Very poor mpg, Bottoming out, & Tranny

ncsportic · 10-03-2009, 05:51 PM

Hey guys, new here. One of the better, if not the best, mustang forums I've came across. Hopefully I can get some help trying to diagnose some problems with my bone-stock '94 V6 (5 speed stick) Mustang.

1) Gas mileage is very poor. I recently reset my trip on a fill-up & it was only at 224 miles when on E. Used "normal" driving habits (ie; not flooring it and proper shifting) throughout the tank. No leaks in gas tank. Air filter is clean. Correct tires on the car. Why might this be?

2) I can sometimes smell antifreeze. No leaks. No antifreeze mixing with oil. I blew a v-belt one time (2 months ago) and went a few blocks to make it home & antifreeze was flying all over when I opened the hood. Yes, I know, that was a huge mistake and could have overheated the thing by doing it. Could the smell just be be from that one time?

3) There's an annoying presence of grinding in the transmission. It shifts just fine, but it's as if something is moving around in there. Sure it's a throw-out bearing. Someone said it was that or a Pilot bearing. What do you think it is?

4) I "bottom out" when taking off & going over bumps whenever there's someone in the back seat & sometimes when someone is in the passenger. There's no scrapes on the bottom of the car, so it's not technically bottoming out but it sounds like it is. I can't seem to find where the car is scraping or rubbing against causing the noise. It's not the wheel well. Previous owner told me he put softer springs in the rear so it would be comfortable for him (he was the only one that ever rode in it). I replaced the rear springs with takeoffs from a stock '97 V6 mustang & it still does the same exact thing. What might be causing this? What can I do to stop it?

I traded my '99 Taurus for this Mustang back in August. Previous owner said there was a blown engine at 106k miles & he replaced everything under the hood from a '96 V6 Mustang with 29,000 miles that got totaled when it was rear-ended. It's pretty clean under the hood, so he might be telling the truth but is there any way to tell for sure? I mean, who would trade a Mustang for a Taurus?

Thanks for all your help, my local shops are "too busy" to help.

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Shaunmac9128 · 10-03-2009, 05:58 PM

For gas mileage you might want to change your 02 sensors, bad o2 sensors can cause bad gas mileage. Could be clogged cats but doesn't seem like it. Tune up is never a bad idea when seeing bad gas mileage, maybe change your fuel filter as well. As for the "bottoming out" that same thing happened to me a while ago and it turns out I had what I think was a brake line running under my car above the driveshaft and the clip that held it in place and it was bouncing off the driveshaft when I had 1 or more people in my car or hit bump, it sounded like bottoming out so just an idea get under the car and look around to see if you see anything hanging. Sorry I can't help you with the other two.

brent4 · 10-03-2009, 06:12 PM

x2 on a tune up and checking the o2 sensors..as far as the bottoming out check your shocks and struts.

jthorn9 · 10-03-2009, 06:20 PM

94-early 96 had head gasket issues, I'd suspect that could be your problem with the anti freeze and mpg.

mustangman02232 · 10-03-2009, 06:20 PM

tune up, clean the MAF, what do you run for tire preasure? i used to run 40 front and 33 rear because of less rolling resistance = better fuel milage. any CELs? have you ever done plugs/wires?

2.) any leaks under the car? any drips from the weaphole in the water pump?

3.) most likely a syncro on its way out

4.) where do you hear the scraping, do you have a vert? is your exhaust still intact?

ncsportic · 10-03-2009, 06:57 PM

I'll be storing the Mustang for winter soon, so I'll be sure to add a tune up to my project list. Thanks for that information.

I'll check & see if there's anything hanging the next time I find a chance to get under the car. Never thought of the brake line.

I hope it's not my head gasket. I've always wondered about the head gaskets. I know the labor cost is very expensive. What will happen if it is the gasket and I just keep driving the car? I'm aware of the antifreeze in the oil, but what else happens when a head gasket begins to go?

No CEL. I'll check the plugs to see what kind of condition they're in. How do you tell a bad plug wire? I'm not aware of where the water pump is located. The gasket in the oil pan needs to be replaced, so there's a drip of oil maybe once a day. Sometimes I see a few drips of water come out of my cat? I have a coupe. The scraping is in the middle-back. I really can't tell if it's on the left or right side.

Thanks again guys. I'm a little ignorant beyond the basics of automotive.

navigator8320 · 10-03-2009, 07:34 PM

i get about 224 for my tank on the surface streets, and like 300 for pure highway and have done since i got the car. is that not normal?

ncsportic · 10-03-2009, 10:08 PM

Quote:

Originally Posted by navigator8320

i get about 224 for my tank on the surface streets, and like 300 for pure highway and have done since i got the car. is that not normal?

'94-'04 Mustangs' gas tanks hold between 15.4 and 15.7 gallons, respectively.

so, you're getting about 14.5 mpg city & 19 mpg highway. mine is just about the same as yours. we should be getting 19-20 city & 29-30 mpg highway, give or take a mile or two.