Thermostat cover interchangeability?

vrg3 · Post by **vrg3** » Mon Feb 16, 2004 5:13 am

On our cars, the thermostat is installed in the water pump, and then a cover is installed over it that the radiator hose attaches to:

Is that cover shaped significantly differently on turbos and on non-turbos?

entirelyturbo · Post by **entirelyturbo** » Mon Feb 16, 2004 6:17 am

I would think they can interchange. It's just a bent pipe with two bolt holes. The only difference I would think might be worth noting is a possible higher flow for the turbo one, but that's mere speculation.

What do the part #'s say? Are they different?

THAWA · Post by **THAWA** » Mon Feb 16, 2004 6:24 am

yeah they're different part numbers

vrg3 · Post by **vrg3** » Mon Feb 16, 2004 2:50 pm

Yeah, it's a good thought, but the numbers are different...

Turbo: Part number 11060AA060
Non-turbo: Part number 11060AA070

However, the fitment requirements of good OEMs far exceeds that of most ordinary mortals... Most of us wouldn't mind using something that mostly fits.

I doubt the flow could be much different, but it's possible. I was thinking that the only possible differences would be a slightly different flange shape or bolt pattern, or the angle that the pipe comes off at.

I do know the gaskets and thermostats are the same part numbers.

Has anyone tried using the non-turbo thermostat cover with the turbo?

THAWA · Post by **THAWA** » Mon Feb 16, 2004 3:15 pm

It looks to be the angle at which the pipe leaves the water pump area, but this makes me wonder why they have two different water pumps. I know the turbo one has more room for other things to come out, but why make a new water pump housing for the n/a and not just plug the holes on the other one? Know what I'm saying?

vrg3 · Post by **vrg3** » Mon Feb 16, 2004 3:32 pm

Yeah, I see what you're saying. The turbo pump has to route the hose to clear the exhaust, I think. But it should be just as usable on a non-turbo if you didn't weld on the nipple for the turbo.

Kind of like them making different intake manifolds. Pretty much the only differences I can see between turbo and non-turbo manifolds are two nipples -- one for the blowoff valve right by the brake booster nipple, and one for the pressure sensor and auxiliary purge control on the front right runner.

In the end it's probably a cost-minimization issue. Even tiny amounts of extra metal can add up to significant costs when multiplied over a large number of vehicles.

THAWA · Post by **THAWA** » Mon Feb 16, 2004 4:10 pm

makes sense, but seems like designing and producing a new thermo/waterpump housing would be more expensive than two plugs, but then again, I know nothing about the costs an stuff.

vrg3 · Post by **vrg3** » Tue Feb 24, 2004 8:05 pm

I have the answer.

And, man, is it dumb.

The turbo and non-turbo thermostat covers are mirror images of each other. If you hold them with their flanges together the pipes go off in the same direction.

Another way to look at it is that they're the same except that the flanges rotated 90 degrees with respect to each other. Since the flanges are 180-degree-symmetrical but not 90-degree-symmetrical, that means they can't interchange.

THAWA · Post by **THAWA** » Wed Feb 25, 2004 7:26 am

so it other words themouting holes are on opposite sides?

vrg3 · Post by **vrg3** » Wed Feb 25, 2004 3:24 pm

Yeah, I suppose... If you look at the flange as having 4 corners, the mounting holes on the turbo housing are in the corners that the mounting holes on the non-turbo housing aren't.

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Thermostat cover interchangeability?

Thermostat cover interchangeability?