Don't know if I trust the "trusted" mechanic

I bought a 2001 GMC Sonoma Extended Cab 4x4 with 159,000 miles for $2,600 two weeks ago. I know enough about cars to have checked all the lines., reservoirs, belts, body undercarriage, for any wear, tear, leaks, or rust and saw none. Have been driving the truck (which drives beautifully) for two weeks. I took it to a “trutsed” mechanic for a diagnostic and they are saying the truck needs $1,050 in repairs (see attachment). All of these repairs go against what I have looked for and experienced with the truck. I have had no indication of any problem relating to the repairs they tell me are needed. No temp fluctuation, no leaks, no fluids replacement… nothin’. Should I trust these guys or my instinct?


The estimate for repairs/maintenance shouldn’t be presented with illegible scribbling.

Take the vehicle to a shop that will PRINT out the estimate.


Well he thinks the radiator, oil cooler lines, blower resistor, serpentine belt and tensioners, are bad and some kind of switch and maybe some other stuff. I would have a second look see at those if they have not been replaced recently. The cooling system may have the Dexcool in it that is well past time to replace it and has gummed everything up. But certainly a second opinion or a further explanation wouldn’t hurt.

If you have looked under the hood and seen no evidence of problems with the oil cooler hoses or the belt and tensioner and radiator cross this shop off the list of ‘trusted mechanics.’

It’s hard to tell if any of the recommendations are legitimate without being able to see the truck.

If the blower resistor needs to be replaced the a/c heater fan will not work properly at all speeds.

If the oil cooler lines have any oil on them they need to be replaced.

If the serpentine belt is worn down or cracked it should be replaced, and doing the tensioner at the same time on a car of that age is wise.

The radiator may be sludged up internally, may have cold spots in the core, may be showing signs of leakage at the seams. Hard to tell without seeing it.

The 4WD switch may be sticking or failing and not engaging the 4WD properly. You want that to work when you need it.

All of these items are quite common repairs on an aging S-10, by the way. As are idler arms, intake gaskets, and fuel pumps.

On a side note, in this day and age a “written” estimate does not mean written. It means computer generated on shop management software with documentation for reasons for the recommended work. And if it were me I would take you to the truck and point out to you why I recommend these items.

The truck can run and drive fine with even with those issues shown on the estimate. Given the age and miles I would not be surprised if some deeper digging uncovered even more issues.

It looks like they have a somewhat odd labor rate at 88.50 an hour.

Regarding the blower motor resistor it should be kept in mind that if the resistor is faulty then it’s usually that way because of a dragging blower motor. In other words, the resistor is a symptom rather than a cause of the problem.

Get a second opinion. If it doesn’t match with the first one…forget about it. Go with your instinct. If something goes wrong…you’ll know about it.


We have tons of S10s and Sonomas in our fleet. We have tons of GMs with the 4.3 in our fleet

I have 0% doubt that you engine oil cooler lines are leaking, and quite possibly badly leaking. That is based on experience. And they are a MF to do on your setup, with the 4x4

I don’t doubt that one or more of your fan speeds are missing. That is almost certainly the reason the blower resistor is being recommended. Caution . . . on some models you have to make a cut in the hvac housing, in order to replace the resistor. If yours is one of these, it will clearly say “cut here” on the housing

As far as the radiator goes . . . you have a typical aluminum radiator. Meaning aluminum core and plastic tanks. It’s very common for the tank seals to go bad at this age, if it’s still the original. Even worse is when the tanks get brittle and crack, also not uncommon at this age

Just because there are not niagara falls sized leaks on your driveway does NOT mean you have no leaking components.

For example, the rear main seal and/or plate are leaking on almost every single 4.3 in our fleet.

Many/most of the items on that list are things I would expect on a 14 year old vehicle of any brand name

I suggest you put your truck on jackstands, and crawl underneath for a look. No offense, but it may not be as pristine as you imagined

I’m not saying you have a bad truck. But let’s be realistic. You have a relatively old truck, and it’s got some miles on it. You should expect several hundred dollars, if not more, in repairs every year from now on. Especially because it’s 4x4 . . . many more things to break, wear out, leak, etc.

I think your mechanic deserves the title “trusted”. They’ve done a good job from what I can see. And the itemization is quite complete, down to the parts costs and time it will take to do the job, all of which looks reasonable. The items suggested are what a good mechanic would find by doing a thorough inspection. There may be some misunderstanding here between what you wanted by a “diagnostic” and what the mechanic thought you wanted. Suggest to discuss with the mechanic what the priority of these items are. You may be able to defer many if not all of them.

Just b/c those items are written down doesn’t mean you have to do them. It is your truck after all. The list is just the shop’s recommendations for what’s needed. For example, the blower resistor. The blower resistor on my Corolla has been funky for 20 years, the lowest speed hasn’t work. No problem, I just don’t use that blower speed. 2 out of 3 blower speeds is good enough for my purposes. As well it might be for yours.


“Suggest to discuss with the mechanic what the priority of these items are . . .”

You always have good ideas, and follow common sense. A person could do very well, following your advice

That is truly meant as a compliment


I have 0% doubt that you engine oil cooler lines are leaking, and quite possibly badly leaking. That is based on experience.

There are 2 kinds of oil cooler lines on those trucks. Those that have been replaced, and those that need to be replaced.

And they are a MF to do on your setup, with the 4x4.

??? 2 wheel or 4 wheel, they’re all easy money. Nothing hard about them, just a little dirty.

After buying that pickup with those miles and that price, trust anything but your instincts. I would change the anti-freeze and let things go except for the belts, tighteners and parts related to alignment. Now I’ll read the list.

Price for all repairs sounds good and trustworthy. The drawback is the possible catastrophic failure of engine or transmission: then you are out all you spent on it because the repairs are more than the value of the truck. Barring those two failures before 200,000 miles it’s all OK.

Because of the age of this truck, it’s bound to have some faults.
To me the belt and tentioner…radiator and related parts…and the tranny lines would be the three that I would not wait on. Those are things that when those go bad, it leads to more damage.
The rest I think you can wait on if your pockets are just not that deep.

As far as the hand written estimate goes I don’t have a problem with it because, I too hand write mine, but I do have a computer generated blank form that I use and I try to write with my best penmanship. Not everyone has access to a computer right in the shop.


Thanks @db4690

It pays to get a used vehicle inspected BEFORE buying.

I agree that an inspection is a good idea, before buying

However, I don’t think OP bought a bad truck. It sounds like a S10 4x4 truck, in typical condition. Even the few low mileage S10s in our fleet need quite a bit of work, due to their age

An interesting note, based on experience . . . the S10 truck seems to eat bushings and steering components at a much faster rate, versus the Colorado, which was the replacement

It’s not really a valid comparison, since the the S10 is a very old design by now, and the Colorado has much more modern front end components

I’m not saying the first generation Colorado is a great truck, though. it’s certainly more modern, but I’m not sure if it’s better

Reading between the lines . . . if that’s even possible . . . I don’t think anybody was actually implying that OP bought a bad truck

But even if he had payed for an inspection, and the mechanic handed him that very same list of recommendations, it’s quite possible OP would still have bought the truck. In my neck of the woods 4x4 S10s are quite uncommon, versus RWD S10s

Yes, but he could have negotiated a better price knowing the needed repairs.


I doubt it

In my neck, of the woods, 4x4 S10s command a premium, due in part to their relative scarcity

I’m only talking about S10 pickup trucks, not the various SUV derivatives. Those are a dime a dozen, and a pristine example would not be worth much at this point

Does the blower blow on all speeds? If so, you don’t need the switch or resistor. If not, it’s probably the resistor, not the switch. Why would he be suggesting you need both? Is the radiator leaking? If not, you don’t need one. Are the cooler lines leaking? Same thing.

In summation, if it ain’t broke, don’t fix it.

If it’s about to be broke, you soon will be.