car no heat/overheating; normal temp and heat under heavy acceleration

Asked by Mar 28, 2016 at 06:46 PM about the 1994 Ford Mustang Coupe

Question type: Maintenance & Repair

I have a 94 v6 mustang and it drives fine for a little
bit sometimes (heat works) but inevitably I lose
heat and shortly after that, temp starts to rise. But,
if I put it to the floor,  about 75% of the time, it
cools down to normal and heat will work. It's very
short lived because in about a min or 2 it will
happen again. It happened 4 times when I tried
getting to work in a 7 mile span from my house. It
won't overheat at idle even though most of the
time it has no heat at idle ( it was checked in below
freezing temps after a drive cause that's the only
way of getting it up to temp). All that being said I
am just finishing up school for automotive
technician and I know it can't be thermostat due to
no heat issue. I have flushed the system twice and
bled air out at least 5 times. I don't think the heater
core being clogged would cause an overheating
issue
I'm leaving toward water pump and guess some or
all fins are worn/erroded. Has radiator and
thermostat replaced about 15k miles ago due to
overheating. No coolant in oil and vice versa. I do
have a lean code for bank 1 but only bank 1. I'm
lost and don't have a lot of money so all help would
be appreciated. Sorry such long description

1 Answer

85,345

Sounds like you know the bases...usually it is low coolant or air pockets in the system. And if you have good flow threw the radiator, watching with the cap off you can tell, all that is left would be the water pump, the fan clutch if there is not an electric fan, and thermostat. Possible the thermostat is not good.

Your Answer:

Ford Mustang Experts

  • #1
    Tom Demyan
    Reputation
    5,150
  • #2
    F_O_R
    Reputation
    1,710
  • #3
    Bob Beaman
    Reputation
    1,450
View All

Related Models For Sale

Used Chevrolet Camaro
242 Great Deals out of 26,852 listings starting at $4,000
Used Chevrolet Corvette
86 Great Deals out of 15,067 listings starting at $3,700
Used Ford Mustang SVT Cobra
229 listings starting at $6,999
Used Ford F-150
2,283 Great Deals out of 198,756 listings starting at $1,300
Used BMW 3 Series
998 Great Deals out of 30,043 listings starting at $900
Used Jeep Wrangler
208 Great Deals out of 14,987 listings starting at $3,000
Used BMW M3
13 Great Deals out of 1,493 listings starting at $5,400

Used Cars For Sale

2018 Ford Mustang For Sale
18,270 listings starting at $12,950
2017 Ford Mustang For Sale
97 Great Deals out of 6,018 listings starting at $16,991
2016 Ford Mustang For Sale
36 Great Deals out of 2,335 listings starting at $12,991
2015 Ford Mustang For Sale
22 Great Deals out of 2,386 listings starting at $12,991
2014 Ford Mustang For Sale
23 Great Deals out of 1,755 listings starting at $7,986

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.