Where is the Thermostat?

**craig_the_german** · 19-06-2010, 06:54 PM

Hi all,

It appears that the thermostat on my 1.6L has stuck open....on these cold days / nights just never gets to 90deg anymore

The question is....where abouts on the engine do I find it? I have read somewhere that on the 1.6 it is a separate housing on the side of the head??????

Can you get an aftermarket thermostat or need to buy the whole housing/unit/whatever?

Thanks

**Speed** · 19-06-2010, 07:26 PM

Here's a quote I copied from google, sure its a 1.8 but same principle being plastic "housing" of a radiator hose.

The thermostat on the 1.8L turbo is in the bottom of the water pump housing. You will need to change it from underneath the car but it is easily accessed and not difficult to change. Removing the splash shield under the radiator will give you clear access to the thermostat housing on the bottom of the water pump and you will have plenty of room to work. Remove the splash shield. Beside the thermostat housing there is a water pump housing drain plug. You can remove that plug to drain the water pump housing if you want to but it really is not necessary and if you remove that water pump drain plug you will need to replace the O-ring seal on it before reinstalling it. It is not even necessary to remove the radiator hose which is connected to the thermostat housing. Just put a drain pan under the thermostat housing and loosen the 2 bolts securing the thermostat housing to the bottom of the water pump housing and then lightly thump the thermostat housing with a hammer to jar it loose from the water pump and allow the coolant to drain into the drain pan until it stops. Then remove the 2 bolts securing the thermostat housing to the bottom of the water pump and drop the thermostat housing. Remove the old thermostat and the old O-ring seal and clean the O-ring seal groove. Place the new O-ring seal in the seal groove and be sure to install the new thermostat with the spring side of the thermostat facing UP INTO THE WATER PUMP HOUSING. And be careful not to over tighten the thermostat housing bolts because they strip easily. I don't have the exact torque specs on those bolts but I expect it would be about 80 to 85 "inch" lbs.

Yes you can buy aftermarket thermostats, thats what I'd do but others may disagree.

**craig_the_german** · 19-06-2010, 07:41 PM

Hi,

I have tracked down part numbers for aftermarket thermostats. I just wanted to make sure that I was pulling the right bit off the engine to change it. I guess if I just follow the top radiator hose back, it should join the engine at the thermostat housing.......or it does on most cars.

**Jmac** · 19-06-2010, 08:18 PM

Originally Posted by Speed

Here's a quote I copied from google, sure its a 1.8 but same principle being plastic "housing" of a radiator hose.

Yes you can buy aftermarket thermostats, thats what I'd do but others may disagree.

Sorry but the 1.8 is different, best to use the correct method of checking parts i.e use your vin number its the DNA of the vehicle even if you have to call VW or an independent with access to a catologue or use the vague VAGCAT. 1.6 if it is AKL will have to have the complete housing replaced which is around $250 from memory. The plastic seat will be broken inside and keeping the stat open and flooding the engine with fuel as the temp sensor will naturally tell the ecu the engine is still cold. So to conclude you cant use an aftermarket Stat for the 1.6
Cheers
Jmac

**craig_the_german** · 20-06-2010, 02:23 PM

Hi all,

Thanks for your help.

I decided this morning to take a look at the thermostat and if I needed a housing then arrange to buy one this week.

After working out which plastic housing bolted to the engine block was the thermostat housing (of course I pulled off the one that looked like the housing only to find it wasn't)

I removed the thermostat housing, and found nothing wrong with it. I removed the thermostat and rang my local Autopro store...who happened to have one on the shelf.

The guy removed just $19 from my wallet, I returned home, refitted the new thermostat, took the car for a drive.....problem solved.

Heats up to 90deg quickly and remains steady at 90...

Sometimes you can be lucky

**audi-tone** · 20-06-2010, 02:31 PM

good work mate. out of curiosity, 82 or 87 or 92 degree thermostat? mine's having trouble (albiet a 1.8t) getting to 90 on cold mornings, and its an 82 i believe (oem is 87).. in saying this, get it to 90 and it wont budge at all from that position... silly thing

**craig_the_german** · 20-06-2010, 05:29 PM

I fitted the 90deg one as that was the one listed for my engine.

**Speed** · 21-06-2010, 09:49 AM

Hi all,

Thanks for your help.

I decided this morning to take a look at the thermostat and if I needed a housing then arrange to buy one this week.

After working out which plastic housing bolted to the engine block was the thermostat housing (of course I pulled off the one that looked like the housing only to find it wasn't)

I removed the thermostat housing, and found nothing wrong with it. I removed the thermostat and rang my local Autopro store...who happened to have one on the shelf.

The guy removed just $19 from my wallet, I returned home, refitted the new thermostat, took the car for a drive.....problem solved.

Heats up to 90deg quickly and remains steady at 90...

Sometimes you can be lucky

Thats fantastic news. I didn't think you would have to replace the housing.
Good work!

**Jmac** · 21-06-2010, 06:47 PM

Originally Posted by Speed

Thats fantastic news. I didn't think you would have to replace the housing.
Good work!

Great its fixed, ah being around the product for nearly 20 yrs you might get it a bit wrong sometimes, but just for the record some 1.6 Mk4 motors DO have the full electronic thermo in the whole housing . good job it wasnt or your $19 dollars would have been $250 and buy the way you r mechanic is robbing himself for $19, i would be questioning the quality at that price. Anyway not for me to say.
Hey speed you might want to check if im right

Jmac

**Speed** · 21-06-2010, 07:07 PM

Great its fixed, ah being around the product for nearly 20 yrs you might get it a bit wrong sometimes, but just for the record some 1.6 Mk4 motors DO have the full electronic thermo in the whole housing . good job it wasnt or your $19 dollars would have been $250 and buy the way you r mechanic is robbing himself for $19, i would be questioning the quality at that price. Anyway not for me to say.

Jmac, I have about 14 months experience with VAG cars and don't doubt your knowledge.
In this case it just worked out much cheaper for the owner, who has every right to use aftermarket products.

He said that he bought the aftermarket thermostat from his local Autopro, so no mechanics got robbed.

Hey speed you might want to check if im right
Jmac

No thanks, I'll take your word for it.