P261B, high coolant temp light,, water pump?

P261B means the water pump has been clocked at under 900 RPM when it should be more than that.

Pretty commonly that'll be the pump. If you want to be more sure before you replace it, you can follow the troubleshooting workup for that code in the repair manual (more info).

 

NO. It could be several things, including a leak and low coolant level.

 

It was the water pump the last time I experienced that code...
It doesn't hurt to take out the pump and spin it by hand to see any resistance... Mine was seized

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What that light means "for sure" is the engine is way too hot and running it for three hours is a sure way to blow a head gasket in an all aluminum engine. Spewing coolant out of the cap is another sure sign that its way too hot.

As Chapman and "everyone" indicates, the code says change the pump. It seems quite a few people have trouble believing folks these days.

I tell my wife and friends they need to pull over safely and have the car towed if they see a temperature light. I also monitor it in my car so that I might get an early heads up on an over temperature.

 

It can take 30 minutes to operate the radiator fan. Usually turning on the ac will test it. When driving the fan is rarely needed.

The display is a "P10 HUD OBD2", ebay.

 

I can't speak for "everyone" but what I said was a little different ... because I'm always harping on the "trouble codes don't tell you to do something, they give you info about a situation" business, I'd break character to stop now.

The info that P261B gives you is that you have a situation where the tachometer signal from the pump is being read as less than 900 RPM, when the pump should be going faster than that.

I suggested that the reason for the pump RPM being too low has commonly turned out to be the pump itself, but that's me talking, not the code. And there can be exceptions, like more rarely a wiring problem getting power to the pump. Or even a problem with the tach signal coming back from the pump. So if a person wanted to go through the P261B troubleshooting workup before just condemning the pump, that wouldn't be an insane thing to do.

Other people will see the code and go straight for the pump, and that's not insane either, since that will be the culprit often enough.

 

When the writing is on the wall and ignoring it is risking the engine because of overtemp and your family by getting stranded, its time to act. Expecting everyone (no quote) to be an Ivan with a Picoscope and a milliohm meter is a bit much.

 

Should have been "It"... Typo, my bad...

Also, just to note that I also heard that noise and felt vibration came from water pump when I received the code, and noise and vibration both gone after I unplugged the pump.

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Some people have a tendency to beat things to death and seem to be waiting for the bad part to jump out and grab them by the nads.

 

Agreed that an issue involving overheat needs to be solved without wasting time, and that the owner (or mechanic) needs to take an honest look at his or her own situation, skills, and available tools and resources.

If it is practical to follow the troubleshooting steps for the indicated problem—promptly—that will be the straightest path to a correct solution without misspent cash, repeat problems, and do-overs.

If that isn't practical, of course no one is saying "do nothing" is an option. Progress still has to get made somehow, even if it's by guessing at a likely part and spending the money to see if that does the trick. Sometimes it won't, but it can be a reasonable gamble for someone who knowingly chooses it.