Currently looking at a 2005 Gt and the body has almost 140,000 miles on it. At 133,000 miles, the current owner rebuilt the engine and put in new head gaskets, timing chains, and rebuilt the whole top end of the engine.
Would it be a good idea to try and buy this car? He wants 8k for it, but not sure if I should stay away from rebuilt engines

 

Depends on his abilities. If after talking to him I felt like he knew what he was doing ......... then sure.

 

If you don't know who the owner selling the car is personally? I would ask to see receipts of all rebuilt parts and also look over the car with a fine tooth comb before forking over 8k for a 16 year old GT that has 133k miles on it!

 

I'd be leery personally, even if a well known shop did the work. Why?? Like mentioned above, it's an old used car with every component having the same mileage and age related issues. Why worry about the engine work too?
Beware of potential 'money pit' cars. Laying out $8k now may lead to another $5k in no time at all. I realize money is a serious issue with many used Mustang buyers but I'm sure there are some other much nicer 2005+ Mustang GT cars available with half the miles and perhaps prices in the low to mid teens. If it just can't be done financially, then roll the dice and hope for the best. Do as much research (especially a test drive) as possible. If doubts, walk away and save your wallet.

 

Coupe or convertible? Might make a difference, but not much...

Current values 'round my part (Houston) are as follows for a 140K Mustang GT Premium with standard equipment, silver paint, good condition, according to KBB.com That might or might not vary for the Deluxe and/or other options on the car, but goin' with all standard/silver 140K Premium GT for this purpose:

Good Condition (Bumps and bruises nothing huuge, but still pretty nice):
Coupe: 4400-7000 Private sale, 3400-5400 Trade in.
Convertible: 4500-7500 Private sale, 3400-5900 Trade in.

Very Good Condition (Minor blemishes, but no bad bumps/bruises):
Coupe: 5200-8000 Private sale, 4100-6400 Trade in.
Convertible: 5200-8500 Private sale, 4100-6800 Trade in.

You find an 'Excellent' (flawless), that's rare, so not doin' that. Looks like overall a small bump for a convertible compared to the coupe these days on the '05s.

So what your guy's asking for is the top value private party sale of a Very Good in my area. Yours may vary. Of course, that's all just a guess. And if it were Excellent, then right in the middle.

If this was an Excellent condition and is in fact flawless in every conceivable way, but with the engine stuff done, that's a 7K car and you hope it doesn't blow up. If it's not, 6K, maybe 5K, and then I'd be ok with it.

And... it will still break. Maybe not the engine. But something.

Because Elderly, for a car. : You're going to throw more money at it. It's not an 'if'. It's a 'when'.

Welcome to the forums! Hope that helps!

/For me, I wouldn't be scared of the engine, I'd be concerned he wants so much for it if the condition's not Excellent. In my area, of course, maybe yours they're 15K for that.