Hey everyone. I have a two part question with my 98 f150 5.4l 2v.

1: I'm thinking the blend door may need replaced. Sometimes in the mornings when I actually get heat, I'll hear a thunk in the dash. Then I get heat for the defroster. Any of yall think that could be the blend door?

2: The engine doesnt heat up very high. The coolant is full and good, and I have a 195 degree thermostat in it. The most it'll get up is towards the bottom of the normal area.

I also thought that maybe these two might be tied together if it's not getting hot enough. Thoughts?

 

Where you live impacts engine temp. My engine will be at the bottom of the range today, it's 15 out...

 

I'm in southeastern Tennessee. It was the same way during the summer as well.

 

This is as hot as it's gotten since I've owned it.

 

That gauge is merely a reference. Hook up an OBD-II scanner and see what the PCM is seeing as an exact temp.

 

will do bud. Thanks.

 

The 195* Stat is spec.

Gauges are perfect...that's where they ride. Hell, even your warm idle is spot on....725/730 Rpms.

Everything looks good to me.

 

Thermostats stick open all the time.

I had a brand new motorcraft tstat that stuck open , engine coolant didnt above 166.....got code for it eventually, cant complete drive cycle if engine doesnt get above 170.....it will throw a code for that. Put in new stant.....195 on the money
read it with scanner......replace tstat if needed. Im guessing it needs it. I could see mine reading low a hair from normal....it was just a hair....a 30F hair

 

This reminds me to check my thermostat. It seems like it takes forever for my truck to heat up.