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matthewlookingbill19

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Discussion starter · #1 ·
🚨🚨COOLANT BYLASS VALVE WRITE UP🚨🚨

I've never done one for these write ups so bear with me. But there's just not much info on this so figured I would try and help out.

My wife's car had a Engine Maintenance Required warning pop up (NOT MAINTENANCE REQUIRED, BIG DIFFERENCE) car is a 2020 Rav4 with 34,000 miles.

After research I figured it was the coolant bypass valve. Seems to be pretty common. I did not take it to a dealership to have diagnosed as they wanted $79.99 just to scan the car. No thank you. Also Dealership was charging $153 just for the part. I took my chances and ordered the part on Amazon for $40, with a 20% discount came out to $33 total shipped. That's with the valve and hoses.

Now mind you, I'm no mechanic but can do minor things. This Job can be done with little to no experience and save you about $800-$900.

This is how I did the job.

Tools i used. Vice grip Pliers, 3/8 Rachet with 3 inch extension, 10 MM socket and 12 MM socket, pick tool for clips, jack, one jack stand, and whatever you use for removal of tire. I used 1/2 impact wrench with 21MM socket. Two inch mirror with flexible cable ($6.99 at harbor freight) so u can see blind spots.

Step 1- remove valve sensor. Use mirror and pick tool.

Step 2 - use pick tool to carefully remove white clamp on heater core hose attached to VALVE. That clamp does not come all the way out. Just back it off enough to remove heater core hose. Push hose out of the way for remainder of job.

Step 3 - behind the valve at the bottom you will find a 12mm bolt that hold the blue clip heater core hose in place. Must loosen this enough to move right side heater core hose adaptor to gain access to the 12mm bolt that's attached to the bypass valve. (YOU DO NOT NEED TO REMOVE THE HEATER CORE HOSE WITH THE BLUE CLIP OR TAKE BOLT FROM BOTTOM ALL THE WAY OUT. JUST LOOSEN AND IT WILL GIVE U ENOUGH ROOM TO GET BYPASS VALVE BOLT OUT!!

Step 5 - remove 12mm bolt securing the bypass valve. Set bolt aside.

Step 6 - With 10MM socket remove bracket holding the O2 sensor wire. This is accessed easily behind motor and i have picture of it. This will help get to hose clamp that is hidden behind motor. Also reference picture please. Set bracket aside.

Step 7 - With Vice Grip pliers remove hose clamp behind motor. Probably toughest part of job. But if I can do it anyone can. You will lose some coolant here maybe half gallon if that. Place bucket on floor to catch what u can.

Step 8- there will be a plastic hose clamp holding two hoses on the bottom hose. Just unsnap the hoses.

Step 9 - jack car enough to remove driver front tire. (Some turn wheel all the way right to gain access. I preferred just removing tire) some folks have taken the battery out, battery tray out, air box out to gain access to bottom hose. Thats more work in my opinion.

Step 10 - laying down on floor you will see bottom hose. Very easy to get to. But my clamp was turned wrong way. If that's the case. Just twist to access then with Vice grips take clamp off and pull hose off. Some coolant leaks here to. Not much

Okay the hard part Is done. Now your bypass valve is off. Here's how I put it on.

Step 1 from top of engine route the bottom hose down to fender well. Put clamp on bottom hose and attach. Put tire back on and jack car back donw.

Step 2 - put hose on back of engine and hose clamp

Step 3 - put 12mm bolt back in and bolt down bypass valve

Step 4 - tighten bottom 12mm bolt that you loosed earlier

Step 5 - snap valve sensor back on

Step 6 - put 10MM bolt back on holding o2 sensor wire bracket.

Step 7 - but all plastic clips back on bottom hose.

Step 8 - top of coolant and use a bleeder kit like shown in picture. YOU MUST BLEED SYSTEM TO BURP ALL THE AIR OUT. HERES HOW

Step 1 - top off coolant and fill funnel about half way. With other person (I used my wife) turn car on with NO AC OR HEATER ON DO NOT NEED TO DO THAT WITH THESE CARS. I learned that from car care nut on YouTube. Turn car on rev to about 2000 rpm and hold steady. Watch your radiator fan. Once it kicks on and off TWO TIMES you are done. Takes about a good 10-15 minutes for this. While this is happening you will see a ton of air bubbles coming out of radiator.

Once this is done your problem is over with and you saved a bunch of money.

I hope this helps someone. Again I've never done a write up.
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EXCELLENT WRITE-UP! I have been waiting for this for years. I have some questions. 1. Did you lay on top of the engine from the front or did you lean over the fender from the drivers side? 2.Did you use your mirror to see the bolts and that pesky hose clamp on the back of the engine? (maybe you could explain more how you held the mirror and positioned work lights?) 3. How long did the entire job take you? Lastly, PLEASE attach a link to Amazon or a picture of the Amazon part title so we can find that cheap bypass valve with hoses. Again, GREAT JOB and thanks for posting.
 
Discussion starter · #7 ·
EXCELLENT WRITE-UP! I have been waiting for this for years. I have some questions. 1. Did you lay on top of the engine from the front or did you lean over the fender from the drivers side? 2.Did you use your mirror to see the bolts and that pesky hose clamp on the back of the engine? (maybe you could explain more how you held the mirror and positioned work lights?) 3. How long did the entire job take you? Lastly, PLEASE attach a link to Amazon or a picture of the Amazon part title so we can find that cheap bypass valve with hoses. Again, GREAT JOB and thanks for posting.
1) yes, got some scratches on my stomach for proof lol

2) I bought a 16 inch flexible mirror. I just bent it to where I could free up both hands and see clamp

3) about 90 minutes to take off (this isn't including all the reading and researching trying to figure out to do it. Then 30 minitrd to put the new one on and another 15 minutes to fill and bleed coolant system
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Hello everyone
I ordered a valve and pipe kit from the same place as matthewlookingbill19, with the difference that I had to pay more for transport because I am in Canada. Now it is out of stock and the price is going up.
My money was well invested because the brand valve as AISIN, the pipes nothing to say about the use.
*. Rockauto sells the valve AINSI for $60.00 and without the hoses.
I started looking for a purchase on the internet, AISIN is a Chinese company, so I looked on Aliexpress/Amazone.ca and I can assure you that it is the same pipe/valve assembly. If you, like me, don't want to be stuck at the last minute and pay for an OEM that is defective anyway, buy online. Normally between $40 and $60 you will get a good deal.
I'm the planning type, especially for $60.00
 
Hi
I'll give you the formula again:
E= R x I
-----------------------
E= voltages
R = Resistance
I = Current
So: 12V / 26.2 = 0.5 Amp
The temperature has no effect on the formula and for me on the result.
OMG, I learned the Ohm's law in the school (grade 7).
And if you worked as electronics tech than you should know relation between resistance and temperature.
 
And if you worked as electronics tech than you should know relation between resistance and temperature.
For something like an incandescent light bulb, the resistance goes up significantly from cold when power is applied. Thermisters are designed to change resistance linearly as they warm up. But for other resistors (carbon, wire wound, film, etc) they change very little with temperature unless they go over their watt rating.
 
Thanks for posting!

Dumb question - what is the purpose of this valve? I understand the purpose of a coolant bypass hose - but why would you ever wish to close it / why does it need a valve?
 
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