I just bought a 2003 tiburon gt 6sp. The card runs and drives great, brought it home and went to start it and nothing, car starts right up with jumpers, drive it around some shut it off and it starts, drive it around some more and shut it off and it wont start again. Started checking somethings with a volt meter and I have 12.2 volts when I touch the negative side of the battery and the frame. Start it back up and while I am testing it the volts drop down too 11.1 and stay there, also the temperature pegs instant when the volts drop. The starter is new and so is the battery. I noticed that my valve cover is leaking a bit and the alternator is covered with oil, is the oil causing my charge issues and why do I have a positive feed on the negative side of the battery? Once the car is running the lights dont dim and the car runs fine it is just starting the car. Also there is a full stereo system in the car but while i was testing the volts i had the stereo playing and it didn't effect the charge at all. Just feeling frustrated and don't know where to start

 

What voltage do you get when the engine is running?

 

The reason you are getting a voltage reading at the "frame" is because there is a poor ground connection between the battery and other metal parts. Start with the ground cable from the battery to the engine and make sure it is clean and tight.
Just looking at them does nothing, they have to be loosened and retightened. Then check the wires coming from the engine or battery negative cable that go to the sheet metal. They could be either dirty or missing.

 

my car was charging while it was running at 13 to 14 but it dropped to 11.2 for some odd reason while we were checking things. We did alot of checking and cleaned all of the grounds and cables, I think that my alternator is bad because it was soaked from oil because the value cover is leaking down on top of it. We pulled the alternator and I am going to replace it, plus the value cover gaskets and the intake gasket and plug and wires while it is all apart. Hopefully all this fixes the problems. Would anybody know if the timing belt breaks in these cars if it ruins the motor or it just breaks and you can replace them? I have no records of the belt being done and the car has 204k on it. Thanks

 

Make sure the ground strap that goes from body to intake plenum is clean and tight. It's located on the rear of intake on the pass side mounted with 2 10mm bolts. Other end goes to firewall. If loose or missing this will cause all the problems you described.

 

My guess right now would be what everyone else suggested: a bad ground. Make sure it's clean and a solid connection. Maybe even replace the cable entirely.

 

Ok, so we took the alternator off because it was loaded with oil from the value cover leaking, cleaned it all up and had it tested and it tested good. Put it back on last night and had the battery charging and was showing 12.86 volts, turned the key and nothing. So far we have checked all of the grounds and cleaned them and made sure that they had a good ground. I am stumped I have no clue where too look at now, Could it be something in the ignition or one of the relays? Just trying to avoid having a large bill at a garage thanks. Also what doesn't make since is that they car will turn over with jumper cables or with the battery charger hooked up

 

Please tell what grounds you checked and there locations. I personally had this very problem years ago and it kicked my butt. I too had a bad voltage drop but not as bad as yours. I had about 5volts from negative batt post to plenum . Reading shouldn't be over .5 volt. That's 1/2 volt. My problem was the ground strap that I described in my first post. Is your ground strap there? Located on pass side top of plenum. On my problem the 2 10 mm bolts on plenum we're loose.

 

12.86 is too low. It shoudl be chargeing more than that. What was the alternator putting out when it was tested? If it was good (14v+) then it's the cables.
Maybe this will help:
Testing battery and charging system

 

ok so my brother was up working on the car yesterday while I wasnt there and I told him to check the ground strap that was hooked to the intake and the firewall. Here two of the bolts were loose and one bolt was cross threaded, tightened it all up and the car fires up now every time. Thanks for all of the help and information, saved a lot of time and money. Would anybody know what the best timing belt kit would be for this car. I have no information from the previous owner on when or if the timing belt has ever been done, the car has 204k on it. We inspected the belt yesterday and there is signs of cracking in the belt, so while it is apart we are going to replace it. Also there is a ticking noise at the top of the motor sounds like it is under the plastic cover where the timing belt is and water pump, anybody know what that might be? It doesn't do it all the time and if it is making that noise when I start it, it usually quits once I run the car for a bit. Ive seen a bunch of videos on youtube with the same noise but nobody has said what the noise may be. Thanks again for all the help Erichshonda and novaResource and hanky!!