2002 Prius ICE won't start after oil/ATF fluid change

After dreaming of owning a hybrid for quite some time, I finally picked up a 2002 prius with 62K miles. Bought a few weeks ago from a neighbor, where it was sitting undriven for 2-3 years. The original 12v battery was pretty weak (would only hold charge for 12 hours), but the hybrid battery seemed ok (no more ECU errors after letting the engine charge it for some time).

So, it drove great for a few weeks, but this morning the ICE wouldn't start.

The dashboard now has the following lights (it was all fine before)
low oil pressure light
hot coolant light
check engine light
car with exclamation point sign
Turtle sign

The diagnostics so far:
1) Standard ELM327 ODB2 Bluetooth scanner says that there are no codes stored in the ECU
2) oil dipstick shows oil almost to the top marker
3) inverter fluid shows a little movement (barely noticeable) when the car is on


Oil and oil filter were changed 3 days ago on Monday night. I used a mixture of about 1/4 quart of Mobil Super 5W-30 Conventional Motor Oil (fresh from the store), 1 quart of 10w-30 Pennzoil and 1.5 quarts of 10w-40 SuperTech 10W40 Motor Oil (both probably around 5 years, got from the previous owner)

ATF fluid was changed on Wed night 1 day ago. I used Toyota ATF Type T-IV (also probably around 5 years, got from the previous owner), 2.5 quarts, simple drain and fill.

What I tried so far:
1) another battery/jump-starting - same result
2) disconnected the battery for 10 min to reset the ECU - to no avail


I thinking the possible culprits could be:
- clogged oil filter
- broken oil pressure sensor
- broken oil pump
- broken/stuck thermostat
- broken coolant temperature sensor
- wrong oil type (1x10w-30 and 3x10w-40 instead of recommended 5W-30)
- air in the oil pump

Could anyone suggest what I should check for next?

Also, where I can borrow a hybrid-friendly ODB2 scanner/diagnostic tool around San Jose airport (San Francisco (South) Bay Area in California). Any friendly prius owners with a good scanner in the area?

Thanks a lot!

 

Thanks. Just spoke to the previous owner and he swears that 10w-30 is what's recommended in the maintenance book he has and that's all he used before. The 2002 prius manual says 10w-30 is ok for the temperature range 0 to 100F, so I'm not sure how it could cause the "low oil pressure light". Perhaps the oil pressure sensor is faulty - any way to check that?

The strange thing is that the ECU wouldn't even attempt to start the engine. Perhaps there is some type of electronic/electric fault somewhere?

 

Thanks for all the points. Here are the answers.

> 1. Did you install a new 12V battery? If not, do that now.
Yes, but not a new 12v prius battery, but a used one from a UPS. I don't think it's a battery, as I tried connecting it to a brand-new battery from another car (bypassing the one in the trunk) - same issues.

> 2. How many quarts of Toyota ATF T-IV did you fill the transaxle with? Your post says 2.5 quarts. The
> correct qty is ~5 quarts and the oil level should be at the bottom of the transaxle fill hole.

About 2.5 quarts, until it started coming out of the fill hole. I didn't do a full flush, hence half of it remained in other places of transmission.

> 3. 10W-40 viscosity oil is too thick and is not helping. The correct viscosity is 5W-30.

Ok, but the prius manual says 10w-30 is ok for warm climates. Would the wrong viscosity really stop the ECU from trying to start the engine?


> 4. Your OP indicated the following quantities of oil were used: 1/4 + 1 + 1.5 = 2.75 quarts which is not
> enough oil. However in that same post you indicated 1 + 3 quarts of oil. So which is correct?

Sorry, that was a "copy-n-paste" error. I think it was about 3 quarts. One thing I forgot to do is to warm the engine prior to draining the oil. In any case, the oil level is about quarter inch to the "full" mark on the dipstick.

> The engine oil capacity spec is 3.9 quarts and 3.5 to 3.75 quarts should bring the oil level up to the top
> dimple, depending upon how well you drained the old oil.

Yes, it's almost to the top.

> 5. When the car has a no-start issue so soon after it has been worked on, first consider what work
> may have done incorrectly. Hence my questions 2-4 above.

Yes, thanks.

> 6. If you don't find obvious problems, then it is time for you to purchase Mini VCI so that you can
> retrieve the DTC logged by your car which will give you a clue about the no-start problem.

Ok, great. Would Mini VCI allow to trouble-shoot hybrid-specific issues or should I try to get the ScanGauge II?

> 7. You provided a long list of items that you thought may be the root cause - rather than continue to
> guess, take care of #1 and #6 first. Good luck.

Ok, thanks

 

> 1. When the car is IG-OFF, what is the voltage measurement across this used UPS battery?

Around 12.5v. I've also tried another (almost new) battery and it had 13.6v

> 2. I am wondering if your transaxle is sludged up. When you drained it, ~5 quarts of used ATF should
> have come out and you should be able to add ~5 quarts of new ATF. A flush is not normally needed.

Interesting. Only 2.5 quarts came out and I have driven the car just before doing the change. Any idea why only half of it drained and what to do about it?

> Just to make sure we are on the same page: the transaxle ATF drain plug is located on the sheet steel
> transaxle oil pan which is painted black. This is not to be confused with the inverter/transaxle
> coolant drain plug which is located on the transaxle aluminum case which is closer to the engine.

Yes, I used this guide (google "the pan that can change-transmission-fluid-in-2002"), but without dropping the pan.

> 6. Mini VCI provides the same diagnostic capability as a Toyota dealer tech enjoys and supports all
> Toyota vehicles. It definitely is the best diagnostic tool available and its price is minimal - so it is a no-
> brainer choice.

Ok, great. I'll try to get it soon. Thanks again.

 

> Not starting: does it turn over at all?

No, the ECU doesn't event attempt to start the engine

> Try a double-key turn start? (1) START, (2) IGN/ACC, (3) START (easy test for obscure problem)

You mean turn the key twice in rapid succession?

 

Yes, I'm pretty sure, as I still have 3 bottles with the ATF fluid (two unopened and one half-full). Great, that's a good idea, I'll try it.

 

BTW, If I want to drop the ATF pan, I absolutely need a new gasket, right?

 

Yes, I spoke to Lucious Garage yesterday, I need to tow the car 50mi one way and pay $75 to have it diagnosed. I'll try to find some DIY option first.

 

> Try a double-key turn start? (1) START, (2) IGN/ACC, (3) START (easy test for obscure problem)

Tried it this morning - didn't do anything.

I've also noticed a strange hissing sound coming from somewhere near the engine block for the first 20 seconds when I turn the car on, it sounds like a pump running without oil/coolant. The noise is on the passenger side of the engine, so probably not an inverter coolant pump. Is oil/coolant pumps electrically driven in a 2002 prius?

 

The gasoline engine wouldn't start at all, the ECU would not even attempt to start it.

 

Ok, thanks a lot. I'll try to get the miniVCI cable for WinXP then. I hear there are 16 and 22pin versions. I found one on amazon (Fotga Newest V8.00.034 MINI VCI for TOYOTA TIS Techstream Diagnostic Cable & Software) - is it the best one out there for the price?