Author Topic: White powdery residue  (Read 1198 times)

TA301

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White powdery residue
« on: October 08, 2023, 04:43:14 PM »
Noticed this around the thermostat housing as well as the area on the timing chain cover. Corrosion?
« Last Edit: October 08, 2023, 04:45:04 PM by TA301 »

Wallington

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Re: White powdery residue
« Reply #1 on: October 09, 2023, 02:03:22 AM »
Are you talking about the bottom of the casting? Dried/evaporated coolant does that. Keep an eye out for a slight weep or anything spilt. Wipe it clean before next drive. Or are you looking at the chunks?

TA301

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Re: White powdery residue
« Reply #2 on: October 09, 2023, 01:34:45 PM »
The chunks of white residue/deposits.

nUcLeArEnVoY

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Re: White powdery residue
« Reply #3 on: October 09, 2023, 02:02:43 PM »
Antifreeze dries to a white powder residue. You may have a small leak there. The only way I've ever had the thermostat housing seal was with straight RTV, which is what the service manual recommends. Paper gaskets just wouldn't work for me.
1979 Trans Am 400/4-Speed W72/WS6 - Starlight Black Hardtop

Zach

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Re: White powdery residue
« Reply #4 on: October 09, 2023, 10:19:58 PM »
+1 to use straight RTV, tried it twice with gaskets and never worked. Haven't had an issue since(With the water neck that is, I chase water leaks every other week).
1977 #s W72 400 4 Speed Trans Am
1971 351c 4 Speed Mustang Mach 1

Re: White powdery residue
« Reply #4 on: October 09, 2023, 10:19:58 PM »

TA301

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Re: White powdery residue
« Reply #5 on: October 10, 2023, 05:37:08 PM »
It has thermostat housing specific silicone gasket as seen in the picture. Looks like there could be a pin hole breach of the "gasket"

Re: White powdery residue
« Reply #5 on: October 10, 2023, 05:37:08 PM »
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