t can sounds more like the pump to me. But without being there, kind of hard to know. If the check valves are burnt, as mentioned, get that sorted out first before putting on that pump or it will kill it in short order. And everything else in the system as well. Take the hoses off the check valves and start the engine. If you feel/hear/see exhaust coming back through, change out the valve(s).

The check valves are more like reed valves, but they can get burnt through and leak exhaust gasses back into the AIR system which is not a good thing. There are 3 check valves for your application, one for each cylinder bank, and one for the CAT tube going between the beds of the catalytic converter. 22040903 (or equivalent) will work. They changed part numbers on these like Pro-Stocks changed head gaskets. Almost every hour. I suggest Delco brand if you can still find them as they're the most durable IMO. The valves have female threads, tubes have male threads. That's important. The OEM style has never been cheap, and they're not cheap if you can find them in the secondary market. If you replace the pump, and the check valves have never been changed, I'd get new check valves at this point as well. They're not designed to last forever.

Standard Motor Products (SMP) shows an AV7 and AV7T as fitting your application as well. I don't know what, if any, difference the "T" makes. GM now has the "gold" series valve, but it's just a re-numbered SMP valve. Not that they're bad, I just have no experience with them.

 

Thanks for all the input. Joe, I was typing GM 7849159 and only getting the one. I now see that if I leave out GM I get two more, thanks. I will replace the check valves also, off to find them now.

 

It's definitely the pump, if I use a stethoscope I can hear it even more through the case.

 

Turns out someone listed a different pump under the part number and when I received it, it didn't match up. I cleaned the old one up some and some penetrating oil I was using on the bolts got in it and now the original pump is way quieter. Also some of the noise turned out to be the belts. I replaced all of those too. Since a pump is at least $180 I'll wait and see how long it stays quiet before I try again.

 

That's a bummer that you got the wrong part though. Were you ale to get your money back through Ebay or another vendor?

 

The seller took it back and refunded me. I made sure he knew the box was incorrectly marked and the part number on the pump in it was for a Crossfire Corvette. Bolts would line up but they were threaded differently and the valve bolts in the back were a different size.