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I been replacing A/C compressors on my STS for the past 4 months....

The first two installed locked up on me????? .......... as a result the car was running kind of hot.....

However I discovered that I also needed a new radiator thought this was the problem.... I had it replaced... the water pump has been recently replaced, as well as thermostat....

I also replaced it with a third A/C compressor which seems to be working fine...

Today was the first day i was really driving it all day with A/C on....I drove it this morning about 30 miles with A/C on in 104 degree weather coolant temperature didn't go past 225... mostly stayed at 223 degrees F... so the cooling system is working fine.......

i live in Phoenix Arizona it gets crazy hot here lol

however, in mid day in moderate traffic temperatures hit 110 degrees accordin to external temp in climate contrl....and my coolant temp hit 234Degrees after driving for about 20 mins or so with a/c on ...i shut off the A/C and temperature dropped to 228 in about a minute.... should i be worrying ????? about the coolannt temp??

i'm kind of paranoid since i recently replaced the engine and my old engine had blown out gaskets due to overheating....

Also my a/c blows cold but only through defroster and feet ....also rear vent... but not the front vents....is this a programing error?????????
 

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White Diamond '03 DHS (with DTS floor shift)
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The vent problem is a vacuum leak. Start with the parking brake release diaphragm and work your way back.

Many things could cause the higher engine temps. Check the cap, purge line & cooling fans. Have the coolant tested for exhaust gases.
 

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I spoke with a Dealership service technician he said on a hot day here 232 degrees on those type of cars is not bad sitting though not moving...... I had the whole cooling system inspected nothing leaks is fine.............. the cap is working fine too....and fans are both good.....


I honestly think it may be another faulty compressor that tends to want to lock up a bit from time to time and heats up the engine a couple of degrees above normal.....???????? because the car runs below 220 degreees with no a/c......

I dont know....
 

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White Diamond '03 DHS (with DTS floor shift)
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I suppose those temps are probably normal in the ambient temperatures you mentioned.

Are you using new A/C Delco compressors?
 

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IVANQ, I also live in Phoenix so I understand your concerns about the cooling system. Sorry to hear that you've gone thru so many compressors...as Ranger suggests, AC Delco is better than the rebuilts from Mexico - hopefully your next one is a keeper. I wanted to add something that might be helpful about your vents not working. I had a similar problem with my SLS during accelerations where the vents would "drop out" and then at stops, come back online. I found the problem: under the right front wheel well (you may have to jack up the front) there is a vacuum reservoir made of black plastic that looks like a cylinder with hemispheric ends. There is a nipple on it that has a rubber vacuum hose (short, less than a foot) that connects to a plastic line that eventually controls the vent dampers. Heat, battery acid spill and road-splash can deteriorate that vacuum line allowing leaks in the system. I replaced mine (Checker Auto parts sells it by the length) and my problem was solved. The dealer wanted $100 to do it! Maybe that's all you need to do - it's a simple fix.
Did you get the process for changing the compressor on this forum? If you have it anywhere, I'd appreciate a link to it. Hopefully, mine holds out as it was replaced 5 years ago too.
 

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Discussion Starter #6
yeah but any temps above 230 running worries me........

thats the thing the compressors are refurbished.... they come with one year warranty exchange only so i haven't been wanting to just throw away 200 dollars and invest in a new one....
 

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IVANQ, I also live in Phoenix so I understand your concerns about the cooling system. Sorry to hear that you've gone thru so many compressors...as Ranger suggests, AC Delco is better than the rebuilts from Mexico - hopefully your next one is a keeper. I wanted to add something that might be helpful about your vents not working. I had a similar problem with my SLS during accelerations where the vents would "drop out" and then at stops, come back online. I found the problem: under the right front wheel well (you may have to jack up the front) there is a vacuum reservoir made of black plastic that looks like a cylinder with hemispheric ends. There is a nipple on it that has a rubber vacuum hose (short, less than a foot) that connects to a plastic line that eventually controls the vent dampers. Heat, battery acid spill and road-splash can deteriorate that vacuum line allowing leaks in the system. I replaced mine (Checker Auto parts sells it by the length) and my problem was solved. The dealer wanted $100 to do it! Maybe that's all you need to do - it's a simple fix.
Did you get the process for changing the compressor on this forum? If you have it anywhere, I'd appreciate a link to it. Hopefully, mine holds out as it was replaced 5 years ago too.

what does ur SLS coolant temperature usually sit at during this time of year with the a/c on????
 

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Since I have the SLS, I don't have a digital readout like the STS. I can say that the temp gauge normally reads "dead center" below 105 outside, and if it's over 110 (like we've had recently), it goes about one needle-width over center. Sorry, that's not precise - but I had a complete coolant flush about a year and 1/2 ago. I still watch it just in case. By the way, for your vent problem...do you hear an occasional noise from the dash almost like a flapping sound before they quit?
Greg
 

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Discussion Starter #9
Since I have the SLS, I don't have a digital readout like the STS. I can say that the temp gauge normally reads "dead center" below 105 outside, and if it's over 110 (like we've had recently), it goes about one needle-width over center. Sorry, that's not precise - but I had a complete coolant flush about a year and 1/2 ago. I still watch it just in case. By the way, for your vent problem...do you hear an occasional noise from the dash almost like a flapping sound before they quit?
Greg
ohhh thats right sls don't have digital.... sounds like it just above 200 degrees ..... yeah the compressors i been dealing with all come from checkers and are refurbished which i been hearing more and more there garbage.....

as for the vent problem the ac blows good just out of the defroster and feet and nothing at all comes out from the front vents doesnt matter if its stopped or running...... except for the rear vents which works perfectly....

and i really havent noticed any flapping noice or haven't listened for it... ill definitely take a look underneath though...
 

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The rear A/C vents don't work on vacuum so they should be OK. Sorry to hear about the Checker's bad compressors...I will steer clear of them, but I've had good luck on other parts from them. You may have a complete vacuum loss to that venting system in front. I think the default is heater and possibly defrost. Check that reservoir for a bad hose - I think it's directly under the battery area.
 

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Defrost is the default mode. You have a vacuum leak. Does your parking brake release when you put the car in gear?
 

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Discussion Starter #12
Defrost is the default mode. You have a vacuum leak. Does your parking brake release when you put the car in gear?

i was testing out the parking break and checking out the coolant temp...

of course the parking break wasn't releasing so it was a definite vacum leak.... i poked my head by the reservoir area and there was a hissing sound it was comming from a small hose...... it was disconnected i immediately plugged it in and right away the front vents were blowing cold air!!! problem solved....

the coolant temp dropped down to 216 from 223 degrees immediately after and ac had been blowin for good 10 mins.... i thought everythin be fixed i walk inside come back and is hitting 226 .... 228.... all the way to 232 the car is sitting though....so i turn off the ac and it sits at 232 and doesnt come down.....

however i was checking out the big hose that wraps around right above the water pump agaisnt the radiator and it wasnt as hot as i expected and it was soft.....from past experiences of high temperatures shouldnt that hose be real stiff at higher temperatures???? or am i wrong???
 

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IVANQ, glad to hear that at least one problem was solved. Keep an eye on that reservoir hose as they do wear out being exposed to weather and heat (from under the car). As for your coolant issue, is the belt on the water pump tight and operating correctly? I don't recall if you said it was replaced - it's under a protective housing.
 

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Discussion Starter #14
IVANQ, glad to hear that at least one problem was solved. Keep an eye on that reservoir hose as they do wear out being exposed to weather and heat (from under the car). As for your coolant issue, is the belt on the water pump tight and operating correctly? I don't recall if you said it was replaced - it's under a protective housing.
Belt on the water pump hmmmm it seems to be working correctly no i never replcaced that belt ill take a look at it though.... thx
 
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