TB Plate Gasket

[secondchance]

Talking to Marc Haibeck when I met him at Carlisle, he mentioned reason for TB plate corrosion was due to paper gasket seeping coolant over time.
Any suggestion for rubber type gasket material and where I can find them? I figured I can use a standard gasket for template and cut one with a exacto knife.

[tomtom72]

Okay don't laugh too hard....but what about taking a no-hub coupler and steal the rubber gasket from it, they're all over the place in the plumbing dept @ Home Depot. Use a heat gun/hair dryer to make the rubber sleeve lay down flat after cutting it?

Or, go get a small roll of flashing tape, the kind that is self stick with the wax paper on one side and try to cut a gasket from that?

Or ask your dentist for a tooth dam?

fwiw, when I did my injector r&r, back in 10/05, I had a case of the pox on my cover plate and some of the surrounding area on the T/B, mostly near the driver's side corner/side of the opening.

I used white vinegar and a brass brush to neutralize & clean the white stuff up. I did another bath w/ contact cleaner, and had to use a small screw driver to do some scraping & more brass brush action with both solvents. When I was back to aluminum, I used some baking soda solution & the tooth brush a few passes and then let it dry so if I didn't get all the white crud I maybe could see it better on a dry piece than when wet. The key, IMHO is the white stuff and that ya gotta remove it all.

Upon reassembly, using a replacement gasket from KWRacing, I coated all the sides of the gasket paper with a thin coat of permatex rtv, even the inside of the bolt holes. I kind of encapsulated the paper.
.....but it still has not come back since 10/05....:mrgreen:

Oh, I also cleaned up every ground wire termination I could locate while I had the plenum off.......which proly had more to do with the "cure" ? I used GK's star washer + dielectric treatment outlined for the SIR TSB.

:cheers:
Tom

[secondchance]

Thanks, Tomtom.
I think I will try flashing material.
Have you got your car sorted out? New DIS?

[tomtom72]

Thanks, Tomtom.
I think I will try flashing material.
Have you got your car sorted out? New DIS?

:thumbsup: I hope you didn't choke on your coffee after reading my thoughts on the subject.

Yes! I now have my ZR-1 back.....:dancing:mrgreen:

In my haste to get the plenum buttoned back up I bent one of the pins on the large connector....:redface:........but I managed to straighten it back out and upon reassembly was happy to not have a 42 any longer!

[secondchance]

:thumbsup: I hope you didn't choke on your coffee after reading my thoughts on the subject.

Yes! I now have my ZR-1 back.....:dancing:mrgreen:

In my haste to get the plenum buttoned back up I bent one of the pins on the large connector....:redface:........but I managed to straighten it back out and upon reassembly was happy to not have a 42 any longer!

Glad to hear it was just a bent pin.:thumbsup:
Choke? Hell no.
I cleaned out under the plate like you did - perhaps not as thorough but scraped off stuff that sorta looked like play dough. I did use plenty of sealant but after a discussion with Marc, thought I would take the one step further.
I don't want to short circuit the coolant since I drive year around and also prefer stock look.

[VetteMed]

you could try toilet shim material, it's red rubber that comes in a square 5 or 6" wide. It's about 1mm thick.

[secondchance]

you could try toilet shim material, it's red rubber that comes in a square 5 or 6" wide. It's about 1mm thick.

Between the tank and the commode?
For me its easier to get EPDM flashing sample since I am an architect.:mrgreen:

[VetteMed]

Between the tank and the commode?
For me its easier to get EPDM flashing sample since I am an architect.:mrgreen:

No, it's for leveling the bowl with respect to the floor. There's a thick seal between tank and bowl. :mrgreen:

[secondchance]

No, it's for leveling the bowl with respect to the floor. There's a thick seal between tank and bowl. :mrgreen:

Thanks for the clarification. Either a flashing or a toilet bowl leveling seal to correct GM's screw up! We must really, really love them LT5s...:mrgreen:

[Aurora40]

The thing is aluminum. I'd think if you left it in a bowl of coolant it shouldn't corrode. Also, doesn't the gasket allow coolant to contact the back of the insert even if it is working?

I'm not saying it's not that, but it just seems weird. And the TB doesn't seem to suffer the same problems around the TB insert. That said, I've no idea what causes it.

But you could probably clean it up and repaint it and if it went another 18 years, that's not too shabby?

[tomtom72]

Not to be a wise guy......:o

The reason for the "rot" is electrolysis. The existence of two dissimilar metals in the presence of water and a stray electrical current. The screws which are not aluminum, I don't know what they are, thread into aluminum. Add in the car's electrical system and it's good to go. Only salt water would be a better environment for this to take place. I had to learn this stuff when I was into boating as a hobby.

In boating we used a couple of standard things to ward off electrolysis to our "underwater" metals, usually aluminum & s/s, in small pleasure boats.
Provide a blocker current using the "MerCathode" system.
Use of Zincs.
Most of us used both and checked that all our grounding points were good. Oh, forgot one. Don't leave your boat in the water.

In our case I guess the coolant gets absorbed into the gasket and then comes into contact with the screws which are in the aluminum. Add in the car's electrical system & dirty ground points and you have all the conditions for electrolysis to happen. You can change the screws I guess? Or stop the gasket from absorbing the coolant as best as you can? Oh, fixing the ground points is a good idea also....if you can find and get to all of them. The "inserts" in the T/B are aluminum so no net effect at that contact point.

Ya know this just hit me..... a BFO. Maybe GM invented Dex-Cool to take the "salt" out of the equation? Silicate coolant will eventually make salt as it "wears" out ( well kind of make salt ). Remove the silicates and you remove the salt and slow down or prevent the electrolysis. The only corrosion that would take place is from "destructive cavitation".

Sorry for the ramble guys!:redface:

[secondchance]

Not to be a wise guy......:o

The reason for the "rot" is electrolysis. The existence of two dissimilar metals in the presence of water and a stray electrical current. The screws which are not aluminum, I don't know what they are, thread into aluminum. Add in the car's electrical system and it's good to go. Only salt water would be a better environment for this to take place. I had to learn this stuff when I was into boating as a hobby.

In boating we used a couple of standard things to ward off electrolysis to our "underwater" metals, usually aluminum & s/s, in small pleasure boats.
Provide a blocker current using the "MerCathode" system.
Use of Zincs.
Most of us used both and checked that all our grounding points were good. Oh, forgot one. Don't leave your boat in the water.

In our case I guess the coolant gets absorbed into the gasket and then comes into contact with the screws which are in the aluminum. Add in the car's electrical system & dirty ground points and you have all the conditions for electrolysis to happen. You can change the screws I guess? Or stop the gasket from absorbing the coolant as best as you can? Oh, fixing the ground points is a good idea also....if you can find and get to all of them. The "inserts" in the T/B are aluminum so no net effect at that contact point.

Ya know this just hit me..... a BFO. Maybe GM invented Dex-Cool to take the "salt" out of the equation? Silicate coolant will eventually make salt as it "wears" out ( well kind of make salt ). Remove the silicates and you remove the salt and slow down or prevent the electrolysis. The only corrosion that would take place is from "destructive cavitation".

Sorry for the ramble guys!:redface:

You are absolutely right. It is dissimilar metal, aluminum vs. steel bolts, and electrical current present due to grounding. My guess is if I can completely isolate TB plate bolts (go to gasket that will not get wet and completely keep the coolant migrating near bolts) I may be able to keep this from happening. Even in high rise construction if aluminum piece has to be anchored to steel embed (typically at balcony rail attachment to conc. slab), we call for neoprene isolation pad - not 100% because of steel bolt and nut but cuts down on corrosion considerably.
Hmmm... Neoprene is another perfect candidate for this as well...

[tomtom72]

I have a question:

What is the potential for electrolysis if s/s bolts are substituted for the standard bolts used on our aluminum motors? Assuming the same degree of coolant migration & grounding conditions with standard gaskets without the benefit of rtv treatment & grounding correction, of course.:mrgreen:

I know from my boating experience that if nothing is done to prevent electrolysis you will eventually need a "rose bud wrench" to remove those s/s fasteners....except for the "ny-loc" type nuts.

:cheers:
Tom

[Gunny]

Apologies if this is a dumb question ...

Would bypassing the throttle body solve the problem?

[secondchance]

Generally we do not use a lot of stainless steel in construction due to cost except for decorative elements (i.e. entry canopy, trellis work on top of the building). Even then they often get eliminated during the "value engineering".
Having said that, stainless steel is far more corrosion resistant due to chromium content but the key word is "resistant" not "proof".
My guess is in the long run and depending on severity of condition, even SS will corrode but at much slower rate.