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First time poster, sorry if this is in the wrong place. Long time lurker, finally created an account. You guys have been great help over the years.
Vehicle: 2010 LS460L Problem: coolant levels low, even after refill Work done so far: new water pump and gasket. Dealership said it was leaking, decided to handle myself. Unbolted and found the gasket failed on the bottom closest to the center of engine. Bled the lines (I think). Suspect of continued problem: water pump bolts not torqued right. Found online for general Toyota/Lexus it's 15 lbs. Did that for all bolts.
Later discovered this article and found each bolt is different. Basically the short 12mm bolts (A) are 15 lbs, but the longer ones (B) are 17 lbs. Then there are the two 14mm bolts (C) which say 35 lbs. Also attaching picture from the article so you can see A-B-C.
Questions:
1. Do you agree this is the likely culprit? There is no evidence of weird smells inside or colored exhaust. No water on the ground.
2. If so, do you trust those torque specs? 35 lbs seems a lot.
3. Is it possible air bubbles could somehow be causing a loss of coolant and my problem is not a leak from the water pump? Again, I *think* I got them all out from standard bleeding process, but I've been fighting it for a week now.
Upon getting it to temp and driving it (less than 5 mi), I lose about 1/2 cup to 1 cup of fluid (full line - cold to just below low line - cold). No apparent leaks anywhere...probably a slow burn off the engine. From there, it hardly drops, but I don't have a good way to measure the rate.
Any ideas, comments, suggestions, thoughts would greatly be appreciated!
I agree with Boykie. But because you're uncertain about bleeding the air out, you should do it again. This includes opening the plastic bleed screw and also squeezing the hoses. Be sure to run the heater as well. It can take a couple of tries. Also, the coolant tank cap has a gasket that can go bad. New cap is the solution.
Thanks guys...looking like I'm going back in there even if it's not the problem (although it likely is). Might as well ask....what's the torque spec for the thermostat? I did 15 lb on each of those 3 since they were the same as the little ones for the water pump. Thank you.
Morning all thanks for the kind recommendations and information. Thought I would offer an update. The night prior to me starting this thread, I bled the lines one more time, but this time revving the engine with the heater on full blast. There are so many methods and opinions out there on how to do it, I think this last time finally resolved the air issue for me.
What this means is that I didn't retorque anything (yet) on the water pump or thermostat housing. Been holding steady at full (cold) in the reservoir for the past couple of days. I was really surprised to find out these air bubbles somehow caused a loss of coolant....
Anyway I know my torque settings are wrong so I'll still have to get back in there at some point. I hate that lingering feeling that something could break due to negligence. Thank you!
Yeah, if you didn't bleed with the engine revving at some point before, that's part of the service procedure. This is from the LS600, but the engine is a relatively similar 5.0L V8:
- Turn off A/C from the HVAC controls
- Remove the radiator neck vent plug
- Slowly add coolant to the reservoir until it reaches the FULL line
- Repeatedly squeeze the radiator hoses by hand and add further coolant as needed
- Idle the engine for 10 minutes, adding coolant as needed to keep the reservoir level at the FULL line
- Add coolant to the reservoir to bring it up to the base of the filler neck
- Run the engine at 2,000 RPM for 5 minutes
- Shut off, let cool, and add coolant to restore level to the FULL line
People have listed other procedures, but that's how Toyota states to do it, as found in the service manual. I drained all the coolant from my radiator and engine block to replace it, then filled in this way and haven't had problems.
If you have an air compressor, I also highly recommend checking out a vacuum filler tool for cooling systems. You use a Venturi-based nozzle to pull all air from the system, then open a valve to draw in coolant from a bucket or bottle to fill. I have this one, but there are plenty of other options: https://www.ecstuning.com/b-schwaben...l/003466sch01/
Water Pump Torque Specs
