This is my first posting…
I (stupidly) bought an '04 Dodge Neon SRT-4 that the previous owner had modified. The dealer of course assured me that it was not modded and I am not a mechanic so I couldn’t tell the difference.
Anyway, does anyone have any advice as to how I can teach myself about turbo engines and their maintenance and modifications?
I may be a girl, but I can at least change out a radiator, belts, and other basics. Thanks!!
What is wrong with it?
Only thing with a turbo is to let it idle for 1-2 minutes before you shut it off.
Have you found out what all was changed?
We need more info.
I don’t know of any modern turbo engine that requires 1-2 minutes of cool down before idle after normal driving. This is true of turbo engines of the 80’s. If you track or race the car your advice is solid otherwise old wives(mechanics) tales dating back to the 80’s.
To OP, If you are not running into problems don’t worry about the engine. Change the oil every 3000 miles. I would find a Neon or (SRT) specific forum and post there.
Turbo engines are nothing special in terms of maintenance except they require deligent following of changing oil and likely synthetic.
Note SRT life’s are typically short mainly by previous owners and somewhat design as they were a really cheap speed thrills vehicle. Enjoy it while it lasts 
How was it mod’d? The SRT-4 came from the factory with a turbocharger. It also came from the factory without mufflers. The turbo and catalytic converters were enough to keep it quiet.
It has a turbo timer so I’m not too concerned about letting it idle whe I stop driving (but I do know to let it idle).
It smokes (blue smoke) when I start it in the morning, and sometimes I get black smoke when I suddenly accelerate. So I know it’s burning oil, but I don’t know where it is coming from.
The reason I posted was because I haven’t been able to find a mechanic who can solve the burning oil problem so I figured I’d educate myself about turbo engines, hence I need a teacher or something. The SRT-4 specific forums aren’t much help because they assume you are the mechanic who modded the car; I don’t even know what all mods were made.
I’d guess that it is more than likely the turbo that is causing the smoke screen. Have about $1200 for a new one and a couple of hours of work if it is?
Turbo timer is an aftermarket mod.
A likely item for smoke is your turbo may be leaking oil past its seals. You can sometimes acquire used ones for cheap for those modder’s who don’t think their stock turbo is big enough.
I’d be happy with a stock turbo, so I’ll try looking for one. I’d just hate to replace the turbo and then not have that be the issue. Is there a test or something I can do to check if the seals are leaking?
Have you thought of paying a diagnostic fee at the dealer or trusty independent. In my case I own a Subaru WRX and my locale Subaru dealer only charges $40 for diagnostic of an issue. It may be money well spent.
the black smoke might indicate a rich fuel mixture.
I asked about a modded Civic where I work when I noticed it spit some black smoke when it was accelerating. Was told the guy removed his o2 sensors and the catalytic converter and runs the fuel mixture rich enough for an engine twice it’s size. He had an aftermarket turbo installed, but he doesn’t have it on there right now. He doesn’t really let the RPMs go over 2500 unless he’s racing it, so I can’t imagine how big the smoke trail would be if he really let into it.
Do you think that a dealer diagnostic would show something that two garages couldn’t find? If so, I’d definitely spend the money to get a correct diagnosis. I don’t want to fry my engine anymore than it might be.