How do you replace a thermostat on a 2007 Land Rover LR3?

Answer 1

How To: Replace your Thermostat

My LR3 made it to 112,500 miles before the check engine light came on. Using my trusty Faultmate, it told me that I had a thermostat that was opening too soon or stuck open.

So, I needed to replace this vital part of the cooling system. Your engine doesn't like to be cold. So when it's started cold, the thermostat closes off the radiator to the engine so that the engine can heat up on its own. After the coolant reaches 190 degrees F, the thermostat starts to creep open to allow cold coolant from the radiator into the engine. After everything is up to temp, the thermostat is full open to allow the radiator to do its job and dissipate heat.

This is a simple job, total time 1 hour tops.

Tools needed:

- Torx wrenches (T-25 I think, but not sure)

- Metric sockets and ratchet

- Channel Lock pliers

- Needle nose pliers

Parts needed:

- New Thermostat

- New Thermostat housing gasket

Step 1: Remove the engine cover. There are 4 bolts on the top that make this quick work.

Step 2: Locate the thermostat housing. This is the thing you are looking for:

Step 3: Remove the 3 hoses attached to the thermostat. Use the channel locks to loosen each clamp, and then remove the hose.

Step 4: Unscrew the torx screws, and remove the thermostat:

Step 5: Take the housing into the garage and remove the old t-stat. To do this, press down on the top of the thermostat, and then twist it one way or the other to get the two tabs out of the slots.

You should have this:

I looked at my old thermostat... sure enough, the rubber seal had separated from the plunger, allowing cold coolant to leak by:

VERY IMPORTANT STEP 5A: If you look at the picture above, you will see that the old thermostat has a little metal cup/tip on the end of it. That actually belongs IN the thermostat housing! If yours comes out with the old one like mine, get some pliers to pull it off, and then place that cup back in to the bottom of the thermostat housing, it will be very obvious where it goes.

Step 6: Start assembling the new thermostat into the housing. These pictures show the steps:

Step 7: Remove the old thermostat gasket from the engine and replace with new:

Step 8: Re-assemble everything in reverse order. Your new thermostat should be good to go!

Clean everything up, and then open your celebratory beverage!

This is a simple repair that would have cost you hundreds of dollars at the dealer, but you can do it in about an hour!

Last edited by navydevildoc; 02-03-2011 at 10:34 PM.