Was i misadvised by my mechanic?
Forgive any noobish terminology in my post. I'm a real inexperienced, unknowledgeable driver when it comes to car faults and stuff, I've only been driving for 10 months or so.
Last week I was driving along and everything was fine, until i pulled away at some traffic lights and it felt like the engine just wasn't pulling as hard, the accelerator seemed less effective. I initially wondered if this was a recurrence of a fault i had experienced about 7 months ago where i had a siezed break caliper causing the break pad to prematurely wear out. (At the time I hadn't had the car or been driving long enough to have noticed that the handling was "different" to how it should have been so the brake pad wore right down) after a couple of minutes, an error appeared on the display saying there was an issue with the drivetrain.
We took the car to our mechanic who said the drivetrain message was meaningless and advised it was probably clogged fuel injectors and advised a long drive on our local high speed road at a lower gear than normal to clear the ports. I went for an 80 mile drive along a 60-70mph road (40 miles out and 40 miles back). This did NOT fix the issue, in fact, every time I hit any type of upward incline, the power in my car failed and I'd be trundling along at 30mph on the 70mph road with black smoke coming out my exhaust. I'd been told to expect smoke as the injector ports cleared.
I took it back to the mechanic the next day who said that loads of errors were flagging up when they plugged the car into their diagnostic thing and it might take a long time to figure out the cause. Today (6 days later) they've said the car's ECU is flooded with diesel. A quick look on Google says that this can cause drivetrain issues, which is exactly what my display message said, and the first thing you should do when this happens is to not turn the car on or drive it...and I was advised to go for a 1-1.5 hour drive! Furthermore, my searches show this is not a rare issue so I don't think it should have been out of the question for the mechanic to investigate a bit further into the error showing on my screen, but he seemed to have never heard of a drivetrain before and I am quite worried by all this.
I'm supposed to be driving 200+ miles in 3 days time to take all my family's luggage to London for a family holiday. Now I'm going to have to try and squeeze luggage for a family of 6 into a toyota aygo (my partners car)! And I have no idea when I'm going to get my car back.