Mishimoto
Reference: MMTS-MOP-18E
Cooling
Mishimoto Thermostat with Housing – Jeep Wrangler JL 3.6L
The factory plastic thermostat housing on the 3.6L Pentastar is a well-known source of coolant leaks and overheating in Jeep Wrangler JL models. The Mishimoto thermostat with a cast aluminum housing replaces that plastic part and opens at 195°F, matching factory specs. Fits JL 3.6L Pentastar models from 2018 on. The kit includes the housing, thermostat, gasket, temperature sensor, and O-ring, backed by Mishimoto's Lifetime Warranty.
The factory plastic thermostat housing on the 3.6L Pentastar is one of the better-known weak points on a Jeep Wrangler JL — over time it cracks and starts leaking, which leads to engine overheating. The Mishimoto thermostat with a cast aluminum housing fixes that at the source.
Technical specifications
- Housing material: cast aluminum — more durable than the factory plastic housing
- Thermostat opening temperature: 195°F, matching factory OEM specs
- Fitment: Jeep Wrangler JL 3.6L Pentastar (2018 and newer, 2-door and 4-door, including Rubicon and Unlimited); also fits Jeep Gladiator JT 3.6L (2020+), Jeep Grand Cherokee 3.6L (2016–2022), Dodge Durango 3.6L (2016+), and Dodge Ram 1500 3.6L (2019+) — does NOT fit Ram 1500 Classic
What's included
- Thermostat housing
- Thermostat
- Gasket
- Temperature sensor
- O-ring
Who it's for
This is a good option if your Wrangler JL has enough miles on it that a preventive swap of the factory plastic thermostat housing makes sense, or if you've already noticed signs of a coolant leak in that area of the engine.
Unlike the factory plastic housing, the Mishimoto version is cast aluminum, which — as the manufacturer notes — eliminates a common source of leaks and overheating. Installation is simple and takes about 30 minutes, with no modifications required.
Why it's worth it
- Aluminum housing instead of a crack-prone factory plastic one
- Thermostat calibrated to factory specs (195°F)
- Simple installation (about 30 minutes) and a lifetime manufacturer warranty
Not sure if this fits your engine? Get in touch — as an off-road workshop, we can help you pick the right part and install it if needed.
Frequently Asked Questions
Will this thermostat fit my Wrangler JL?
Yes, it fits Jeep Wrangler JL with the 3.6L Pentastar engine, model year 2018 and newer (2-door and 4-door, including Rubicon and Unlimited).
Does it fit other models besides the Wrangler?
Yes, it also fits Jeep Gladiator JT (2020+), Jeep Grand Cherokee (2016–2022), Dodge Durango (2016+), and Dodge Ram 1500 (2019+) with the same 3.6L Pentastar engine; it does not fit Ram 1500 Classic.
At what temperature does the thermostat open?
It opens at 195°F, matching factory specifications.
What's included in the kit?
Thermostat housing, thermostat, gasket, temperature sensor, and O-ring.
How long does installation take?
According to the manufacturer, installation is simple and takes about 30 minutes, with no modifications required.
