Q: Engine overheating replacing thermostat

asked by on July 25, 2016

I own a 3500 express van with a 5.3 votex engine. I replaced the water pump a year ago and put in a new thermostat 2 times. 2 weeks ago my engine started to overheat again. So I replaced the thermostat, and it was OK for a few days. Then it started to overheat again. I checked the water and it was low, so I added some. The van drove OK for a few days, but now it’s overheating again. So I decided to completely take out the thermostat to see how the van would run without it. I drove down the road a few miles and ENGINE flashed on the screen display. This time it wasn’t boiling over, and it didn’t reduce the power like it did before. Is it OK to run the van like this without the thermostat? I don’t want to ruin my engine What are you thoughts and ideas? Thank you.

Hello. Let me start off by saying that it is just as bad, if not worse, to run an engine with no thermostat as it is to run it with a bad one. It will also cause engine damage. It sounds like there is a head gasket issue with the engine.

If it primarily overheats under load then it has combustion pressure getting into the cooling system which will ultimately causes this to occur. I usually look for bubbles in the cooling system when the engine is running and do a block test to verify this.

If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to you home or office to diagnose your overheating issue and repair this.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for 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

Get a quote

What others are asking

Hey i have a 2002 Mercedes Benz E430. I replace the radiator and refill the coolant level. The problem is my car runs hot and it s

If you recently replaced the radiator, there's a possibility that it could have air in it, which will require the system to be bled. However, there may also be other issues that cause it to run hot. When you mention...

Replaced water pump (no noise before just leaky) now there's loud humming noise and I don't have heat. Haven't tried driving yet.

Hi there. From the description you have provided, you replacing the water pump and now you have a new noise and no heat, are an combination of things going on. First, the loud humming noise coming from the water pump/timing...

Misfire and low oil pressure

The oil light comes on when the oil pressure drops below a certain level: usually about 8 psi. Since the oil pressure will depend to some degree on how fast the oil pump is turning, you are probably seeing it...

Related articles

How Do I Prepare My Car for Summer?
Summer's Summer's heat, dust, and stop-and-go traffic will take their tolls on your vehicle. Follow these tips to ensure optimum wellness of your car: Air Conditioning: Have your air conditioning inspected by a qualified technician. Newer models have...
How Long Should an Engine Last?
A car engine can last hundreds of thousands of miles. Get your oil changed often and don't ignore car warning lights to make your engine last longer.
How Much Power Does the AC Draw From the Engine?
Most cars these days come with air conditioning as a standard feature – gone are the days...