Aluminum thermostat housing getting eaten up

[62ChevyStep]

History: I replaced my aluminium thermostat housing this summer, it was leaking around the base, I had noticed antifreeze pooling on my intake. Flushed, treated the whole system with prestone cleaner etc. refilled with fresh antifreeze and now six months later it's doing it again?

Anybody have this problem before? the thermostat housing getting eaten away?

I am ready to just pay the 150+ and buy a Stainless Steel housing and call it good.

[john]

I just bought a chrome plated steel thermostat housing from Summit Racing. I think my old one is probably pot metal. The new one is the O ring type. Part # SUM-G3801 $7.95 I figure steel is the next best thing to stainless and worth a try for the price.

[62ChevyStep]

Originally Posted by john

I just bought a chrome plated steel thermostat housing from Summit Racing. I think my old one is probably pot metal. The new one is the O ring type. Part # SUM-G3801 $7.95 I figure steel is the next best thing to stainless and worth a try for the price.

Thanks John for the information! I know the junk I am buying isn't worth the cardboard it comes in. Mr gasket my A**!

I will go and check it out.

Derek

[PrerunnerRob]

You have a problem of electrolosis(sys?) going on in your cooling system, where water flows through 2 dissimilar metals and creates an electrical charge. There is company out there that makes a radiator cap wit a cathode or anode, I forgot which one it is that will prevent this. The metal attached gives itself up to be eaten rater then other engine parts.

I found it, and here is the link

http://www.radcapproducts.com/radcap.html

[rodnok1]

I gave up on alum thermo housing along time ago, I get stock style ones from NAPA($10-15). They have every type around. I treat the outside with high temp brake and throw it in the oven(claen and preheat the part). Always make sure to run a file over the thermo housing everytime you change the gasket(do it to new housing even) and do a light pass on manifold to make sure it's flat as possible. I usually make my own thermo gaskets for sbc's, I can make them thicker than the crap that comes from parts store.

[62ChevyStep]

Originally Posted by PrerunnerRob

You have a problem of electrolosis(sys?) going on in your cooling system, where water flows through 2 dissimilar metals and creates an electrical charge. There is company out there that makes a radiator cap wit a cathode or anode, I forgot which one it is that will prevent this. The metal attached gives itself up to be eaten rater then other engine parts.

I found it, and here is the link

http://www.radcapproducts.com/radcap.html

Thanks for the information, seems weird though that more of the others don't seem to have the same trouble?

I will change my thermostat housing get one of those Rad caps and see what happens. I dont have anything unusual: reg radiator, 350SBC, cast heads, edlebrock intake, etc?

[PrerunnerRob]

You reaaly run into it it seems like when you mix aluminum, steel, and copper(radiator and heater core) together. The aluminum acts as the anode when you introduce it into the system, otherwise the copper or steel surfaces get eaten up.

[1oldtruck]

I've had the same problem with a chrome plated housing. Not sure what the base metal is....perhaps steel or pot metal....

[62ChevyStep]

Originally Posted by 1oldtruck

I've had the same problem with a chrome plated housing. Not sure what the base metal is....perhaps steel or pot metal....

yeah mine was chrome plated too, but the base metal was toast six months later X2. I went to NAPA and got a OEM Cast Iron one for now (not ) but am running a mild 350, that soon will be out and replaced by a fresh 383, and I will spring for a polished stainless steel one on that motor.

[stsalvage]

well i got a FULL on fix it for this problem Use distill water meaning the water you buy in sparklets drinking water has no minarals in it like LIME Use distill water and you will never have this problem again DO not use Tap water use Bottled water only and it will not eat any of your truck or car alum Parts you should look at the owners manual of a new car or new truck with alum radators they will tell you not to use tap water in your car the Lime in your tap water will eat your car up if your have a alum Block use distill water only

[glennhuff]

I would go with the cast iron too. I have had aluminum and the fancy chrome one's get eaten up. Both the distilled water and the sacrificial anode are also a good idea.

Glenn

[jon6.0]

At least it's the housing that is getting eaten away. I just noticed coolant pooling on my Holley aluminum intake and took off the chrome thermostat housing. It looked like barnicles were inside my housing. Since the housing is steel and the manifold aluminum, guess what was eaten away. Yep my manifold. So instead of buying a new manifold I cleaned it with a file as flat as possible and used isopropyl alcohol to clean it. Then the JB weld went on to fill in the dips and valleys. I am actually waiting right now for the JB Weld to cure so I can file it all down flat. I already bought a new housing with a O-ring seal, so hopefully this fixes it. If not I guess I'll coat it in gasket sealer. I don't want to buy a new manifold since I am buying Vortec heads soon and will need a new manifold for those heads.

[stepside66]

I just went and bought a nice billet aluminum thermo housing for 40 bucks it swivels HOPEFULLY mine dont get eaten up I had my intake powder coated but I am through with those cheap ass MR Gasket ones they arent worth the 9 dollars

[metalmassfab]

Originally Posted by stepside66

I just went and bought a nice billet aluminum thermo housing for 40 bucks it swivels HOPEFULLY mine dont get eaten up I had my intake powder coated but I am through with those cheap ass MR Gasket ones they arent worth the 9 dollars

This may hurt a little; a lot of the so called 'billet' thermostat housings (and other items) are nothing more than polished castings. An easy way to tell is look inside of it, should be a machined finish. Also, if the hose neck part is one smooth piece all the way down to where it meets the swivel base (as yours appears to be), you've been had. The true billet housings are usually 3 pieces; the base that bolts to the manifold, the t-stat tower, and then the actual hose neck. The hose neck is usually threaded into the tower piece, and you can see distinct machine markings around the joint. The reason for this is that it is a whole lot easier to machine straight parts and thread them together than it is to machine a one piece part that has an angle, or changes direction. I bought one of those 'billet' polished housings, and was pissed when I saw white spots inside it. Those white spots were corrosion that was already eating it up. Cheap cast aluminum is nasty stuff. A good, real billet unit should be machined out of marine grade aluminum like 6061, and will probly be at least $80. Sorry for the long one, this is another sore spot!