Long time to warm up

99yota4

99yota4

New member
Hey guys I've been really busy with my last semester of college and haven't been on the forums in a while. I recently noticed that my runner is taking forever to warm up and sometimes doesn't even reach the half way mark on the temp gauge. I checked my radiator coolant levels and there's a little in the reserve. My mileage seems like it also dropped but I can't connect the dots. Any ideas? Current 4runner status: 1999 4wd auto w/ 125k miles, replaced radiator hoses and thermostat in september last year. Also when fan blower is on i can hear water trickling down somewhere and it seems to be only when the truck is started up and a few minutes after.
 
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Thanks THEREALTOR1, but I'm still puzzled on how an o2 sensor can affect engine operating temperature?

Anyone have other ideas? Where can I start looking to fix this problem where the temp gauge rarely goes up to half way like it used to and it takes forever at even getting there. Thanks in advance!
 
I know you said you checked the tank but did you check the radiator fluid level? If you're rad. is full it sounds like your thermostat might be stuck open.
 
Ehhh I really wouldn't put too much faith in the engine temp thermostat reading as it really only is a dummy reading, ie 3 position switch (cold, normal and hot). So somewhere in between and your safe.
 
that's what a couple people have been telling me. I'm thinking about getting the OEM toyota thermostat and replacing the generic fail safe one i got from autozone.

I've also heard that the temp gauge is not accurate at all but I'm just used to it warming up and staying at the mid level as it gave me a safe feeling that my motor is running right.
 
99yota4 said:
that's what a couple people have been telling me. I'm thinking about getting the OEM toyota thermostat and replacing the generic fail safe one i got from autozone.

I've also heard that the temp gauge is not accurate at all but I'm just used to it warming up and staying at the mid level as it gave me a safe feeling that my motor is running right.
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You seem to have done your homework on the troubleshooting yourself, and thats cool, but I can tell you from a first hand 6 month experience that I watched my temp gauge go from 1/2 as a norm, down to about 3/8, but I really didn't know why. Then my gas mileage started going to ****. Then one day my CEL lit up with all the other bells and whistles (this was about 90K miles). After I replaced by aforementiond 02 sensor, my mileage has picked back up and my thermo is running right at 1/2.

They suggest you replace it every 75k, so if you haven't, then its not gonna hurt you to do so. Just my input, hope it helps.

PS: If you research that particular part, its not your normal 02 sensor in the sense that you may think of it(at least it wasn't for me).
 
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Look down at the front where the lower hose attaches to the engine (your t-stat. housing) Theres probably some white and pink crusty stuff around the block area. If there is your water pump is leaking. Look also around and behind the crankshaft pulley and timing belt cover. You may see some dried white and pink stuff there also. That will cause the waterfall sound you hear. It's an air pocket in the cooling system. As for taking a long time to warm-up. Ditch the autozone t-stat and get an OEM one. An O2 sensor is not going to make your vehicle take a long time to heat up. If the t-stat is stuck open the ECM thinks the engine is always cold. Therefore it stays in open loop (rich fuel mixture) trying to get it up to temp. It also keeps the vehicle out of overdrive if it's an automatic until proper engine temp. is achieved. Hope this helps
 
attitudeofgratitud said:
Look down at the front where the lower hose attaches to the engine (your t-stat. housing) Theres probably some white and pink crusty stuff around the block area. If there is your water pump is leaking. Look also around and behind the crankshaft pulley and timing belt cover. You may see some dried white and pink stuff there also. That will cause the waterfall sound you hear. It's an air pocket in the cooling system. As for taking a long time to warm-up. Ditch the autozone t-stat and get an OEM one. An O2 sensor is not going to make your vehicle take a long time to heat up. If the t-stat is stuck open the ECM thinks the engine is always cold. Therefore it stays in open loop (rich fuel mixture) trying to get it up to temp. It also keeps the vehicle out of overdrive if it's an automatic until proper engine temp. is achieved. Hope this helps
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It's very possible i'm wrong, wouldn't be the first, and won't be the last, but can you share with me how the b1s1 o2sensor only affects my t4R temp gauge (ie warm up/ idle throttle time)?
 
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THEREALTOR1 said:
It's very possible i'm wrong, wouldn't be the first, and won't be the last, but can you share with me how the b1s1 o2sensor only affects my t4R temp gauge (ie warm up/ idle throttle time)?
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I agree that the O2 sensor has an effect on the warm up period. I just threw a P0135 code which is the heater circuit for O2 sensor - bank 1, sensor 1. It has an effect on when the ECU goes into closed loop operation while it's warming up.
 
brian2sun said:
I agree that the O2 sensor has an effect on the warm up period. I just threw a P0135 code which is the heater circuit for O2 sensor - bank 1, sensor 1. It has an effect on when the ECU goes into closed loop operation while it's warming up.
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Damn, to the 3rd page? Between that and the poor gas mileage as indicated in the OP, the O2 is my first thought. Some feedback from the OP or others who posted in the thread would be nice so we could actually help pinpoint the trouble area...
 
The o2 sensor does play a very small part in heating of the engine. And I mean SMALL. Rich mixture=higher combustion temps. Not enough a factor to see on a engine temp gauge though. The reason for richer fuel is to get the cat up to temp for emissions. Not getting the engine temp up.
 
i appreciate everyones input! Thanks guys, so i've had the P0420 code for a while now and i replaced my 2nd o2 sensor (the one after the catalytic converter) and i cleared the CEL. it eventually came back after a couple months so i'm starting to think my cats are actually bad. I've been driving around for a while with the CEL on and i've been assuming that its just the p0420. I'll make a run to the store to get the code read to see if there are any other codes on there. I do have a spare A/F sensor (the front o2 sensor before the cats) so I might change that as well. I'll try and do some investigating for any leaks or white and pink crusty leaks.
 
I forgot to ask, how do i get rid of these "airpockets"? WHen I replaced the radiator hoses and the t-stat, I did run the truck for a 15 minutes with the radiator cap off and adding fluid as necessary which i was told is the way to "BURP" the system.
 
attitudeofgratitud said:
The o2 sensor does play a very small part in heating of the engine. And I mean SMALL. Rich mixture=higher combustion temps. Not enough a factor to see on a engine temp gauge though. The reason for richer fuel is to get the cat up to temp for emissions. Not getting the engine temp up.
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I agree. Thinking about it more, I also don't think the O2 would effect the heating of the engine enough to make a difference that you could see on your gauge. The engine is running and it's generating the same friction and heat so the only things I can think of that would make it run cooler than normal and enough to show a difference on your gauge are a thermo that's stuck open or your gauge, coolant temp sensor, or wiring is jacked up.

Also OP, how long is a "long time"? My runner always takes about 8-10 minutes to get to operating temp in the winter. And normal OT is a little below 1/2 on the gauge.

99yota4 said:
i appreciate everyones input! Thanks guys, so i've had the P0420 code for a while now and i replaced my 2nd o2 sensor (the one after the catalytic converter) and i cleared the CEL. it eventually came back after a couple months so i'm starting to think my cats are actually bad. I've been driving around for a while with the CEL on and i've been assuming that its just the p0420. I'll make a run to the store to get the code read to see if there are any other codes on there. I do have a spare A/F sensor (the front o2 sensor before the cats) so I might change that as well. I'll try and do some investigating for any leaks or white and pink crusty leaks.
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Look at your cat after a long drive at night. If it's glowing red, it's definitely clogged. Smelling like rotten eggs is another symptom. But, a cat can go bad without showing either of those symptoms so you never know. I don't believe that has anything to do with your warm up/OT though.
 
brian2sun, when i say long time i'm talking like almost until the end of my trip and it's still not warmed up. (20-30 minutes) Last weekend when i went up to the mountains to go board, i was UNDER the C (cold) line about an hour into the drive and in the mountains. That's when i freaked out because regardless of the weather outside, the motor should maintain a constant operating temp.

The smell of rotten eggs is tough to decipher but i do smell that gassy smell like when you start ur car up on an early cold morning. White fog or smoke or steam seems to come out of the exhaust longer than usual now a days but i think thats due to the weather.
 
If you know anyone with a laser thermometer (or you could buy one), you could go around the motor and compare the temps with a local 4runner and see if the engine is in fact running in the normal temp range. If it is, then you know the gauge, sensor or wiring is messed up.
 
99yota4 said:
gauge, sensor, or wiring, and not the thermostat being stuck open?
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What I was saying is.. If you can find another 4runner with the same motor to compare it to, take readings around both engines with a laser thermometer and compare them. If your engine is running at the same operating temp as the other 4runner then you know you're thermo isn't stuck open and it's a gauge/sensor/wiring issue.

That's if you know somebody local with a 4runner and can get your hands on a laser thermo. Otherwise, buy a t-stat for $15 and put it in in 15 minutes.
 
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