scutch

Hi,
Is it likely that the thermostat housing needs replacing? Is that common? Do the pics look like it is coming from the housing, or spillage from elsewhere? Although from where? Probably the housing, but I just haven't seen that mentioned much in coolant leak posts, although a thorough search is challenging.

First I was blowing cold air with the heater on while idling. Coolant level was just below the low line. I added coolant and fixed that. Today I went for a pressure test on the cooling system and they said they saw no active leak because the car was hot, they think, but said they saw coolant stains around the water pump and thermostat housing. It seems obvious from the pic that the water pump needs replacing after 183k.

I looked around and saw no other leaks or pink spots. I know the cap, radiator and hoses were replaced and system flushed 2 years ago, by same shop. The temp of the car always stays right in the middle and I have no other issues.

I'll add half a liter of coolant and it will be down to just below that low line in a couple days, and then seems to stay there. Maybe because that is the same level where the leaks are?
Thanks Eddie

Anfanger

The water pump and the thermostat eventually start leaking and have to be replaced. It is especially common in high mileage vehicles.

swfla

iTrader: (1)

It could be either or both. I say this based on threads I've read over the years. On a 2007, it seems prudent to replace both, unless you're selling it or living on Ramen noodles.

bearcav

This may be the valley plate leak...coolant disappears but no obvious leak.

swfla

iTrader: (1)

Excellent point. The tiny housing stain doesn't account for the amount of coolant being lost. Many posts about valley leak being hidden but causing frequent issues. For searching this forum, Google works better. Type in your specific subject and model and also "Club Lexus forum", google search will return many forum specific posts. Like this. LS460 valley plate leak "Club Lexus forum"

scutch

I'll be getting the pump and thermostat replaced. Is the valley plate seal another two hours of labor if I buy the seal for my guy who is doing the work, or is it gentler on the wallet? Is it recommended to replace that seal if it's not leaking right now? I haven't looked it up yet on the message board.

Hoping the shop who did the pressure test checked the valley plate. I called them. And they said they didn't. I guess it takes a little work to get to it.

Would anyone have the needed valley plate seal or gasket numbers?

Striker223

It's an RTV sealant not a gasket

scutch

I had the thermostat housing and water pump changed in mid December and that seems to have been the only problem. I was never able to see for sure if there was a valley plate leak, but fluid levels are steady. Still not quite sure where all that coolant was going after the heater started blowing cold at idle and I kept adding coolant over a week until I had added 2 liters. But I'm also not quite clear how the overflow system works and it's relation to the levels and why they go up and down. I guess I would fill it up cold and then after the first cycle it would suck all that in to the system replace what had drained out over the past year. Then I would add another half liter and the same thing, fluid I added was gone and level was back down to just below the low line. Does that sound right?

Also, I spent some time trying to figure out exactly how much coolant to buy for this job, because I kept seeing 11 quarts in other posts. My mechanic said the capacity is 16 quarts. Then other posts said 2 gallon containers. Finally I called Lexus service and then bought the coolant at Toyota. They both confirmed it only takes two of those gallon jugs of coolant. My mechanic said he used about 1 and a half. I am guessing the difference is total removal of all coolant, and just a drain and fill of what comes out when you open the drains.

I think I paid $36 per gallon from the dealer. 2 gallon containers needed to replace the water pump.

Also, I will again add the secret Bell Lexus Dealer parts site, where as far as I can tell the OEM parts are cheapest and free shipping over $100, but if you just go the Bell Lexus dealer site you will find a parts page that looks like you have to put your name and all info in and then they will get back to you.
https://parts.belllexusnorthscottsda...s__LS-460.html
This page lets you just search and buy the parts yourself. Lexus won't let them post this page for some reason.

Thanks for the help.

Anfanger

parts.lexus.com does not require any personal information just your car information. However, if you want to confirm fitment, you will have to provide your VIN.

texas008

available online at many toyota dealers:
Toyota 50/50 pre diluted super long life antifreeze/coolant
(00272-sllc2)
MSRP:$26.47 Discount:$6.63 (25% off) Sale Price:$19.84