Battery acid leaking on PCM
#21
Instructor
I just experienced the same problem in July
I had a lot of battery damage on my used FRC when I bought it. Frame corrosion, vacumn lines obliterated, acid on PCM cover etc. I decided to tackle all issues by removing the fender and having non restricted access to the whole area around and under the battery. I pulled the PCM and cleaned the case with CRC Battery cleaner (Find at your local auto parts store)which is a foaming product and is a lot less messy than baking soda and water. Has the same effect. I pulled the battery, battery stand, PCM, and PCM bracket. Sprayed the whole area with Battery cleaner including all wiring harnesses. Degreased everything, lightly sanded any corrosion damage, primed and painted areas damaged by the leaky battery. I used CRC Electronic Contact spray and sprayed the PCM Contacts and wiring harness contacts. Examined the PCM Wiring for any damage, there was none. Sprayed all wiring under the battery area with the CRC Battery Cleaner, used degreaser and soap and water. Reinstalled the PCM. Reconnected it. Started the car to make sure no codes. All OK. Found the damaged vacumn lines. Cut back the source line until I had good line and spliced in new line using 1/8" emissions hose and splices from the local auto parts store. Did the same for the supply line that goes to the large grommet on the firewall behind the battery. Before connecting the source and supply lines to the vacumn cannister near the passenger door, I encased the vacumn lines with 1/4" ID Rubber Fuel line in the battery area. No more worries about battery acid damaging vacumn lines. The fuel line hose is almost indestructable. While I had the fender off I changed out the vacumn cannister check valve (Get from dealer, it's cheap). I tested the HVAC operation before putting the fender back on. All worked fine. Cleaned the fender inside, access cover and reinstalled. Everything is still working a year later. Also switched to an Optima Red Top battery. You don't have to remove the fender, but I wanted to see all the damage and fix it. If you just remove the access panel, it's a lot easier if you lossen the bottom of the fender to swing it out away from the PCM and vacumn canister. Its an easy DIYer. And yes, I'd stay away from that dealer. If the car's not under warranty, then as suggested go to a good 'Vette shop and create a lasting relationship. This is a Corvette not a Cobalt. Dealers are pretty much useless with Corvettes unless they have a Corvette savvy reputation. Good luck. DON'T FORGET TO DISCONNECT YOUR BATTERY PRIOR TO REMOVING THE PCM CONNECTORS OR CONNECTING THEM!!!!!!
#22
Guest
Posts: n/a
I assume you took it in to a Dealership (i.e. Stealership). Thank them (and pay them) for their diagnosis and get it out of there!
Search for fixes. You must remove battery, use a lot of baking soda and water, they have acid cleaner/detecter, use it. You must remove and clean connectors. Also will need to paint. Some vacuum lines are bad (this affects your HVAC). Other people have fixed this.
Replace battery with an AGM (non-leaking battery) like an Optima, Excide Orbital, Sears Platinum.
Check your codes from the DIC (search for how to do this).
Good luck !
Search for fixes. You must remove battery, use a lot of baking soda and water, they have acid cleaner/detecter, use it. You must remove and clean connectors. Also will need to paint. Some vacuum lines are bad (this affects your HVAC). Other people have fixed this.
Replace battery with an AGM (non-leaking battery) like an Optima, Excide Orbital, Sears Platinum.
Check your codes from the DIC (search for how to do this).
Good luck !
#23
Le Mans Master
I have asked this before and I will ask it again - why doesn't some Forum Vendor sell a 3rd party solution like a full height replacement tray or something that is corrosion proof? Guess I will have to make one myself? There has to be a relatively simple fix.
#25
Guest
Posts: n/a
#27
Le Mans Master
I already did the Optima Red Top two years ago when I first read of the leakage problems, but I am still thinking there is acid in there somewhere if something went really wrong.. not true?
#28
Safety Car
True! Contrary to what has been said, the Optima, along with the Exide, are not gel cells. They are Lead-acid in an absorbent glass mat, in a sealed case.
#30
Le Mans Master
Member Since: May 2007
Location: hagerstown md
Posts: 5,383
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St. Jude Donor '08-'09
If you have the Delco with the green eye, trash it! I checked mine at least a couple times a week, and no signs of leakage. Then the positive terminal came out of the battery and leaked acid. Be warned!