Auto Mechanic help please

[Big Cliff]

One of the young students staying with us for the winter and going to college here in Lindsay has a 1998 Jetta GL, 2L.

 

He is not getting hot air from the heater, I think it might be the thermostat but apperently it isn't too easy to change on these (I've never tried on a jetta so I don't know).

 

The Temperature gauge only comes up to about 30%

 

When the heater fan is turned off the Temperature gauge does move up to about the normal position (about 50%).

 

As with most students today, he is tight for cash so I'd like to try and help him fix it here if we can.

 

Thoughts/suggestions/ideas please.

[BillM]

Thermostat for sure.. You'll need to get the car in the air and remove the PS power, after that that T-stat is accessible. More of a pain in the ass job than anything else, not very difficult.

 

http://www.youtube.com/watch?v=fG1tcauAGFc

[Big Cliff]

Thanks Bill, you are right, it does look like a bit of a PITA job LOL. Well, guess what I am going to be doing today! Would be nice if I had a heated shop I could pull it into but it won't fit in my little shop.

[Terry]

Piece of cardboard in front of the rad

[4x4bassin]

Sounds like a thermostat but make sure the rad is topped up with antifreeze. If it is low this could be the problem as well.

[Big Cliff]

Piece of cardboard in front of the rad

That was what we did when I was growing up LOL, It sure would be a lot easier than crawling around on the ground under the car.

[Big Cliff]

Sounds like a thermostat but make sure the rad is topped up with antifreeze. If it is low this could be the problem as well.

Thanks! We did check it and it seemed fine.

[Renegade67]

Sounds more like the flap in the heater box is stuck closed;

 

Is there a strange noise from inside the dash?

 

My guess would be he needs to replace the small electric motor that moves the air recirculation flap.

[DanD]

It's not much help; but here's an exploded view of the water pump, pump housing and thermostat.

The cardboard thing will probably work; but make sure you beat it into his head to watch his temp gauge.

 

Just to add; if you get that engine running at its proper temperature, his fuel mileage will go up considerably.

 

Dan.

Edited November 26, 2013 by DanD

[Big Cliff]

Sounds more like the flap in the heater box is stuck closed;

 

Is there a strange noise from inside the dash?

 

My guess would be he needs to replace the small electric motor that moves the air recirculation flap.

 

No strange noise from under the dash. Would that cause his engine temperature to run cold then warm up when the heater fan is turned off?

It's not much help; but here's an exploded view of the water pump, pump housing and thermostat.

The cardboard thing will probably work; but make sure you beat it into his head to watch his temp gauge.

 

Just to add; if you get that engine running at its proper temperature, his fuel mileage will go up considerably.

 

Dan.

Thanks Dan, while the cardboard thing seems like a good idea for a quick fix, I think I'll just help him change the thermostat and have it done properly.

[Raf]

what stupid stupid place to put the thermostat.

 

what happened to up top where it is easy to get at?

 

it's propably the original in there too.

[Big Cliff]

what stupid stupid place to put the thermostat.

 

what happened to up top where it is easy to get at?

 

it's propably the original in there too.

I remember the old days, lift the hood, undo two bolts, replace thermostat and you were on the road again in 10 minutes. And yes it is probably the original still in there, I am going to head into town shortly to pick up a new thermostat and gasket, hopfully it will all be done by mid afternoon.

[Raf]

just be careful when you put it back on not to over tighten the bolts, it's likely an aluminum housing that you don't want to crack. (7 ft lb is not a lot)

Edited November 26, 2013 by Raf

[DanD]

It called reverse coolant flow; many of the manufacturers are doing this now. It supposedly helps get the engine up to temp faster and it also stabilizes the coolant temp faster. With the thermostat on the bottom, the rad is allowed to get warm coolant before the stat opens. So when the thermostat does begin to open it won't slam shut again by cold coolant in the rad.

It all about emissions and getting everything up to temp and keeping it there as fast as possible.

 

Dan

[Big Cliff]

just be careful when you put it back on not to over tighten the bolts, it's likely an aluminum housing that you don't want to crack. (7 ft lb is not a lot)

Thanks! Have torque wrench and I will use it!

[Big Cliff]

It called reverse coolant flow; many of the manufacturers are doing this now. It supposedly helps get the engine up to temp faster and it also stabilizes the coolant temp faster. With the thermostat on the bottom, the rad is allowed to get warm coolant before the stat opens. So when the thermostat does begin to open it won't slam shut again by cold coolant in the rad.

It all about emissions and getting everything up to temp and keeping it there as fast as possible.

 

Dan

Learn something new every day! Thanks!