I purchased a 86 Jaguar XJ6 vdp about a month ago, and am working on a list of repairs. There is a component near the top of the engine on the drivers side that looks like an alternator, but from what I gather, it's actually an air-pump. The belt is not attached, and for good reason, as the pulley will not turn. Its completely frozen up.
The engine seems to run okay without it. Does anyone know exactly what this pump does, and if I am doing a dis-service to the engine by not having it replaced and hooked up?

 

The pump forces fresh air into the exhaust manifolds where it is mixed with residual unburnt gasoline and ignited. The sole purpose is reduce pollution. I don't believe any harm will come by running the engine as-is.

 

As mentioned, you're OK without it.

As used on your car it really only served any purpose on a cold engine, pumping air into the exhaust ports. Although the pump is turning at all times a temperature controlled diverter valve dumps the pump output into the air filter cannister once a certain coolant temp was reached....157ºF, I think.

If you ever wanted to replace it any parts store can fix you up. It's the same pump was used on umpteen GM cars in the 70s-80s.

Cheers
DD

 

I removed my (working) pump about 2000 miles ago. It has absolutely no effect on the engine or performance. It de-clutters the engine bay quite a bit especially if you need to get to the AC compressor. If I had known it would be needed I would have saved it, however, it is now in a scrap yard in Jackson, Mi.

 

Thanks! I appreciate the technical insight an your helpful answers.

Best regards!
Jay Hieb

 

I wondered about that too when I was doing ac work. I noticed that it doesn't engage. I live in hawaii so I bet its not needed and that's y it never engages. Thanks for the info guys