Thermostat question

[Smallblock454]

Hello,

i have a 2003 (2004 in the US) 986S MT.

The PET says that there is a thermostat with a separate housing available. Part number is 996 106 125 52.

The after market thermostats seems always to come as a unit with housing and insert. For example the Wahler ones.

Can somebody confirm that the OEM thermostat is 2 separate parts - thermostat housing and thermostat insert itself. And that the thermostat insert part is swappable while you keep the old housing.

Thanks & regards
Markus

[JFP in PA]

Yes, they are two separate parts, but here comes the rub: The thermostat is a bayonet mount type that requires a special tool to insert it. Porsche gets over $100 (US) for the tool, but you can either fabricate one out of some plastic pipe, or buy one from LN for less than $15:

[san rensho]

Or just use a couple of screw drivers to push down on the thermosstat and then twist it to get it out.

[Gelbster]

Knowing Markus, he'll make the tool himself from depleted uranium :-).

[Smallblock454]

Hi,

thanks guys. I have an old Mercedes thermostat which is made the same way. Housing and insert. So i had the opportunity to test if i could change the insert without rocket science tools made from depleted uranium.

Well, first i searched something that fits over the cap of the thermostat, just to press the two flaps down that hold the insert. Found a plastic cap in the bathroom and it was pretty easy to get the insert out.

But how to get it in? The plastic cap didn't work. Too flexible, couldn't generate enough pressure to fit it in. Tested the 2 screwdriver method with two bigger flat blade ones. Nope, that didn't work. Went to the cellar to look for a metal tube that might fit – unsuccessful. Also no other tools in that big toolbox that might solve the problem.

Decided not to drive to the hardware store, because in the end a complete Wahler thermostat incl. seal is only 11 Euros more than an insert without seal. Doesn't make sense from a ecological point of view, but if i add time for fabricating the tool myself and driving and buying stuff at the hardware store it seems to be cheaper than to buy a complete unit. So i ordered the complete one.

Conclusion: you can change the insert but you need to have a special tool made from metal.

Thanks & regards
Markus

[JFP in PA]

Originally Posted by Smallblock454

Hi,

thanks guys. I have an old Mercedes thermostat which is made the same way. Housing and insert. So i had the opportunity to test if i could change the insert without rocket science tools made from depleted uranium.

Well, first i searched something that fits over the cap of the thermostat, just to press the two flaps down that hold the insert. Found a plastic cap in the bathroom and it was pretty easy to get the insert out.

But how to get it in? The plastic cap didn't work. Too flexible, couldn't generate enough pressure to fit it in. Tested the 2 screwdriver method with two bigger flat blade ones. Nope, that didn't work. Went to the cellar to look for a metal tube that might fit – unsuccessful. Also no other tools in that big toolbox that might solve the problem.

Decided not to drive to the hardware store, because in the end a complete Wahler thermostat incl. seal is only 11 Euros more than an insert without seal. Doesn't make sense from a ecological point of view, but if i add time for fabricating the tool myself and driving and buying stuff at the hardware store it seems to be cheaper than to buy a complete unit. So i ordered the complete one.

Conclusion: you can change the insert but you need to have a special tool made from metal.

Thanks & regards
Markus

You are correct that it needs to be stiff, but it can be fabricated from PVC plastic pipe or a hunk of metal pipe using a file in about 10min. Or you can purchase LN's version for $15, which is a copy of the factory tool and works perfectly.

[Xcellr8]

NAPA sells a Motorad thermostat (insert) part number 462180 that comes with a cardboard tool that I have used successfully.

[Frodo]

Will be doing WP & t'stat soon (waiting for parts).
I didn't order the t'stat removal tool because I thought I still had one from the last time
I did this job. (I actually probably do have it...I just have no idea where)

Anybody got one laying around where they could shoot me a diameter of the tool? Let's say OD.

TIA

[JFP in PA]

ID 35 MM
OD 40 MM

Notches at 12 and 6 O'clock position: 15 MM wide, 10 MM deep

[Frodo]

Perfect! Thank you sir. I'll get right to work on that!