S1 Hot Air Temp Control?

The item on the back plate of the air filter housing contains what I assume controls via vacuum the blending of cold and hot air from around the exhaust manifold. Can anyone tell me the correct part name? Not getting anywhere with my online search. Thanks.

Jeff H.

You are right about what it does. It’s an AC/General Motors thermal vacuum switch. LOTS of GM cars and others of the period use it. Here’s a quick link to one on Ebay:

Jag part number is: c33025

1 Like

Lots of discussions on I think the Etype forum

We have four classic Jaguars that I do most of the repairs, servicing and restoration work on. Having the proper technical data on these cars has removed a lot of the mystery (but not all of it) in keeping them looking and operating their best. In addition to the owners manuals, I have found the Repair Operations Manuals and Parts Catalogues all help me in many ways to sort out the parts I need and be a smart buyer.
Attached is a picture of the Series I XJ6 Parts Catalogue, RTC9106, that I purchased on eBay for probably about $30.

The part you are asking about, part number C33025, is shown circled on page 22 64.

When armed with the correct technical data, like the Parts Catalogue for your Jaguar, sorting out most parts identifications is quick and easy. :slight_smile:


Thanks everyone!!

Paul, I will track a copy down. Agreed they would make life easier.

Jeff H.

1 Like


fully subscribing to everything Paul said the original parts catalogue for SI cars is available online https://parts.jaguarlandroverclassic.com/older-vehicle-information. True, not the real thing, but better than nothing, in any case.

Good luck


75 XJ6L 4.2 auto (UK spec)

Thanks Jochen, that will help until my paper copy arrives.

Jeff H.