GRRR - Can't fix overheating problem :(

[rauldejesus]

Man, I'm so fustrated.

My girlfriend's 1998 2.0 Beetle was overheating, I know the beetle was due for a water pump change due to milage but there was pressure on the upper and lower radiator hose so I figured her problem was not the water pump.

I replaced the thermostat but the car was still overheating. I noticed that the fans didn't spin. The fans did spin when the AC was on. I changed the fuses on top of the battery and noticed a badly burnt fuse.

I replaced the fuse and the fans started spinning! I thought the problem was fixed, I didn't have problems for 2 days but then I got a call from my girlfriend because her battery was dead. It seems that the radiator fan spun all day while she was at work.

I replaced the radiator fan switch located on the bottom of the radiator. I thought that would fix the problem but today the fans refused to spin, it only spun when the AC was on. I could not make the fans work again w/o AC being turned on. This resulted in the car overheating again, I knew it was overheating because the red temp guage was blinking.

I'm at a loss, I don't know what else to do, I'm tired of replacing parts only to find out that the parts I replaced were not broken.

The only last thing I can think of is the "radiator fan relay box" under the car batter. I don't know what that part is called so I don't know how much it would cost to replace.

Does anybody have any other ideas? Does anybody have any other troubleshooting they would like me to perform?

PS. When I was taking out the old fan switch as soon as the connector was removed from the fan switch the radiator fans started spinning, I figured this was a "fail on" feature. I quickly unplugged the battery so my fingers would get chopped off. When the new fan switch was put in place and all connectors replaced the fan won't come on, even when the connector was not connected to the fan switch.

Please help, I'm really desperate.

[blue'99]

If the overflow tank is low the red temp warning will glow, even with a cold engine! Earl

[lucian]

Same problem on my 99 (60000 miles). The dealer replaced the water pump.

[rauldejesus]

It was just wierd that the car didn't overheat last week when the fan was spinning. The only problem was the fan didn't stop spinning when the car was cool, so I replaced the fan switch thinking that would fix the problem but now I can't get the fan to spin.

I agree, the pressure could be the steam pressure. I did my best to burp the system when the fan switch was replaced (lots of fluid spilled out). I thought maybe the steam prevented proper temp readings for the fan switch but I have a blister on my finger to prove that the fan switch was indeed hot

I might test the impellers. For now I'm going to test by driving with the AC on, so the radiator fan will keep spinning.

raul

[Metal Man]

If you take the small hose off of the top of the overflow bottle and rev the engine the coolant should piss out good and strong if the pump is good.

[rcy]

Did you check the fuse on top of the battery again? You might also have to replace the whole fuse box if it was damaged when the fuse melted. Or it's possible the fuse blew again, indicated something else causing the fuse to blow.

[jrgrey14]

Hey i had this happen and i know what the issue is!!!

Replace the water pump!!!

The turbine inside the pump is plastic and one of your fins broke off and took out the thermostat, so no matter how many times you replace the thermostat, the issue will come right back!!! so there is the answer!!

[Jpleau]

I had the EXACT same problem as you. When I brought it in to my local VW dealer they said it was probably the water pump ("and while we are in there, you might as well repalce the timing belt"). $1000 later, I had the exact same problem.

I looked around on my own and found the same fuse completly blown and melted. My mechanic friend installed a 30AMP in-line fuse and went around the fuse box. Now the fan works perfect. When the engine gets hot, the fans come on just like they are supposed to. If only my VW dealer had a clue.

Jpleau

[set]

It's the water pump..Same thing happened to me. Change the timing belt also.

[lukeca]

Well I have to agree with checking the fuses above the battery again, when mine were badly melted I replaced just the fuse and had that same issue where the fans would not stop spinning after the car was shut off. I bypassed that fuse with a new fuse holder I bought from autozone and I haven't had any trouble since.

Here is an image of how to bypass the fuse:


It was pulled from this post:
http://forums.newbeetle.org/showthre...5&pagenumber=7

[99beho]

I have the same problem with my daughters 99 2.0, the fans will not come on, the WP is new, the fuses are good, the only thing that I have not replaced is the temp sensor, I ordered one, it has a green top, but is not the right one, four pins that are to small. Is the temp sensor on the right sde of the motor in a tube, is it the forward or aft sensor on the tube? Driving me nuts...help!!!!!

[D2Beetle]

Originally Posted by rauldejesus

Man, I'm so fustrated.

... Does anybody have any other ideas? Does anybody have any other troubleshooting they would like me to perform? ...

Please help, I'm really desperate.

I am understand your frustration, as I to have 1 98 2.0 NB, it would work for a day, then over heat, on other days it would overheat just minutes after starting.

Ok, I had the same problem, except for me only one fan would come on, briefly and then go off. I bought a maintenance book and decided to solve the problem myself; after replacing all temperature sensors, control modules and thermostat.

There was only one thing left (actually two) the water pump; so I took it to my local mechanic and he changed the water pump, timing belt and associated parts; the problem was solved.

I had the plastic impeller, the mechanic showed me the pieces and what he said was that the plastic blades were breaking off in small pieces and interfering with the thermostat affecting its operation; at some point the plastic impeller snapped of completely. I do not remember how much I spent doing my own work, but it was several hundred dollars. I considered it a proactive approach to car maintenance.

Don't be stubborn about it, change the water pump and timing belt. You'll be happier...

On a secondary note; I to have a melted 30 amp fuse, however, if you have voltage (continuity) on both sides it’s not the fuse.

[99beho]

I changed the water pump, but still have the problem, I guess it is off to change the sensors.

[D2Beetle]

Originally Posted by 99beho

I changed the water pump, but still have the problem, I guess it is off to change the sensors.

What about the timing belt and its associated parts?

[99beho]

Actually the PO changed the WP, I have the old one in a box, I doubt that the timing belt was changed, but why would that effect the fans coming on? I could see the WP effecting flow, but my car does not get hot unless I stop and go, as long as the A/C is on making the fans turn. I am checking the sensors and relay first.

[D2Beetle]

Originally Posted by 99beho

Actually the PO changed the WP, I have the old one in a box, I doubt that the timing belt was changed, but why would that effect the fans coming on?

I doubt there is a direct correlation between the timing belt and the fans; change all the sensors, I think there are three of them. At least you'll solve it through process of elimination; that's what the end result was for me.

FYI - Something to consider: My wife had a Subaru GL (mid 80's) and for (as it appeared to us) no apparent reason, it would just overheat. Despite the many trips to the dealer (who wanted to take the motor apart at my cost) the problem was never resolved. A few months after we sold the car we got a recall notice in the mail from Subaru regarding a defective timing belt.

So, apparently there can be an indirect cause and effect between overheating engines and timing belts.

[99beho]

The other thing that may or may not be a player, I'm almost sure that the PO did not use G12 anti-freeze, this would not effect the fan, but it could effect the heat.

What should I pay for a coolant temp sensor and where do listers buy their parts from?

Thanks for the info!

Randy

[D2Beetle]

Originally Posted by 99beho

The other thing that may or may not be a player, I'm almost sure that the PO did not use G12 anti-freeze, this would not effect the fan, but it could effect the heat.

What should I pay for a coolant temp sensor and where do listers buy their parts from?

I do know the owners manual does warns against using and/or mixing an incorrect coolant type. Not certain what the outcome would be in either case if you did not follow those instructions.

I got all of my parts from the dealer and I do not remember specific prices, as it was a few years ago; however the only part I remember making a fuss about was the control module that is in the lower left front, at the bottom corner of the radiator.

[99beho]

Got it fixed. It ended up being the coolant temp sensor, it was the original. Mine was the blue topped not the green, the green would not work, different wiring. Glad to have it fixed!

[ResidentEvil]

Originally Posted by 99beho

Got it fixed. It ended up being the coolant temp sensor, it was the original. Mine was the blue topped not the green, the green would not work, different wiring. Glad to have it fixed!

How much and where did u get your sensor from.?..and did u install it yourself?
Where is the sensor located on the car?
Ive got the same problem