I asked ChatGPT to fix my car and it was a mess

Photo: iStock/Robert Way/Drazen_

Since ChatGPT emerged as an artificial intelligence tool, it has gone from simple language processing to being used for almost anything – such as creating recipes, offering movie recommendations or getting it to explain complicated topics.

I'd err on the side of caution when it comes to using ChatGPT and other AI tools. Not that I think they're going to take my job, but I don't like that people think they are going to take my job.

That said, curiosity has us here at Drive wondering what would happen if we asked it to fix a car?

As someone who has trained themselves to do almost anything to an internal combustion engine vehicle, I wanted to see if ChatGPT knows what it is talking about.

Starting out simple, I thought I would ask it to tell me how to change a flat tyre.

For starters, I'm very impressed that it starts with safety instructions such as finding a safe space, putting on your hazards, and applying the parking brake.

I thought I would catch it for not giving the instruction to crack the nuts off before actually jacking the car up, but nope, it's got that step too.

The only thing I would pick on in this situation is the fact that the space-saver is not mentioned. It is recommended that if you drive a front-wheel-drive car, you put the space-saver on the back. Nor is there any mention of how to get the wheel off if it's stuck.

I thought I would try something a little more complex for the AI, explaining common symptoms for a faulty ignition coil but also common symptoms with other issues.

It gave me a plethora of solutions to check out and why they may be causing those issues, including fuel system issues, air-intake problems, engine sensors, fuel leaks, and spark plug/ignition issues.

It offered the following solutions:

"How to Fix:

1. Check and replace the fuel filter if it's clogged.
2. Inspect the fuel injectors for any signs of blockage or malfunction.
3. Examine the air filter and replace it if it's dirty.
4. Clean or replace the MAF sensor if necessary.
5. Replace faulty spark plugs or ignition coils.
6. Inspect fuel lines for leaks and replace any damaged parts."

It's certainly not wrong, but it's quite broad. The question I asked was also quite broad. There are a few issues with that statement. Checking the injectors isn't as simple as just taking them off your car and looking at them – often, they can be clogged with partials not visible to the human eye. Nor is it a particularly easy job for a beginner.

The order of troubleshooting should probably start from easy to hard, so check the air filter and MAF, inspect fuel lines, check the fuel filter, and check spark plugs. Then, injectors should be your last action.

But since we are trying to diagnose a faulty coil, I asked, "How do I know if the coil pack is faulty?". It came back with a bunch of correct symptoms and gave some advice on what to do.

Starting with a visual inspection, "Look for any obvious signs of damage to the ignition coils, such as cracks, burns, or loose wiring". – Correct.

"If you have a coil pack with multiple coils (e.g., one that controls multiple cylinders), you can try swapping the suspected faulty coil with one from a different cylinder. If the misfire moves to the cylinder where you swapped the coil, it's a good sign that the coil is faulty." – Correct.

"If you have access to an OBD-II scanner, check for any error codes related to misfires (P0300 or specific P030X codes)." – Correct.

"You can test the ignition coil's resistance using a multimeter. Each coil type has specific resistance values for primary and secondary windings." – Correct.

An impressively accurate but broad answer.

This is where I feel ChatGPT failed when we started getting specific. I wanted to see if it could catch the signs of a head gasket failure from the point of view of a non-enthusiast; someone who doesn't really know how to change their oil and check other components.

I gave it the prompt, "I own a 1990 Toyota Corolla. The car gets hot when driving for a short while. Once it gets hot, it struggles to start again. It runs rough when hot. What's wrong with it, and how can I fix it?".

It gave me the first check solutions that I would also look at – a failing radiator, a stuck thermostat, a clogged coolant system, or a malfunctioning water pump.

But then it goes into "faulty ignition components" for the hot start. I would probably also check this, but it's unlikely that it would have something to do with the issue as a whole – which is where I think ChatGPT could cause some problems.

It also tells me to check the fuel system and engine temperature sensor. I would likely check the engine temperature sensor, too, to ensure it's not giving a false reading.

It also tells me to check vacuum leaks. Again, it is unlikely it would cause my fictitious overheating issue.

The most concerning thing here is that it's telling me to check out and possibly spend hundreds of dollars replacing sensors and components rather than doing a simple compression test or checking for milky oil.

After I told it that everything above was fine, it further advised me that it could be the crank position sensor or the engine control unit before finally telling me it could be a head gasket failure.

Saying something like, "Check the ECU before your compression" could lead an owner down a serious rabbit hole of chasing non-existent issues.

I finally told it that my head gasket was blown and asked it, "What should I do now?". It imparted some mildly accurate and broad information: buy the parts, take the head off, check for damage, and reinstall.

There were a few issues. It's commonly known that you might not be able to see a warp in the cylinder head by eye alone.

Also, the majority of cylinder heads are now made from aluminium, which tends to warp after being torqued down, meaning in almost all cases, they need to be machined. It certainly will need to be resurfaced because I told it my car was running hot.

It also says, "The cost can range from $1000 to $2500 or more, especially if the engine head needs resurfacing or replacing". That's an extremely ambitious price guide. Paying someone for the full job usually starts around $3000 for parts and labour.

The bottom line is that ChatGPT is just short-handing information it finds online. While it is an okay tool and somewhat accurate, it's unlikely it will ever take the job of a mechanic.

I tried to think of things that a non-enthusiast would ask, and of course, asking vague questions leads to vague answers.

I think the main problem is that it's giving answers that the people who will understand them would've already tried, and the people who don't understand will likely not benefit from.

AI needs human-fed resources to give you solutions, so you'll need to continue going to a mechanic to diagnose your car's issues.

Zane Dobie comes from a background of motorcycle journalism, working for notable titles such as Australian Motorcycle News Magazine, Just Bikes and BikeReview. Despite his fresh age, Zane brings a lifetime of racing and hands-on experience. His passion now resides on four wheels as an avid car collector, restorer, drift car pilot and weekend go-kart racer.

Read more about Zane Dobie