NO heat and temp gauge not moving

[Shaggy433]

Ok so I have been looking around on here for a while with not much luck finding what I need. My 94 Ex suddenly has not much heat blowing out. The air does come out where its suppose to (defrost, vent, floor) but its lukewarm at best. Now the temp gauge has never really worked, the highest I've ever seen is on the N and now it doesn't move at all. When I went to work this morning it was working just fine. I checked the antifreeze level and it was good and after about ~45 minutes of driving it was not hot. The upper rad hose was not hot nor was the lower. I'm leaning towards the T-stat but not 100% and figured I would ask you (yes you!) so what say yee?????? T-stat? heater core? Something else I haven't even considered????

 

[lynchy wa]

It does sound like the thermostat mate. No heat and no engine temp usually point to that.

 

[dogfriend]

Thermostat might be in backwards. Spring side toward engine. Its possible to get it in backwards = no heat.

 

[2TimingTom]

T-stat. They are cheap and not to be replaced occasionally.

 

[Shaggy433]

Ok thats what I thought. I'm going to replace the t-stat now and possibly the temp sending units as well I will let you know how it goes!

 

[Shaggy433]

ok so it was the thermostat so it is all working fine now!

 

[huntman58]

glad to here ya got heat again as its that time of year when we all want it .

 

[lynchy wa]

Good stuff

 

[Currency]

Glad to hear you got everything working again. I know what its like not to have heat, I think my issue is the blower which works 94% of the time, or just whenever it wants to

 

[Shaggy433]

yeah it is quite nice having heat again! Now I just need to figure out why after fixing this my truck wont go into overdrive and what my sporadic CEL is all about. Do first gens store trouble codes or do they only show while the condition is happening? On my 10 minute drive to work the CEL would come on for a few seconds then shut off for a few.

 

[Tony H]

They do store some codes.
Probably a lazy O2 sensor.
Early 'X's seem to have this issue.
If I drive Long Hwy miles (200 without slowing down)then slow down in traffic, the CEL comes on for a bit then goes off.
It's been doing it for years.

 

[Shaggy433]

ok when I get off work I will check the codes and see what happens

 

[Shaggy433]

ok so I finally had the time to pull the codes.

KOEO 157 186 332
KOER 111

I replaced the DPFE a ~2 months ago because of a 332 code and it went away so I know how to do that one....
but the other two I'm not so sure. I am going to clean the MAF tomorrow and see if that does anything. Do the 157 & 186 get thrown because of the same thing?

 

[DeRocha]

ok so it was the thermostat so it is all working fine now!

Glad to hear you found the problem.. In normal operation the T-stat is constantly opening and closing to keep the temp in the normal range ~195F. When the T-Stat is stuck open it continually allows the radiator to cool the engine and exhibits the exact symptoms you described.. Another way to tell is if you let the car idle for 5min or so you will see the temp gauge rise to "Normal". When you start driving the air flow through the radiator will quickly drop the temp into the Cold range..