I drove around for a while with my AC always on to keep the fan running before I got to replacing the switch…haha. Then I found out it was just a bad connection to the switch. I hope the car is running well - it looks great from what I’ve seen in pictures!!

@@OlisGarage thanks 😊 oli. Yeah currently had a water leak from the ex owners diy fix . Replaced the water pump too . It’s running great again . Keep your videos coming I enjoy watching them .

That is actually not correct. The thermostat is perfect for the vehicle. Upgrading to a lower temperature is unnecessary. I don’t think it hurts anything, but it’s definitely unnecessary. These cars are not on the verge of overheating. Not trying to be rude, just trying to make sure people don’t think these cars are borderline overheating. Later VWs (I can 100% confirm through 2005-I just dug through the manual) actually used a thermostat which isn’t fully open until 105C or 221F (it starts opening at 85C). That is much hotter than the thermostat in these cars which is fully open at 87C. The radiator fans are similar. The newer VW fans come on at 92-97C or 197-206F. That’s the low speed. The cabriolet radiator fan comes on at 93C. Coolant also doesn’t boil until around 115C or so when it’s under slight pressure and properly mixed. One last tidbit. The coolant temperature gauge in the newer VWs isn’t accurate. It is literally coded to display right in the middle for a whole range of temperatures. This is so that people don’t think their car is overheating when the gauge goes slightly past the middle.

Good luck with the mk2! I need to do a video on timing the engine with a timing light too, just for completeness. But the static method works super well in my (and quite a few people on the internet) experience.

Thank you!

Good point. The other way to check that is to monitor the gauge. If the temperature keeps climbing and the fan doesn’t turn off, then something is wrong with the fan or the wiring.

Have you tested the thermostat in boiling water?

@@OlisGarage yes I have. The thermostat is good and so is the water pump. Just put a new headgasket in 2 days ago (head was decked professionally) timing is mint and she runs like a champ but still over heats. Fan is bypassed and on a switch (i turn it on at aroumd 120f) when I squeeze the bottom hose on radiator it does put flow back into overflow tank. Could it be just reduced flow? The rad is literally the only thing g I haven't replaced yet . It seems to have flow though however the top will be hot and the bottom cold

@@OlisGarage i do not think the thermostat is opening but I'm not understanding why it wouldn't be. It works fine while boiled as does the old one

Oh wow, interesting. Good catch. That would’ve been upsetting if it’s totally dead!

Hello Siener, yes I did! Thank you for that. Sorry I forgot to respond saying thank you..I am not the best with keeping up with everything haha. Hmm. There is a voltage regulator which does matter. Does your fuel gauge indicate properly? I need to review exactly what the voltage regulator feeds power to. Put your engine to top dead center (little dot on the flywheel) and then check the camshaft gear and see if it is at top dead center. There is a little dot which should be in line with the valve cover. Google should reveal some images. I’m currently working on making an in detail timing video, but am not done yet

Hmm. Something is wrong here. Even with no thermostat the car will get hot enough to turn on the fan in maybe 10-20 minutes of running. Are you sure that the coolant system is filled correctly?

Yes I believe it's 60% water 40 % coolant? When I breach the fan it turns on and both the top and bottom pipe gets hot,

I drove 2 hours without my cars needle even going to half when I got to my destination my fan came on, I drove home 2 hours non stop without any overheating issues, a week later I drove about 20 minutes and my car overheated and coolant all ran out the top as it boiled over out of the bottle, I checked my car and noticed the thermostat didn't open it was stuck on closed when I tested it, so I replaced that but they gave me a 82°c thermostat not a 87°c

Replaced the thermo fan switch and its fixed thank you

Gauge randomly going to 0 indicates that the gauge is broken. I have a video on repairing the gauge. I’ll dig a bit about the coolant temp sensors

It certainly is annoying. But hopefully the replacement lasts a long time.

@@OlisGarage keep the video coming. Incidentally I'm trying to get an Air Intake Boot. Besides e bay do you know anyone who might have an NOS part. Thanks in advance

@@walterbutscher8438 try to find the part number and just google. That’s what I do, especially for something that is harder to find. Websites that come to mind: Werk34 might; they’re out of Germany. Or vwheritage. Sometimes busdepot has rubber pieces like that.

@@OlisGarage thanks bud I appreciate it

Year and model? But yes, fan switch. Ac makes the fan come on automatically (even if ac doesn’t work). Then you also have an after run fan switch that makes the fan come on when you shut it off. Mounted on the back side of the valve cover.

@@OlisGarage it’s a 1989 Jetta GL 1.6TD. Think I’ll just replace relay, switch, and fuses anyways. It’s all old and those parts are all cheap. Thanks

Is the thermostat opening at the right temperature? In my thermostat replacement video I show how to test a thermostat in boiling water. Is the fan coming on? Is the radiator clogged? Does the water pump work?