I have 08 350. A couple weeks ago I had a mobile mechanic replace my alternator. Now I have a coolant leak and I can’t figure out where it is. He had removed the radiator etc.I will fill to near full and it will be low and the fans will kick on the next day and I have to put more distilled water in to top off. (Originally had red /pink )
When I’m looking under the car I don’t see any leaks. I’m confused. Any help ? Thx

 

It is easy to crack a plastic radiator when removing the hoses. You may have a hairline crack that isn't visible when the car isn't running and/or the system isn't completely pressurized, while up to temp. Inspect around the hose bibbs while the engine is running and hot. If you have a leak, coolant will be visible. Do you ever see any on the ground?

If you don't have a leak, then your mechanic did not get all the air bled out of the system after reinstalling the radiator. This is not good news either because trapped air can lead to spot overheating that can cause cracks and failures in the heads and block. But, you are likely OK if you haven't notice any other issues, other than the loss of coolant.

There are many procedures to avoid trapping air. If your mechanic is any good, he shouldn't cause any issues like cracking the radiator or trapping air!

 

thsnks for your response. The mechanic mentioned trapped air and had me get the car up to temp with the radiator cap off. Hairline fractures on the radiator could be a possibility , I’ll go out and check and see if there’s any water under it. I wonder if I can’t locate any issues if k-seal could seal the issue

 

I wouldn't run any additives. Instead, get to the bottom of what caused this. If your mechanic isn't willing to troubleshoot a problem he likely caused, find a new mechanic quick! Trapped air can eventually work its way out, but not always. If it remains, it can cause further, more serious issues than having to add coolant repeatedly. You could end up with warped or cracked heads!

 

I sent a photo here to my other mechsnic and he said this is likely the issue. Photo attached. I actually just put some k seal in because it worked on my old vw cc. How long should I run the engine with the radiator cap off?

 

That rad is a ticking time bomb replace it ASAP.

 

That rad is done, replace it as soon as you can before the seam blows completely. The way to properly bleed air out of one of these cars is STUPID easy and doesn't require any special tools at all. There is a air vent port under the engine cover near the front of the engine in the valley, open it and run the engine and all air will be removed.

Takes less than 5 min to do, heck I'll go out and take a picture for you right now....






10mm deep well, use a 6-8 inch extension to make it as easy as possible

Do not use ANY type of sealer/magic in a bottle or you will loose your heater core as maybe some of the coolant directors/restrictors in the block coolant passages. Those fixes never work and this type of failure is not something they are able to address on their best day anyway.

 

It seems to have fixed the leak anyway , I would have not used it but I already had. I’m wondering did mt mechsnic do soemthing wrong to cause my radiator to not work ? And why do you say it’s a ticking time bomb ? Does taking the radiator cap off and running the car not get the air out only the vent ?

 

after he out my alternator in he put all new anti freee inn and ran the car without the radiator cap on for a bit so he said it was important to get the air out. So did he not do it right or long enough ? Or do you think he did get the air out. What caused this failure in the radiator ?

 

It will explode on you. 100% since it can't reseal the crimp seam.

Yes, you will still have air in it since the cap is BELOW the top 1/4 of the engine coolant loop, not purging the air may have contributed to higher than usual operating pressures and hotspots.

 

Hi loliwin55,

I hope your radiator is not leaked. Maybe the coolant residue seen outside of the radiator on the pictures was the result of coolant spilling when running the car with radiator cap off.

If so, try bleed the air out of the cooling system by following video instruction titled "Toyota Cooling System Bleeding for V6 2GR-FE 3.5L THE RIGHT WAY" from "The Car Care Nut" YouTube channel.
I have a 2008 ES350 , too, and successfully replaced the coolant by following his instructions.

Video link:

 

to find coolant system leaks, the best way is to use a pressure tester. 80 bucks for good ones on amazon

 

Auto parts stores will loan you one for free, often. You pay a deposit and you get the deposit back when you return it. It's how I found the leak in my 2GR-FE radiator. No guessing.

 

The plastic tanks, the tank seals and the metal are fragile when new, but when old, they get brittle and prone to leaks. So, your radiator was likely old and brittle, and succumbed to the stresses put upon it during removal and replacement. I'm not sure of the miles/age on your ES, but if I was to remove my 11-year-old radiator to do this job, I would replace the radiator as part of the job. They're not very expensive, and prone to leaks eventually, so why not replace it once it's already removed, not unlike the way mechanics replace the water pump when doing a timing belt, even if the water pump isn't leaking.

 

I agree, this is something that should've been recommended as part of the alternator replacement as old fragile radiators love to crack and leak from breathing on them the wrong way.