Another cooling system question
#32
Rennlist Member
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Sure, it only takes 3 hours to change a head gasket on a NA with a few guys... that's out in a field, YMMV. ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
BTW, do you have an infrared thermometer gun? It would be handy to have and to take a bunch or readings (different parts of the radiator, expansion tank, front and back of the head, etc.).
Also, do you have a set of these?
![](http://www.harborfreight.com/media/catalog/product/cache/1/image/370x/9df78eab33525d08d6e5fb8d27136e95/i/m/image_1505.jpg)
I was thinking, when the engine's hot, and you open the expansion tank cap, you get hot coolant rushing into it. You can clamp off the large hose the the expansion tank, open the cap and make sure you're getting flow through that lower, small hose (#32 was it?)
Since your expansion tank is cold, could there be some blockage in one of those hoses?
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
BTW, do you have an infrared thermometer gun? It would be handy to have and to take a bunch or readings (different parts of the radiator, expansion tank, front and back of the head, etc.).
Also, do you have a set of these?
![](http://www.harborfreight.com/media/catalog/product/cache/1/image/370x/9df78eab33525d08d6e5fb8d27136e95/i/m/image_1505.jpg)
I was thinking, when the engine's hot, and you open the expansion tank cap, you get hot coolant rushing into it. You can clamp off the large hose the the expansion tank, open the cap and make sure you're getting flow through that lower, small hose (#32 was it?)
Since your expansion tank is cold, could there be some blockage in one of those hoses?
#33
Race Director
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You may still have air in the system.
Also I have seen new radiators run hot for a time before the break in. Seems like the inside does not transfer heat that well when brand new and they take a few miles before they run really well.
Also I have seen new radiators run hot for a time before the break in. Seems like the inside does not transfer heat that well when brand new and they take a few miles before they run really well.
#34
Rennlist Member
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When I had this problem it was a bad brand new thermostat. Before I installed it, I tested it on the stovetop with a candy thermometer. It was opening way late like around 205F then would close too early around 180F. What's worse is that I didn't believe that a new OE thermostat could be defective, so like the bucket-head that I can be, I installed it only to watch the temps run at the third mark even in cold weather. Popped the old T-stat back in and it ran fine again. Apparently, there is a bad batch of these T-stats floating around. I've heard of people having to get 3-4 of them at the dealership in order to find one that responds properly. Also, check your timing belt tension. You should be able to barely turn the waterpump pulley using the web of your thumb and index finger. If your belt is too loose, it might be slipping on the WP pulley and not circulating well.
--Lizard
--Lizard