I pulled out the file on my car and took a look at the CarFax supplied when I purchased it. No record of any engine work. This got me to checking some of the posts here about 3.8 V6 coolant leaks, which got me wondering about my LeSabre'* manifold and head gaskets. Had they ever been replaced..?

I bought the car with 104,000 miles on it and it appears to have had regular LOFs every 6 months since new. That'* real good news.

Tires rotated at 886 miles.
Cruise control switch replaced twice in the first 14 months.
Both front door regulators replaced at 2 years.
Throttle body replaced at 3 years.
Fuel injection system flushed at 4 years.
Had a coolant chemical flush and fill at 49,000, along with a transmission service (filter kit & fluid) - at 4 years.

That'* it. With no engine work listed, I'm really suspicious of the condition of my intake and head gaskets. Not to mention the hoses and other elbows and such.

I do get a hot coolant odor in the cabin on cold start-ups, so I'll take that over to it'* own thread.

Not all service stations participate in the national database. If could have been done, but you never know until you open it up.

You can look at the date stamps on top of the black intake plenum. If the year is newer than the model of car, at least the plenum and plenum gasket was changed.

And I wouldn't worry about the head gaskets. Can't say as I recall someone here in the last 10+ years have bad head gaskets. Its always the intake gaskets.

Unless you over heat the engine, normally the head gaskets are fine.
The UIM & LIM gaskets you should consider changing if original.
The original LIM was nylon and you can do a conductivity test with VOM to confirm.
I used the fel-pro metal LIM & the Dorman kit for the upper.
It is good piece of mind to replace both as well as have the metal coolant elbows installed. I also installed all new hoses. Use the delco hoses preferable or gates.
For coolant I use Long Life Prestone, and flushed well to get rid of the dexcool, as some was still found in the system.
I run Chevron Techron Concentrate as a fuel injector cleaner 3x per year.
If the transmission has not been serviced lately, consider dropping the pan, inspect for any clutch material, change filter again, and use the latest standard of fluid Derron VI (6)
The new dexron 6 is synthetic and the transmission shifts great with that fluid.
I installed a trans go shift kit because mine was offering up hard shifts when hot, the shift kit fixed that.

I'm about to do a drain and fill and had planned on using DexCool. From what I've read, if I change it every couple of years it shouldn't cause any problems.. assuming no air gets to it. I'd really like to NOT use DexCool, but it'* supposed to have lubricants required by certain engine parts (water pump, for one) that other brands don't have - or does your Long Life Prestone have those? Or is it all hype?

I know they meet OEM requirements, but that doesn't always mean they've got all the additives. I'm just wonderin' - not sayin' your wrong to use Prestone...

Dexcool, or 'mixes with any type' coolant. The concern with lubricants and rust comes about when you use straight water in the cooling system.

Also, be sure to use distilled water too, so that you don't have to deal with mineral buildup. Of course I say that, and I never do, but then again, I have to deal with mineral buildup every time I have the coolant in for a period of time. Thankfully it'* rare however in my case, because my cooling systems have a knack for dumping themselves for one reason or another every couple of years.

If you are planning every two years anyway, you may as well go with the 'mixes with any' coolant.

Definitely distilled water. I even use that in my windshield washer reservoir. When I lived in the Md./Va./D.C. area I saw so many cars with massively clogged nozzles.

Interesting, Prestone now makes the "new" Dex-cool extended life in both full strength and 50-50 pre mixed.
Antifreeze / Coolant | Prestone®
The first two Prestone are the longer engine life, is what I use, and will mix with all others.

I tried to find out if the water in the 50/50 was distilled. I even pulled the MSDS sheet on it and - nothing.. just says WATER. Since we're supposed to use distilled water, should we expect it in the 50/50..? Or go with full strength and a jug of distilled from the supermarket - to be on the safe side?

I managed to find out more about the water from Amazon'* page on this - Prestone Longer Engine Life 50/50 contains demineralized water. This is slightly different than distilled water but in most cases, these are interchangeable. I'd guess for auto coolant mixtures there'* little difference.

Each process leaves behind it'* own list of substances which are difficult to remove. Here'* a good explanation of both.

Demineralized vs. Distilled Water

Some good information there, Thanks.
If you are just draining & refilling, the 50-50 should do just fine.
I went with one jug of full strength and two 50-50 which brought me to about -50c
I would like in the future on my Pk Ave to find a local shop that has a coolant recirculating machine, that uses the Prestone or would allow me to use my own Prestone coolant.
These machines use demineralized water mixes in most cases.
This would fully flush the existing system, to be spotlessly clean again.