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97, 97, RIP 98, 99 STS with Jakes studs
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Discussion Starter #1
So my 99 is having some issues. About to roll 300,000 kn's. HG's done when it was around 150k.

3 rads, water pump seal, 2 pairs of used rear shocks (2 more going in this spring), 2 used compressors, 1 used strut, (2 NEW used struts ((20k on them)) going in this spring), one coil that went dead, cat is cooked but is "tricked" into being good :cool2:

Started noticing cold air with the heat on, and rising temps at idle. Temps would drop and heat would blow with a bit of RPM.

So i got to digging, and i remembered:

Shortly after the engine was done, i capped off what i *thought* was the purge line. It was the metal line that goes across the front valve cover, into the alternator, and into the rad. Well, the line did not line up properly with the spout on the alternator, and the few-inch long rubber piece was bent and crimped. No ammount of bending could get it straight. So i plugged the line at the rad, and the line at the end of the valve cover. No issues for 3-4 years that its been until now.

I notice that line is different from the older models i was used to. I have flow at the nipple in the resevoir, but i see that line comes from near the TB. I think i should try again and put it together properly. I dont think im remembering correctly what i looked at, its minus 20 out and i need to check again.... I checked out my 2001 and it doesnt have the long metal line above the valve cover.

So: if it comes from the rad, through the alt, into resevoir, i dont see this purging any air? I think the spout on the rad is less than 1/2 way up from the bottom. Doesnt seem ideal, so maybe im wrong. I can only guess i have air in my heater core. There is no shortage of coolant, ive checked multiple times and its dead on the line at cold. I also did the thermostat when i did the WP seal, with nipple up at 180. Nothing has been touched since last summer. Just this last week or 2 started blowing cold air.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,453 Posts
Re: Purge line - with coooled alternator?>?

Your alternator was 'water-cooled'. That has nothing to do with the purge line for your car - it runs from the hollow bolt/nipple at the water pump cover area, through the throttlebody heater circuit, over to the top side of the surge tank. That line MUST flow a constant, steady stream of coolant any time the engine is running.

If the throttlebody coolant circuit is clogged it is perfectly OK - and better - to simply bypass it, using a length of proper sized reinforced rubber fuel line direct from the hollow bolt/nipple to the surge tank side nipple.

If you defeat the purge system you have BIG troubles.
 

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Registered
97, 97, RIP 98, 99 STS with Jakes studs
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718 Posts
Discussion Starter #4 (Edited)
Re: Purge line - with coooled alternator?>?

good info, and thanks. Ill take a look and also be sure there is actual flow. No issue doing the bypass, ill take a look at that too. Its just so cold out, very painful, i hate doing this in the winter. Hope this fixes it.

EDIT:

aaaaaaaaaand i pulled the line from the tank, dry and plugged solid.

Edit2:

Hmmm. Car is still pretty cold, needle is only 1/4 way to half, but no flow from the hollow bolt on the crossover. I moved the line direct from that bolt to the resevoir for now. TB is bypassed.
 

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White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
Re: Purge line - with coooled alternator?>?

aaaaaaaaaand i pulled the line from the tank, dry and plugged solid.
That is good news. You may have one of the few '99's that has an overheating problem that is not a bad HG. Count your blessings and make an offering to the Northstar Gods.
 

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97, 97, RIP 98, 99 STS with Jakes studs
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718 Posts
Discussion Starter #6
Re: Purge line - with coooled alternator?>?

This engine was studded around 4 years ago.

I just shoved a spike through the center of the bolt and cleared the blockage. Fired it up and its flowing now.

Thanks for the help guys :) Hope the heat stays hot now.
 

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'98 STS (RIP @ 206,xxx miles)
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4,854 Posts
Re: Purge line - with coooled alternator?>?

....I just shoved a spike through the center of the bolt and cleared the blockage. Fired it up and its flowing now.
Do not be surprised if the problem returns. Next time remove the hollow bolt to clean out the blockage instead of poking the material into the cooling system where it is almost certain to plug the hole again.

You will need a 15mm deep socket to remove the hollow bolt.
 

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97, 97, RIP 98, 99 STS with Jakes studs
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718 Posts
Discussion Starter #8
Re: Purge line - with coooled alternator?>?

yes im farmiliar with it now. I just hadnt done any actual engine work since last spring. Nobody wants to fix these cars up here any more :p I still buy a couple here and there but refuse to touch anything with any signs of rust now.

Anyhow, issue seems fixed. idled at the bank for a while, temp stayed 12oclock and had consistent heat.

Looks like i should remove the wp cover and do a cleaning inside too.
 
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