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Discussion Starter · #1 ·
My wife has a 01 glx. The car was fine when we parked it but now 3 month later when I try to drive it I keep getting the blinking temp light. Idling forever its fine under 40 mph its fine. But I have noticed it does run hot if you reduce speed or turn on the heat it stops. I have also noticed the BOTTOM hose gets VERY hot. The TOP hose is very cool. I pull out the thermostat and checked the water pump which I replaced a while ago fine and dandy. I boiled the thermostat and it didn't open until the water got hot and boiling. Does anyone know the coolant route flow or the opening temp for the thermostat so I know which way to continue? Also when it runs hot the fans also work.
 

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In my case, it was the water pump. It also may be the bottle with the coolant, or simply a thermostat.

You really should have it looked at. Has the timing belt and water pump been replaced?
 

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Discussion Starter · #3 ·
Yes all that was done except the thermostat. Im just tryin to figure if its the thermostat or the radiator. The timing belt and water pump were both good.
 

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blinking light

Blinking temp. light only means it's low on coolant at the reservoir or the switch in the reservoir is defective. You can always use a smart phone and this OBD2 tester (ELM32) on ebay and then download the application for a few dollars and you can see exactly what the coolant temperature is.
I bought the elm32 for around $20 on ebay and the apple application (dash command) for $10 this way you can see exactly what the coolant temperature is. I believe 180-205 F' the thermostat operating temperature. At idle your temperature starts to rise and I believe around 210F the big electric fan kicks on at high speed and cools system back down to 205F
 

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Only time my car ever blinked the temp light was when the spherical coolant reservoir was low on coolant - back when I had a slow leak. Topping it off with some distilled water should work if it's not super low. If the light goes away then you're all set.

The ELM32 Bluetooth OBD2 tester is pretty awesome to have too, saved my ass when I installed the timing belt kit from ECS that came with a faulty thermostat. They're supposed to open up around 87 degrees Celsius but I was sent a defect. =|

I use Torque Pro on Android which is awesome for oh so many things.

I don't think you can test if the radiator is clogged until you're sure the thermostat is working..
 

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Discussion Starter · #6 ·
Ok so blinking light is low coolant?? i always tought it was running hot does the vw have a signal for overheating??
 

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You've done a timing belt/water pump/tensioner on this already, right?

I would suggest coolant temp sensor, and a new thermostat. When you replace the stat, stick your finger in, to the left. You can feel the water pump impeller. If you can move it, it's bad.
 

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Discussion Starter · #9 ·
yep I did that the impeller was good. I changed the whole thing less than 1000 miles ago so all is good. I do have a question

blue light = cold engine
flash blue = ?
red light = overheat
flashing red= ?

Im getting flashing red sorry if i didnt clarify that before.

I think I need to get a ob2 scanner to see the real temp.
 

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Blinking blue is a malfunction in the cooling system, usually a coolant temp sensor. Flashing red means low coolant.

Sent from AutoGuide.com Free App
 

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Discussion Starter · #11 ·
okay im going to go out and replace at the themostat first and see what I get . I'll post my results
 

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Discussion Starter · #13 ·
Well now i'm getting the TOP hose hot and the bottom cool, they both have pressure. I tried driving it today and right before I got the blinking light maybe 3 miles the cars a/c got so hot I turned it off, which make me think its the radiator, I've tried burping and I get no air, Is there a verified method beside jacking up the car on one side and then just driving the car?? Also does anyone know which hose is into and out of the radiator??
 

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radiator

I believe the top hose is the input to the radiator and the bottom is the out when the thermostat opens. I would find a way to monitor the coolant temperature before you burn up your engine. These coolant systems are self burping since the reservoir is mounted at the highest level, in other words the air bubbles will flow to the top and displace the reservoir coolant so you just need to add more coolant or distilled water especially after a repair where you had to open/drain the coolant system.
 

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Discussion Starter · #15 ·
Ok I used a scanner and the temps were good looks like 190 - 195 but this is after i took out the thermostat that I had just purchased from autozone the heat works and everything but I filled the car wit just water until I get the g-12 put in this evening. One problem that bothers me is when I first start @ idle I get no coolant out of the small return hose on the reservoir, but after the car gets hot water flows, i dunno is it because the water evaps or because my 4 month old autozone water pump is broken, maybe the steam is pushing it up.
 

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It is possible to have an air pocket in the block; the Volkswagen factory repair manual recommends the use of a vacuum filling tool. I bought an Uview airlift brand tool and it works great. Whenever I am doing any cooling system work; it is the only way that I fill my system, it is very quick and you don't have to worry about air pockets ever again! :)

https://www.google.com/search?q=uvi...c6TyAS63oKgCQ&ved=0CAYQ_AUoAA&biw=320&bih=416
 

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once again

Once again guys these beetles have the reservoir at the highest level of the coolant system so you don't need to purp out the air pockets it'll do it on it's own as you drive. You just need to watch the reservoir level and keep adding coolant for the next couple days.
 

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Or you can burp it out and not worry about getting the low coolant light several days later. Its super easy to do and takes only a few minutes.
 
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