Audi 90 Car Thermostat Replacement at your home or office.

Our mobile mechanics offer services 7 days a week. Upfront and transparent pricing.

Estimate price near me

Service Location

customer ratings

(25)

Included for free with this service

Online Booking

Mechanic comes to you

12-month / 12k-mile warranty

Free 50 point safety inspection

Our certified mobile mechanics can come to your home or office 7 days a week between 7 AM and 9 PM.

customer ratings

(25)

Car Thermostat Replacement Estimate for Audi 90

Audi 90 Car Thermostat Replacement costs $182 on average.

CarServiceEstimateShop/Dealer Price
1993 Audi 90V6-2.8LService typeCar Thermostat ReplacementEstimate$277.45Shop/Dealer Price$349.02 - $503.08
1990 Audi 90L5-2.3LService typeCar Thermostat ReplacementEstimate$244.53Shop/Dealer Price$307.40 - $447.10
1989 Audi 90L5-2.3LService typeCar Thermostat ReplacementEstimate$244.53Shop/Dealer Price$307.40 - $447.10
1988 Audi 90L5-2.3LService typeCar Thermostat ReplacementEstimate$244.53Shop/Dealer Price$307.36 - $447.03
1991 Audi 90L5-2.3LService typeCar Thermostat ReplacementEstimate$244.53Shop/Dealer Price$307.42 - $447.15
1988 Audi 90L4-2.0LService typeCar Thermostat ReplacementEstimate$231.59Shop/Dealer Price$291.22 - $421.22
1995 Audi 90V6-2.8LService typeCar Thermostat ReplacementEstimate$314.44Shop/Dealer Price$393.45 - $553.08
1994 Audi 90V6-2.8LService typeCar Thermostat ReplacementEstimate$271.95Shop/Dealer Price$340.92 - $493.04
Show example Audi 90 Car Thermostat Replacement prices

Car Thermostat Replacement Service

What is an engine cooling system thermostat and how does it work?

The car's engine cooling system thermostat is a small valve within a cooling system passageway that opens and closes in response to the temperature of the circulating engine coolant. When your car is first started and the coolant is cold, the valve in the thermostat will be in the closed position, circulating the coolant flow only within the engine instead of flowing to the radiator, which allows the engine to warm up fast, promoting fuel efficiency, low emissions, and reduced engine deposits. Once the engine coolant reaches the design temperature, usually around 195 degrees, the valve will open and close as you drive in order to maintain a coolant temperature typically between 195 to 225 degrees Fahrenheit.

Thermostat

When to consider replacing the engine cooling system thermostat:

  • Engine overheats. A thermostat with the valve stuck closed is a common cause of engine overheating. However, since there are other causes of overheating, a mechanic will thoroughly inspect the cooling system prior to condemning the thermostat. Since it is usually not known how badly the engine overheated, the mechanic will also try to determine if there is evidence that the cylinder head gasket was blown. If so, it would be repaired prior to replacing the thermostat.
  • Temperature gauge reads too low or too high. Thermostats can get sticky, causing the engine temperature to stray from the optimal range. Your dash-mounted temperature gauge will notify you of this malfunction.
  • Cooling system repairs. All thermostats eventually fail. Therefore, if the cooling system is already open for major repairs, such as water pump or radiator replacement, it is recommended to install a new thermostat simply as insurance against future breakdown.

How do mechanics replace the engine cooling system thermostat?

  • Once the engine is completely cold, the radiator cap is loosened and enough coolant is drained from the radiator so the coolant level is below the thermostat housing.
  • The thermostat housing is removed and the thermostat and gasket are extracted. Note that some cars have more than one cooling system thermostat and both might need replacement.
  • All mounting surfaces on the thermostat housing are cleaned of old gasket material. A new gasket is applied and the thermostat is re-installed in the correct orientation and with the temperature sensing cylinder facing downward towards the engine.
  • The thermostat housing bolts are tightened to original equipment manufacturer (OEM) specifications using a calibrated inch-pound torque wrench.
  • The cooling system is refilled with the appropriate coolant type and the system is fully bled of all air.
  • The car engine is run until the normal operating temperature is reached, and while taking precautions with the hot coolant, the coolant level is rechecked while confirming there is flow through the radiator — either visually or with an infrared temperature gun. This will confirm the thermostat is open. Finally, the engine is checked for leaks.

Is it safe to drive with an engine cooling system thermostat problem?

No. If it has been determined that there is a thermostat problem, it should be repaired right away. Failure to do so can cause substantial and costly damage to the engine.

When replacing the engine cooling system thermostat keep in mind:

  • Engine overheating due to causes other than a faulty thermostat, will themselves damage a thermostat. Therefore, always replace the thermostat if the engine overheats, even if the thermostat was not the initial cause of the overheating.
  • The thermostat should be replaced anytime you have major work done on the coolant system. It is convenient and costs little during such repairs and insurance against future breakdown.
  • OEM thermostats are the best ones to use and you can request your mechanic to install only the OEM thermostat. Dealer supplied, OEM thermostats are sometimes more costly but are generally higher quality and specifically engineered for your car.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee


Meet some of our expert Audi mechanics

Real customer reviews from Audi owners like you.

Excellent Rating

(25)

Rating Summary
20
4
0
0
1
20
4
0
0
1

Theodore

16 years of experience
1488 reviews
Theodore
16 years of experience
Audi TT L4-2.0L Turbo - Thermostat - Woodinville, Washington
It is really a pleasant to have Theodore to take care of my issue. After 5 fours of his hard work, my problem has gone and the car is all right after that.

Gary

27 years of experience
226 reviews
Gary
27 years of experience
Audi A4 L4-1.8L Turbo - Thermostat - Travis AFB, California
Gary arrived early and took the time to explain what was wrong with my car. He was very professional and very respectful. Very knowledgeable and an outstanding mechanic. He was able to fix my 2002 Audi A4. I was very satisfied with the repair the he completed. (Cooling system/temperature passage replacement). I would definitely recommend him to my family and friends with their automotive problems. Donelle

Joshua

27 years of experience
709 reviews
Joshua
27 years of experience
Audi A4 L4-1.8L Turbo - Thermostat - Danville, California
I would consider using the service again

John

20 years of experience
533 reviews
John
20 years of experience
Audi TT Quattro L4-1.8L Turbo - Thermostat - Orlando, Florida
John is always great. Arrives promptly, explains things well, and gets the job done.

Excellent Rating

(25)

Rating Summary
20
4
0
0
1
20
4
0
0
1
Number of Audi Thermostat Replacement services completed
275+
services done by our mechanics
TOTAL NUMBER OF EXPERT Audi MECHANICS
700+
experts on our platform

Recent articles & questions

How to Clean Your Catalytic Converter
Before looking into a catalytic converter cleaner, check it for clogging, internal part damage, and poor fuel economy.
P0439 OBD-II Trouble Code: Catalyst Heater Control Circuit
Trouble code P0439 means the catalyst heater control circuit has sent the PCM a below-acceptable voltage reading.
P0360 OBD-II Trouble Code: Ignition Coil I Primary / Secondary Circuit Malfunction
Trouble code P0360 means the powertrain control module (PCM) detects a problem with the primary or secondary circuit of an ignition coil.

I hear chirping from under the hood most prevalent while braking. The noise stops when the car is no longer moving.

Hello there. Thanks for the detailed description on your inquiry - it really helps us out. Based on what you have indicated, my first assumption would be that you have a loose serpentine / drive belt or a pulley that...

Truck wont start with brand new battery?

There are several possible reasons for a vehicle to crank and not start. A bad fuel pump, clogged fuel filter, faulty injectors, bad ecu, failed ignition coil, or a malfunctioning sensor. It will first be necessary to figure out if...

Car begins to shake at or about 50 mph. It's almost like a motor mount maybe broken. Could that be the issue?

Hello there, many faults will cause a vibration above 50MPH in your 2009 Chevrolet Malibu. It is great you have noticed the vibration is not in the steering wheel, as this rules out potential issues. The vibration is not likely...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com