Questions About T5 Manual

I just recently bought an 03 with the 3.8 V6 with the 5 speed T5 manual Trans and I'm experiencing some issues and want to know if it's me or the car.

Let me start by saying I'm a rookie when it comes to manuals. I can do everything just fine but I'm just slow with shifting and using the clutch.

With that being said I've been having some seemingly at random issues. First off and the most common is it kind of starts sputtering while shifting. Most common gear it happens in is 3rd. Usually when I downshift from 4th to third but I've had the issue in 4th and 5th as well at random times. I'll shift and when I let the clutch and everything will be good for 2-3 seconds then it starts jerking like it isn't all the way in gear but I know it is. So I have to take it into neutral then back into gear and that fixes it. I'm not slamming gears and the shifter is tight and my muscle memory knows where all the gears are so it's not that I'm in the wrong one. But sometimes it does it usually not tho. So I'm not certain if it's me or the car. I've heard manuals have issues shifting in the cold but it's been 40-50 all week here in Ohio.

2nd, a couple nights ago I turned it on, in neutral and it started acting like it was gonna stall but after 5 or so seconds it evened out and was smooth. Then it did it later when I was pulling into my parking spot at home when I had it in first and was using clutch control to creep into my spot in first. Then tonight I was coming up to a stop with the clutch all the way in and when I came to a stop it stalled.

3rd, I'm getting terrible mileage. I had another 03 with the same engine. It an auto with 100k more miles and was the reason I got another V6 cause it got great milage. A full tank would last me all week to work and back just under 40 miles round trip. Prolly 180-200 miles per fill. This one uses up a quarter tank going 30ish miles on the highway. Granted my tires are not the greatest shape, but the tires in my other stang weren't much better. I usually shift around 2k rpms and I never drive fast never have my foot in it really. It hangs around 2k rpm at 70m mph.

I know it's a lot to read, but if you made it this far I appreciate it and look forward to any advice
Thank you in advance
 
Regarding #3 with your mileage... whats the history of the car? Is it in need of a tune up? 1/4 tank for 30 miles is terrible... leads me to believe something is wrong.
 
Regarding #3 with your mileage... whats the history of the car? Is it in need of a tune up? 1/4 tank for 30 miles is terrible... leads me to believe something is wrong.
I don't know the complete history, I do know it was a 1 owner before I got it. He had told me of the work that was done to it. Nothing about plugs or wires or the coilpack that I remember tho
 
Coil pack issue will give a check engine light and bad stumble.

If you haven't done so I would do plugs, fuel filter, some good fuel injector cleaner and air filter.

Best way to check mileage is record number of gallons put in and how far traveled for that tank. Keep a log - date, fuel put in, mileage. After three or more tanks you will have a good base line.
 
Agree on pulling codes, then def. Do the basics plugs,wires,coil pack,air filter ,gas filter, p.v.c.valve, clean the maf sensor.
When I buy a car I do all that and flush and change all the fluids, this way I know its all new and good to go.
 
Coil pack issue will give a check engine light and bad stumble.

If you haven't done so I would do plugs, fuel filter, some good fuel injector cleaner and air filter.

Best way to check mileage is record number of gallons put in and how far traveled for that tank. Keep a log - date, fuel put in, mileage. After three or more tanks you will have a good base line.
Yea my old 03 stumbled sometimes and had a rough idle but never got a check engine light. Changed coul pack and it solved the issue. But this wasn't a hard stumble or a stall like in the case with my new one.
 
Last edited:
Agree on pulling codes, then def. Do the basics plugs,wires,coil pack,air filter ,gas filter, p.v.c.valve, clean the maf sensor.
When I buy a car I do all that and flush and change all the fluids, this way I know its all new and good to go.
That's litterally everything I did on my old 03 with the same engine, except the gas filter. The engine ran great and got like 22-24 mpg. Was great
 
  • Like
Reactions: nickyb
So I went up and got it scanned. P0136. Bank 1, #2 oxygen sensor which explains the bad MPG, but would that cause the stuttering as well? Seems to do it worse when it's cold when the heater circuit for the O2 sensor would be cold

The mustang does have a slight exhaust leak that I haven't looked into. That comes from underneath the passenger floor boards. Would this cause the sensor to read wrong maybe?