No heat, core flushed. What is the thermostat o-ring P/N? (1 Viewer)

[Randy88FJ62]

I bought my 62 and the heater never worked. The previous owner had the water pump and thermostat done and I assume he did not put in the thermostat o-ring.

What is the part number for the thermostat gasket and o-ring so I can let my local dealer know what they need to order me?

Searches aren't going well for me so far. Heater core was flushed by me after taking the dash apart and removing in completely.

 

[bhk]

90430-43002 Gasket, Thermostat (the o-ring)
61341-61030 Gasket, Water Outlet

The P/N's are the same for the 2F and 3FE

 

[Randy88FJ62]

perfect. Thank you for taking your time to assist.

 

[Spike Strip]

The valve on the Firewall is working?

 

[micruz60]

Do you have heat at the rear heater? As opposed to the dash ones?

 

[Vandyfan]

My 88 FJ62 is my daily driver (50+ daily miles M-F). The one thing I could always count on was a damn good heater. Until a week ago. Then it started overheating. I changed the thermostat after breaking 3 of the 4 bolts, but still no heat and still overheating. Has to be the water pump right? Will tackle water pump tomorrow at the earliest, weekend at the latest. Looks like a time consuming job, so any tips would be greatly appreciated!

 

[Elbert]

My 88 FJ62 is my daily driver (50+ daily miles M-F). The one thing I could always count on was a damn good heater. Until a week ago. Then it started overheating. I changed the thermostat after breaking 3 of the 4 bolts, but still no heat and still overheating. Has to be the water pump right? Will tackle water pump tomorrow at the earliest, weekend at the latest. Looks like a time consuming job, so any tips would be greatly appreciated!

sounds like the water pump....if its never been replaced especially

 

[gregnash]

Having a similar issue to @Randy88FJ62.... front heater decides when it wants to put out hot vs luke warm air. However the rear heater puts out decent heat consistently. If it ever gets above freezing for more than a few days I will try flushing the heater core. I did replace t-stat and oring at the beginning of 2016 but wondering if I should again??

This whole not having "hot" air from the heater is getting old with how cold it has been.

 

[Randy88FJ62]

To answer questions above:
Rear heater removed completely and all lines removed up to engine where rear heater is bypassed.
Heater core flushed and visually inspected.
Firewall control valve moves up and down

So once I get in the o-ring and gasket swapped I hope I have hot air.

If not then I will start hunting hoses and the firewall mixer valve.

 

[gregnash]

Otherthing maybe to check that proper hoses are hot going to the valve and whatnot to ensure there is not a blockage in a hose.

There was a pic of one recently where a PO got overzealous with tightening the hose down on the valve and crushed the pipe, which restricted flow severely.

 

[Randy88FJ62]

Good point. Once I swap o-ring and gasket I will then start hunting down the small details. I firmly believe that the PO had the work done by a shop that did not install the water pump and thermostat correctly leaving me without heat all this time.

 

[houstonfj40]

There was a temptation on the 62 to not remove all the hoses when changing the thermostat. You can accomplish, but then need to slide the housing back over the thermostat and top gasket, knocking it out of place. I know because I believe that is what happened when the PO had shop install, I felt the same temptation, this is what it looked like when I removed, so I removed everything and lowered straight down. All good now, proper temp on gauge and very good heat.

 

[Randy88FJ62]

So people mention gasket and o-ring. I haven't reviewed the exploded views in the FSM yet.

houstonFJ40,
I assume your picture shows the gasket and then the thermostat would sit on top of this?

 

[bhk]

The "o-ring" is 16346 in this image. The housing gasket is 16341.

 

[houstonfj40]

Like picture from bhk mine picture is what it looked like when I removed it, wrong. The o ring rubber gasket goes on top of thermostat and then final top housing/neck. Clean surfaces up well.

 

[gregnash]

Yeah there is a HOUSING gasket that goes between the top and bottom sections of the T-stat housing. Then there is an O-Ring that sits on top of the t-stat itself (brass part) that makes a seal between the t-stat and the upper housing only allowing coolant through when the proper temp has been met and the t-stat opens.

My situation is a little different, again leading me to the core needing to be blown out, as I get heat to my rear heater, temp gauge works properly but only front heater puts out the luke warm air. So either my heater core is dying or clogged. Wondering too if the fins of the core are blocked by garbage and fuzz and thus it is not properly cooling.

 

[Randy88FJ62]

Still not sure how the entire system works. How does not having this O-Ring affect heat output when the truck has fully warmed up?

Shouldn't heat be getting to the heater valve and core once the car is warmed up regardless of T-Stat position?

 

[houstonfj40]

Randy that issue in picture never allowed my truck to get to temp. I did not have heat in cabin. Would be warm at best. I also live in Texas! Temp gauge never above bottom tick, now all good. Easy place to start for me.

 

[Randy88FJ62]

My truck always gets up to 188°F normal running temperature. This is apparent in the stock gauge somewhere in the middle and I have a digital gauge which displays the temp.

hmm.

 

[bhk]

Randy that issue in picture never allowed my truck to get to temp. I did not have heat in cabin. Would be warm at best. I also live in Texas! Temp gauge never above bottom tick, now all good. Easy place to start for me.

Exactly. During normal operation, the thermostat restricts flow to maintain the temperature rating of the thermostat as a MINIMUM. Without the o-ring, coolant flows unrestricted and doesn't come up to temperature.

Randy88FJ62 - sounds like your thermostat is operating normally It's easy enough to check if you just want to rule it out, but sounds like you might be dealing with an obstruction like gregnash's. Did you do the rear heater bypass or was that done by the PO? Maybe verify that your supply and return lines are plumbed correctly?