What to Inspect Buying Turbo/Supercharged Mustang

MattMan02GT

Active Member
Jul 24, 2018
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Albany, NY
Good morning all. I'm in the market for another mustang. Looking at one that is already Turbocharged or Supercharged. What should I look at prior to purchase other than the usual look it over top to bottom for damage and leaks?

Looking at a Turbocharged one this week and I plan on asking to do a compression test on it either myself or pay to take it to a shop if they don't trust me to do it in their driveway.

The car has 130k on the stock motor with a turbo for the last 20k or so. Maybe I'm a pessimist, but how long will a 4.6 survive putting down power 400+ whp on 10psi even a safe tune...
 
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McFly2

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Nov 21, 2020
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Take a OSB2 scanner with you if you have one.. Look for codes. Look at fuel trims: Os2;s -fuel pressure or any other live data available. Motor that is charged could be ok if it was not abused. A visual of rear tires and burned rubber in fender well is a clue. Ask for any videos owner has on phone. Most will proudly display abuse.
 
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MattMan02GT

Active Member
Jul 24, 2018
111
8
28
32
Albany, NY
Take a OSB2 scanner with you if you have one.. Look for codes. Look at fuel trims: Os2;s -fuel pressure or any other live data available. Motor that is charged could be ok if it was not abused. A visual of rear tires and burned rubber in fender well is a clue. Ask for any videos owner has on phone. Most will proudly display abuse.
Good call on bringing the scanner. That will also let me check to see if all of the monitors are online or if he's reset the computer, too. What would stand out to you as a red flag with O2 readings, fuel trims, and fuel pressure?

I know the car has been raced a moderate amount. I think it's been used as a fun DD, but also as a toy. I asked the question "hey man, any idea how quick it runs the quarter mile?" to see if he would brag about what he runs every weekend or something like that. He said the previous owner ran low 12s at the track but he has personally only raced people on the highway and beat a GT500, terminator, GTO, and S197.

I know replacement mod 4.6's are relatively cheap and plentiful still, I'd just prefer to get a few years of fun before I pop a motor and have to replace it!
 

McFly2

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Nov 21, 2020
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Cincinnati
If #1 O2 bank 1 and 2 sensors are there: should read between .1volt - .9volt. I'm not sure on downstream sensors.
Short term fuel trims are normal at +5% to -5% for stock engines. Long term fuel trim depends on set up. Fuel pressure is 40 psi stock.
I dont know anything about charged engines, really. Scanner might show a hidden code and what is online: MAF etc. You might research the subject before you look.
 

GT4Lyfe

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Feb 21, 2021
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Everything. Anything super or turbo charged especially, as that needs fine tuning. Actual tuning, proper setup, and boost levels. Plus who knows if the previous owner did a compression check on it? These cars get tracked hard. They get pushed hard. Look at the videos on youtube. Then something blows or starts to, they cover it up, and sell it. Not everyone does this, but some do. Be real careful. Verify it has a actual tune, check trims and obd2 as stated, do a compression check, etc.
 

MattMan02GT

Active Member
Jul 24, 2018
111
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32
Albany, NY
Everything. Anything super or turbo charged especially, as that needs fine tuning. Actual tuning, proper setup, and boost levels. Plus who knows if the previous owner did a compression check on it? These cars get tracked hard. They get pushed hard. Look at the videos on youtube. Then something blows or starts to, they cover it up, and sell it. Not everyone does this, but some do. Be real careful. Verify it has a actual tune, check trims and obd2 as stated, do a compression check, etc.
I will be looking over the car with a fine toothed comb and laying on the ground to look underneath, etc. He is totally good with us taking the car for a test drive so I'm thinking local streets then the highway to evaluate the tune.

He doesn't have the tuner that was used on the car (supposedly tuned by a reputable shop in Delaware) and said the tune is spot on/hasn't been adjusted in the 5,000 miles he's had it. I am bringing my obd scanner to check for any codes or if he's reset the codes for the showing. If it didn't have an actual tune I'm assuming it would blow up the first time we hit boost lol. I do want to do a compression test and will be asking him about it. Like I said I know junkyard 4.6's can be found relatively cheap, but I'd like this motor to last at least a few years until I can build something with forged internals.

I appreciate the tips so far and welcome and more. Checking the car out tomorrow night!
 

MattMan02GT

Active Member
Jul 24, 2018
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Albany, NY
So I checked out the car tonight and test drove it. The paint isn't perfect, but it's fresh. It has a ton of power. The most fun I've had since I sold my motorcycle.

The transmission is "built for 650+ hp" I'm told, would that be why first and second gear would be noisy? Somewhat of a wine that came and went as you're on and off the gas. There was a little bit of a vibration in the car almost in first and second but once you got to third I don't remember it and it seemed fine at highway speeds. This rules out a driveshaft or tight rear end pinion gear to me?
 

GT4Lyfe

Member
Feb 21, 2021
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Eh I'd watch it. I have 3.73 gears myself and I have no noise or vibration and these have been in here for years. Definitely check the rear fluid.
 

MattMan02GT

Active Member
Jul 24, 2018
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Albany, NY
No I'm saying I think the vibration was more from first and second gear in the transmission. I'm not sure if this is a normal thing with a trans built to handle that much power, like do they use straight cut gears that are louder for example? It has the stock 3.27's in the rear since those are ideal for a turbo application
 

McFly2

Member
Nov 21, 2020
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Vibration not normal: noisy and a little on and off wine. Let me think..... What year mustang and how much? The whine could be super charger? You are going to need to get clarity concerning the vibration and noise in first and second. Sellers mechanic or seller who installed transmission could give insight?
 

MattMan02GT

Active Member
Jul 24, 2018
111
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Albany, NY
This car had a turbo. I've never driven a car with a turbo before only a diesel heavy duty truck. You hear that turbo whistling and whining with the revs, but there was also a little bit of a vibration. I'm thinking something with the transmission, but the seller insists That is how it's driven the 6,000 mi he's own it.

The car is a 2000 and they are asking 8600 or BO. Unfortunately the car was built two owners back and about five states away so we'd have to go with someone local if I took it to a shop
 

EdMac67

New Member
Nov 8, 2018
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That sounds kinda shaky, unless you know what shop built the trans and what they did to it. I went for a ride a while back in a friend's '04 Terminator Coupe, and that 6-speed didn't make any noise in any gear, with 605 RWHP on tap. The 6-speed was whisper-quiet as the rear tires were breaking loose at 80+ mph!! :O_o: