[flash]

acck - you were typing at the same time i was editing

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[968TDG]

Ok, so I need to put some effort into figuring out if both fans work at both speeds. The engine was hot when I was bleeding it, I'm not sure if it was above the thermostat operating point or not, what is the best way to tell this? looking at the temperature gauge? I did not thoroughly flush the radiator, I could pull it back out to do so, but it seems like I should look into the fan operation and triple check the bleeding again first.

Is it possible that the new thermostat is opening too late? Would this explain the symptoms, or would it not make sense that it cools down as soon as i start driving?

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[flash]

the thermostat point for a stock temp thermostat (182 F or so) should be just above the 8 o'clock line, which represents 176 degrees F - i would make sure it is well above that point before bleeding

it is very possible for the thermostat to be late - they vary a lot - i always check mine prior to installation

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[968TDG]

Do you see any down side to going to a 160 degree Thermostat as Pete suggested in one of the forums, other than slower warm up time? Is there any real danger in this?

Also, in another forum, someone mentioned replacing the fan relays with a VW relay (something that apparently you had suggested). Would you suggest doing this as well?

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[flash]

i opted not to change the thermostat setting - i don't have a problem there, and was worried about heat soak in our climate causing it to run hotter on hot days

i am running the vanagon lower temp switch - it did lower the overall running temps

i still have a bit more variance than i want, but i think it is related to something else that i am currently working on - i may yet switch to the lower thermostat though

after i make another change, i may have more information on this

sorry that wasn't a definitive answer

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[968TDG]

Alright, so I just did a little bit of observation. Here's what happened:

-I turned on the car, waited for it to heat up.
-While waiting, I checked the radiator tubes with an infrared temp sensor, and measured the top tube heat up to 170 F while the lower was staying at 75 F.
-As the gauge reached the 8 o'clock tick, the lower tube heated up fairly rapidly to 140. The fans did not come on.
-I drove the car around the block to heat it up and get the fans blowing and also to see if i could get it to warm up above the 9 o'clock mark.
-When driving the gauge stayed right at the 8 o'clock mark, but when I stopped and idled back at my house, it slowly rose to about the 9:30 position. Only when it got this hot did the fans finally come on.

So, the Thermostat seems to work, it cools the engine while the car is moving, but the fans are coming on "late"

Do the temp sensors go bad like this, causing the sensor to switch late?

If so, Flash, your non-definitive answer is actually a definitive answer, so you're right, which happens all too often in my opinion [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]

So I'll try replacing it.

Thanks
Phil

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[flash]

yeah - sounds like the low side of the fan switch is out

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[968TDG]

Hope so, I will get a switch today and try it.

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