1995
Formulated by chemist Robert Hooper. Improving it since.
A+
Better Business Bureau, accredited since 2002
95%
Success rate with repair shops and dealers
1,100+
Field repairs by one technician, on video
69/69
Public reviews of that technician, all five stars, 2013 to 2026

Blown head gasket? Read this before you pay for a replacement

The verdict on your engine can be reversed.

A mechanic said blown head gasket and quoted more than the car is worth. Since 1995 the people who invented chemical head gasket repair have been putting those engines back on the road. Sixty seconds tells you if yours is one of them.

Does my engine qualify?60 seconds

What it costs

Twice the power. Half the bottle.

Thermalweld is engineered to fully repair any 4, 6, or 8-cylinder gasoline engine with just 8oz — half the bottle. Every 16oz bottle you buy isn't one treatment. It's two. Pick your engine below, or let the qualifier pick it for you.

EngineKitPrice
4 or 6 cylinder gasThermalweld, 4 / 6 cylinder 2 treatments$119
$59.50 ea.
8 cylinder gasThermalweld, 8 cylinder 2 treatments$129
$64.50 ea.
Hybrid (Prius, Camry, CT200h, C-Max)Thermalweld, hybrid$109
Cadillac NorthstarNorthstar kit, all aluminum V8$275
Diesel, under 10 gallon cooling systemSmall capacity diesel$144
Diesel, 10 to 20 gallonMedium capacity diesel$179
Diesel, over 20 gallonLarge capacity diesel$209
Extra strength additive, for severe cases on tech support's advice$15
Buy on thermalweld.com  ·  15% off five or more treatments for shops
16oz bottle 2 treatments any 4, 6, or 8-cyl gas engine $129 ($64.50/treatment)
$2,000 to $7,000

What a shop charges to replace a head gasket, when it will do the job at all. Most say replace the engine.

"At 190,000 miles you're not going to put $7,000 into a head gasket. A Toyota can go 300, 400,000 miles, and we can fix a Toyota in 15 or 20 minutes."Dave Whitmer, 1,100+ field repairs
"Thousands of cars are lost every year simply because people poured a pour and go product in there. There is no product capable of fixing your car that is compatible with antifreeze."Robert Hooper, chemist, inventor of Thermalweld

The guarantee

Fix or free. Cracked heads and blocks included.

30 days, money back. If Thermalweld does not repair your head gasket, cracked head or block in the first 30 days, you get a full refund or a free re-treatment, your choice.
After 30 days, for as long as you own the car. If it ever fails, we send a re-treatment for $25 shipping and handling.
Honored even if it turns out not to be a head gasket. Tech support reviews the case with you before any second treatment, so nobody pours chemicals into an engine that needs something else.

Original owner, non transferable. Full terms at thermalweld.com/warranty. Refunds and re-treatments: technicalsupport@thermalweld.com or (844) 796-7968.

The record

Numbers, not adjectives.

Customers in their own words, with the vehicle and how far it has gone since. Read all of them at the links below.

1997 Lincoln Town Car
250,000 miles · 2,900 miles later
Six months and 2,900 miles later the car is still going strong. Saved a $4,000 repair.
Ernest Hamilton, thermalweld.com
1999 Cadillac Eldorado
Six years later
It's six years now and the car is running beautiful, no problems with head gaskets leaking.
Joseph Chiantese, thermalweld.com
2018 Toyota Prius
300,000 miles
Fixed it right up. Stopped misfiring and shaking immediately and no more white smoke.
2010 Cadillac DTS
Hydrolocked, 1,500 miles from home
A local mechanic said the car was doomed. I ordered the Northstar kit, followed Robert and Dave's instructions, and the car is running again.
Raymond Hane, Google
Honda Civic
1,000 miles, no coolant loss
I tried K-Seal and Titan sealer, both didn't work. Drove about 1,000 miles and the water level did not change. Did not clog the heater core.
Francis Ponsones, Google
Toyota 4Runner
16,000 miles, then a second car
After 16,000 miles, still running great, no overheating. My daughter's car blew its head gasket two weeks ago. I'm glad I kept his number.
Matthew Ramos, Google
2010 Toyota Prius
Three quotes over $3,000
I was stuck, couldn't afford any of them. Dave came to me, charged $425 and had my car humming. No misfiring and no exhaust smoke.
Ron Milne, Google
Pro-Masters, Oxnard
5 cars and 3 trucks, no failures
I run an auto repair shop. I offer this option when the mileage is very high or replacement is too expensive. All of the vehicles are still on the road.
Frank Magana, shop owner, Google

Who answers the phone

The chemist and the technician. Not a call center.

Call (844) 796-7968. Technical support and new orders Monday to Friday 6 AM to 5 PM Pacific, Saturday 6 AM to noon.

Robert Hooper

Chemist · Inventor of Thermalweld · Since 1995

Formulated Thermalweld in 1995 and created the category of chemical head gasket repair. Thirty one years later he is still the scientist behind the formula, still improving it, and still on the support line. Twenty of those years were spent in the field doing the repairs himself.

Dave Whitmer

Mobile technician · 1,100+ repairs · Tech support since 2016

Runs Ideal Head Gasket Repair, a mobile service covering Los Angeles, the San Fernando Valley, Ventura, Santa Barbara and San Luis Obispo counties. $450 in your driveway, most vehicles, in about an hour. If the repair does not hold you pay only the $125 service call.

Sixty seconds. Then you know.

Answer seven questions about your engine. You get one of three answers: this is your kit, call us first, or don't buy this.

Does my engine qualify?   Call (844) 796-7968