Saab 900 Engine Coolant Thermostat: A Detailed Guide for 1979-1984 Models
Keep your classic 900's engine temperature in check by understanding how to choose the right replacement thermostat.
- A failing thermostat usually gets stuck open, causing the engine to run too cold.
- Choose aftermarket brands like Gates or Beck Arnley; avoid Professional Parts Sweden due to widespread reports of poor quality.
- The correct OEM temperature is 89°C (192°F); using this rating is important for proper engine function.
- This is an easy, one-hour DIY job that can save you significant labor costs.
Is Your Saab 900 Thermostat Failing?
A thermostat failure in a classic Saab 900 typically happens in one of two ways: stuck open or stuck closed. The symptoms are usually easy to spot if you watch your temperature gauge.
🎬 Watch how a new thermostat fixes an inconsistent temperature gauge.| Failure Mode | Symptoms | Severity |
|---|---|---|
| Stuck Open (More Common) | The engine takes a very long time to warm up, or the temperature gauge never reaches the middle. The gauge might drop towards cold when driving at highway speeds. You may also notice poor heater performance. | Moderate |
| Stuck Closed (More Serious) | The engine overheats quickly. The temperature gauge will climb into the red zone. You might hear gurgling or boiling sounds from the engine bay. | Critical |
Choosing the Right Aftermarket Thermostat
For a vintage car like the 1979-1984 Saab 900, parts quality can vary widely. While a genuine Saab thermostat is always a good choice if you can find one, several aftermarket options are available. They are not all created equal.
Brand Quality Tiers
Based on owner experiences and mechanic feedback, here is a general breakdown of the available brands:
- Tier 1: Recommended Aftermarket: Brands like Gates and Beck Arnley generally have a positive reputation in the import car community. Gates is a well-known manufacturer, and Beck Arnley often sources parts from original equipment suppliers. These are solid choices for reliability that comes close to OEM standards.
- Tier 2: Use with Caution: Motorad thermostats have very mixed reviews. While some owners have no issues, many report premature failures, especially the thermostat getting stuck open. Their patented "Fail-Safe" models are designed to lock in the open position if the car overheats, but this feature can sometimes trigger unnecessarily, permanently ruining the new part.
- Tier 3: Avoid: Forum discussions among Saab and other European car owners are overwhelmingly negative regarding Professional Parts Sweden (PPS). Reports of parts being poor quality, failing immediately, or arriving broken are common. It is strongly recommended to choose a different brand.
Pro Tip: The correct original equipment temperature for your Saab 900 is 89°C (192°F). While thermostats with lower temperature ratings are sold, sticking with the OEM temperature is best for overall engine health, emissions, and fuel economy.
Expected Costs for Replacement
Replacing the thermostat is one of the more affordable repairs for your Saab 900.
| Part or Service | Estimated Cost |
|---|---|
| New Aftermarket Thermostat | $12.49 - $28.02 |
| New OEM Thermostat (If Found) | $15 - $40 |
| Shop Labor | $100 - $180 |
Frequently Asked Questions (FAQ)
Is it difficult to replace the thermostat myself?
No, this is a great DIY job for a beginner. The thermostat is located in a housing where the top radiator hose connects to the engine. The job requires draining some coolant, removing two bolts, swapping the part, and refilling the coolant. The entire process usually takes about an hour.
🎬 See this step-by-step walkthrough for replacing the thermostat yourself.Do I need a new gasket?
Yes, always use a new gasket or seal when replacing the thermostat to prevent leaks. Some thermostats come with a new gasket in the box. Make sure the mating surfaces on the engine and the thermostat housing are clean before installing the new part.
My car has a new thermostat but the temperature is still acting weird. What else could it be?
If a new, quality thermostat doesn't solve the problem, check other cooling system components. This could include the engine coolant temperature sensor, the radiator fan switch, or even a clogged radiator. Also, ensure the system was properly bled of air 🎬 Watch this clever 5-cent trick to help bleed your cooling system. after the replacement.
Are there any recalls for the thermostat on my Saab 900?
No, searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls or technical service bulletins (TSBs) related to the engine coolant thermostat for the 1979-1984 Saab 900.
Helpful Videos
Technical Specifications
OEM Part Numbers: 30577561 5958749 8389512
Standard Opening Temperature: 89°C / 192°F
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.