No Heat But Running Hotter Then Normal

[Lvnmarks]

When I parked her on Monday night all was good, then we got a foot of snow and she sat for a day and a half. I just replaced the engine with a new 185* thermostat a few weeks ago LOOK HERE. Put all new coolant and put 1500 miles on it before this happened.

I have a small leak around the thermostat housing and the new block heater but I keep it topped off until I can get it fixed. This morning on the way to work I had no heat until the needle was past 3/4 and then the needle feel below 3/4 and I lost it again. The car was still hot so I couldn’t check the level but there is plenty in the jug. So what do you think? Blend door actuator maybe but why was the car getting to hot?

I'm searching for the answer now but figured I throw this up right away.

 

[tixer]

it looks to me like your thermostat may be faulty? I always test mine in a pot of water on the stove, and use a thermometer for comparison.

But if the thermostat is sticking closed, you will have no heat (due to no circulation) and the temperature will register higher (assuming the sensor is located in/around the engine) because the coolant is not circulating through the radiator to be cooled.

If it weren't for those wild temp swings, I'd suspect the heater core, but my gut tells me the problem is elsewhere.

I'd imagine that an air bubble could cause this behavior also?

 

[Lvnmarks]

I was thinking about a T-state change in the mean time and I read that the heater core is the highest point for burping. I'll replace it tonight and see what happens.

 

[95blklsc]

I have gotten a bad thermostat before, I always check them on the stove first like tixxer said above.

 

[budpytko]

Bet he didn't "burp" it correctly. He said he added the coolant in the "NORMAL" way. Should fill in from the crossover pipe! not the overflow tank! He got a BIG bubble!

 

[jackofroses]

if the t-stat is closed, which is very near the very top of the system, and you fill that top hose with water, it sould seem that mostly only water would escape while you were connecting the hose. I have no idea whether the cap needs to be on or off at this point.as the filler cap id considerably lower than the t-stat housing

i once had an isuzu which had a bleeder on the t stat housing. seem of those would be handy on a 4.6

 

[LeoC2]

Moose had the same problem last Winter. Suddenly I'd loose heat and the temp gauge would then rise and I'd even get a temp warning on the display. I kept filling with coolant but the problem would return and I'd still be low on coolant. When I had the station do a pressure test they found no problem but after that the problem went away! Apparently the pressure test forced the air bubble out and all is good in Moosedom since.

 

[Lvnmarks]

I'll boil the t-stat tonight, change the leaky gasket and refill the system with a good burping. I'll keep you updated, I ordered a Blend door actuator just in case.

 

[Lvnmarks]

Got her running right again, checked the t stat and it is opening and closing properly. Topped off the coolant and ran the system with the hose off the housing to burp it. All seems good now, also replaced the gasket on the housing and it has stopped that leak but I still need to address the block heater when I get a chance.

 

[SCTBIRD1173]

Glad you got it fixed, nice work.

 

[Lvnmarks]

New problem now, last night my blower motor started to make a fapping noise and went away when I only hit the brakes. Made allot of noise yesterday and then today the motor stopped all together. Sounds like these motors are easy to get to but I need to double check to make sure it's not the resistor that everyone seems to talk about.



I'm going to have a new car by spring if this keeps up...

 

[tixer]

I'd be looking for debris caught in the squirrel cage. If it stopped when you hit the brakes, it is possible that the debris shifted forward out of the way of the fan, then when you accelerated, it moved back into it. (and perhaps subsequently blew the fuse)

I'd just pull the motor and fan assembly, and see what it looks like in there. On my '86, this was accessible from under the hood after moving some wires out of the way. I'd almost wonder if it is inside the passenger compartment these days though.

The worst case scenario is that the bearings in the fan failed, in which case you'll be pulling it anyway.

 

[Lvnmarks]

Well I went over a hard bump and it started working again, but then when I shut the car off It stopped. I'm just gonna pay the 60 bucks for new motor and throw it in...Good thing it's not cold out.

 

[chris2523]

you have checked the power plug right? its common for them to come loose.

 

[Lvnmarks]

Well I was sick all weekend so I couldn't get to the blower till yesterday. Checked for power at the plug and that was reading good but the ends were corroded so I cleaned them up the best that I could.

The blower only works when I started the rotation by hand so I went ahead and replaced it with a new one. It was only $50 from Napa with my discount.

Took about an hour to reinstall it and as always I used anti-seize on the hardware and the motor shaft. You can see the commutator on the old one was well used. I may take it apart and keep it for a back up our if I need a 12v motor for some oddball project down the road.


To keep corrosion away I used some dielectric grease in the connector to keep it dry for another 12 years.

 

[tixer]

Yup. she's a gonner

 

[Lvnmarks]

Unfortunately the new motor it's a bit louder, I'm considering getting a motor craft one.

I was also hoping this would fix the low velocity in the system but it didn't, I know the air should be coming out faster then it is.