Any problems if I install a 195F Thermostat?

[copo]

No Heat, Help

Just wondered what the car/computer will do if I install a 195F thermostat instead of the 180F factory recommended stat.

I've had a new heater core installed and I have hardly any heat. I'm going to have a new 180F installed Thurs, it was replaced in April. Also last April a new water pump and rad flush and new coolant was installed.

With the old core after a couple of miles I had heat galore and could use low speed fan and even back the cold/hot control to 1/2 way. I'm getting pissed with this heater.

Any comments, I did read that the new heater cores for these cars don't work as well. I don't get it, all it is is a mini rad that water runs in and out of.

 

[TurboDave]

Putting a hotter thermostat in isn't going to cure your problems. It's obvious that your problems started with the new heater core.
So your problem either lies with the heater core, OR the heater control valve that supplies coolant to it.

 

[Chuck Leeper]

???

Could be an air lock in the core.. Also, look at the attachment of the air director door cable. It's a cheapo plastic part that's on the upper rh end of the heater box just to the right of the console.
If it's broken off, the door could be shut or partly shut....
Also, as Dave said, look at the heater control valve and check to see it has vacuum to it.

 

[scottyb]

I agree with Dave. If 170 degree water doesn't produce heat, then the problem lies in the heat "transfer", not the water temp. You need to verify:
water flo to the heater core
proper operation of the water valve
water flo thru the core
proper operation of doors under the dash to direct air thru the core.
fan

You will be wasting your time with a 195 change. A new radiator should have no effect beacuse the stat stays closed until 170, and that's plenty hot.

 

[copo]

The heater was working fine before the heater core was replaced.
Does the heater control valve suppose to be in the up position when the heater is on? It is if that's the case. It only goes down when the AC is on so it shuts water supply off to the heater core. Is that the correct way it's suppose to work?

 

[scottyb]

Yup, the arm on the valve belongs up. Give it a light tug to make sure it's all the way. I have to tug mine to get it to open all the way, which is rarely necessary here in FL.

 

[copo]

When I remove the vacuum line from the heater control valve I do not feel any suction. Is there suppose to be any? If there's suppose to be then where do I check to see where the problem is. The other end is connected ok on the side of the pass fender connection.
The heater control valve is up when I have the control on heat and if I put the control lever on AC it goes down. Can I rule out that the heater control valve is working ok?

I need as much info as possible, since the garage that changed the heater core is going to look at the heater problem for the 3rd time. Any help is appreciated.

 

[scottyb]

I'd say the valve is working OK. I'd prolly crank the car up cold, turn the heat on low fan, and monitor the temps on the inlet/outlet lines of the core and lines on the other side of the valve.

If all get equally hot as the engine reaches operating temp, then you need to check the under-dash doors that direct air, starting with vac connections. This is assuming that water flow is good thru the core. Also consider that the core has trapped air, or partially blocked.

If they don't get equally hot, then the fluid isn't flowing or the valve is internally bad (if that's possible).

??

 

[copo]

The guys at the garage went backwards in the install right back to the core (taking the heater box out) and verified that everything was replaced correctly the other day. After driving a few miles I can wrap my hand around the top rad hose and leave it there and I won't get burnt. The lower rad hose is cold and the 2 heater hoses are more than warm.

Before Heater Core Change: Excellent Heat
• Hot rad hoses, can’t touch it long
• Excellent heat on low fan speed
• Have to move hot/cold slide control lever to ½ way after about 3 miles
• Plenty of heat after a couple of miles no matter what the outside temp is due to the Turbo Engine.
• April 2003, water pump changed, rad flushed, thermostat changed, did not see the old thermostat so I can’t verify that they changed it. It’s their word to me.

After Heater Core Change: Barely any heat
• Upper rad hose a little warm on the hand (can hold my hand around it)
• Lower rad hose cold
• Both heater hoses warm
• High speed fan needs to be on continuously
• hot/cold slide control needs to stay on hot
• From my legs up it’s cold
• Same amount of heat in -30c or -1c , so outside temp doesn’t matter

This is not normal. I don't want to have to start driving with a piece of cardboard in front of my grill.

 

[TurboDave]

If the lower rad hose remains cold to the touch even after warm up, there's something amiss in the coolant flow.
Doesn't sound like there's any cooland flow at all. I'd have to wonder why the engine doesn't overheat

Sounds like the thermostat is opening (warm upper hose), but no coolant is being pulled from the rad. by the water pump. The lower hose should be quite warm and the upper one, should be the hottest.

Sounds like a "mighty" air pocket in there somewhere. When the water pump was replaced, was all well back then?

Remove the radiator cap, start the car and let it get up to operating temperatur. Once warmed up, watch the coolant flow, it should be very week, but when you reach up to the throttle body and run the rpms up to 2000 or so you should see the level drop several inches and should be able to see coolant flowint out of the tubes and a good clip.

 

[87 WE2]

Check the thermostat, sounds like it might not be opening by your last description, both hoses should be hot. Do you have a water temp guage?

 

[scottyb]

I second the air pocket idea, but surprised no overheating??? Get the guys at the garage to do another proper flush.

 

[copo]

Everything worked perfect before the heater core change. And no I have no temp gauge. If I did where is the best place to install it. Electric or mechanical? If the Tstat went the day it was installed which I dought then it must be stuck open since the engine is not warming up the water to 180 before it opens.

The other day I could stick my finger in the rad and not get burnt after a 4 mi drive.

 

[Chuck Leeper]

???????????

The stat is either not opening or is in backwards. The reason the upper hose is warm is there's some circulation thru the bypass hose.
The idiot lite won't come on til 230*, or some where in that range. Being you are in very cold weather, the bypass flow is likely allowing continued operation w/o the lite coming on...

 

[87 WE2]

Or the water temp idiot light is burned out in the dash I have seen that before. The idiot light sending unit could also be bad not sending the signal to light the TEMP lamp in the dash.

Behind the turbo theres a sensor in the front of the intake manifold next to the left of the thermostat houseing. I usually just pull this usless idiot light sending unit out and replace it with and electical sending unit & install an electrical water temp guage in the car.

The thermostat sounds like its hanging up, in backwords as mentioned, or has just gone bad. I have had brand new ones go bad in 1 week. Just replace the stat since its an easy task and see what happens if its not that it only cost you $10 for the stat & o ring no biggy. I would start there....(make sure you put it in the right way....)

 

[copo]

The garage is doing the Tstat Thurs cause they changed the core and since then I have no heat. So which way does the Tstat go in so they know in case they don't? Does it look like a Chevy Tstat for a 350? If so which way does the bulb face (the end with the stamped Temp rating), in or out or up or down if I'm standing in front of the car looking at the fire wall? I have never replaced one on the GN, only Chevys so I don't know if it's up or down like a 350 or if this sucker stands on it's side.

 

[6pack]

Originally posted by copo
The garage is doing the Tstat Thurs cause they changed the core and since then I have no heat. So which way does the Tstat go in so they know in case they don't? Does it look like a Chevy Tstat for a 350? If so which way does the bulb face (the end with the stamped Temp rating), in or out or up or down if I'm standing in front of the car looking at the fire wall? I have never replaced one on the GN, only Chevys so I don't know if it's up or down like a 350 or if this sucker stands on it's side.

Should face in towards the engine

 

[gofstbuick]

As stated above, the bulb should face towards the engine (or towards the intake manifold. I too believe that a large air pocket may exist. When changing coolant, I fill the radiator and place a large funnel on the top of the radiator fill hole, start the engine, turn the heater on high and fill the funnel over half way. I then allow the thermostat to open at least twice. The opening and closing of the thermostat should purge air from the radiator fill hole. I monitor the temps from the funnel. Once the thermostat opens a second time, I throttle the engine up (the coolant level will drop in the funnel) and add coolant if needed and install the radiator cap. I run the TB bypass hoses, so I also open the hoses slightly to purge any air from the steel heater hoses. Get an air pocket there, and that may cause your steel heater hoses to deteriorate.

 

[copo]

There's air in there. The tubes we'ren't flowing for about 10 min then I saw fluid running and finally went down a bit when I reved it. Got more heat finally. How long do I run the engine for with the cap off to get all the air out?

 

[gofstbuick]

As the thermostat opens a few times, the fluid in the funnel will gurgle. That is how you know the air is being purged. Allow the thermostat to open and close until you don't see it gurgle anymore. Then purge the TB hoses, by loosening the hose until coolant comes out of it, then tighten the hose clamp. Since the TB hoses are above the upper radiator hose, air will trap there.