Suggestions for care for high mileage gen 1?

When was the last time the iridium spark plugs and the engine air filter were changed?

When was the last time you changed the transaxle ATF, and the engine and inverter coolants?

The high mileage engine oil formulation is supposed to help if your engine is burning oil. Unless that is a problem, use of that oil is not going to do much for your car. There is no reason to change engine oil more frequently than 5K miles assuming you are using a decent brand of oil and oil filter.

It might help for you to use a bottle of fuel injector cleaner, like Chevron Techron. The correct gasoline octane is 87, regular grade.

For fun, you can disconnect the 12V battery to allow the ECUs to power down and reset. However I doubt that will do much for your car. The engine ECU will adjust to the current conditions that its sensors report.

 

I would not do any fuse changing or modifying anything. I would continue doing what you are doing. If you start using a higher octane gasoline you are just wasting your money. My suggestion would be to put a container of Chevron Techron in your gas tank. If it does not help it sure will not hurt anything. Any auto parts store has it. I put it in my car about every 6 months.

 

The only thing I would say is, keep doing what you're doing.

Did you change the transaxle fluid yet? Spark plugs x2? Engine coolant? Inverter coolant? It might be worth it to replace injectors at this point but, its hard to say. Other than that, I would fix it as it breaks. You have to remember your car may not be worth much so putting a lot of money into it has to be weighed. I try to avoid putting a lot of money into my 01 because HV battery or transaxle failure could occur at anytime. You might also consider throttle body cleaning. Other than that, these cars require very little attention.

 

For a current value estimate, our recently totaled 2002 with 264k on the odo was valued at $5100 by our insurance co. We had the HV battery replaced 44k miles ago, and a nice full-size spare. nothing else really changed from when it was new. As to maintenance, I agree that if you haven't cleaned the throttle body for a few years (or had it done) it would be a good idea.

 

If wondering about dirty injectors, there may be some ways to investigate whether they might be involved. One is simply to touch a mechanic's stethoscope to each injector while the engine is running. I've read that you might actually hear the difference between the sharp metallic tickticktick of a clean injector and the thumpthumpthump of a grubby one.

Injector issues can be of two kinds: they might all be passing less fuel than they did when new, or they might be passing mismatched amounts. The first you can check by using a code reader to read the fuel trim from the ECM. This is a standard OBD-II parameter so you shouldn't need a Prius-specific scanner to read it. The ECM can learn a trim of up to about + 20% to compensate for slow injectors, so if the trim is anywhere up near that number, the injectors could be due for a cleaning. But if the trim overall doesn't look bad, there could still be differences between cylinders, and that might be visible if you look at the ends of the spark plugs for deposits and they aren't all pretty much the same.

From this forum there've been two sets of injectors, that I know of, sent off for professional cleaning/rebuilding with before/after testing: mine (engine running pretty well but at 204000 miles I was curious how they were doing), and another member's who at 165000 did have a rough-running problem.

Comparing the two, you can see that the first set really was surprisingly clean even at 204000, not much room for improvement, and the second set clearly was dirty: overall the flow rates were down 20-25% (past the limit of fuel trim the ECM can learn), and there was about a 32% imbalance between the best and worst.

I'm not sure what makes the difference between injectors being very clean at 204000 or dirty at 165000. I had bought my car at 126000 and never used any injector cleaner in that time, and never been picky about where I bought gas. Just lucky, I guess.

Another thing you can see in those injector-cleaning threads is that the two bottles of injector cleaner the other member tried really didn't have any significant effect, while sending the injectors for the clean/rebuild service totally did bring them back, both sets showing almost exactly the same test results after cleaning.

I still have that second restored set, for anybody who'd like to cover my $83.60 cost for the restoration. That'd be the same cost as sending your own out to Rich, but without having to wait for him to turn them around. Then the old ones could be sent out themselves for restoration any time that's convenient.

Rich provides a serial-numbered test result printout for each set he does, and engraves the serial numbers on the injectors.

-Chap

 

fuel mileage...check toe in, tire pressure, brake drag, fuel quality (excess alcohol) and time to go closed loop (lazy o2 sensor, coolant temp. sensor, thermostat).