Mark Dean

Hello, as i stated in my introduction i'm 18yrs old and just bought my first car being a 2002 Mustang gt 5spd. Totally factory stock, one owner with, what for it....214k miles. My buddies totally flipped out and proceeded to give me the "You Dumb A**" speech. It has always been dealership serviced and adult owned but he was honest and said he ran it hard a few time at the track (claims he ran 14.40s) but well maintained. One of my class mate's Mom has a 99gt 5spd and hers has 276k miles ! Previous owner of my Mustang just put all new Accel coils, 9mm Accel wires, Autolite double platinum plugs, all new brakes and other normal maintenance item's. Will this high mileage end up biting me and what other item's should i replace now or in the near future?...Oh and he has ran Castrol 20w50 in it after the 100k mark, the dealership made him provide his own oil but said it wouldn't hurt a thing?
Thank You

rebus20

If it runs good and you got a good deal, drive it and laugh at your friends for paying more.

Mark Dean

The only thing i notice is a thud or low tone popping sound coming from the air cleaner box under acceleration and a intermittent miss from the exhaust out back?

dawson1112

My last 2000 mustang gt had 241k on it when I sold it. Ran great. The 4.6l engines hold up really well as long as the oil is changed on schedule. How ever,,
He did not put acel wires on the car, simply because the 99-04 mustangs did not have wires. They use a COP ( coil on plug. ) No spark plug wires. Each plug has its own coil that sits directly on top of the plug.

Mark Dean

Dawson, thank you for pointing that out, i wonder what he ment by "9mm wires"?...Would you happen to know why the popping is going on inside the air cleaner box? It's only under acceleration and it misses ever so slightly out the tailpipe. Otherwise it runs pretty strong.
Thanks, Mark.

dawson1112

Id say you either have a small vacuum leak someplace, the maf needs cleaned, or you have some weak or failing upstream 02 sensors. Its possible that you could also have an exhaust leak before the upstream sensors, leaking exhaust manifold or leaking exhaust flange or gasket. Any extra 02 that is not metered through the mass air flow will cause the engine to miss and sputter since the computer is getting false information.


As for the wires lol I have no idea why he would say he put 9mm accel wires on a COP engine.

Z28KLR

20/50 is way too heavy for that engine, unless it's in there as a means of covering up severe mechanical wear. And even then.... Next oil change switch to 5/30.

Only thing I would be remotely concerned about on a high mileage 4.6 that has been well maintained is timing chain guides and tensioners. The tensioners fail, causing wear to the guides. The plastic material the guides are constructed of ends up usually in the oil pan and then obstruct the pickup tube, leading to oil starvation. Or if the guides really fail then cam timing slips and your engine is toast instantly.

Typical symptom of worn/failing tensioners is a rattling noise on cold startup, lasts about half a second usually.

Mark Dean

Thanks for the great advice ! I'll dump that heavy oil at next change and i hope the previous owner wasn't trying to cover something up. I'll also check all the vacuum lines and see if i can locate and bad gaskets so i can eliminate that popping sound. I just noticed the miss gets slightly more noticeable the warmer the engine gets ?

Mark Dean

Another question about the oil and fuel. I'm wondering why the dealership didn't advise against using the 20/50 or probably did and that's why he had to supply his own ?.
My friends all run 91 octane premium gas with no alcohol, plus they use alot of gas treatments, good idea ? I want to start out right on taking car of my car. Unfortunately i don't have a "Daddy" to hand me a credit card every time something needs repaired. Besides, i want to work on my own car so if anything happens, i can repair it myself and not rely on a dealership or mechanics. Most my friends are pretty cool, but have newer Camaro's and Challenger's (most being V6's Lol). couple wicked quick Foxbody's nobody wants to mess with and a 65 Chevelle 454 4spd that looks amazing, but is a painfully gutless Lol. Anyway thanks again for helping out ��☺

Z28KLR

Factory tune calibration is for 87 octane fuel, no need or benefit in running 89/91/93 until or unless you get the car tuned for it. Your assumption on the dealer making him supply his own oil would be correct.