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Discussion Starter #1
Hello everyone!

I am starting to worry about the temperature of my GTV. I just took the time and calculated the actualy reading on the temp gauge - it actually reads 215!! The car would warm up to 215 and stay there forever.

I'm starting to wonder if that is caused by a leaking head gasket which I have just replaced. I heard that the exhaust gas would go into the coolant and boil it up. But I found no sign of leaking gasket, the coolant is like new with no oil or anything in it.

Or is that a malfunctioning thermostat? I just got it from IAP with all new hoses and everything. Or a rusted radiator?

May that be just a malfunctioning temp sensor & gauge? How can I get a reading of the actual coolant temp without opening the cap? I have a temp gauge laying around (an oil temp), is that possible to fit it onto the existing sensor hole on the manifold? What size is the hole?

Sigh :confused:

Thank you very much. :D
 

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Possibilites:

1. Thermostat installed backwards? Bulb side toward hot (engine side of the line)
2. Radiator crudded up? If you've never had the radiator cleaned and rodded, now'd probably be a good time. It's only about $40 and that way you'll KNOW it's not a crudded up radiator.
3. Head gasket? (not likely) since you're not losing coolant.
4. I assume the fan is installed on the water pump?
5. Low coolant level. I assume you've checked that.
6. Gauge error. Try taking a themometer and putting it in the top radiator tank and see what your reading is. One of those electronic kitchen ones should slip in. See if there's any significant difference. Just keep the radiator cap off while warming up. Make sure to clean the contacts of the wire attached to the sending unit.
7. Ignition timing way off. Check it with a timing light.
8. Mixture super lean. Motor probably run bad and have signs of lean running on the plugs.

My Alfa runs at about 185 deg around town. No more than 200 deg on the highway at 70 mph. Summer.
 

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In addition to Roadtrip's very extensive list, has the cooling system been properly bled? These questions may help in the diagnosis;
What was the temp before the head gasket was changed?
Does it run hot only at idle, at high speed or all the time?
 

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Papajam's correct. I should have listed that near the top of the list to check. Trapped air in the system can affect the flow of coolant. Just aft of the thermostat housing there is a plug with a standard hex head. Remove the plug and ensure there is not an air pocket there.

I suspect, by now, any air pocket would have worked it's way out, but it never hurts to check . . . and it's quick and easy.
 

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Discussion Starter #5 (Edited)
I've just checked the accuracy of the temp sensor & gauge. It is WAY OFF.

I warmed up the engine to about 135 on the temp gauge, turn off the engine, keep the power on (so there is still reading on the gauge). Unscrew the bleed plug on intake manifold, drop in the gauge I just bought from Kragen. It reads only 120. I would like to try the same method at normal temp (195?) but I'm afraid of doing something bad to the engine.
Is that an indication that the gauge is off?

I'm hesitated to say I've properly bleed the whole system. I fill up to the plug on water pump, close it. Fill up to the bleed screw on manifold, close it slightly. Warmed up the engine, and saw bubbles and steam coming out from the bleed screw. Locked it when no more bubbles and the thermostat was opened. Then I close radiator and fill the overflow bottle.

But it seems there is some air trap in the hose connecting the bottle and radiator. Should I remove the bottle and radiator cap, hold the bottle above the radiator until I see coolant coming out? Should I do that when the engine is warm? Hot? or cold?

RT, what is that procedure called? I don't know what to tell a radiator shop to have that done. Thank you. :D

2. Radiator crudded up? If you've never had the radiator cleaned and rodded, now'd probably be a good time. It's only about $40 and that way you'll KNOW it's not a crudded up radiator.
 

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Aluminum Radiator

Hi,

I have a race spider and have had some high temperatures on race day so I got in my head an Aluminum radiator.
I am working with Ron Davis Racing Radiators to have a CUSTOM MADE one for the 101 spider. I have already installed an off the shelf one for my ex GTV also race car and it worked BEAUTIFUL. I hope to have mine finished by June, I will be in the shop next week and it takes them 2-3 weeks to make. Once I have tested it I will announce it to all the 101 Spider owners. If you find this to be a good route need to ask for P/N 22163 and ask for a fill neck and cap. It will take some work to adapt for not hard, then run your GTV ad hard as you can and see the temp stay COOL!!!:cool: :cool: :cool:

http://www.rondavisradiators.com/ Ask for Tim, great help!

Good luck,
 

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Bleeding out the air

Hey Jim and RT:

What is the proper way to bleed the air out of the coolant system? Here is my assumed list:

1. open the heater valve on the dash to allow the heater core to fill.
2. vent the intake manifold at the thermostat vent as well as at the heater hose attachment.
3. fill till its overflowing at each. Close heater hose first. Then thermostat vent.
4. button it all up

Is that the jest of it or is there more to it than above? Also, what ratio of coolant/distilled H2O do you use?

Thanks for the help!

John M
 

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I don't think it's necessary to purchase a Alumminum radiator for street use. You'll be running to cold.

I've seen a lot of Alfa race car's, running stock radiators. Sometime's the aluminum's cool the engine to much. There a lot harder to maintain too. If and that's if you really need a better cooling radiator, you can always have a core added.

p.s.I'm not saying Aluminum radiators are bad.
 

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$$$

I agree with Sniady, the Aluminum 4 street may be too cold. They start arround $300 plus instalation and hoses.

Good luck,
 

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Alfa_Chan - I guess it's certainly possible that the gauge is off. I know oil pressure gauges are notoriously inaccurate, but I haven't seen an Alfa water temp gauge way off. They usually park themselves at about 190 deg when the engine is warmed up.

Here's another simple way of checking the accuracy of your gauge/sending unit.

1. Remove the sending unit from the intake manifold.
2. Boil a medium size pot of water on the stove. Put a regular kitchen thermometer to keep track of the temp.
3. Dip the sending unit in the hot water (key must be on) and compare readings from the dash gauge to the kitchen thermometer. Chances are the kitchen thermometer is, by far, the most accurate one. Let the water cool down and keep comparing readings.

If you think the dash gauge itself may be the problem, I have an extra that I could loan you. When the car is cold and the ignition "on," does the needle return to the 100 mark (lowest reading)?

A 15 degree discrepancy between your aftermarket gauge and installed gauge may indicate that your engine is fine.

I'd do a check in a pot of hot water as indicated above. That way you KNOW if the gauge and sending unit is accurate, as you have a very accurate kitchen themometer to compare against.

As far as the radiator shop goes, just tell them you'd like it cleaned. They'll know what to do. They'll take the top and bottom tanks off the radiator put the core into a vat of really caustic stuff to clean it out. They may even take some thin rods and run them up and down the cooling channels to get the tough crud out. I'd recommend not hanging around the radiator shop too long, however. They look like a post-nuclear torture chamber . . really stinky, filthy, and the chemicals around there make my skin crawl. Also, you may note that the guys who work there often start to take on a slightly mutant look.

John M - That sounds good to me for a bleed procedures. Tell you the truth, I've never had much trouble refilling or had trapped air in the Alfa system.
 

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Radiator Suggestion

On my race car, I took a stock radiator and had a couple rows added. Before I did this, my race car would run hot (around 215-225). I had it made bigger and it dropped to 200. Then I made some ducting out of aluminum directing and trapping air infront of the radiator and it dropped to 190. Hasn't missed a beat once! I think it was about $150 (clean rad tank and install bigger core)once all things were said and done.

Try Welding Works in Northridge, they do all our radiators.
 

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Discussion Starter #13
I'm thinking getting one of those infra red temp reader from Craftsman, would that help to determine how "off" my gauge is?

The gauge didn't move when I got the car, it was stuck by the plastic in front of it. Is that possible the bottom of the needle is magnetized by one of the coil when it was stuck? Just a thought. :D

I saw it on the Kragen catalog that the Alfa thermostat is rated @ 195, is the IAP one @ 195 too?

Thank you.
Thank you RT :D

Roadtrip said:
Alfa_Chan - I guess it's certainly possible that the gauge is off. I know oil pressure gauges are notoriously inaccurate, but I haven't seen an Alfa water temp gauge way off. They usually park themselves at about 190 deg when the engine is warmed up.
 

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I've heard that the infrared readers are pretty good, but I doubt that you've got to get that scientific or expensive about it. I'd just do the "pot-of-boiling-water" test on the temp sending unit and crossference against a known-good mercury thermometer.

Magnetized needle . . . . I think you're really reaching on that one. If you're in doubt about the mechanical integrity of the gauge, you can always get one on ebay real cheap.

Yes, the normal thermostat spec is 195 deg.
 

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Chan,

I'll bet that your gauge's needle got damaged by the glass pressing against it. Perhaps the pin that the needle rides on got bent. Like RT suggested, try a different gauge.

Aluminum radiators and infrared readers?? You're one of those guys that loves to buy the latest and greatest toys, huh? :)
 
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