Coolant disappearing (1 Viewer)

[Grumvee]

Hi folks!

Just got a new-to-me 2011 LX 570 in my garage. Something strange is going on with the cooling system.

I bought the vehicle from a one-owner in TX who took it to Lexus for everything. I had that dealer do an inspection. Not super impressed with their inspection.

When it arrived at my house (via a shipper), the coolant reservoir was empty. I filled it, drove it for maybe 25 miles, and it's empty again. No evidence of where the coolant is going.

Any thoughts?

Obviously there must be a leak somewhere, right?

<Sigh>

 

[1world1love]

Any smoke from the exhaust? Or from the engine block?

Have you removed the engine covers? Any sign of residue around the radiator cap? How is your oil level?

 

[Grumvee]

Hi @1world1love —

Yes, first thing I did when I got the truck was tore out those god forsaken covers

No smoke from exhaust or engine block.

Some white residue from around radiator cap, but nothing significant.

Oil level is normal.

Prior owner paid Lexus to replace radiator 30k ago.

 

[1world1love]

Ok, it probably had a cracked radiator which is pretty normal for early 200s, but most people would have the water pump replaced as well. If you are losing that much in a short time, that would be the next suspect. As far as I know, those are the two most failure prone items in the cooling system in a 200.

Without an obvious leak, you might see about a pressure test.

 

[TXMeatball]

Losing coolant with what seems like a healthy engine screams valley plate to me.

 

[Sandroad]

It may have just not been filled properly at the radiator change. When cool, check the level in the radiator, add as needed, then refill the expansion tank. Then drive it for a while and see what happens.

 

[bloc]

Likely the system was low enough to take all the coolant from the reservoir. The question is how much it takes over and over before it stabilizes. If it was low enough to have air in the heads that is a problem.

As for where it’s going I’d suspect valley plate leak. No way it was dealer serviced with low coolant for 30k after a radiator and they wouldn’t notice the level being low from the job.

 

[Sandroad]

Likely the system was low enough to take all the coolant from the reservoir. The question is how much it takes over and over before it stabilizes. If it was low enough to have air in the heads that is a problem.

As for where it’s going I’d suspect valley plate leak. No way it was dealer serviced with low coolant for 30k after a radiator and they wouldn’t notice the level being low from the job.

Your more generous about dealer servicing than me. After the new radiator it could have appeared full and never been rechecked after purging. After all, it’s the same dealer that completely missed the empty reservoir in the PPI. That said, it should certainly be inspected for the valley leak since they could have missed that too.

 

[Grumvee]

Thanks folks. Ugh, I'm getting pretty worried now.

If it is a valley plate, any ideas on the rough cost for the repair? (at an indie shop, not the dealer)

If it is a valley plate issue, should the PPI have caught that?

@bloc, how low is so low that air could have gotten into the heads? How would I know?

 

[1world1love]

I totally forgot about the valley plate. That seems more common in GX and IS though, but there have been a few threads I have seen.

 

[1world1love]

Thanks folks. Ugh, I'm getting pretty worried now.

If it is a valley plate, any ideas on the rough cost for the repair? (at an indie shop, not the dealer)

If it is a valley plate issue, should the PPI have caught that?

@bloc, how low is so low that air could have gotten into the heads? How would I know?

Im no expert but it seems like after 30k miles if air had gotten in, it would have manifested in some way by now.

Also, at 30k, that is at least 5 service appts where nobody noted anything about an empty coolant res. Or did they? Have you checked the service history on Lexus.com?

 

[nwfl4runner]

One very simple possibility is that your overflow is cracked/leaking. That was the cause of my overflow being low. When COLD, is your radiator full?

 

[BVE]

I’m pretty sure I have a valley leak as well. Probably a 2k fix or a lot of your own time and patience. Someone on another similar thread said something like “2 grand buys a lot of coolant.” and I’m in that boat right now.

 

[Grumvee]

So... the prior owner (who bought it new) doesn't know anything about cars, but took it to Lexus for everything, religiously. All major services, oil changes every 5k, etc. Even did a $1k service on the leather seats, new tires, and a new battery soon before selling it.

She (and I) were relying on Lexus to properly service the car (and properly do a PPI). In hindsight, I should have of course insisted on a third party PPI (the PPI also missed a broken passenger seat heater and ventilator, and what appears to be major seepage around the power steering reservoir/hoses). But, anyway, I'm at where I'm at now...

Here's the service history related to the cooling system
- 90k: radiator replaced due to leak (but they didn't do the water pump, thermostat, or hoses, according to the records)
- 100k: coolant replaced as part of 100k service
- 118k: current mileage

No notes of low coolant or topping up during the service records from 90k onward, but I suppose it's possible they did that and simply didn't note it in the records.

So far the reservoir has drank 1 and 2/3s refills. It's at the top now, and I'll see what happens by tonight.

----------

(@nwfl4runner - It would be great if it was just a cracked or leaking overflow tank, but I would think I would see some evidence of dripping or where it was going, which I'm not.)

 

[nwfl4runner]

(@nwfl4runner - It would be great if it was just a cracked or leaking overflow tank, but I would think I would see some evidence of dripping or where it was going, which I'm not.)

FWIW I had zero signs of dripping/leaking. Started after I swapped radiators. Swapping a new one in fixed it.

 

[CharlieS]

I think it was covered well above.

I wouldn’t freak out without getting eyeballs on it.

I’d get underneath and remove the skid plates to see if you can identify any coolant residue or crust. Sometimes it becomes pretty obvious when you see the pink liquid or crusty crystals.

If it is at the front right it may be your water pump, if at the back more likely valley plate, on or under the radiator/radiator support the radiator or reservoir.

If it was the common radiator crack, you’d see pink liquid and crusty at the top of your radiator and potentially sprayed all over.

Not likely burning it if you don’t see big clouds of white exhaust smoke and the sickly sweet smell of coolant.

Not likely a head gasket if you don’t have intermix in either your oil or radiator/reservoir (milkshake).

 

[1world1love]

I agree with Charlie. I would check things out a bit more before you make any conclusions. look around underneath, especially directly behind the back of the engine. Like Charlie said, you may need to drop the stock skids, but it is easy.

And if it is a valley plate, look at the bright side - it is not a head gasket and the fix is pretty permanent. Consider it a 120k maintenance item that you will never have to do again. I know that is not comforting, but there are not many major repairs that are common on these trucks. You already got the radiator out of the way, although it would have been great for them to do the water pump, et al as well, but in the scheme of things, this may be the most major repair you ever have to do.

 

[KLF]

Might want to pick up one of those cheap endoscope cameras, take a peek under the intake plenum. Look for the dried crusty puddles of coolant that indicate the valley plate leak.

 

[Cruisin911]

With losing that much coolant, my money is on valley plate or cracked reservoir. Cracked reservoir should be obvious on the ground in that area. With 1 2/3 reservoirs emptied, if its a valley plate, you'll be able to see the pink crust above the transmission bell from below as it comes down the side. If you're really inquisitive, a flashlight and inspection mirror with the cover off should remove all doubt.

 

[bloc]

Your more generous about dealer servicing than me. After the new radiator it could have appeared full and never been rechecked after purging. After all, it’s the same dealer that completely missed the empty reservoir in the PPI. That said, it should certainly be inspected for the valley leak since they could have missed that too.

I’m probably not more generous, but the odds of six services without a tech noticing an empty reservoir are pretty low.