Where is the best place to get an engine diagnostic?

I’m looking for something cheap.

I know of one in Anchorage , Alaska. Is that close to you ?


I’m in Denton Texas, I guess maybe a franchise if anyone knows of one.

Probably best to avoid a franchise (i.e., Midas, Firestone, Pep Boys, etc.). For a competent diagnosis it usually works well to use a well regarded independent mechanic. Dealers can be useful if the problem is unique to a particular make or model, but they can also be pricier. More information on that the problem is would help to guide people who may have other suggestions.


I’m sure you’ll get exactly what you’re willing to pay for.


It is generally best to avoid a franchise for the simple reason that any type of franchise business has higher overhead than a similar non-franchised business would. Why is that? Because a franchised business has to pay all of the same costs that a non-franchised business would pay, such as rent on the building, utilities, wages, insurance, cost of goods sold, etc–however on top of that, they have to pay franchise fees plus a percentage of gross sales to corporate. The only way franchised businesses make it work is by reducing quality/using cheaper materials/cheaper ingredients.

That being said, if you are unwilling or unable to pay shop prices, then you will need to either do nothing (keep driving it until it dies), find a friend who can help you work on it, or purchase the tools and equipment and DIY.


Depends. Newer American car? Luxury German brand? 15 yr old dodge?

How about telling us a little about your car. Make, model mileage etc. Is the check engine light (CEL) on? Are you having trouble? If it is just the CEL go to most auto parts stores, frequently they will read the code for free. Do not listen to their diagnosis, write the code down and post it back here. It will look like P0123 . It is not a definite diagnosis but will start to point in the right direction.

If you go cheap you will get cheap results.

The best place to get a “diagnostic” done is at the place where the necessary repairs will also be done, so you should first locate a well-reputed mechanic in your neck of the woods and let him perform the diagnostic. Some shops will waive the diagnostic fee if they do the repairs.

As was said, chain/franchise joints should be avoided if you want a highly competent mechanic to work on your car.

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If a check engine light, have the code read at any parts store for FREE. That being said, there is a lot this can leave to guessing unless the problem is so incredibly obvious.

Also remember that you get what you pay for and this applies to ANY industry/service. I provide IT services. There is a guy in town that is like 1/3 my price and have seen some of the most expensive repairs due to his work. He literally GLUED a USB memory stick into the side of a laptop computer, making a relatively simple repair impossible. Basically he needed the data on the hard drive and memory stick but I had to hack the laptop apart because of all the sloppy gluing. He also had no backups. It was like an epoxy of some sort and it didn’t seem like the glue was cheap or crappy which would have been a help in this case. I charge by the hour so he ended up paying a pretty penny to get his data back because this was a very tedious process to get the thing apart without destroying his data. Basically I found a service manual for his model online and had to literally cut the thing apart, making sure to avoid the area where the hard drive was contained. Getting the USB stick usable again was also a trip. The guy uses the cheapest aftermarket parts for everything but the big one that gets people are the cheapo no-name power supplies (China Amazon/eBay crap) for both desktop and laptop models that fry motherboards and sometimes show signs of melting from extreme heat. Then there is the use of pirated software that is outdated and/or filled with malware, outdated an unsupported operating systems “shoehorned” onto newer hardware because the owner “didn’t like the look of Windows 10.” NOTE: Simple utilities can make Windows 10 look and feel a lot like Windows 7 in less than a minute and you still retain the support of the modern OS, instead of spending hours to do it wrong. Yes, people continue to pay money for service like this “because it is cheap.”

The same hold true for cars. I have seen and owned some cars that were real basket cases because of work done by the previous owners or hack mechanics. I once had an old Jeep with the vacuum ports on the intake covered up with various sizes of shell casings and shotgun shell hulls. It worked but sometimes it would backfire and blow these casings off. I eventually replaced them with a more proper repair but this thing eventually became a JEEP=Just Empty Every Pocket type of deal due to many repairs like this and I traded/sold this thing off and was done dealing with it.

Sometimes I get potential customers calling and their whole focus is on getting a low price. They often ask if I will match prices from this other guy on labor rates and parts. My response is “No, and you don’t want me to.” These people become headaches when the repair you told them not to do doesn’t work and get pissed. They are best left to this “other guy” in town.

I needed a new fuel pump in my old 1997 Ford once. I found them online for like $60 while the cheapest I could find on an OEM Ford Motorcraft unit was $400. EVERYONE with any knowledge of cars suggested I buy the Ford unit and avoid the cheapos like the plaque. I followed their advice and have never had any issues with the fuel pump since it was replaced with a proper unit.

Doing a cheap hack job of a repair will cost you more in frustration, time, and possibly money than taking it to a competent shop that charges a normal rate.


Going by price alone is not a good way to get diagnostics done. The mechanics have to be competent to interpret the test results properly. The shop I use chargers a high hourly rate, comparable to a dealer, but they are all well experienced mechanics. I know when I take it to them any repairs will be one right the first time or all ensuing labor is free. Ask everyone you know who they use. Eventually one or two will get more compliments than the others. They one of them.

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I’m not aware of any auto-repair shop that will provide an engine diagnostic for cheap. If you find one that does a good job, let us know. In my experience the shops that charge the highest diagnostic fee do the best work. Ask if they’ll apply a % of the diagnostic fee to work you hire them to do.

If you have a warning light, many auto parts stores will read the codes for free, and yo can post them here for info.

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How good a job can one do oneself? I check the compression of my engine, and the timing. It does well on the emissions test. Fuel mileage is good. I’ve heard about valve lash and more exotic tests, but wouldn’t more obscure defects show up in easier tests?

Yes, but most–if not all–mechanic’s shops will not accept that page of codes from an auto parts store, and will insist that they do their own diagnostic prior to repairs. If the OP is capable of doing the repairs himself, that printout from the auto parts store is fine, but it will be close to worthless if the OP has to pay a shop to do his repairs.

Another reason shops do this is not just about the money they make. Any random person can get a code read at AutoZone and take the print out to the shop. I was setting up a computer at a local shop once and could hear all their phone calls. People would call with a check engine light code over the phone and ask how much it would cost to fix the problem. I will never forget one of these callers who wasn’t sure if they owned a Plymouth Voyager or a Mercury Villager. They don’t even know what kind of car they drive and yet they expect the mechanic to give them an exact price over the phone.

The same deal applies to all service businesses. In my line of work, sometimes I get calls where someone wants an EXACT price for what it is going to cost over the phone. They don’t like that I have to see the computer before giving them the exact price. I tell them if they want an estimate, go buy a PowerBall or MegaMillions ticket and add up all the numbers. I explain to them that any estimate over the phone should be at least that accurate. Also, requiring $100 upfront has really run off some of the nutcases I used to have to deal with. If my estimate was wrong at all which is more likely than not, they people go into a mad rage and act like I am ripping them off or whatever.

Also, whenever they bring something in, I have a list of what I want. If it is an issue with a laptop computer, of course I ask them to bring the computer and power adapter. $100 upfront is also on that list. Sometimes people will try another little trick. They drive from 30-50 miles away to drop off a computer or at least they CLAIM to drive that distance. Of course they will have the laptop and power cord but not the $100 I require upfront. Of course you get the sob story about how they had to take off work and burn all this gas to bring the thing to me or whatever when I won’t accept it. I USED to fall for this scam but no more as I always got burned when I made an exception. I have heard every excuse in the book and so have mechanics or any other service business that deals with the general public. I make no bones about it and tell them that I gave you a list of three things to bring and that you didn’t bring one of them. Now of course I usually make an exception of they forgot the power cord because I have them for all but the most oddball models. There is almost always a bank or ATM machine nearby and I make sure to point that out when they “forget” the money. Often they don’t have an answer for that and just leave.

Of course they try to gaslight you and make you the bad guy for wasting their time. not taking care of your fellow man, etc. Apparently this little trick works often enough as I deal with it more than you would think. For being a “bad person” I sure have a lot less stress and drama to worry about while actually getting paid for my work and parts, not just having it left behind repaired, threatened, or whatever.

These experiences are just another reason mechanics will not just accept that paper slip with read codes from the parts store. This is also why I have been moving more and more into commercial and governmental work since they just want it fixed and don’t care about every little penny.

Quite a few years ago, we had a question posted by someone about his “Toyota Accord” (or, was it his “Honda Camry”??).

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I think it was something like that here as well. They said they had a Voyager van and he said something about it being a Plymouth Voyager. The person who you could tell was nuts said “It is a Mercury Voyager van.” The mechanic tried to ask which model it was so the person started yelling and he just hung up the phone.

My best example of this is a guy who drove from a pretty good distance to bring me a computer for service and brought everything but the computer! Oh the joys of dealing with random people!

Your garage. Get a scanner and do it yourself. If it’s just a generic OBD2 issue, you can get a decent one for about $50. If you want a near-OEM functionality, Autel has one for around $600. Trust me it’s worth it not to depend on some grease monkey.

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This person wants something cheap so I doubt they will buy a scanner to get codes they would not know what to do with .

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