Heater

210

Asked by Jan 03, 2016 at 05:57 PM about the 1992 Ford F-150 S 4WD LB

Question type: Maintenance & Repair

Heater doesn't heat, also in warmer weather it
overheats at times. Thinking  thermostat,  and
possible heater core.

3 Answers

195

Sounds like youre on the right track with the thermostat and heater core. First, Id check to see if you have air in the system. Air creates a barrier that the fluid cannot travel past and in turn, not travel to the heater core. Are you low on coolant? Is it leaking coolant? Is coolant level dropping but no visible leak? If yes to the latter, it could be a possible head gasket failure (you may see white smoke coming from exhaust pipes), but I would start with the easy stuff, like the thermostat and checking for air in the system.

210

I just checked fluid / coolant. It's was good, but there was a brown sludge looking stuff under the cap.

195

Could be oil. Was there a lot or a little? The oil system is pressurized at a maximum of 100ish psi (when cold..goes down when warm) and the cooling system is about 16psi max. If the head gasket is compromised, the leak will take the path of least resistance whether its into the cylinders, into the oil system, into the cooling system, or leaking outside the block. IF you have a chance, find a shop with a coolant pH test to verify if you are bleeding compression into the cooling system. These tests aren't fool proof but are a good starting point. Another place oil can leak into the cooling jackets is the front timing cover. Any visible leaks around there?

Your Answer

F-150

Looking for a Used F-150 in your area?

CarGurus has 226,285 nationwide F-150 listings starting at $1,250.

ZIP:

Ford F-150 Experts

  • #1
    OJ
    Reputation
    9,750
  • #2
    dandyoun
    Reputation
    4,670
  • #3
    tennisshoes
    Reputation
    3,380
View All

Related Models For Sale

Used GMC Sierra 1500
1,233 Great Deals out of 63,047 listings starting at $1,200
Used Ford Mustang
437 Great Deals out of 42,789 listings starting at $1,488
Used Ford F-250
416 listings starting at $2,900
Used Ford Explorer
1,166 Great Deals out of 64,659 listings starting at $1,200
Used Ford Ranger
154 Great Deals out of 5,230 listings starting at $999

Used Cars For Sale

2018 Ford F-150 For Sale
17 Great Deals out of 134,722 listings starting at $18,092
2017 Ford F-150 For Sale
199 Great Deals out of 17,277 listings starting at $17,990
2016 Ford F-150 For Sale
232 Great Deals out of 7,621 listings starting at $16,997
2015 Ford F-150 For Sale
459 Great Deals out of 11,016 listings starting at $9,000
2014 Ford F-150 For Sale
741 Great Deals out of 14,773 listings starting at $9,880

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.