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Why is my car overheating?

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Old Aug 10, 2009 | 08:10 PM
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Default Why is my car overheating?

I have an 02 z28 a4 with 49,000 miles. I daily drive it and sometimes when I am on the freeway with the A/C on my temp. gauge starts rising and I'm just cruising, not flooring it! I have checked to see if I had coolant and I do. What else could be the problem? THANKS
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Old Aug 10, 2009 | 09:08 PM
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make sure your radiator/condensor passage is clear of debris. good to wash out though each side with a garden hose/pressure washer. does it happen with a/c off?
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Old Aug 10, 2009 | 10:30 PM
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yeah a dirty condenser is most likely your problem if it only happens with the a/c on
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Old Aug 11, 2009 | 12:31 AM
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Originally Posted by lakefx7
make sure your radiator/condensor passage is clear of debris. good to wash out though each side with a garden hose/pressure washer. does it happen with a/c off?
Alright I'll try that. And i don't recall it happening with the a/c off. It may have happened once, not sure though.
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Old Aug 11, 2009 | 09:16 AM
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If you use a pressure washer on the condenser your a ******* idiot.

The fins on the condensor are very fine and will bend when using a garden hose on them if not done correctly.

Take off the lid and the big black pastic cover under it and you can easily get to the back of the rad. Hose out the radiator/condenser and go under the front to hose out the rest of the condenser.
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Old Aug 11, 2009 | 10:44 AM
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What do you consider temp gauge raising. What temp are you actually running at with the A/C on vs Off
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Old Aug 11, 2009 | 07:56 PM
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Originally Posted by TooLateVTEC
If you use a pressure washer on the condenser your a ******* idiot.

The fins on the condensor are very fine and will bend when using a garden hose on them if not done correctly.

Take off the lid and the big black pastic cover under it and you can easily get to the back of the rad. Hose out the radiator/condenser and go under the front to hose out the rest of the condenser.
I use pressure washers to do this at work (gm shop) we use lower pressure tips. if you think a garden hose pressure could bend the fins you are beyond a ******* idiot. i have seen colllisions where core supports have bent the radiator/ condensor in a 15 degree v and they still dont leak, but you are much smarter so ill shut up.
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Old Aug 12, 2009 | 08:12 AM
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Put a 160 stat in it
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Old Aug 12, 2009 | 09:54 AM
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check and make sure that both fans are kicking on
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Old Aug 12, 2009 | 11:29 PM
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Originally Posted by joshctr1
Put a 160 stat in it
^^^ Won't do a damn thing if it's overheating on the highway. Really doesn't do much at all...


The first thing to check would be just make sure you don't have crap all in your radiator. You might also check and make sure the little plastic splitter deal is still under the car. A buddy of mine took his off after he cracked it, and his car would run 20-30 degrees hotter without it.
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Old Aug 13, 2009 | 10:06 AM
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Originally Posted by lakefx7
I use pressure washers to do this at work (gm shop) we use lower pressure tips. if you think a garden hose pressure could bend the fins you are beyond a ******* idiot. i have seen colllisions where core supports have bent the radiator/ condensor in a 15 degree v and they still dont leak, but you are much smarter so ill shut up.
Well maybe you might want to include that important point next time wise guy.

All it takes is for someone that doesnt know any better, to do a search find your post and think its ok to blast the condenser with 1500psi and close that bitch up tighter than a ticks ***. Then come back on here and ask why his A/C isnt cold anymore.
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Old Aug 15, 2009 | 09:17 PM
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could bad lifters have anything to do with it?
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Old Aug 16, 2009 | 06:36 AM
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Make sure your fan's are turning on when the AC is on, you might have a messed up fan relay if they don't turn on
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Old Aug 17, 2009 | 01:56 PM
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Originally Posted by mook99ta
What do you consider temp gauge raising. What temp are you actually running at with the A/C on vs Off

Sorry its been awhile but when the a/c is OFF and windows down its around 210 sometimes a lil above then goes back down. When a/c is ON it starts at 210 then when im on the freeway for while it starts raising to the 3/4 mark and sometimes past it towards the red! So calculations would be around 235-250.
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Old Aug 17, 2009 | 01:58 PM
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Originally Posted by jimbo98z
^^^ Won't do a damn thing if it's overheating on the highway. Really doesn't do much at all...


The first thing to check would be just make sure you don't have crap all in your radiator. You might also check and make sure the little plastic splitter deal is still under the car. A buddy of mine took his off after he cracked it, and his car would run 20-30 degrees hotter without it.

The plastic splitter? You mean the black clearance deal?
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Old Aug 17, 2009 | 02:04 PM
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Originally Posted by mlbz28
Sorry its been awhile but when the a/c is OFF and windows down its around 210 sometimes a lil above then goes back down. When a/c is ON it starts at 210 then when im on the freeway for while it starts raising to the 3/4 mark and sometimes past it towards the red! So calculations would be around 235-250.
If you're not overheating in the city.....your probolem is not a dirty condensor. Your problem is airflow at mid to high, constant rpm's.

Either your front lower air dam is gone, bent, messed up or you have something thats blocking your airflow through the condensor and/or the radiator.

On the highway...your fans should not come on. The lower air dam does all the cooling needed while cruising.

Do you overheat....during stop and go city driving...while using A/C?



.
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Old Aug 17, 2009 | 02:41 PM
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Originally Posted by LS6427
If you're not overheating in the city.....your probolem is not a dirty condensor. Your problem is airflow at mid to high, constant rpm's.

Either your front lower air dam is gone, bent, messed up or you have something thats blocking your airflow through the condensor and/or the radiator.

On the highway...your fans should not come on. The lower air dam does all the cooling needed while cruising.

Do you overheat....during stop and go city driving...while using A/C?



.
No it does not overheat during stop and go city driving while using a/c.
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Old Aug 17, 2009 | 03:10 PM
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Originally Posted by mlbz28
No it does not overheat during stop and go city driving while using a/c.
Then check the lower front air dam, make sure its not only in perfect physical condition....but make sure it does not push backwards much at all. Its not very flexible, it should not move that much. Just bends a little bit.

People have parked right up close to those cement parking logs and the lower air dam has sat bent all the way back for hours, or even days. That screws it up because then its pushed way back and the air flow up into the condensor is killed.

Make sure all the rivets/bolts are there holding it on.

.
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Old Aug 17, 2009 | 09:50 PM
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Originally Posted by LS6427
Then check the lower front air dam, make sure its not only in perfect physical condition....but make sure it does not push backwards much at all. Its not very flexible, it should not move that much. Just bends a little bit.

People have parked right up close to those cement parking logs and the lower air dam has sat bent all the way back for hours, or even days. That screws it up because then its pushed way back and the air flow up into the condensor is killed.

Make sure all the rivets/bolts are there holding it on.

.
Ooooohhh man i took mine off cuz i thought it was just a clearance precaution, and i thought it looked kind of tacky! Well i guess its going bak on. Ill see wat happens! THANK YOU!
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Old Aug 17, 2009 | 10:04 PM
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Originally Posted by mlbz28
Ooooohhh man i took mine off cuz i thought it was just a clearance precaution, and i thought it looked kind of tacky! Well i guess its going bak on. Ill see wat happens! THANK YOU!
Holy ****, thats funny.

Air dam cools at cruise speeds

Fans cool at low speeds and stop and go driving


Do not remove stuff


.
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