How many miles is too many!?

StanglovR1

Member
Mar 29, 2012
79
2
9
Boston
Hi guys,

I've always wanted a 99-04 mustang. We'll i found the exact one I'm looking for the only issue is the milage on the car. It appears to be very well kept but it has 130k+ miles. How strong are the 4.6L? Any common issues/replacement/service intervals to look for?
 
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i got mine knowing nothing about mustangs, wish i got a pi motor or paid more for a cobra now, but the 4.6 is used in crown vic police cars and taxi's that are constantly beat on and they depend on them, got mine with 140k cus it was a good price and all it needed was motor mounts, hit 150k and the rear main seal just broke so i gotta replace that. overall, to they seem to be strong and durable, if its what you want then its worth it.
 
That makes sense Ford would do that, but i didnt put that together. I live in a city and havve been in many crown vic, old cop car turned to cabbies. Seeing how they drive them and the tough miles they put on them is a bit more assuring
 
The timing chains gave way on my 2000 GT at 145k miles. This set off a cascade failure that created a boat anchor. Some model years are more prone to this problem. It's also affected by maintenance (quality of oil).

Some ppl report no visible signs of wear on the timing chain adjuster at 150k and others report all plastic gone and down to metal. The plastic is important because it ends up clogging the oil pick up.

An oil filter cutter offers a way to screen for this failure.

Broken motor mounts is another common issue.
 
As stated, the lowly 2v 4.6, while not the shining gem of the modular family power-wise (2v, 3v, 4v, 4.6-5.4-6.8), is an extremely durable engine. Police departments and taxi companies can attest to that. I see plenty of oil field company trucks with these engines as well and they all take a beating.

As with any engine, seals, gaskets and hoses don't last forever so expect some leaks on a 10+ year old car. Other than that mileage doesn't really phase them. I've changed the plugs on an old 2v 5.4 with 255,000+ miles and the thing was still running well. In the 10 years i've had my 'o2 the ONLY things i've replaced were the driver's window and a leaking ABS control module. Maintenance stuff aside that's literally ALL i've replaced. Not bad for 10 years and 75k
 
I would rather buy a car with 130K highway miles than one with 25K city miles. It all depends on how it was used and serviced. It may be that at 130K it is just getting broke in, or it may already be worn out. How was it driven, how was it serviced, those are the two biggest questions that need to be answered.
 
My 97 GT just ticked over 200k and I wouldn't hesitate to take it across the country. In fact, last fall I took it to Colorado and got 27+mpg in the mountains. The car still feels solid with this many miles, I even have AC! (knocks on wood).

I did replace the chain guides around 175k miles. They had some moderate wear, but it was just as much an excuse to swap in PI cams as checking the guides. ;) If you maintain the car well, and take care of issues before they become a big problem, the car will last nearly forever. It is when people decide to stop maintaining that the major issues crop up. In police and taxi service, it is common for these engines to rack up 3-400k miles.

I personally think maintenance is more important than driving the car hard. Nearly every time I drive the car, it gets spun to red line at least a couple times. I somewhat regularly go to the track and it still runs stronger than ever.
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I agree with maintance over miles, high highway over low city miles. My Grand cherokee has 223k and drives great but i also take good care of her. But some cars are just built like sh*t and wont get over 150k even if they are maintained to the T.

As Bullitt said how it was driven also.... concerns me? Being a sports car i think a lot of people tend to beat on them. I think the occational rev is good, clean out that carbon ;) but I had a friend who worked for Cadillac he told me horror stories about the northstar engines being all gouped up because its a race engine and the 90year old owner never went over 30mph!
 
Mine is about to tick over 150k miles. Been boosted since 130k. Major issues for me, been through 2 clutches, motor mounts, rack bushings, intake manifold, rear carrier bearings, blown out spark plugs and 3 frozen rear caliper brackets.

Not much considering I fixed them all correctly the first time. I've had the car almost 7 years and 100k miles now. It is my daily driver, I change the oil regularly and same with all other fluids..fix something the right way and it'll last a long time for you!
 
Mustangs last forever... I got mine with 109k on it and it had about 140k when it was totaled and still ran amazing, people could never believe it had that many miles on it. No leaks anywhere and the only one I fixed was an axle seal(they are kind of bad for that). If it hasn't been treated like :poo: it's probably good to go a hell of a lot more miles and even if it has been it still probably is unless you're real unlucky. A lot of my miles were pretty hard miles, I had fun with that car. I worked with another tech at our Ford dealer that had an 03 with about 220k pretty much same story all around.

One big big suggestion though is to replace the spark plugs when you get it... They blow them out a lot and nobody I know has ever seen one blow out a factory plug so I don't know if people change them hot or just don't torque them right or what... I do know that mine blew one out and made me afraid to mess with them and then it blew another one and so then I replaced them all after that and never had another problem.
 
Hi guys,

I've always wanted a 99-04 mustang. We'll i found the exact one I'm looking for the only issue is the milage on the car. It appears to be very well kept but it has 130k+ miles. How strong are the 4.6L? Any common issues/replacement/service intervals to look for?
As far as the Modular engines the 4.6 is a very good engine. As the other guys have said it all depends on how it was drove before you owned it. The engine itself is powerful and you can make some serious power with it, but as a stock engine the magic number of HP is 450 mostly because of the rotating assymbaly (aside from the crank rated to 600HP).

As a stock engine N/A it will come to about 250HP even with high milage. Some problems you may run into are things like the CATs will get plugged up after a long time on high octane gas. Also you might run into a problem with your MAF getting dirty and not reading correctly. Even more so if you have a cold air intake. The bigest problems that this year model had, but mostly in the F-150s were that the spark plugs would blow out of the head. That was due to the fact that when the heads were machined and assembled, some how the spark plug ports werent threaded correctly. Thats about the extent for problems you may run into on easy run Modular engines. Harder run engines of course you could have more problems.

If you are into the power gain and want to beef up your poney power then the best 2 ways are: 1. Purchase a Kenne Belle 2.1 L intercooled supercharger kit. This kit does not come with everything you need so if you puschase it you will need a complete parts list to make it all work. This supercharger is manufactured ti fit and be completely compatible with your stock engine aside from a few extras but nothing major. 2. Bolt ons such as heads, stage 1 cams, intake manifold, and headers ect.

Any more questions just ask.
 
too many miles happens when a rod/bearing lets go or a piston breaks up. lol. my dad has a 94 tbird 4.6 with 260k and its still a champion. the trannys suck but the motor is nice