Sherlock Holmes and The Mystery of The Trained Ear

Greetings Fellow Car Talkers,

Wanted some feedback on a situation I just found myself in. The vehicle in question is a 2001 Chevy Impala with 175,000 miles. After years of faithful service and problem free service she has apparently given up the ghost. In January at about 165,000 miles I had a shop, other than my trusted one, replace all the engine gaskets. Apparently I had a slow coolant leak and a finicky thermostat too boot. Why not my trusted shop? Short answer is the wife, but I’ll save that for another post.

Work was done and she purred like a kitten until about two weeks ago when she began over heating and no hot air out of the vents. The coolant reservoir was at the right level. When I opened the radiator cap there was rust and this thick sludge. It was like a damp rusty sawdust. Added some water to the radiator and made to my trusted shop. They told me it was time to say my goodbyes. They told me that the antifreeze and oil had cross contaminated not only causing probable heat damage but pitting and scarring as well. The manufacturer coolant recommended is Dex. Apparently this stuff is extremely corrosive to metal accept aluminum.

Though the heat damage was a possibility they felt that the Dex had done the most harm etching and pitting everything it came into contact with. There is no coming back from that I was told. I trust these guys and have gone to them for years. I didn’t want to hear what they had to say but if they say that’s what it is then that’s what it is. I asked a couple of questions about the problem and if they could tell if the gaskets had failed. What really surprised me though was their reply that they didn’t even raise the hood. They told me that as soon as they turned the key they knew what had happened. The engine sounded fine and smooth to me when I drove it there. When I stopped by their shop to empty the car out in preparation for the junk yard to pick it up I fired it up one last time. To me it sounded fine.

Maybe I’ve watched too much tv where an old car whose motor is shot sounds like empty soup cans and gravel in a clothes dryer. I am guessing that to an experienced and trained mechanic, there are things that they can hear that the rest of us can’t. Again I trust these guys but this was surprising.

I appreciate commentary from anyone in the know.

Thanks for taking the time to read my post and thanks in advance for any/all replies.


Old School Ninja

Had the coolant ever been serviced as far as you know?

If not, that’s what is known as Dexcool sludge.


Agree with @Tester. I hate Dexcool for many reasons but the main one is why use a coolant that will cause problems as it ages or has another coolant mixed with it. I always flush Dexcool out and use the good old green stuff. Did you junk or keep the car? Even Sherlock Holmes can have an off day.

As for the trained ear; many mechanics seem to hear things that I can’t. They knew from hearing the exhaust that I had a bad exhaust valve. Yes it did have a slot cut into it by the hot gases.

The reals pros have such a frained ear. I give them respect for this.
We DIYers hear most things, some more than others.
Some people like my wife either hear things that aren’t there, or they wouldn’t hear if the rear hatch lid fell off and was being dragged down the road by the wires.
I hop in the wifes van and I hear a problem before we are down the road 100 yds. “How long has it been doing this”…wife; " What!!!

When I bought my Pontiac it had the Dex. I talked to two dealers about it and an independent bout keeping it. The jist seemed to be that you have to change it out at five years and you have to be super careful of introducing any air into the system. So I kept it in and hasn’t been a problem but once it sludges, good luck.