What Causes A Thermostat Housing To Crack

My engine light came on and I took my 2016 Jeep Cherokee latitude in and it is still under 36000. This was just after a hard freeze and I purchased and had the vehicle less then a week. They kept it 2 weeks and then the repaired it saying it was just a simple mechanical malfunction of the thermostat housing. What would cause such a malfunction?

The T housing was actually cracked and the base (where it mounts to the head) didn't have a gasket. So I have all the parts on order and hopefully this will solve my coolant leak during warm up idle! New issues.I went against the old advice 'never stick your hands where you wouldn't stick your face' and felt the inside of the head. I was replacing the thermostat in my '06 Saab 9-3 2.0T today and when I was reinstalling the housing, the corner of the housing cracked. I know this operates in a high pressure and hot environment, but is there a way to fix the crack? Prices and shipping time for a new one are tough to.

Over tightening causes leaks. The housing uses the seal on the T-Stat to provide a seal to the water pump housing. I'd drain the coolant and check the seal on the t-stat, and the housing to see if it's warped. Could be that the t-stat housing was over torqued 2 years ago, and warped it.
If a vehicle is overheating, a bad thermostat could be the problem, and a damaged thermostat housing is more likely to produce a coolant leak, either from a cracked or warped housing or a failed seal to the engine. The thermostat housing can be made of metal or plastic. Also, can a leaking thermostat housing cause overheating?

My car has 32000 miles.
My car has an automatic transmission.

Marvin Sunderland

22 years of experience

Hi there. If the thermostat housing was made of plastic (carbon fiber) and the temperature outside dropped below the freezing point of the cooling system, then the coolant would have froze up and expanded causing the thermostat housing to crack. Also, if the coolant has too much electrolyte causing a slight voltage in the coolant, then the chemical compound will break down causing the cooling system to eat up seals and carbon fiber.

The statements expressed above are only for informational purposes and should be independently verified. Please see ourterms of servicefor more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

how to I turn off the horn on a 2016 denali when the key if left in the car

Hello, thank you for reading in. Your owner's manual should have the exact procedure on how to silence the horn when leaving the key in the car. Typically on these and similar models it is a process of accessing your...

Lightning bolt traction control

Hi Lindsey. Thanks for contacting us today. The lightning bolt light typically indicates an issue with the charging system, such as an alternator fault, battery fault or electrical sensors related to this system. This could also trigger some of the...

Car will jump start fine. But when I try to start it from the new battery, it all goes black and power goes out completely

Hi there. It sounds like your new battery may be faulty. If the vehicle jump starts ok, then this is a sign that the new battery is not providing enough cranking amps to engage the starter. It may have a...

My cars ac only blows out through the defroster vents not the other vents I play with all the buttons but it doesn't work.

Hi There, It sounds like you may have a faulty blend door actuator. Inside your vehicle's vent system, there are small doors that open and close to change the flow of air running through the system. These doors are operated...

What Causes A Thermostat Housing To Crack Without

I replaced wheel speed sensor. But abs and engine light still kn. What could it be

If the ABS wheel speed sensor was faulty, once the new hub/sensor is installed, and you drive the vehicle, the warning lights should go out. To determine what is going on, you can manually erase the trouble codes using an...

Wiring Diagram on the Blower motor resistor

Hi Chanel. Since we can't attach images or files on this platform, your best resource is going to be purchasing a service and repair manual for your 2010 Chevrolet Malibu to review the detailed wiring schematic for each mechanical system....

Crankshaft position sensor causing check engine light to come on.

The first step to take would be to have a check engine light is on inspection performed by a qualifed professional. This will help to deterimine if the crankshaft position sensor is faulty or not. Consider YourMechanic as a certified...

What are the steps for bleeding my liberty if I cannot remove the bleeder screw?

The manual states to fill the reservoir up to the fill line with the engine off. Once the coolant is up to the top hot fill line start the engine and see if it drops down in the next couple...

I need a thermostat replacement, will they automatically do the coolant flush?

The cooling system is recommended to be flushed out anytime the thermostat is replaced if the coolant has not been changed or flushed recently. A thermostat does not always require the coolant to be flushed out and would be an...

2012 Jeep Patriot vs. 2012 Honda CR-V: Which One Should I Buy?

What Causes A Thermostat Housing To Crack

The mid-size SUV is a great vehicle for getting a lot of people from one place to another, with a decent price point and pretty good ongoing fuel economy. While they are never going to get the amazing gas mileage...

How to Troubleshoot a Faulty Car Thermostat

What Causes A Thermostat Housing To Crack Repair

When you are concerned about the routine maintenance of your car, it is natural to get to a point where you will ask yourself,...

How to Take the Doors Off Your Jeep

Thermostat Replacement

Jeeps Jeeps have been around since before WWII, and they’ve been modifiable since the very beginning. Because of their unique nature, Jeeps sit in a class all of their own: a coupe, a convertible, and a capable off-roader, all in...