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Old 12-27-09, 10:00 AM
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motor longevity

why so many horror stories about the 'fd' motors?
rebuilds at 80,000 -100,000kms? my honda or toyota just warming up!
Old 12-27-09, 10:16 AM
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The engine his highly stressed with inadequate cooling from the factory.

The turbo system is very complicated, relying on some 70 vacuum hoses placed in a high heat area. They bake from exhaust heat and fail quickly.

The 1st cat is tucked next to the turbo system where it dumps mass amounts of heat in the engine bay.

Plastic engine bay parts (like the AST) bake and fail.

The speed density EFI system is unable to compensate for increased airflow through the engine, resulting in a lean condition.
Old 12-27-09, 10:34 AM
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The original engines often blew prematurely because of coolant seal issues (there was a recall on the cooling system). Rebuilt engines often blow because people mod the heck out of the car and make some mistake that destroys the thing.
Old 12-28-09, 07:24 PM
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Short answer, yes FD engines fail in 60k-100k. Reliability mods can help this substantially, unfortunately there aren't many owners who just install reliability mods and drive the car for 10 years to see how long this engine can really last. They usually get into pushing the power to some degree, so the average engine life is still much lower than most cars.

Originally Posted by Aaron Cake
The engine his highly stressed with inadequate cooling from the factory.
Additionally, Mazda set the thermoswitch to regulate the coolant temps at an unusually high temperature.

The turbo system is very complicated, relying on some 70 vacuum hoses placed in a high heat area. They bake from exhaust heat and fail quickly.
Replacing the hoses with more heat-resistant silicone helps a lot, but still the solenoids and actuators they connect still eventually fail.

The 1st cat is tucked next to the turbo system where it dumps mass amounts of heat in the engine bay.

Plastic engine bay parts (like the AST) bake and fail.
Yep, yep, replace with aftermarket versions that reduce heat and last longer. Although I simply opted to buy replacement stock AST realizing it's got a life of 60k miles.

The speed density EFI system is unable to compensate for increased airflow through the engine, resulting in a lean condition.
This is only an issue if the car is modded by someone uninformed. If you take it to a bush-league tuner shop and they install a full exhaust with no cats then yes this can cause boost increase, lean the AFRs, and blow the engine. This car runs acceptably well with the stock ECU if the boost levels remain at stock. A simple mechanical boost controller is all that is required in most cases.

Dave
Old 12-28-09, 07:29 PM
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Now this is an interesting read. Thanks Dave...
Old 12-29-09, 08:33 AM
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I had an engine built by PFSupercars up in Fredderick that had probably about 600 hp at the crank. Single turbo, upgraded injectors, etc.....I ran this engine into the ground literally during my "fast and furious" phase. However, I put about 25,000 miles on it before it decided to spit out it's seals and wipe out my turbos.
Old 01-04-10, 03:14 PM
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Rx7 Longevity

As a new FD owner, is there a list of modifications/upgrades I should do to increase the reliability of the car?

The car currently has a boost controller (though set to 14 PSI - the guy messed up the installation and then sold the car to me - I am setting this back to stock), a high flow cat (i think), a BOV, and a fluidyne radiator. Other than that, I believe the car to be stock.

David
Old 01-04-10, 04:14 PM
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Originally Posted by dimondjack
As a new FD owner, is there a list of modifications/upgrades I should do to increase the reliability of the car?

The car currently has a boost controller (though set to 14 PSI - the guy messed up the installation and then sold the car to me - I am setting this back to stock), a high flow cat (i think), a BOV, and a fluidyne radiator. Other than that, I believe the car to be stock.

David
There is a large amount of information on reliability mods in the 3rd gen FAQ.
Old 01-04-10, 07:36 PM
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Originally Posted by dimondjack
As a new FD owner, is there a list of modifications/upgrades I should do to increase the reliability of the car?

The car currently has a boost controller (though set to 14 PSI - the guy messed up the installation and then sold the car to me - I am setting this back to stock), a high flow cat (i think), a BOV, and a fluidyne radiator. Other than that, I believe the car to be stock.

David
Start by setting the boost as low as it will go (8psi which is wastegate pressure). If the boost controller setup is really whacked you can just uninstall it and run the stock setup without the wastegate and precontrol solenoids plugged in. The stock ECU is capable of supporting 10psi but if I were handed an unknown car I would run it at 8psi until I was 100% convinced it was running like a champ before setting the boost to where it can theoretically go.

Just check out the FAQ for "reliability mods". There are many of them, so make a list, have a look at the costs, and set a budget, and go for the important ones. If you're not sure how to prioritize, just post your plan and you'll receive feedback.

Dave
Old 01-04-10, 10:07 PM
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Check out the FAQ there are entire sections Threads as well as a number of good websites on the "Bible" reliability mods. Check them out.

As stated, main issues are heating and incorrect tuning (lean fuel etc...) with modifications resulting in detonation.
Old 01-08-10, 08:28 PM
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Another issue that is often overlooked in this discussion are the stock gauges.

You cannot trust your cluster gauges, they need to be replaced with aftermarket ones.

If your water temp shows hot for example, you've probably already fried the engine.

Also a simple water AI would be good on a stock motor to help keep it clean and cool.

Although it can be a little daunting at first, begin learning the twin turbo system it's a little complicated under that UIM. If you go through and do the vac hose job you'll learn a lot about the system AND be able to check out the operation of all the solenoids and stuff while you're in there.

People like to joke and say the best mod is another car for daily driving, but it's true lol. Especially at first when you're just learning the car and don't want to rush things.

Last edited by twinsinside; 01-08-10 at 08:39 PM.
Old 01-08-10, 09:41 PM
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these motors can last if treated properly (warm up, cool down). a few reliability mods can go a long way too.
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