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Discussion Starter #1 (Edited)
Hi guys

Just finished up the big water pump change job last night...not my first rodeo in mechanic work, but first time I've seen this problem.

Symptoms:
  • Temp gauge on the dash shows perfect, right in the middle of the range, as usual
  • Came back from test drive around my block, got back to my house, it was idling in front of my garage, both fans went on and wouldn't shut off
  • Turned car off after about 3 minutes of them running...let it sit for 15 mins...started it back up...no more fans...then started high idling around 1200rpm, also noticed some steam coming from the front rad area, shut off engine immediately
  • Started again after another 20 mins, drove it down my street, all seems normal
  • While on 2nd test drive, had OBD2 scanner hooked up to it to monitor coolant temps, shot up to 213F before I put the heater on max and got back home quick to shut the car off.
  • With heater on high, coolant temps were starting to drop
Work done:
  • Full water pump change with new thermostat and all seals
  • No leaks of any kind
  • All coolant that was collected from draining the rad & water pump were put back into the system with the bleed valve open, solid stream came out before I closed it. I have about 0.25L left in my jug but the coolant overflow tank is full. (I guess this could be a clue for the air pocket? Couldn't fit all the coolant back in, but don't have THAT much left in my jug)
  • System holds pressure just fine, and can be released by opening the overflow tank very slowly
I'm reeeeeeeally hoping this is nothing major...I just bought this car and it had the water pump noise, didn't have this problem with it on the drive home that was ~30km...as far as I'm aware (before doing the pump). Air pocket somewhere? How would I go about getting it out if there is one?

What scares me is that the car is able to seemingly overheat with the coolant temp on the dash showing perfectly normal? In what part of the system is the coolant temp sensor located?
 

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Air pocket somewhere? How would I go about getting it out if there is one?

What scares me is that the car is able to seemingly overheat with the coolant temp on the dash showing perfectly normal? In what part of the system is the coolant temp sensor located?
The V6 has a bleeder valve. I used that when I changed the coolant. What you can do is drain all the coolant out. (reuse the coolant) Open up the bleeder valve and then refill until you see the coolant flowing out at this point you can tighten it up. Drive for a week and the coolant level may go down. This means the air pocket is going down so just top it off. Another thing you can do is squeeze the radiator hose to help burp the air out.

Below is a video showing the bleeder valve location:
 

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Discussion Starter #3 (Edited)
The V6 has a bleeder valve. I used that when I changed the coolant. What you can do is drain all the coolant out. (reuse the coolant) Open up the bleeder valve and then refill until you see the coolant flowing out at this point you can tighten it up. Drive for a week and the coolant level may go down. This means the air pocket is going down so just top it off. Another thing you can do is squeeze the radiator hose to help burp the air out.

Below is a video showing the bleeder valve location:
Thanks DL175. I did use the bleeder valve when I filled the system. After I had a solid stream coming out I closed it and continued filling up the rest of it :(

I'm worried to drive the car now with fear of it overheating. When I had the scan tool hooked up and on the test drive, just doing 50kph down my street (also keep in mind it was 5c degrees last night), coolant temp got up to 213F pretty fast...I didn't dare drive it more. Up to which temperature would you think it is safe to drive? I would have thought for sure the temp would stay around 180 since that's the thermostat I got. 213F is pretty hot... Like sitting in traffic when it's 35 out needing both fans hot... Not driving 50 when it's 5 degrees out... Boo

Also would you happen to know what temp both fans come on at? When it got up to 213F no fans came on. Just want to make sure they still work.
 

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Discussion Starter #5 (Edited)
Is the coolant temperature sensor switch wire connected?
I mean I guess it is because when I start the car cold the gauge is at the bottom.

EDIT: When I looked at the car again this afternoon the coolant level had dropped in the overflow tank, and when I opened the air bleeder a bit of air came out before solid coolant flow. Then I ran the car without the cap on the overflow tank for a while and it took much longer to heat up, drove it around the block and it didn't overheat at all. My scanner was still showing it sitting around 194-204F, though. Hoping it just has a bit more air in it because that still seems quite hot for regular driving around in cool weather.

Thanks for your help!
 

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More than likely you're ok. Getting the air out of the system is important ,especially right after work has been done. I usually rev the engine a little once it starts to warm up . This helps push the air bubble, if any , past the thermostat. I usually leave the rad cap "OFF" while it's warming up too until the engine gets close to operating temp. This expels air also.
I was going to suggest that maybe you got a bad thermostat, is it OEM? Modern cars are so touchy, I won't put any other thermostat in my vehicles now other than OEM.
If the fluid dropped, that's a good sign. Fill it back up , drive it normally and watch your temp gauge for a few days.
If it continues to overheat, then you may have to start looking at your radiator for being plugged and not circulating the coolant. You can watch that with the rad cap off, but obviously be careful around hot coolant.
Good luck...
 
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