NEW IMPROVED T-Stat Housing ALL ALUMINUM**NO O'Rings**

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
So after i repaired my front end from a fender bender i developed a coolant leak at the o ring between the hose conector and the t-stat housing. It was just replaced a year ago. from just working the lower hose on and off i made it leak. ANYWAYS, I always wanted to find a fix for this bad design so i plad out what i would do. This is a proto type for now. when i rebuild the engine i will make one with a better bend in it and have it polished and looking nice.
So all i needed was some 1" SCH 40 aluminum pipe and some Alumaloy - i love that stuff- and a aluminum tstat houseing from GAP, stainless steel brushes and propayne torch. Let me say this. that stuff takes skill. It is critical that you can control the heat just right. think of welding with a wax crayon. to hot and it melts out. This is not a DIY but it is a starting point for someone who wants me to make one for them or have me help with some more details. Just PM m


Do you like my make shift Laythe? I used a file to smooth it down better.






 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Ive driven it 200 miles now with a 195F t-stat. no leaks.

I did bevel the edges all the way in on the pipe so it has a 1/4" bead holding it all together. i have had epic results with this on other projects. As long as you dont go past 500F it will be fine.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Interesting... So the Alumaloy is also holding the sch 40 to the stock neck? It almost looks like you swaged the sch 40.

Never had luck with those rods, although the last time I tried using them was on thin al.

-Todd
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
its all welded at 2 spots, the 90 and the neck, so yes. NO O'RINGS Lol that was the point.
As long as you prep it. sand if necessary, and use stainless steel brushes. smaller ones for tinning the surface. then melt it as if it was soft wax almost sculpting it. then when its all built up, add a bit more heat to blend it. then grind it all off because that is all held with filler in between the joint bevels. i think i went thru 1/4 lb of it befor i figured it down to a skill.
 

annieneff

Veteran Member
Joined
Jan 13, 2011
Location
Seattle
TDI
1983.5 Westfalia tdi (afn), with flipped 5 speed V6 (dvz) transmission
Where did you get/how did you make the fitting that attaches below water pump there, the part with through bolt holes in it that attaches to the block? Something like that would be a perfect replacement for the bottom of the ccv tube too, where the tabs always crack and break off.
Nice replacement make on the bottom radiator attachment! Seems like it should last forever. If it gets to over 500* you'll have a lot more to worry about than the fitting you made. Thanks for sharing a fun inspired project!

Andrew
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I picked up one of those aluminum thermostat flanges from BFI at H20 a couple years ago. I haven't installed it but I have it in the spare parts bin.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
So far the 195 tstat has made a big difference for my heat issues. its been 1k miles and its holding up great.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
its a easy fix for the blend door issue and i think the heather core is on its way out. starting to get coolant smell- started this fall. ill swap it back out to the 185F this summer.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
A forum member asked if i can make him one and i said yes. I would like some feedback as to what everyone thinks about the price range and i would like to hear from members if they are interested in ordering one. the more i make the cheaper it is for everyone. If i make one its costly, but if i make 10 i can go into production mode and really make a nice product. the one i made is unfinished as in its just made to work sort of as a prototype. i plan on doing a full ground up rebuild int he future like all mk3 owners and i thought i would remake this the way i wanted it to be, with a bend instead of a 90 degree. I also would have it smoothed out and even finished with paint if you wanted a specific colour.

Let me know what you think.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
So i developed a leak. its not from the work i did on the tstat housing, it might be the aluminum housing is not seating the oring correctly. i put a new o ring in and it still leaks from somewhere, im taking it apart tonight and going at it with RTV. i hope its not the pump housing. ill update soon.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
GOOD NEWS, it was the hose above, the one to the heater core and oil heat exchanger. the dang hose clamp were not very tight, must have missed them on my "check everything you just did" onceover.

its all good now, took 30 minutes on the lift. glad it was that, simple fix. i was afraid what i did was a bad idea for a moment.
NOT. its an awesome idea and is still holding up nicely
 

starrd

Veteran Member
Joined
Nov 24, 2003
Location
Canada
TDI
1996 Passat
If the thermostat doesn't stay properly aligned in the water pump housing when you put the thermostat housing on you can have issues. A really good trick to hold the thermostat in place is to use a shop vac to create a vacuum in the block to hold it up. Doing this, the thermostat stays in its proper location while you install the o-ring and thermostat housing.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
thats a really good idea. i just put it in slowly and take time to slowly tighten it evenly on either side. so far i have not had an issue with it but next time i will use that trick. hopefully there is no next time for a good few years or longer.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
a little grease is easier than using a vacuum.
im not a fan of putting anyting other then H20 and g12++ in the system. every time i reclaim my fluid with - only used for this- 2 gallon shopvac, i pump the fluid thru a cheep water filter into a bucket. ive never used anything other then distilled and im not going to put grease of all things in the system. its not because its wrong or is bad but its how i like my car to be, im just picky like that.

If i was in a pinch i might. hot wax would probably be much better. candle, drop a tiny bit of wax on it, install.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
I know im reviving a old thread but i wanted to update you all on the status of this part. when i made this part i had 298K miles on it. Now it has 363K. 65K miles and 3 years later ( i dont drive it much any more save for autocross) This mod has held up PERFECTLY. no leaks no cracks no issues with the hose not sealing or holding on. it literally is perfect save for a sharp 90 degree but im sure its not hurting much. I would strongly suggest anyone to try doing this if your sick of plastic being a failing point. That is all!
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
probably due to it being a POS without work. For my application its perfect but for a replacement part it was junk unless you put some time into it. you would have to sand of rile off the casting marks where the oring would go and the slot that accepts the locking clip too. Other than this, it was a awesome part.

If i where to do it again i would put a petcock on it so you can drain the system easily. Im sure you can find them on ebay or somewhere but its going to be a lot of work. To bad.
 

All Stock

Veteran Member
Joined
Oct 6, 2014
Location
Michigan
TDI
AHU
Its mainly the flange part with the o ring seat I need... Its for a conversion...

I just need a lathe lol.
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
MD
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
Hit up the Mk1 & Mk2 classifieds and get a used aluminum thermostat flange and then you can weld to it the setup posted above.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
If i where to do it again i would put a petcock on it so you can drain the system easily.

I did this years ago. Unless you drill a pinhole in the thermostat, you're only going to drain the rad.

If you do drill a pinhole, make it a small one. I had an issue when too large a hole gave me issues.

-Todd
 
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