Weird radiator fan issue

Weird cooling fan issue

Hello again,
My 2001 jetta tdi alh automatic 309xxx, bone stock car has another issue.
When I replaced the cylinder head with a complete Chinese made head after a so-called injector blew up and grenaded my previous head, I did not have this issue. Anyway, I did the timing and water pump before this too. Replaced the radiator due to a leak and the big radiator fan due to old one seizing up, replaced the green coolant temp sensor, replaced the coolant thermal switch, replaced the fan control module,replaced thermostat twice with OEM, and replaced the coolant overflow cap. I checked the fuse box on top of the battery and replaced it as the 30 amp fuse holder was junk, which fixed the no running fans issue. My issue is that the cluster gauge reads temps of 210*F and a couple times close to 220*F before both rad fans turn on ONLY at low speed. I checked for a bad headgasket with the Lisle diesel headgasket diagnostic kit and that came back okay. Thermostat works. Water pump works too.
I am at a loss on what to do, I am tempted to wire in a switch to manually turn the fans on. Is there a way to use VCDS to change when the fans turn on?
I did find the feature on VCDS that does a battery of checks and the fans do turn run on high speed with key on engine off. Not sure if this has anything to do with it but I did order the cylinder head on eBay from the Hans Auto Parts or otherwise known prothe on eBay. .

Sounds like you have a bad temp sensor or the wrong sensor, I know it's new but may be a new faulty one. Use a temp gun and see what it's actually temping at and go from there.



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Confirm the actual temp with a meat thermometer in the tank while it's running

I have replaced the temp sensor with the correct one. Got oem number off idparts and bought off Amazon.

Will need to verify temp at the flange where temp sensor is located and the overflow bottle.

So you put a chinese (prothe) head and an Amazon chinese temp sensor on your car? What could go wrong?

@Tdijarhead
Not sure where you got the chinese temp sensor miscommunication but it is oem. All the parts I buy are oem minus the head. I'm not spending over a grand on a new stripped head on a car worth $1500 tops, that would end up being chinese made anyways, it is only a quick change of branding. And who knows if used is even straight, it'd cost the over a grand by the time a used head has been gone through at a machine shop.

And the chinese (prothe) head is identical to oem... just said China on the side.
Pretty sure oem is made in China anyway, like 99% of everything for mk4 to present VWs.

I wouldn't be in this predicament if that dang so called "rebuilt" injector did not blow up and grenade my oem head.

Not trying to sound like a dick or anything just trying to clear up and misunderstanding and and make some plausible points.
I've owned three mk4 jetta's still got the first one, second got rear ended, this jetta (third) is the only one to cause me so many issues. I do not want to do a hack job but I am at the end and want to wire in a switch to the fans.

Did you search “prothe” on this website. If not please do so, just type prothe into the search box. Or here is a thread dedicated to that infamous purveyor of quality (sarcasm) vw parts.


http://forums.tdiclub.com/showthread.php?t=320500&highlight=Prothe


No heads are not made in China...yet, at least the ones that are offered by the trusted vendors that frequent this site. Maybe they never will be (we can hope) in light of what’s going on in the world now.

If you bought the temp sensor off amazon, then it was likely chinese made despite the oem description. If you went to idparts to get a part number why didn’t you just order it from them? Cheap substandard parts are a known problem in properly maintaining these cars.

Quality parts are an absolute necessity for these cars. It sounds like you’ve amassed a number of questionable parts on your car. I know you probably don’t want to hear it but I would pull that head and send it for recycling today.

Call frank06 and get a new/rebuilt head of unquestioned quality and redo the timing belt and all the rollers and bolts because I’ll bet those came from prothe also. Then slowly replace the other prothe/rothenbacher parts that may be on your car.