Checking coolant when buying a car?

[The motor guy]

I made a booboo when buying an older car and the coolant probably was never changed until I got it. They always say don't loosen the radiator cap on a hot vehicle. How long does it have to sit before you can pull the cap off and not get sprayed with coolant?

 

[Chris142]

Feel the hose. Does it feel comfortable or would you rather not be sprayed by it? Or look in the reservoir.

 

[The motor guy]

Feel the hose. Does it feel comfortable or would you rather not be sprayed by it? Or look in the reservoir.

I've never noticed much difference. The hoses on my diesels seem pretty thick and stiff

 

[Lubener]

I've never noticed much difference. The hoses on my diesels seem pretty thick and stiff

Check it when the engine cools or on a cold engine.....common sense... If you are checking out a used car and its been warmed up before your arrival, beware and walk away.

 

[SC Maintenance]

Check it when the engine cools or on a cold engine.....common sense... If you are checking out a used car and its been warmed up before your arrival, beware and walk away.

Yes exactly. If it’s warm when you get there could be for a reason.

 

[John105]

Good idea. As mentioned I bought a 10 yo LS430 in 2016. Checked 2 days later and ZERO coolant in reservoir and ZERO to be seen in radiator.

I was perturbed. Not only that brakes pulsated and driver look and smart key no workey:

It was purchased from a new car dealer so they addressed the last two issues. It had a 1/1k warranty by NYS law. If it had 900 less miles, 3/3k.

Two problems. Reservoir is stained so level cannot he seen. It is rear facing. So, even though this car was serviced at Lexus its entire life, NOBODY EVER CHECKED THE COOLANT. Toyota SLLC has a 10 yr interval. Shows how much dealer MPIs stand for

 

[martinq]

...
Two problems. Reservoir is stained so level cannot he seen. It is rear facing. So, even though this car was serviced at Lexus its entire life, NOBODY EVER CHECKED THE COOLANT. Toyota SLLC has a 10 yr interval. Shows how much dealer MPIs stand for

It's no different than transmission, power steering or brake fluid. Save money on fluid and just replace the system / car when it's rotted or worn out.

 

[John105]

It's no different than transmission, power steering or brake fluid. Save money on fluid and just replace the system / car when it's rotted or worn out.

The thing that made me angry was the multipoint said $6,700 of repairs needed. Went to indie and they said, “Here’s what you need: $0”. I can’t imagine servicing a Toyota product at any dealer. That’s where folks say, “If I knew it would cost more than a BMW, I would have bought a BMW.” (Saw that on a forum, guy with a ‘07 LS460)

P.s. was at Lexus getting touch up paint. Woman goes that customer was not happy. He said $4100 for service is ridiculous. Man goes, what car? She goes, ‘14 GX (this was spring 2017. Man goes that’s about right.

About right?

 

[The motor guy]

Yes exactly. If it’s warm when you get there could be for a reason.

Depends. They could be meeting you somewhere on their lunch break.

 

[The motor guy]

I've never really understood this though. Water boils at 212 degrees and typically cars don't get that hot. Although it is pressurized

 

[Lubener]

Depends. They could be meeting you somewhere on their lunch break.

or they could be hiding an issue with it.

 

[skyactiv]

I've never really understood this though. Water boils at 212 degrees and typically cars don't get that hot. Although it is pressurized

Easy. They build vehicles able to handle demanding driving conditions that might not exist where you drive. Hot summer days in mountain regions like Virginia, Colorado..

 

[The motor guy]

Easy. They build vehicles able to handle demanding driving conditions that might not exist where you drive. Hot summer days in mountain regions like Virginia, Colorado..

Or It's a lot hotter around the cylinders than it is where the sending unit is placed.

 

[The motor guy]

My question still isn't answered. I'm going to assume that if I can hold hold my hand on the radiator cap and not get burned, then I can go ahead and open it?

 

[The motor guy]

Good idea. As mentioned I bought a 10 yo LS430 in 2016. Checked 2 days later and ZERO coolant in reservoir and ZERO to be seen in radiator.

I was perturbed. Not only that brakes pulsated and driver look and smart key no workey:

It was purchased from a new car dealer so they addressed the last two issues. It had a 1/1k warranty by NYS law. If it had 900 less miles, 3/3k.

Two problems. Reservoir is stained so level cannot he seen. It is rear facing. So, even though this car was serviced at Lexus its entire life, NOBODY EVER CHECKED THE COOLANT. Toyota SLLC has a 10 yr interval. Shows how much dealer MPIs stand for

How did they fix it? Jist add more? Coolant isn't supposed to go anywhere.

 

[John105]

My question still isn't answered. I'm going to assume that if I can hold hold my hand on the radiator cap and not get burned, then I can go ahead and open it?

I believe this statement to be incorrect. I’ve done that before and had my neck burned. To each his own.

Does one open a pressure cooker whose safety was defeated, while pressurized? I did that as well and the liquid hit my apt ceiling.

In my early 20’s, I was not able to prove PV=nrt to be wrong. Why try in 2025?

 

[The motor guy]

I believe this statement to be incorrect. I’ve done that before and had my neck burned. To each his own.

Does one open a pressure cooker whose safety was defeated, while pressurized? I did that as well and the liquid hit my apt ceiling.

In my early 20’s, I was not able to prove PV=nrt to be wrong. Why try in 2025?

I guess since the radiator is in open air, it's going to be the coldest part of the system now that I thinking about it, so then you still have super hot coolant in the block that may start to boil once it loses its pressure

 

[John105]

I guess since the radiator is in open air, it's going to be the coldest part of the system now that I thinking about it, so then you still have super hot coolant in the block that may start to boil once it loses its pressure

The way I see it is the radiator needs airflow to have the heat removed. I wouldn’t expect the coolant in the radiator, to be any cooler in a parked car. There are so many tricks to selling a used car. One I never would have dreamed of.

My spare tire is brand new. You can see the yellow and red dots, and full sized rim mint with grease crayon from Japan.

Dealer said new tires. So they mounted this on the rear left and took a close up. They made sure all pics from rear left had tire mounted. Then, they put it back in the trunk. So I assumed the new tires were OE and the rims were in super shape being a FLA car.

The tires were $80 Rydanz engineered in Europe made in China. I kept them about 6 years until 3/4 were plugged and down to 2-3/32”

 

[Kira]

Not just coolant level but smell.
Pass on a vehicle with the smell of exhaust in the coolant.

 

[FTTSHO]

I learned a very very hard lesson with my 2001 Chevy Blazer with the cast iron 4.3 vortec engine.

I think the previous owner used Dexcool and tap water in the cooling system. I was dumb for not checking the coolant when I bought the truck, and I’ve went through so much trouble trying the clean out the cooling system. I’ve had the truck for 2 and a half years now, and just yesterday I finally got the whole cooling system completely and I mean absolutely completely cleaned out to brand new condition. Had to use Evaporust to remove all rust and Dexcool sludge. I also had to remove all hoses, and flush the block, heater core, and every single coolant passages will bottles of distilled water to completely clean it.


From now on, whenever I buy a car used or even nee, I’m always checking the coolant and all the fluids even before I think about buying the vehicle.

Dexcool hates air, and if the car ever had a cooling system leak, it’s a guarantee the coolant will be sludges up and there will be a hard coating of coolant deposits all over in the cooling system. My suggestion is just don’t use OAT Dexcool. Just regular green and HOAT coolant is more than good.

Always gotta watch out on cars that use Dexcool! If you’re buying a car that uses Dexcool, always check the cooling system. If it’s messed up, you’re in for a ride, either you’ll have to flush the cooling system a million times by yourself, or you’ll have to have a shop flush it really good with a coolant exchange machine, and a cleaner.

Dirty cooling system is a big problem that often gets overlooked. Dirty cooling system can mess up a whole lot of things if it goes unnoticed!