Will the engine temperature display cool if the water pump is shot?

Hi All,

I have a 1999 Tacoma 4x4 with a manual transmission and a 2.7 engine.

I'm getting the tell-tale loud screeching sound at start-up -- as well as a high idle speed and a low running temperature.

Absent the screeching sound, I would assume the problem is simply the thermostat.

But with the screeching sound present, I'm thinking the problem is likely with the water pump.

However, if the screeching sound is being caused by a water pump problem, shouldn't the engine run hot, as opposed to cold?

Thank you so much,

HP

 

sometimes it's just a blet but if you're over 100k I would be looking at replacing that pump anyways.

 

If it screeches, it could be the bearings in the water pump that is bad. Temperature shouldn't play a role.

 

I can't think of anything that would cause a low runnning temperature except a 'stuck open' thermostat.

Maybe a piece of the water pump broke and jammed in the thermostat, or something else got into your coolant and hurt the water pump and jammed the thermostat.

High idle might be caused by the low running temp.

 

A bad bearing in the water pump will make noise, and can cause possible leaking at the shaft, but as long as it spins, the pump will still flow water.

 

Thank you for all the replies and suggestions.

I replaced the thermostat and everything is fine now. Even the screeching went away, though I suspect it will come back.

But I have to ponder whether the cold water flowing through the system could have somehow contributed to the start-up screeching.

 

If the noise went away, then I would be more inclined to believe that you had an issue with belt tension, which was eliminated when you did the repair.

 

I still think the screeching will come back. Keep us posted.