'01 w/no power when cold

[morgant]

I just had some evap and exhaust (cat... it burns about 1qt of oil every 500 miles) work done recently on my '01 Corolla and my garage noted that the remaining check-engine light code was for a stuck-open thermostat. We've had a relatively mild beginning to the season up here in Vermont, but I had noticed that I got plenty of heat nearly immediately when driving the car, so the thermostat must've been stuck open.

Well, I replaced the thermostat on Sunday with what my parts store said was to original spec (180°). Wish you didn't have to remove the alternator, but sure am glad it has a self-adjusting belt tensioner! I did _not_ change the coolant, but noted that it looks like it needs it, so intend to change that this weekend.

It seemed to drive fine on Sunday and Monday, still getting up to temp in a reasonable amount of time and getting plenty of heat out of the heater. However, mid to late this week the outdoor temps dropped to 7°-27°F for a couple days and I've started experiencing a new problem: upon start up, the engine idles fine (and revs fine in neutral), the water temp gauge reads at its lowest, but when I try to drive it, there's just no power at all and seems like it's not shifting. Actually, it seems like I have fine power for the range of 1st, but its like the automatic transmission is skipping 2nd and going into 3rd (it's the 3-speed CE) or something (engine RPMs sound like they completely drop, giving it gas doesn't do anything, and there's zero acceleration... it just limps along at 3-5 MPH).

As soon as the water temp gauge jumps up to 1/3, it's completely fine. My guess (and it's only barely educated) is that the automatic transmission is too cold, not shifting properly and/or causing too much "drag", but as soon as the thermostat opens and the water temp starts to rise, that circulates enough warm coolant through the transmission (since it's an automatic), to warm it up enough to function properly.

So, I fully intend to change out the coolant. I'll also check the transmission fluid & color. I've had the car for two years now and have put about 45k on it, so I should probably change the transmission fluid. Also, I noticed that the replacement thermostat the parts store provided me with did not have a jiggle valve, would that make a difference?

Please chime in with thoughts, suggestions, and/or debunking my theories.

[Milky]

try just letting your car warm up an extra few minutes in the winter. it will bring engine/trans temps up quicker. i dont like to drive any of my cars when they are cold. as in first start of the day, or sat for more than 4 hrs. pretty much, walk outside and turn your car on about 2-3 mins before your ready to leave. it will make all the difference. plus will help improve fuel consumption since your not driving while the ecu is still in cold start mode, which can use more fuel depending on air temps.

the juggle valve will not make a huge difference. it is there to bleed air and allow a little bit of coolant flow. without it, your engine will just reach operating tempreture sooner.

[morgant]

Originally Posted by Milky

try just letting your car warm up an extra few minutes in the winter. it will bring engine/trans temps up quicker. i dont like to drive any of my cars when they are cold. as in first start of the day, or sat for more than 4 hrs. pretty much, walk outside and turn your car on about 2-3 mins before your ready to leave. it will make all the difference. plus will help improve fuel consumption since your not driving while the ecu is still in cold start mode, which can use more fuel depending on air temps.

This is with 2-3 mins of warm up time. I'll try 5-10 mins warm up as well.

Today, I experienced the same issues even though it was about 45°F out. However, I did notice that if I put it in neutral when it was "bogged down" the engine was still running rough. After a second I could rev it up nicely, put it back into gear, and I'd have slightly better power, but it'd slowly wane until I had to put it back in neutral, rev it to get it running smoothly, and repeat. Once the thermostat opened, everything was find again.

I did put in some Iso-heet this morning as I haven't put any dry gas in this season yet, and the running rough seems to persist for a short while even after put in neutral. So we'll see if that makes any difference as well.

Also, I checked the transmission fluid level this morning, cold (again, about 45°F) and it's still a nice red color, but is way above even the "hot" markings on the dipstick. Is that normal?!

the juggle valve will not make a huge difference. it is there to bleed air and allow a little bit of coolant flow. without it, your engine will just reach operating tempreture sooner.

Good to know. Can't complain about the engine reaching operating temperature quicker, esp. for winter.

[Milky]

did you check the transmission fluid with the car running or not? if it was off then it may be normal. you are supposed to check atf levels with the car running and in park.

you also might want to check your spark plugs. it almost sounds as if they are fouled out, or in the process of fouling out. when was the last time they were changed?

[morgant]

Originally Posted by Milky

did you check the transmission fluid with the car running or not? if it was off then it may be normal. you are supposed to check atf levels with the car running and in park.

Heh, oops. Didn't realize it should be running. Will check again shortly.

you also might want to check your spark plugs. it almost sounds as if they are fouled out, or in the process of fouling out. when was the last time they were changed?

Haven't changed the spark plugs in the two years that I've owned it either, so who know when they were last replaced or even looked at. Should I bother checking or just replace?

[fishexpo101]

Have you noticed if your electric fans are running constantly? Possible that the coolant switch connection on the thermostat housing is not making good contact and is reading incorrectly. That will cause the car to take a lot longer to warm up to operating temps.

Definitely check the plugs - could be fouled, which could explain the initial poor driveability until you can get the car up to cruise to help clean them off. If in doubt of they are good or bad - just replace them. Iridium plugs are really coming down in price. Last set of NGK Iridium IX plugs I bought were on sale for less than $5 each.

Could also be some deposits that you stirred up or loosened when you replaced the thermostat. You'll get a better idea when you drain out the old coolant. I'd recommend sticking with Toyota Red + distilled water when you do the coolant. Don't forget the overflow reservoir - remove it if you can, as that can get pretty nasty.