2019 Lexus GX460 (1UR FE) 63k mi; ST Advanced 5w-30 at 3k mi

[sds911]

Well, I took a sample from the dipstick tube. This time Cat labs report 18ppm of Potassium after only 3,000 miles since last oil change. Did not drain oil or change filter (fram ultra) for this sample at 63k miles on odometer.

17 ppm Potassium on 60k UOA with 5k miles on oil.

Lexus dealer wanted to charge $800 to diagnose using compression test, leak down test (or pressure test) even though I have Lexus extended warranty/service agreement.

Toyota dealer will do same test for $200 or less.

What would you do? Wait for level to rise to 200ppm or more? Or have Toyota dealer test system now? Or wait to see what the ppm is if I run on this fill for 5,000 miles, 7,500 miles or even 10k as is permitted by Lexus? Should I send a sample to another lab to confirm Cat lab results?

Supertech Advanced VOA on BiToG indicates zero Potassium.

I’m watching the coolant overflow tank and taking photos to document if coolant level is decreasing. I replaced overflow tank cap last week and new radiator cap in August.

Blackstone lab UOA history on my GX460 for comparison. Blackstone says universal avg is 1ppm for Potassium.

 

[BISCUT]

I'm no pro but 18ppm doesn't seem to be a substantive coolant intrusion. I would expect the numbers to be in the triple digits for that. How about road treatments used for snow/ice in your area?

Just a few thoughts in my head on this. Others with a much higher level of knowledge can help more. They will be along soon!

 

[cptbarkey]

What additives have you been using?

 

[sds911]

What additives have you been using?

No additives to the last oil changes at 60k and 63k. I think the last additive I used was at the 7,400 UOA in 2020, and 17k. You can see the increase in Moly and Boron. So, probably used Ceratec by Liquid Moly. I have used Swepco 502 (micronized moly and helps with sticky lifters) in my 911. I did use Swepco on the GX during break-in. I just checked my UOA posts to confirm - Swepco would show higher moly in the UOA - see 17k UOA higher moly, but normal boron.

But most of the UOAs are just the oil ad packs - 1st is factory fill (Toyota 0w20). I’d have to go back to my UOA posts to see the oils. But, usually Penzoil Platinum, Rotella Gas Truck, Mobil or Castrol products. Later fills are ST Advanced. Some with 5 qts ST Advanced and 3qts Castrol Euro 5w40.

 

[sds911]

I'm no pro but 18ppm doesn't seem to be a substantive coolant intrusion. I would expect the numbers to be in the triple digits for that. How about road treatments used for snow/ice in your area?

Just a few thoughts in my head on this. Others with a much higher level of knowledge can help more. They will be along soon!

Road salt is possible for the 63k fill. But, I usually don’t drive during storms here in Colorado. I think the 60k was changed right as cold temps hit. So, I went with 5qts 0w20 and 3qts 5w30 as temps were 8 or -8 F iirc. The GX460 has a lot of undercarriage protection plates.

And I have a membership to Superstar car wash with undercarriage rinse only a few block from my home. I go there frequently, especially after snow or rain.

18ppm and 17ppm are well above the historical average on my UOAs and blackstone universal avg of 1ppm.

I’ve had coolant loss and the coolant overflow cap was crusty pink from the Toyota/Lexus SLLC pink coolant on more than one occasion. In TX my overflow tank was almost empty and I took it to dealer there. They just topped off the tank iirc.

Wear metals still look good. So maybe I should wait until ppm is higher? But, what is the downside if head gasket leak or oil cooler leak or coolant valley leak is occurring?

My extended warranty is over in 2026 or 75k iirc. Would prefer to make sure the warranty/service agreement covers any repairs.

How would road salt or road de-icing products get in the oil though?

 

[sds911]

Should I change the oil and filter or let it ride? I’ve got 10qts of Valvoline R&P 5w30 in the garage ready to go in with a fram titanium or a Toyota oem filter…and the weather is nice right now.

The new coolant overflow tank cap definitely was a tight fit. So, maybe it makes sense to dump the current fill. Although I still don’t understand how the Potassium is getting into the oil absent a leak somewhere.

 

[cptbarkey]

Have you read about any 2019 coolant valley leaks?
To check it, drop the shields and look behind the engine from the bottom for pink stuff.
I'm not too sure how such a leak would contaminate motor oil.

 

[sds911]

Have you read about any 2019 coolant valley leaks?
To check it, drop the shields and look behind the engine from the bottom for pink stuff.
I'm not too sure how such a leak would contaminate motor oil.

I can’t say for sure about 2019 MY. But, I know it happens on the GX in general. Have to watch the car care nut’s video again on the topic. See if later models have the issue.

 

[cptbarkey]

I can’t say for sure about 2019 MY. But, I know it happens on the GX in general. Have to watch the car care nut’s video again on the topic. See if later models have the issue.

I own a 2010 with 83k, no valley leak yet. I tow quite a bit. Care care nut preaches alot, he has good info but have to sift through his chaff.

 

[sds911]

I own a 2010 with 83k, no valley leak yet. I tow quite a bit. Care care nut preaches alot, he has good info but have to sift through his chaff.

I can check the gx460 owners forum as well.

 

[fantastic]

Take it to the warranty repair and show the the antifreeze oil contamination. This looks like it's getting worse.

 

[Patrick0525]

Is this the original coolant? Or have u changed it ?

 

[sds911]

Take it to the warranty repair and show the the antifreeze oil contamination. This looks like it's getting worse.

I did. Lexus dealer wants to charge me over $800 for diagnostic. They don’t care about my UOAs. Even called Lexus advocate at corporate. Blew me off as well.

 

[sds911]

Is this the original coolant? Or have u changed it ?

This coolant is good to 100k or 10 years I think. I did a radiator drain and fill in August. I was going to do one every oil change. It’s less than a gallon to do just the radiator. My Phoenix test strips indicate the OEM fill is just fine, even before the radiator d&f.

 

[sds911]

I might have Toyota dealer do the compression/leak down tests for 200 or so. $800 is crazy given I have an extended Lexus warranty/service agreement. Just more games to prevent claims.

Or wait till coolant overflow tank goes to minimum fill line.

Lexus and dealer are on notice based on the UOA and my other things like crusty coolant on overflow cap (which I replaced for $12 and change)

 

[rodinator1234]

If you are loosing coolant I would absolutely check for a valley plate leak, very common on the 4.6L and unfortunately not cheap to fix unless you do it your self. Mileage does not matter really. It's more of a time thing. If you have a warranty still get it to a dealer and insist on an inspection of the valley plate area for a coolant leak.

 

[fantastic]

I did. Lexus dealer wants to charge me over $800 for diagnostic. They don’t care about my UOAs. Even called Lexus advocate at corporate. Blew me off as well.

That's awful!
Goes to show "Warranties" are just as good as toilet paper if there's no one willing to listen & take the issue seriously.

 

[mikeduf]

Personally if this were my car and this was happening under warranty, I would take it to the dealership where I purchased it.

I would start to build a record folder of all visits and cost at the same time I would document phone calls to the corporate manufacturer office and mention the dealership name and charges that are being incurred to you to do a diagnostic under warranty.
And of course ask him if those fees are refundable after repairs are done under warranty. Make sure you talk to somebody at a supervisor level not one of the administrative Folks at the manufacturer most of them just feed you canned answers.

Dealerships will feed you canned answers as well, you need to go to the top always. And be very clear that your documenting names numbers because this is going to be a warranty claim and you're tracking it.

 

[sds911]

Personally if this were my car and this was happening under warranty, I would take it to the dealership where I purchased it.

I would start to build a record folder of all visits and cost at the same time I would document phone calls to the corporate manufacturer office and mention the dealership name and charges that are being incurred to you to do a diagnostic under warranty.
And of course ask him if those fees are refundable after repairs are done under warranty. Make sure you talk to somebody at a supervisor level not one of the administrative Folks at the manufacturer most of them just feed you canned answers.

Dealerships will feed you canned answers as well, you need to go to the top always. And be very clear that your documenting names numbers because this is going to be a warranty claim and you're tracking it.

All very good points. Unfortunately, the original dealer is in CA, the extended warranty is through lexus financial services and obtained at dealer in TX, and I’m in CO now. I have all service records, notes and photos etc. Provided to CO dealer and Lexus advocate.

I’ll wait till 7500 or 8k total on this fill and do another UOA. I’ll watch the coolant level as well. The cover that hides the radiator and overflow tank is off and not going back on so I can easily monitor.

And local Toyota dealer said he has lexus trained techs and can do the diagnostic for $200. So, may go that route if coolant level drops. And definitely before extended warranty ends.

I dealt with a similar issue on my 911. Synchros in transaxle were going bad. After trip to 4th dealer (Newport Beach) they finally fixed it. Newport dealer had a tech experienced in tear downs/repairs. In each case at prior dealers, techs agreed there was a problem shifting to 2nd gear. Overruled by service mgr each time. I am persistent. This also was a known problem with the 996.

I will check under the car for leaks and see what I can find on the coolant valley plate leak. May be other options as well with loaner tools from autozone etc or test kits for head gasket leak etc.

 

[rodinator1234]

All very good points. Unfortunately, the original dealer is in CA, the extended warranty is through lexus financial services and obtained at dealer in TX, and I’m in CO now. I have all service records, notes and photos etc. Provided to CO dealer and Lexus advocate.

I’ll wait till 7500 or 8k total on this fill and do another UOA. I’ll watch the coolant level as well. The cover that hides the radiator and overflow tank is off and not going back on so I can easily monitor.

And local Toyota dealer said he has lexus trained techs and can do the diagnostic for $200. So, may go that route if coolant level drops. And definitely before extended warranty ends.

I dealt with a similar issue on my 911. Synchros in transaxle were going bad. After trip to 4th dealer (Newport Beach) they finally fixed it. Newport dealer had a tech experienced in tear downs/repairs. In each case at prior dealers, techs agreed there was a problem shifting to 2nd gear. Overruled by service mgr each time. I am persistent. This also was a known problem with the 996.

I will check under the car for leaks and see what I can find on the coolant valley plate leak. May be other options as well with loaner tools from autozone etc or test kits for head gasket leak etc.

Check passenger side, like where you see AC condensate drain the ground when you park the vehicle. Slide under the GX, behind the passenger front tire. Look up around the transmission tunnel area around the cat on that side around the back of the bell housing. If you see any pink at all any pink crusty stuff at all anywhere you have a valley plate leak.