Electrolysis?

[Ohmess]

So, the first day of the Pittsburgh Vintage Grand Prix was delayed for rain, and several of us were hanging out at the hotel wondering if the races would take place. We had heard it was rather a mess trying to get into the park because of all the people that had been held back, so Tom (VBigDog), his son, DuaneSword and I paid the hotel shuttle bus guy to run us over there. On the way, Tom tells me about the importance of ground straps and how he not only replaced his, but added another onto his differential in order to avoid problems associated with chemical reactions induced by random electric currents.

I made a mental note of this, purchased a few ground straps, and added ground strap improvements to the list of things to do to my car.

Well, over the weekend, I decides to begin dismantling my cooling system in order to install a new tstat housing, tstat, water pump and all new hoses. In doing so, I found this:



I then made note of the fact that my tranny ground location looks like this:



Now, I am pretty sure that black paint has been on my car a very long time (since the late 1970s, perhaps), which leads me to believe that I may well have the electrolysis problem engendered by the lack of appropriate grounds in my car that Tom was regaling me about.

All of this brings me (at long last) to a question:

How can I assess what I am dealing with? I am concerned about possible corrosion inside the engine, within the radiator and inside the heater core.

Do I just flush and hope for the best?

 

[HB Chris]

The water divider corrodes easily, best to find a good used one if it's really bad. The firewall ground strap is important, mine is grounded to the intake runner. Without it according to SFDon, it can cause starting issues and/or Alt issues, he can elaborate hopefully.

 

[Stevehose]

The thermostat housing looks to be just simple aluminum corrosion, flush your block by draining the radiator and unscrewing the drain plug on the back passenger side of the block. Run a hose from the top side to wash as much stuff out as possible. I do this when warm (not hot) like an oil change to get suspended crap out. Don't run cold water through a hot block. New coolant then do it again in a month or so to see if coolant is tainted. This should minimize aluminum corrosion too.

As for grounds, I am not sure what your second pic shows but I ran a separate wire from negative batt clamp to the alternator housing, then from the altenator housing to the block (one of the oil filter bolts). I also have the stock strap from the firewall to the valve cover and battery to the fender.

 

[Peter Coomaraswamy]

Chris, let me know if you need one, I have a couple of the older style dividers (T-stat bodies) laying around but you can get the newer style ones pretty cheap also. Not sure if there really is a performance difference as I had both types on the blue coupe and even in Austin she stayed "cool". Not always so much in the cabin though even with the A/C on.

 

[sfdon]

I've seen things you wouldn't believe.......

You gots to change the fluids.

 

[deQuincey]

The thermostat housing looks to be just simple aluminum corrosion, flush your block by draining the radiator and unscrewing the drain plug on the back passenger side of the block. Run a hose from the top side to wash as much stuff out as possible. I do this when warm (not hot) like an oil change to get suspended crap out. Don't run cold water through a hot block. New coolant then do it again in a month or so to see if coolant is tainted. This should minimize aluminum corrosion too.

As for grounds, I am not sure what your second pic shows but I ran a separate wire from negative batt clamp to the alternator housing, then from the altenator housing to the block (one of the oil filter bolts). I also have the stock strap from the firewall to the valve cover and battery to the fender.

+1
when i bought my coupe, that was the first action, to renew the cooling system, it looked worse than yours, aluminium corrosion allaround

 

[Ohmess]

Thanks guys. Good stuff. I have a new water divider I plan to install. I will also get the ground straps installed as I replace my hoses.

Steve, my second rather dark picture shows the tranny ground location, with no ground and black paint which has not been disturbed by a ground wire. This tells me the ground has been missing for a very long time.

Antifreeze was changed by the seller immediately prior to sale, but changes before that are unknown.

 

[OCCoupe]

Using distilled water vs tap water is important too. No need to introduce unnecessary minerals. I flush with distilled water and use it for the water/coolant mixture.

 

[Stevehose]

The transmission is grounded? I don't rmember seeing this on mine but I will be doing guibo/center bearing soon and will inspect.

 

[HB Chris]

You can ground it to the Zenith manifold, the injected manifold or even a bell housing bolt if it's M8 bolt.

 

[rsporsche]

The transmission is grounded? I don't rmember seeing this on mine but I will be doing guibo/center bearing soon and will inspect.

if you remember Luis' coupe jewelry pics, the small flat cable linked the tranny / bell housing to the firewall.

i am curious whether you need the tranny grounded in addition to the block (separate grounds). i also have the valve cover grounded to the firewall, the battery to the inner fender and the inner fender to one of the oil filter bolts. I will probably do a strap from the oil filter to the alternator (similar to what Steve did).

 

[Stan]

Electrolysis

isn't that what they use to remove unwanted hairs

 

[Stevehose]

So if my firewall and valve cover are connected, why would I need the bellhousing and firewall connected?

if you remember Luis' coupe jewelry pics, the small flat cable linked the tranny / bell housing to the firewall.

 

[rsporsche]

So if my firewall and valve cover are connected, why would I need the bellhousing and firewall connected?

my question - exactly ... just stated more concisely.

 

[Ohmess]

Not sure exactly why, but the spot in my picture is a factory tranny to firewall ground. And as I noted, Tom recommended adding a ground to the diff as well. Maybe Tom will jump in, but my recollection is that the potential for a problem arises with electrical currents running through fluid filled items consisting of dissimilar metals.

SFDon -- that pic is scary!

 

[Stevehose]

So run a ground wire from the diff to where? I would think it is pretty well grounded given the number of big ass bolts holding it on.

Maybe Tom will jump in, but my recollection is that the potential for a problem arises with electrical currents running through fluid filled items consisting of dissimilar metals.

 

[Ohmess]

Actually, that's a damn good question. I think the bushing even has a bolt straight through it. Maybe I'm remembering that part of the discussion incorrectly.

So run a ground wire from the diff to where? I would think it is pretty well grounded given the number of big ass bolts holding it on.