Normal (actual) operating temp 4.6DOHC ?

[russ jerome]

As read with a scanner or infa red heat gun, not from the
dash gauge.

I just finished putting headgaskets in a 175k mile Mark8
and am carefully monitoring the actual temps thru my scan
tool. These cars run "hot" even when not "overheating"?

50% fan duty cycle when temp hits 200* or so.
100% fan request at 215* plus or minus.
AC on and beating the car hard I can get the actual temp
to hit *240 momentarily and then settle down to the low
*230's but not until sensible driving for a while does it
finaly drop into the *120's.......Is that normal?????

The dummy temp gauge in car does reflect roughly 3/4
temp area when the *240 spike it reached. The center
or what we would call "normal" area of gauge is anywhere
from 175*-220*. The gauge buffering is pretty soft, takes
a great deal of heat before it climbs to the 3/4 area.

Im gonna verify the senders accuracy with my heat gun
sunday but wanted your insite before condeming the rad
as the T-stat/waterpump are new and functioning, not
blowing past cap and correctly bled.

 

[russ jerome]

Anybody ever watch there ECT while driving?

Infa red heat gun shows temp 15-20* lower but may
be just heat transfer so I'll grab a sensor to be sure.

 

[kustomizingkid]

I've got some datalogs of my temps... it hovers between about 190-205.... but that is trusting the computer and OEM sensor.

 

[russ jerome]

Thanks, looks like I still have an issue from what I've
read since last post ;(

After repeated burping I had it at 220* beating it to death
for an hour before it heat soaked and went to 237* and
finaly 245*, just too high to be correct.

1: Radiator no longer efficent.
2: Aftermarket t-stat not flowing enough.
3: New headgaskets are not sealing 100%
4: Cracked head (s), never tested when off...

 

[driller]

50% fan duty cycle when temp hits 200* or so.
100% fan request at 215* plus or minus.

Those numbers are pretty accurate from what I have tested.

1: Radiator no longer efficent.
2: Aftermarket t-stat not flowing enough.
3: New headgaskets are not sealing 100%
4: Cracked head (s), never tested when off...

Assuming the proper filling/burping procedures were followed, my vote would be number 1.

 

[russ jerome]

Well Im an idiot for more than one reason, I edited my
first post to show the high temps, posted 100* low...

Secondly I wanted to confirm the repair of the headgaskets
before spending more money on the car. Well two of the
o2 sensors are junk and the other two slow to read, car has
been running very lean during testing so I'll repair the o2s
and relearn fuel trim before retesting.

I work on other peoples cars all week, I always rush my
own repairs after doing quality work on other cars

 

[kustomizingkid]

I know how that can feel... when you work on everyone else's junk yours seems less important... weird huh...

What kind/temp tstat are you running?

 

[driller]

Well Im an idiot for more than one reason, I edited my
first post to show the high temps, posted 100* low...

I knew what you meant anyways.

 

[russ jerome]

What kind/temp tstat are you running?

Murray Plus+ 4089

Swear to God within an hour after installing it I searched
on here and read someone on here not liking the O'Reily
aftermarket T-stat! Heat gun says it opening but unsure
if its flowing 100% at peak temp.....???

I have to install at least the two upline o2 sensors, the car
is running lean with them being basicaly dead and it would
explain the freeway heating.

If I can get this thing to run correctly Im gonna stick a lot
of coin in it, love these cars.