Is it normal to charge diagnostic fees now?

This is actually a generic car repair question: Is it now normal, or acceptable for a mechanic to charge for diagnosing the problem with your car? Here’s what happened: I recently took my car to my mechanic to check out “a sloshing sound” in front of the firewall. (I thought it might just be a blocked drain). The mechanic diagnosed it as a bad water pump & repaired it. The total bill (for the pump, belt, coolant etc.) was $457. The bill had a line item, $115 for preforming an inspection (basically for diagnosing the problem). I’ve never seen diagnosis as a separate line item. Perhaps mechanics have always added that time to the bill & just not put it as a separate line item. Does this normal/right or should I be looking for another mechanic? (other than this experience I’ve been very happy with this shop). Thanks

People don’t work for free and a diagnostic fee is normal . A few shops will waive it if they get to do the work providing the search for the problem was not that difficult . Just be glad you don’t have a Porsche the fee might have been 3 times that.


Agree with @VOLVO_V70 here. Diagnostic fees are very common. The mechanic can’t (and shouldn’t) guess at the problem, they have to work through the diagnostic steps to determine the actual cause of the problem. That takes their educated time and it is time worth paying for. No different than your doctor running tests to find the cause of your complaint.

The flip side… If you take it to a shop and they tell you your flibbit is broken without actually testing it to verify it IS broken and they charge you $300 to replace it. And it doesn’t fix the problem. You are still paying for that new flibbit AND you will get charged for a new flazit-regulator that also might not fix the problem. The shop is just tossing parts at the problem hoping SOMEthing will fix it.The shop will tell you ALL these things really needed replacement anyway and spend your money until either it fixes your car or you tow it away to another shop.

And then you will come and post at CarTalk and ask if they are ripping you off. :crazy_face:

Well worth that $115.


My mechanic has never charged be a diagnostic fee, I don’t know if he just figures it is built into his shop rate, I have never asked him. If I asked him to find out what is the problem and didn’t have him fix it, I would absolutely expect to pay his shop rate for time spent. Over the years I did take a few things to him that other mechanics claimed I needed repaired that I was skeptical about what they were telling me and in all cases he told me they were lying. He never charged mr for that even though each time I asked him how much I owed.

I have however over the years taken 5 people from our church and introduced them to him and they have used him as their mechanic.

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They always charge a diagnostic fee otherwise a freeloader like me would get the diagnosis for free and then do the work himself :slight_smile:
The shop would be out of business soon.
But, then norm, at least with the shops and dealerships I have dealt with is that if you have them do the repair, they waive the diagnostic fee.

I’m a professional mechanic, I’ve been in this business all my life and in 33 years have held every position from inmate to warden, um, I mean from entry level shop assistant to shop owner. It has always been normal, acceptable, and standard policy to charge for inspection, testing, and diagnosis.

Now there may be exceptions here and there. For instance, if you drive up and say “My radiator hose is broken” and I open the hood and see a ruptured hose, I will give you an estimate for replacing all the radiator hoses and we decide what to do from there. Or if you say “My right brake lamp is out” I’ll put a bulb in it and see if that fixes it before recommending anything else.

But anything else gets charged for, minimum half hour of labor rate, up to 2 hrs for diagnosis. The shop I’m managing now even charges for brake inspections, even if we do the repairs, because we do brake inspections better than anyone else.

Any repair facility that offers free testing and diagnostics is simply not to be trusted. Period. Would you trust a dentist who offered free exams?

All the gimmicks and marketing aside the reason is simple. There are 8 hours in a work day. If I work on your car to figure out a problem for free, I either have to pad the repair to make up for that lost time or sell you more profitable services that you may not need. That simple principle holds true for every repair shop and mechanic out there, there’s no way around it. I don’t see where it is in the best interest of the shop or the customer to do anything for free.

Transparency and trust is everything in this business. If I tell you from step 1 what I’m going to do, how much it costs, and guarantee my work, there will never be any surprises or doubts.


Thank you for your thorough response.

My mechanic for MANY years tragically died a few years ago. (He was also a friend, so I completely trusted him). I never expected him to work for free, or to even give me special pricing. His invoices never specified a charge for diagnosing the problem. I
just assumed he charged his regular shop rate for the time he spent working on my car, whether that was hunting for the problem or actually doing the repair.

After Glenn died I started going to a new shop that was highly recommended. The only work I’ve needed since the switch has been routine maintenance stuff - where they tell you the price up front & it rarely varies from the estimate.

I don’t expect anyone to work for free - I certainly don’t want to! But $115 to diagnose a bad water pump? That seems a bit high. The labor for the actual repair work was $300. So, a bit over 1/3 as long to diagnose the problem as to repair a water pump!?!?

Does that sound right to you?

I know I’m just gonna sound like the old fart that I am but - When I was a teenager if I heard that high squealing sound and I could wiggle the fan that was the diagnoses for a bad water pump - but that was on a '69 Chevy clunker not a Prius, right?

I suppose if they hadn’t made the diagnoses a separate line item I wouldn’t be questioning it at all.

Thanks again for your thoughtful answer.

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Different businesses have different approaches to billing. Some shops build diagnostic time into their overall fee structure so that you never see it and some will have a separate line item.
My personal opinion is that I would rather see a separate line item for diagnostic time and materials assuming the diagnosis takes more than a minimum amount of time, say 5 or 10 or 15 minutes. Auto repair seems to be a bit mysterious and I’m for increasing transparency.
To me the diagnostic fee seems a little high, but the overall bill seems reasonable. That business may set the diagnostic fee high to run off the customers who might get a diagnosis and do the repair themselves.

A local auto service chain charges a $45 “electrical systems check” before installing a new battery “for free”. They claim they can’t guarantee the battery without this check.

There really is no relationship between the cost to diagnose and the cost of the failed part. Some of the least costly parts can be very expensive to diagnose. Take an extreme example- a failed diode in your radio may cost $0.50 but take many hours to disassemble and find that failed part.

Water pumps are not like you remember (or me for that matter). They are often buried in the engine assembly, difficult to access and diagnose with reasonable certainty without taking off a bunch of stuff to get to them. Many are driven by the timing belt so getting your hands on them takes quite a bit of work…

The humorous sign comes to mind-

Replacing parts- $100
Knowing which part to replace- $500

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My shop may or may not charge me a diagnostic fee. If they do charge one it is deducted from the repair cost. I had a power steering leak, they wanted to clean it up and bring it back after a while to be able to pinpoint the leak, no diagnostic fee on that one.

It depends on the shop, the problem, and its diagnosis, so it’s important to ask this question up front.

Most of the shops I’ve done business with only charge a diagnostic fee if you don’t hire them to do the repair, or if they find nothing wrong.

This right here. It’s pretty amazing how often a shop that diagnoses things for free finds expensive things wrong with the car. Almost like the two are linked. :wink:

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People are peculiar about what they are charged. I have heard people look at their bill after a meal and seen they were charged for a glass of water and for that reason would never return to that restaurant. I rarely listed ‘diagnosis’ on the list of labor charges but often charged for ‘inspection’ and/or removal of some part for ‘inspection’ and of course compression testing, leak down testing, test drives, etc were charged for but never billed as ‘diagnostics’. Customer perceptions can become a conflict that can be so easily avoided it seemed so I made it a point to bill for time spent at ‘work’ and specified the work done. Ice water pickles and diagnosis were free.

If paying more actually removed the conflict of interest, I’d see the wisdom of paying more than I have to.

The shop I go to charges diagnostic fees. My daughter’s car failed the emissions test. The shop charged $150 for diagnostics and then fixed the problem. The next day, the light came back on. We took it back, the emissions guy found a different code, and was stumped. He then decided it might have the same problem his wife’s Cobalt had: a worn wire. It turned out the insulation wore off a wire and the short set a code. He fixed the insulation and then zip-tied a piece of rubber over the wiring harness to avoid rubbing the wire insulation off again. No charge for the second fix.

Ask the shop owner next time you go there. I expect that they have a policy for this. Probably something like "no charge if all that’s needed is a standard diagnostic inspection and isn’t overly time consuming and the shop does the repair, but there is a charge if the diagnostic inspection turns out to be time consuming.

Perhaps the symptom wasn’t the standard symptom for a failing water pump on that vehicle, so the inspection took longer than a standard inspection. I’ve never experienced a sloshing sound as a symptom for a failing water pump in any of my own vehicles. $457 to replace a water pump doesn’t seem out of line in any event.

My experience for buds who are not lucky to be a regular customer, and assumed they will do the repair, is the diagnostic fee is waived for me but charged for others. if you have the shop do the repair, logic being they would have to do the diagnostics before making the repair anyway and deduct it from the total. If they do not know you, as my bud found out as he did not have the repairs done at the shop got a bill for $250 diagnosis, I guess we still have some old school rules. Maybe I am an idiot, but had 6800 dollars worth of rip rap and shoreline improvements done at the cabins, It was a text conversation, he suggested to hold back 1k to make sure he came back in the spring when the ice is out, to do whatever is needed for the rip rap and new rock wall, and seed and take care of whatever was torn up. I am still on the handshake basis with many. Like the plumber that winterizes in fall and opens the cabins in spring, the dock company to put in and out the docks, the good helper guy that cuts the grass, shovels the roof if needed, paints and gutter guard for leafs along with sweeping the roof and keeping an eye on the place. Also new roof a few years ago for the big cabin, totally verbal, no problem. Do I need the bunkhouse also it is looking old, no he says with a pitch like that you have no worries. Then the gutter guy putting gutters around the big cabin never a bill till they finished the work, I love it!

The local dealer wanted $120 as a diagnostic fee several years ago, we had the problem fixed at an independent for $80 including the time to diagnose. We’ve been doing business with his shop for about 26yrs now and they do a really good job of explaining the bill and what they’re charging for.

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Its kinda the same situation when buying a car. People get all bent out of shape when the dealer adds various fees. I don’t care about fees. I care about the out the door price. How the dealer slices and dices the total amount I pay, doesn’t concern me. A local dealer advertises: Never a dealer fee, which does not mean the total is less.
I know that a mechanic has to charge for diagnostic time. Some list it separately some don’t. The total charge is what matters.
I wife once asked for mayo at a sports bar. The idiot added 25 cents for a packet of mayo. She/we boycotted the place for a year.