Golf IV / Jetta IV :: 2004 1.8T GLI - AC Seems To Be Cycling On And Off Sporadically

Car is a 2004 1.8T GLI. My A/C seems to be cycling on and off sporadically. Some days it will work great and other days it is non existent. For example, this morning I had the A/C blowing ice cold with everything running as it should including the fan. Well now that a couple hours have passed, my A/C is now dead and only blowing hot air in my face as usual. Now, I have had the refrigerant levels checked and refilled twice now by an A/C specialist. He assured that all mechanical aspects of the A/C system are fine and that I might have an electrical problem. With that said, I have gone through a list of possible causes. Here is what I have checked so far.

-All of my fuses including the three on top of the battery have been tested and came out fine.
-Refrigerant levels are within spec (checked for leaks by A/C tech and found nothing. Twice.)
-Both of my fans are working. The small fan engages with either rising temperature or when the A/C decides to work.

As of now it seems that I am not receiving constant power to the compressor as it will engage randomly throughout the day(s) if left on. I have no clue where to look next.

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Golf IV / Jetta IV :: Overheating When Accelerate Hard Or Go Over 50 Mph

I have a 2.0. Custom gt28 turbo project. Been up and running for awhile now. Took it on a 4 hr trip home and drove it back.

All of a sudden after the holidays it started to overheat and I had no heat. It will not overheat when idling. I replaced the thermostat recently. Lower hose gets warm when it opens. I replaced the green top sensor. I have done a wire tuck etc and I am running a closed coolant system. I believe I have gotten the air out of the system.

It will idle all day at 190. But as soon as I drive and accelerate hard or go over 50 mph it overheats and will not cool off unless I pull over and turn the car off. It will steam as if it's losing coolant somewhere but I think it's at the cap (too much pressure?).

I am thinking water pump but I am not sure. I got the car with 124k miles I'm at 127000. I was told timing was done at 90 could the pump be failing already? Also when it overheats I get a cel for misfire is that normal?

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Golf IV / Jetta IV :: VR6 Overheating When Get Stuck In Traffic

My 2002 Jetta VR6 is overheating. The car only overheats when the car is not mobile. If I get stuck in straffic or just let it idle it will over heat. What could it be?

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Golf IV / Jetta IV :: Engine Overheating - No Leakage

Ok I have an automatic 02 gti..the other night as I was driving home it started to overheat And fast..I had to stop about four times to get home so it can cool down a bit..the next morning I went to check for leaks but I didn't have any and my coolant level was good..I turned the car on and let it heat up and I noticed the fan didn't kick on..is the fan not turning on a good sign that it is bad? I ordered a timing belt kit from ecs which came with a new water pump and thermostat but I didn't get to switch everything out in time and now im stuck with a overheated engine..the only thing I did change was the coolant temp. Sensor because it was the easiest thing to change.

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Golf IV / Jetta IV :: Overheating - Fans Not Coming On

As the title says, car is overheating. Car gets to 190F within a couple miles drive. Temperature fluctuates between 190F and 225F.

Water pump was replaced ~2 months ago. Was not overheating prior. Temp reached 190F and stayed. Currently has the "black top" coolant temp sensor.

I noticed the coolant fans are not running after I turn the ignition off. This time of year they would usually be running after turning the engine off. If car is overheated and with AC off the fans do not run while engine is running.

I used the guide below to try diagnosing the cause: [URL] ....

Remember both fans should come on in slow speed any time the key is on and the AC is on - if the temperature is above about 32 F (0 C). Both fans run with key on and AC on

S180 (fuse 8, 30 amps, green plastic, above battery) must be good for slow speed operation.

Fuse and holder look good: no melting, no discoloration.

S164 (fuse 3, 40 amps, metal strip, above battery) must be good for fast speed operation.

fuse looks good: unbroken.

To ensure the AC circuits and the Fan Control Module has power check:

Fuse 5 on the cabin fuse panel.

Fuse 16 on the cabin fuse panel. When this fuse is blown the radiator fans will often run unexpectedly.

Fuse 25 on the cabin fuse panel.

All three fuses look good: unbroken

For the first test of the slow speed fans from the radiator thermoswitch have the key off.....Both fans should run in slow speed.

Passed test: both fans run slow

The second test is for the fast speed fans, key on, AC off.... Both fans should run in fast speed.

Passed test: both fans run fast

If the fans run in the tests above, then you should be good to go. No further tests are needed.

If you have been seeing high coolant temperatures and the fans have not been running, then you may need a new thermoswitch.

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Golf IV / Jetta IV :: 2002 - Overheating When Go For A Drive

So my 2002 Jetta 1.8t is overheating. The water pump was bad. Replaced. The thermostat. Replaced. Radiator. Replaced. Radiator cap. Replaced. We're running out of things to replace! I'm ready to go to a junk yard and get a new block! We've tried about 100 magical "ways to burp it" with no luck. We even tried running it without a thermostat. Without the heater core. EVERYTHING.

The car runs at operating temperature at 4 RPM. But when we take it for a drive, it overheats. There's no heat with the thermostat in unless you rev it at the high RPMs. As for the hoses, top is hot, bottom gets hot. As for the car, it runs beautifully. It gives no codes. No smoke either. Nothing in the oil, nothing in the coolant so I don't think it's the head. It just overheats. This has been FAR too long.

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Golf IV / Jetta IV :: 2002 VW Overheating As Soon As Take It On A Highway

My 2002 VW Jetta GLS 1.8T 5-Speed is over heating

Car is still over heating after replacing the following:

- Head gasket
- Coolant fan module
- Geba Metal Prop Water pump
- Full timing belt kit
- coolant fan switch in Radiator
- Bleed the system of all air blow hot air

So Driving the car around town is ok, doesn't over heat, but as soon as I take it on a highway it over heats. I drove it 50 kms out of the city and it over heated, let it cool down and added water. got it back home. Oil light flashed on as I pulled into driveway, turned it off right away. no external oil leaks. Checked coolant, Oil in coolant. also the coolant was boiling, the level was raising up and lowering. I have been reading the forums for a few hours and the oil in the coolant sounds like the oil cooler gasket. Ok so the fans are running and it still over heats. The old metal propeller water pump was very hard to turn so I replaced it with a Geba Metal water pump. no leaks at water pump. Could it be possible that the Oil cooler was causing air to leak into the cooling system causing the coolant to boil? And then when the oil cooler "o-ring" finally failed it dumped oil into the coolant?

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Golf IV / Jetta IV :: Overheating When At Idle Only On Occasions

1.8 jetta... Seems to do this when at idle only on occasions it goes above 190F. Waterpump was changed about 5k ago so I'm sure its not that. Thermostat still needs to be changed. It seems like if I turn the heat on it stays at 190F.

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Golf IV / Jetta IV :: 1.8t GLI Overheating / Coolant Light On

Mk4 Jetta Gli 1.8t , car was over heating only when sitting 5+ minutes at idle, mechanic said the big fan needed replaced so he replaced it. Car still over heated so i replaced the coolant with G13. It hasn't over heated yet but got in the car this morning and the coolant light started flashing and car was telling me to STOP the car. Checked out the coolant and it was on the low side. What it may be? Leak somewhere? Bad thermostat or water pump gone bad? Timing belt and water pump were done when i bought the car when it had less than 50k miles, car now has 99k miles on it.

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Golf IV / Jetta IV :: 2001 GTI VR6 Overheating - Engine Fan Only Operates With AC On

Engine will overheat unless I turn the AC on. The engine fan only operates with the ac on it seems.

Will not overheat unless in traffic for a while.

Would it be radiator thermo switch or the Fan Control Module?

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Golf IV / Jetta IV :: 2004 - Overheating When Sitting Still Or At Idle

I have a 04 jetta 1.8t that just randomly started having some overheating issues. I just got the car two days ago, and the first day I had it I replaces the coolant temp sensor due to a check engine light. Drove 50 miles and the light shut off. Just yesterday I was sitting in traffic and noticed the temp going above 190 (which it hadn't done in the 200 miles id driven it so far). I brought it home and once I was out of traffic and moving along the temp went right back down to 190. The only time it tries to overheat is when its sitting still or at idle (after reaching operating temp). which is weird.

I was parked in my driveway and let it sit at idle for a few minutes until the temp started significantly rising. i revved it to 2000 rpm (thinking it would rise even more), but to my surprise it instantly went down to 190 again. my big fan isnt running either, but my friend said he doesn't run fans in his and that it shouldn't overheat because of the fan. also, my top hose is warm to the touch, but the bottom isn't. I know your thinking thermostat, but if that was the problem it would :

1: always overheat, or
2: never overheat.

The temp wouldn't fluctuate the way it is.

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Golf IV / Jetta IV :: 1999 - Overheating / Fans Not Running

So my friend, ignoring my advice that this generation seems to be riddled with electrical problems, decided to purchase a seemingly nice 99 Jetta, with a junkyard AEG swapped in(AEG is written on the intake and block like a JY would do). Sun roof doesn't slide back, gets jammed, evidence shows water has built up previously and run down the A-Pillar to the fuse box.

I just got the fans unplugged and verified that the fans with power applied, both have their low/high speeds. The fuses on top of the battery are in-tact, no visible melting, looks like the thing is in ok shape(haven't taken them off to inspect the contacts yet).

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Golf IV / Jetta IV :: Overheating Mainly On Freeway While Having Higher RPMs

I have a 2004 Jetta 1.8t. 160k miles. Bought it recently. It's been overheating on me. Mainly on the freeway while having the RPMs higher than the small streets. I don't see any leaks. I'm not losing any coolant. But I do smell burning coolant. I don't see anything smoking though. I changed out the coolant temp sensor. I have a thermostat but haven't gotten to it yet. Just wanted other opinions before moving on. There is some sort of little motor on the radiator with some coolant hose connected to it. When turning off the car, it stays on and buzzes for a good 10-15 minutes before stopping. I'm not sure if that has anything to do with it. I don't even know what that thing is or called.

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Golf IV / Jetta IV :: 2003 - Overheating / Oil In Expansion Tank

I recently bought a 2003 VW jetta 1.8T with 150,000 miles on it. After the purchase I got about 20 miles down the road and it overheated. I noticed there was oil in the expansion tank. I replaced the head and head gasket on the vehicle. As i was taking everything off I noticed that there was green coolant in the car. WhenI took the head off the pistons were glazed over and a lot of things were charred.

So I cleaned everything and put the new head and gasket on. After everything i cleaned the expansion tank of the oil and put new coolant in. After I drove it around for a little bit and everything seemed fine and there was no oil mixing with coolant. So I left got another 20 miles down the road and it started steaming and the overheated light came on. I checked the engine and there was no oil in the expansion take but the coolant was just pulsing it wasn't a constant flow.

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Golf IV / Jetta IV :: 2002 - Overheating In Traffic - Fans?

So i have a 2002 1.8t that i got in december. Everything has been great so far untill the other day the car overheated on me in traffic. It was a bit warm out maybe 75-80 degrees. I saw the needle start to climb and then the light went on so i through the heat on full blast and it dropped the needle a bit and turned the light off long enough to pull off the highway. I let it cool down and checked things out. I am not low on fluid, an the fluid was changed within the last year with the vw recommended stuff. The radiator hoses are pressurized so i believe that the pump and thermostat are working. I am thinking it could have something to do with my fans. I tested them in my driveway by supplying them with 12v and the spun perfectly. It only happens when the car is standing still for a period of time. Driving at any speed is fine. Is there some sort of switch that tells the fans to turn on?

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Golf IV / Jetta IV :: 2004 - Overheating - Coolant Leak?

My 04' GTI, 24v VR6, all stock, @ 107,000. I had a coolant leak from the t-stat housing. I installed all new housing, seals, and C-Pipe from GruvenParts. Already had a green CT sensor installed and the kit I got didn't come with one, so I didn't change it. Found out the leak was from the t-stat housing o-ring didn't fit the old housing. The new one fits perfect. I put coolant on the seals and burped it. Doesn't leak a drop. But still overheating, all the hoses have pressure and are hot, so no blockage....I noticed the fans were not coming on at all. The fans used to engage every other minute and run for 15 secs on high ONLY. Longer times, if not constantly w/ A/C on. I was wondering how to test the fans, sender, and/or fan control module to see which one of them isn't working. And which pinouts are what?

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Golf IV / Jetta IV :: Overheating / Engine Temp Was Slightly About 190?

So to start off, its 10 degrees here with a -7 degree windchill. With that in mind, I was driving home just now from dropping off a friend, and noticed my engine temp was slightly about 190. Didn't think much of it, but within a mile down the road the temp was crossing the final line before the red 260 degree line. I pulled over and let it get down to 190 (luckily didn't take long) but in the next 3 miles home it rose again, then fell, and then rose again as I drove through my neighborhood. I'm thinking maybe the thermostat is going bad...? There's no way it went from normal operating temp to almost overheating as cold as it is....

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Golf IV / Jetta IV :: Coolant Burning Smell - Car Overheating While Driving

Last night while i was driving my car began to overheat. I could smell coolant burning. I pulled over and opened my hood. The coolant inside the coolant pod was boiling. Some coolant lines were steaming as well. I could also hear a gurgly like noise coming the engine. This is a 1.8t gti

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Golf IV / Jetta IV :: 2000 AWD 1.8t Overheating - One Side Of Coolant Line Hot

After finally getting some issues sorted this weekend (needed a transmission flush) I was driving around a bit to make sure everything was good. On the way back to my house, the car started overheating. I replaced the thermostat this winter (~4-5 months ago) because it was stuck open making things run a little cool.

I was thinking the water pump is probably shot but not 100% sure. the radiator fans both work and when I turn on the heater, it blows hot. Any good way to check if the water pump is dead? I have a little point and shoot infrared thermometer and one side of the coolant line was way hot and the other was fine (cold ~90 deg F).

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