papasmurf

I am doing a full overhaul on my 85 (early) NA. The car was purchased with a new style (laso turbo) water pump already mounted with the belt guide/block off and timing cover trimmed. I had no idea how old the previously installed WP was so I bought a new one (turbo style) and am about to install it. I purchased a new thermostat (stant # 13378) and o-ring (part # 944-106-929-05-M2) for it and mounted it in the WP. The thermostat is the same physical size as the one in the old WP. My question is should the thermostat seal against the smaller internal o-ring inside the water pump there is I am guessing about a 1/2 inch gap at least between the bottom of the thermostat and the small, internal o-ring. Also when I mounted the thermostat there is a slight amount of side to side play even with the new o-ring slipped over it. When the clip is installed it holds it in from falling out but it is oh so slightly loose side to side still.

harveyf

The 1/2" gap sounds wierd, assuming I am understanding your descrption. But generally, the thermostat spends most of its operating time open so any leakage around the perimeter is not an issue. I don't know where you bought your parts but it may be a good idea to call Pelican or Paragon-Products and have a real person tell you whether you have the right items.

Maybe you can get some inspiration from this article:

https://newhillgarage.com/2018/02/04...tem-explained/

papasmurf

I found a similar question someone asked on pelican...the people replied it was normal and correct. I am missing the shim between the thermostat and snap ring though.

harveyf

I assume you are talking about 951 106 155 00 Sealing Ring? You may just have to bite the bullet and buy one, if it is missing. It's been awhile but I remember the last time I did a water pump, the thermostat fit snug and if anything, had to be compressed a little to get the snap ring in.

Dan Martinic

Whenever I've installed a thermostat, it's been tight. You have to ensure it fits into that groove on the inside. I don't recall any play whatsoever. For some, there's that metal ring.. others, it's not needed. I even recall the metal rings in different thicknesses (or maybe it's rubber seals.. can't recall)?

Take a nice ruler and measure the distance between the inside bottom of the thermostat housing and that "groove". That distance varies.. and there are combos to fit tightly

Seattle 993

Papasmurf, if you haven’t pulled the WP I’m not sure I would pull it. Also is a good WP. I’d check the WP bearing to see if it turns with resistance smoothly and has any leaks. If it passes those tests I’d leave it in. More important are the timing and balance shaft belts, those I would absolutely change and while you’re there replace all the rollers - that is time and money well spent. WP generally last 100K, the belts 45K or 3/4 years whichever comes first. Rollers probably a 100K, but if you don’t have records I’d replace these.

I’m only saying this because I’ve replaced WPs In the past when I didn’t need to. I have a 1988 944 turbo S which runs like a Swiss watch And I just tend to be careful about maintenance and oil changes. And I don’t track the car.

Good luck on whatever you decide.

thomasmryan

measure the depth of the snap ring groove and then use the proper thermostat/o-ring combo for that depth.

clarks procedure for the 7mm or 4.5mm gap depending on your pump clarks

do test the thermostat on the stove prior to installing it.