GoWesty Thermostat Housing Kit

Made in the USA


VW Part #: 025121117

Works With: 1986-91

Weight: 4.00 lbs

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Price Range: $173.45 - $243.45


Final Price: $173.45

This thermostat housing kit is offered in two levels of quality: Standard and Deluxe. The differences between these two offerings are oulined below.

Not so long ago, the OEM plastic lower thermostat housing went out of production and quickly became NLA (no longer available). Because of this, we were forced to put on our engineering hats and design a replacement part. We used our expertise in thermodynamics and fluid dynamics to ensure that our thermostat housing unit works perfectly—and won't introduce any "mysterious" problems that might occur if strict attention to detail were not applied. The process was definitely trickier than one might expect. The original thermostat housing was made of injection-molded plastic (on 4WD Vanagons, it was crafted of cast aluminum). Because we used an entirely different manufacturing process, we had to make design decisions based on how coolant flows and behaves at varying temperatures.  The most important improvement we made was eliminating two specialty VW hoses with connecting ends of varying diameters (025-121-058E and 025-121-058B). Our removable fore/aft nipples eliminate the need for these specialty formed hoses, replacing them with consistent-diameter hose (included).

Fast forward a couple of years and the OEM plastic part and an aftermarket cast aluminum part are now also available. We are offering all three varieties to satisfy the needs of the market, with the plastic part being the least durable and least smart. The cast aluminum part is an improvement over the plastic part, yet still inferior to our stronger and highly corrosion-resistant billet anodized part. So, whether you are looking for something on either end of the spectrum, or somewhere in between, GoWesty has you covered.

Kit includes: Metal lower thermostat housing (cast aluminum in the standard kit or GoWesty-designed annodized billet aluminum in the deluxe kit, as shown in the main image), sending units, connectors, fasteners, and Loctite thread locker. The deluxe also includes hose. Both thermostat kits include the GoWesty Temperature Gauge Calibration Kit. We developed this device after experiencing temp gauge anomalies on some in-house installations. Theoretically, any temp gauge in a water-cooled Vanagon should read the same with any of the three types of senders VW used. In practice, we've occasionally found slight differences in coolant temp gauge readings after installing our thermostat housing kit. This is due not only to a difference in the included sensor, but also a lower electrical resistance in the whole circuit due to a nice, new all-metal thermostat housing (and the subsequent elimination of the old, corroded wire). Instructions are included to calibrate the temperature gauge (if necessary).

NOTE: This kit does NOT include the thermostat cover (often referred to as the "upper thermostat housing"). That part is still available new—although it rarely needs to be replaced.

Product Videos

IMPORTANT: Installation instructions NOT included. We recommend that this product be installed by a professional shop that is familiar with the Vanagon cooling system. Properly bleeding the system is of utmost importance. Installation requires a pair of pincer pliers for the ear clamps. Sold separately below.

Thermostat Housing Instructions

This product fits all 1986-91 watercooled Vanagons EXCEPT DIESEL. If you have updated an early-model Vanagon to the 2.1 cooling system, this kit will also work.

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