• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

98 XLT heat works but no temp gauge


beech2000

Member
Joined
Dec 6, 2013
Messages
11
City
Northwest Georgia
Vehicle Year
1998
Transmission
Manual
Rather than thread hack I decided to create a new one for my problem.
My problem has been in inoperative engine temperature gauge for about a year.
The cab has some heat but not great. I replaced the temp sender and operationally checked it with a hair drier before mounting. gauge responded quickly. When mounted the gauge moves only a needle width from buried.
I also replaced the water pump and thermostat with a 192F from AZ. Coolant was nice and green before and and now. I flushed the heater anyway and all is clear. Heater core replaced by me several years ago. Purged air out from heater hose as best as know how.
My problem is strange.
The heater diverter valve has a vacuum hose to it. When I draw vacuum from my mouth the gauge quickly goes to normal. I've been all over the Internet trying to find vacuum schematic as my sticker is long gone but no luck.
Question: should there be a constant vacuum to the diverter valve?
Question two: what's the smaller quarter inch hose that tees off the diverter valve for?
I will try to attach a picture of the current plumbing at first chance.
Engine is 4 banger 2.5 L Manual trans. 250K miles
 
Last edited:
BOTH heater hoses should get too hot to hold comfortably. If not, either the core is blocked or there is low coolant, or a bad pump is possible with eroded impeller blades.
If the thermostat is not snugged tightly into the housing, with the rubber sealed to the machined flat, and the legs bent to hold it in place, it will leak, and allow low temperature.
The upper hose should stay cool from startup cold, with very slight warming until the thermostat opens, and the hose will get hot all of a sudden. If it warms slowly, the thermostat is leaking coolant, and needs replacement or proper installation.
If you go into the system again, and remove the stat, make sure you install a name brand, such as Stant or Motorcraft, or Robertshaw. Stats made by Larry's Pizza and Thermostats are not likely to work too well. Bend the legs to fit tightly, and keep the rubber tight.
tom
 
BOTH heater hoses should get too hot to hold comfortably. If not, either the core is blocked or there is low coolant, or a bad pump is possible with eroded impeller blades.

If the thermostat is not snugged tightly into the housing, with the rubber sealed to the machined flat, and the legs bent to hold it in place, it will leak, and allow low temperature.

The upper hose should stay cool from startup cold, with very slight warming until the thermostat opens, and the hose will get hot all of a sudden. If it warms slowly, the thermostat is leaking coolant, and needs replacement or proper installation.

If you go into the system again, and remove the stat, make sure you install a name brand, such as Stant or Motorcraft, or Robertshaw. Stats made by Larry's Pizza and Thermostats are not likely to work too well. Bend the legs to fit tightly, and keep the rubber tight.

tom



Good info on t-stat. Both hoses get hot beyond touch when I draw vacuum to the control valve and gauge then reads normal.


Sent from my iPad using Tapatalk
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top