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Discussion Starter · #1 ·
Could it be that I have another defective thermostat?

Just changed out my T-stat & put in a brand new 160 T-stat and car is behaving exactly the same?

While warming up the car (idling) the coolant temps eventually reach 160deg F, then drop (as they should) which would indicate the thermostat has now opened & is allowing the coolant to circulate thru the radiator now.

Continuing idling...it will eventually reach 175 deg, where the chip has been programmed to start the fans. Coolant temps drop to 165 and fan shuts off. So far this is operating normally (as it should be).

However, am experiencing abnormally low coolant temperatures as soon as I start driving the car. Seems that the air being forced thru the radiator is dropping the temps to much. Yesterday while driving on the 401 enroute to the Buick meet in Whitby....was cruising at 70mph on the highway and outdoor ambient temps were maybe 70deg F.

Both my ScanMaster and my VDO electronic coolant temp gauge are reading the same.

I would think that I have a defective thermostat which is staying stuck open ?
It seems very strange that I would experience the same thing with 2 different thermostats?

What else could it be? Anyone have an ideas or suggestions.....this is really pissing me off! :yup:

By the way, the only change I have made to the cooling system since last year is a new AC Delco water pump, new Alradco Aluminum Radiator.

My set up also has Ramcharger Dual Fans.

Any and all comments / suggestions are welcome.


Thanks,

Dave
 

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All I can say is try a 180 stat and see where it goes...
 

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However, am experiencing abnormally low coolant temperatures as soon as I start driving the car. Seems that the air being forced thru the radiator is dropping the temps to much. Yesterday while driving on the 401 enroute to the Buick meet in Whitby....was cruising at 70mph on the highway and outdoor ambient temps were maybe 70deg F.

Both my ScanMaster and my VDO electronic coolant temp gauge are reading the same.



So what are the temps are 401??
It was Chilly yesterday AM? I was probably around the 160* myself going there & maybe 168* (guessing from past days) on the way home
 

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You didn't mention how low the temp is getting. Mine runs at 168-175 crusin on days like today (no AC on)
That's with a bone stock rad and fan, 160 stat with Eric's chip.
If you have a super efficient cooling system, then ya throw a 180* in there
 

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Discussion Starter · #5 ·
engine coolant temps too cool

All I can say is try a 180 stat and see where it goes...


I do have a new 180 T-stat here Norbs and was thinking I may drop it in.....however, since my chip is set up to activate fans at 175deg F.....I would have a big problem with the 180 stat. Since it would likely never reach 180deg as the fans would be on at 175 and will be running constantly.
Unless I get Bob Bailey to re-burn me another Extender Extreme Chip with fans set to turn on at 195deg F. :dunno:

Dunno?
 

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Discussion Starter · #6 ·
engine coolant temps cont'd

However, am experiencing abnormally low coolant temperatures as soon as I start driving the car. Seems that the air being forced thru the radiator is dropping the temps to much. Yesterday while driving on the 401 enroute to the Buick meet in Whitby....was cruising at 70mph on the highway and outdoor ambient temps were maybe 70deg F.

Both my ScanMaster and my VDO electronic coolant temp gauge are reading the same.



So what are the temps are 401??
It was Chilly yesterday AM? I was probably around the 160* myself going there & maybe 168* (guessing from past days) on the way home
Hi David,

On the way there yesterday cruising on the 401 my engine coolant temps were between 142deg F and 148deg F.

On the way home it was 148deg F to 152deg F range while on the 407 Hwy.

Only change I made over the winter is adding a new AC Delco water pump and an Aluminum Alradco Radiator.

Certainly sounds like another defective thermostat to me?
May zap the thermostat housing with an infrared temperature gun to verify the temps.

Could it be the temperature sensor? Where does the ScanMaster get it's signal from when displaying the temperature?

dave
 

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Discussion Starter · #7 ·
engine coolant

You didn't mention how low the temp is getting. Mine runs at 168-175 crusin on days like today (no AC on)
That's with a bone stock rad and fan, 160 stat with Eric's chip.
If you have a super efficient cooling system, then ya throw a 180* in there
]

Hi Jim,

I may go with the 180 stat or a 170 stat from a small block chevy (will see if I can cut it down to 54mm OD to fit). If not, Meziere offers an aluminum inline thermostat housing that I can install in my upper rad hose and will accept the 170 stat as is. Just won't run a T-stat in the Buicks factory housing on the manifold.

Still will require getting a new chip burnt though as the fan on set point would need to be changed.

dave
 

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Hi David,

Could it be the temperature sensor? Where does the ScanMaster get it's signal from when displaying the temperature?

dave
Off hand I think the SM gets the signal from Green Wire on Top on Intake???
I have the duals with stock rad & it runs 185ish even in 100* after a pass at BPG so with a new rad it just may need a 180 & chip fix??
You can check Steve's site Vortex Buicks to confirm the Green Wire. You may just have a very efficient system & might need to bump the chip to maybe 185ish with a 180 stat??
You could check with Bob & see what he says BUT yesterday was hot for us but not Hot compared to August.

Just test the thermostat on a pot of water to see what temp it opens. I do that to all of them to make sure they are working as they should be. A steam hole can also drop the temp 1*-2* if it's bigger than a large pinhole.
 

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Go back and read what you posted. While idling it comes up to 175. Exactly. While driving at highway speeds...it goes abnormally lower. Exactly. Upgraded cooling fans that will suck a small child through...and an upgraded rad...and you get low temps at highway speeds. Throw a higher rated stat in it...and it'll force the temps up. You may need to go to a 190...experiment. Mine runs at 165 on the highway...but I run the smaller FBODY rad that has less capacity...so the water temp stays at 165. What the others don't know is that the 02 sensor won't read correctly with temps that low...but we'll talk about that later.

Brad
 

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Dave

The size of your rad, nor the amount of fans should matter at all....
the thermostat should keep your engine at a minimum temperature of
160.

If the theory of a big rad and fan are making it cooler than how do we get any heat in the winter when the temps are -20

Something is going on there, try the 180 stat and see if it regulates properly... it should not matter if the fan is running, if the stat works properly there will be no flow of coolant to the rad until you reach 180.

Also, when idling in the driveway you will reach whatever temp the fan it programmed for, there is
no airflow through the rad to bring it down to the thermostats regulated Temp.


]

Hi Jim,

I may go with the 180 stat or a 170 stat from a small block chevy (will see if I can cut it down to 54mm OD to fit). If not, Meziere offers an aluminum inline thermostat housing that I can install in my upper rad hose and will accept the 170 stat as is. Just won't run a T-stat in the Buicks factory housing on the manifold.

Still will require getting a new chip burnt though as the fan on set point would need to be changed.

dave
 

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Dave

The size of your rad, nor the amount of fans should matter at all....
the thermostat should keep your engine at a minimum temperature of
160.

If the theory of a big rad and fan are making it cooler than how do we get any heat in the winter when the temps are -20

Something is going on there, try the 180 stat and see if it regulates properly... it should not matter if the fan is running, if the stat works properly there will be no flow of coolant to the rad until you reach 180.

Also, when idling in the driveway you will reach whatever temp the fan it programmed for, there is
no airflow through the rad to bring it down to the thermostats regulated Temp.
Agreed. When the thermostat is closed, there is little circulation thru the radiator unless someone drilled holes in the thermostat. Therefore the car should be running at least at the thermostat rated temp unless it is defective and staying open, or, as I said...someone drilled a bunch of holes in it....

A little bird told me & I Quote "Also, the o2 should be in closed loop at 140 so it will still work...."
Correction 145* on a TT chip so I ASSume that Bob's chips are similar?
 

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Another option, how is your temp sensor plumbed? I had a low reading issue because the factory temp sensor and aftermarket gauge sensor had both been installed into the factory temp sensor location. A brass T block was installed causing the temp to read low, as sensors were outside block in T block. I re plumbed and got proper readings.
 

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Discussion Starter · #14 ·
engine coolant temps

Agreed. When the thermostat is closed, there is little circulation thru the radiator unless someone drilled holes in the thermostat. Therefore the car should be running at least at the thermostat rated temp unless it is defective and staying open, or, as I said...someone drilled a bunch of holes in it....

A little bird told me & I Quote "Also, the o2 should be in closed loop at 140 so it will still work...."
Correction 145* on a TT chip so I ASSume that Bob's chips are similar?



No hole(s) drilled in the 160 T-stat David. :yup: Installed intact just as I rec'd them from the vendor. :usa:

Will check to verify what temp Bob Bailey sets his closed loop at in his extender extreme chip.

thx.
:cheers:
dave
 

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Discussion Starter · #15 ·
engine coolant temps

Another option, how is your temp sensor plumbed? I had a low reading issue because the factory temp sensor and aftermarket gauge sensor had both been installed into the factory temp sensor location. A brass T block was installed causing the temp to read low, as sensors were outside block in T block. I re plumbed and got proper readings.
Good Question, I just ran out to have a look under the hood....I have the VDO temperature sending unit in the manifold on passenger side (close to radiator hose). Not sure if this replaced the factory unit or not? Where does the factory coolant temperature sending unit go? Is it a different spot? :dunno:
If not, guess the VDO unit has been installed replacing it. Its been 3 or more years since I installed this as I did it when installing my VDO gauges in the GNX dash mount.

Keep in mind that it has worked perfectly up to this point too. :yup:

dave
 

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Good Question, I just ran out to have a look under the hood....I have the VDO temperature sending unit in the manifold on passenger side (close to radiator hose). Not sure if this replaced the factory unit or not? Where does the factory coolant temperature sending unit go? Is it a different spot? :dunno:
If not, guess the VDO unit has been installed replacing it. Its been 3 or more years since I installed this as I did it when installing my VDO gauges in the GNX dash mount.

Keep in mind that it has worked perfectly up to this point too. :yup:

dave
Same place I installed mine. The VDO should read correct along with Scanmaster. Pull it out & put in in a pot of water & see what temp it opens
 

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Discussion Starter · #17 ·
engine coolant temps

Same place I installed mine. The VDO should read correct along with Scanmaster. Pull it out & put in in a pot of water & see what temp it opens
Yeah, the VDO coolant temperature sending unit is in the passenger side of the manifold.....understand that this was used for the factory temp idiot light.

Seems like I left the factory coolant sending unit installed in its original location , on the intake manifold to the right (drivers side)of the rad hose. So I have had both installed for years as they are independent of each other.

Checked out the 160 stat that I took at last week. Put it in a pot of water on the stove and monitored it with a thermometer.

It began to open at about 145deg F and was fully open around 160deg F. Also checked the closing function while cooling down.....it didn't fully seat itself in the closed position till mid 140's. :dunno:

Decided to try my new 180 stat in the same pot of water: started to creep open at just over 160deg F and was fully open at 180......was not fully closed until 162 deg (ish). :confused:

Looks like I'm gonna be throwin in the 180 T-stat and giving it a try. :yup:

Let ya know.
:cheers:
Thanks,

Dave
 

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If it starts opening at 145 then thats Low!
The 180 sounds closer to a 160*??
I'm going to test a few of my old ones & see what I get? :dunno:
 

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Yeah, the VDO coolant temperature sending unit is in the passenger side of the manifold.....understand that this was used for the factory temp idiot light.

Seems like I left the factory coolant sending unit installed in its original location , on the intake manifold to the right (drivers side)of the rad hose. So I have had both installed for years as they are independent of each other.

Checked out the 160 stat that I took at last week. Put it in a pot of water on the stove and monitored it with a thermometer.

It began to open at about 145deg F and was fully open around 160deg F. Also checked the closing function while cooling down.....it didn't fully seat itself in the closed position till mid 140's. :dunno:

Decided to try my new 180 stat in the same pot of water: started to creep open at just over 160deg F and was fully open at 180......was not fully closed until 162 deg (ish). :confused:

Looks like I'm gonna be throwin in the 180 T-stat and giving it a try. :yup:

Let ya know.
:cheers:
Thanks,

Dave
It's working normally. What's happening is the stat does not snap open and closed at a given temp. It slowly opens/closes. The stat is staying slightly open...so you still have slight coolant flow...and that's why it's not coming up to 160 at highway speeds.

Brad
 

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FYI cylinder bore wear increases at lower temps, so running at 160 all the time is not the best thing.
 
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