Might Be Looking To Buy A 99-04 Gt

chriskarel

Member
Jul 22, 2013
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Hi guys, I may be looking at 99-04 GTs soon. Possibly a Mach 1 if I can find a cheap one. I'm just wondering what are the common problems with these years. I know of the spark plug issue already, not how to fix it tho.

Any other advice when shopping for one? Thanks.
 
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Depends on your definition of "cheap". I wouldn't expect to pay less than 10K plus for a Mach 1 and a Cobra will be even more.

You'll prolly wanna go with a Cobra of the Mach 1 if your goal is 300rwhp and you are hoping to get that more or less out of the "easy" box. The GT motors require head work, cams and exhaust improvements as well as fuel system improvements to see "reliable" 300+rwhp numbers. From the factory the GTs were making 260hp at the flywheel. On a manual car you usually see around 10-15% parasitc drag loss through the drivetrain on the dyno, so a couple buttons on the calculator shows that a stock GT is around 220-225rwhp. You would be looking to pick up an additional 85-100 hp to be in the 300rwhp club. If I were buying another Mustang, I would save my pennies and find a nice Termi.

Best of luck with your new purchase!
 
Long time owner here with 170K original miles. I haven't experience any major problems. Only had one plug blowout due to not using a torque wrench on it. Had to replace the rear axle bearings. Minor ones are my driver side window motor is acting up. Not sure if it's the motor or switch. Also, the seatbelt has long been a nag as it doesn't retract fully. I'm sure there's a fix out there, just haven't done it. Steering rack has a creak/knock in it but doesn't affect any performance. You must use 75W-140 weight in the rear...the 90 lets it get too hot back there. Rear window defrost grid is failing on several lines. Heat/sunshine will make the headliner material fail at the rear and on sun visors if left down all the time. Last 2 summers have had to add refrigerant to the A/C. Rear pinion seal is leaking. Captain Obvious moment here...Usual wear and tear parts I've replaced are coils, plugs, shocks, belt, hoses, thermostat, filters, brake pads and rotors. Cleaned the IAC valve, mass air sensor, throttle body. Overall a very reliable vehicle.
 
These cars are known for being very reliable when maintained properly. Think of it this way- the same 4.6L Mod motors in the Mustang GT see extreme duty use in Taxi Cabs & Police cruisers across this nation & take a beating all the way to 200k miles & beyond. The plastic Intake Manifold WILL crack eventually, mine made it to 80k miles before popping on me and spewing coolant all over the motor which fried a few coil packs. Replace it with an FRPP manifold and you'll be back in business. The IAC, MAF, Throttle Body will all eventually require cleaning or replacement at some point to keep the car running well. You'll also have to keep an ear open for the notorious Ford TOB (throw out bearing) with all manual Transmission cars. They will make an annoying "Wurring" type sound and eventually lead to a grinding sound when they get really worn out. If you replace it with the Heavy Duty FRPP TOB you likely won't experience the problem again. My 00' GT has 85k on it and drives me nuts with the sound, so I just crank the music up for the time being. If you get a GT (mid-year 00' & later) with the TR3650 Transmission they're known for being extremely notchy when shifting into 2nd gear especially when cold. A fluid change can help with this problem & it did with my previous GT.

I can't think of much else at the moment, and those are really very minor issues. Overall they're a great car that can be had for a nice price. But if you're looking for 300RWHP I would bypass a GT completely and go straight for a Cobra/Mach 1. The motors in the GT's honestly don't respond that well to bolt-ons like say an LSx motor does & they almost require Forced Induction to make serious power. It can certainly be done but if my entire goal was to make HP I wouldn't buy a GT for that. Although, I have a buddy with an 00' SS & I can actually keep up with him especially out of the hole and through 2nd/3rd gear despite him having a pretty big CI advantage. He doesn't care to hear it though. haha
 
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