DEAR CAR TALK: I have a 2010 Chevy Tahoe approaching 125,000 miles. It runs great. Doesn't even rattle.
I had it checked out and serviced at 100,000 miles. Does it need a 125,000-mile service? -- Steve
DEAR STEVE: Heck yeah, it does.
If you went to the doctor and got a clean bill of health at age 65, do you think you'd still need another check-up at age 75?
Of course, you would. In fact, you'd be wise to get one at 66, right? And the same is true for your older car. At minimum, you should keep doing the recommended maintenance.
Even if the maintenance chart at the back of your owner's manual only goes to 100,000 miles, you should extrapolate and keep going. So, for instance, if your Tahoe calls for an oil and filter change every 7,500 miles, then you'd be due at 97,500, 105,000, 112,500, etc. The same would be true for brake fluid, coolant and everything else.
Maintenance aside, it's important to get someone to put their eyes on your car as it gets older. Like us, when cars get to more advanced ages, parts are more likely to fail.
For example, if your mechanic spots a small leak from a transmission cooler line, he can fix that for $150. If it went undetected, you could be looking at a rebuilt $2,500 transmission.
Or he could spot some rust on one of your brake lines. That's rarely a problem with cars that have 25,000 miles on them. But it sure can be with 125,000. Catching something like that could keep you from plowing into a turnip truck.
Hopefully, you have a mechanic you trust, Steve, who's interested, who can service the car, and give it a careful inspection every time you go in for maintenance. So, make an appointment with him.
And while you're at it, sign up for an annual physical, too.
DEAR CAR TALK: I have a 2015 Honda Fit that has been losing antifreeze for about two months. It started with a very small amount, then got much worse.
My mechanic couldn't find a leak. But he did find that cylinder No. 3 is misfiring and making the car sputter sometimes. My mechanic thought it might have a bad head gasket, so I had it towed to the Honda dealer.
The dealer says they don't see any problem with the head gasket. They say it might be a bad fuel injector or burned valve, which, of course, cost $1,000 more. What would you look for if it was brought into your shop? Thanks! -- Jaimee
DEAR JAIMEE: First, I'd look at your credit limit. Actually, I'd be thinking along the same lines as your mechanic.
If you're losing coolant and it's not leaking out, it has to be burning up and coming out the tailpipe. That means it's getting into the cylinders somehow, where it doesn't belong.
What's the most common cause of coolant in the cylinders? A blown head gasket. The fact that one of your cylinders is misfiring also lends credence to the head gasket theory. If enough coolant is getting into cylinder No. 3, it could interfere with combustion and create a misfire. And the problem with the "fuel injector or burnt valve" theory is it doesn't explain your coolant loss. The head gasket theory explains everything.
So, what I'd do is look harder for a head-gasket problem. We'd put a pressure tester on your cooling system and then get the engine up to operating temperature. Then we'd shut off the car and pump the pressure up as high as we could get it, maybe double its normal operating pressure -- and hope the hoses don't blow. Then we'd let the car sit overnight.
If there's a puddle on the floor in the morning, then you do have an external leak, and you can locate it, fix it, then go back to looking at other causes for the misfire. But more likely, during the night, coolant, under pressure, is going to seep into one or more of your cylinders. And that's a sure sign of a head-gasket failure -- at best. At worst, it's a cracked cylinder head.
But let's not catastrophize, Jaimee. A head gasket is expensive enough. So, start by having a mechanic of your choice do a really thorough, overnight pressure test. I suspect the answer is going to come up "head gasket." Condolences.
Ray Magliozzi dispenses advice about cars in Car Talk every Saturday. Email him by visiting cartalk.com
