This is going to sound weird, but I need you to read this and give me some feedback/help if you can...

I bought a 98 Cobra a couple months ago that had a loud noise coming from the crankshaft area. I pulled the engine, and pulled it apart to see what was wrong. It turned out that the car had been stroked, and has a high performance crank, pistons, and rods and was all balanced. There has clearly been a lot of money invested in the car. The noise was a rod bearing that had gone bad. SO, I had the engine rebuilt, got a new oil pump and put it back in the car. It started on the first turn of the key. BUT, the engine isreally noisy when it's first started until it's in the normal heat range.

I've been taking it really easy on the car while it breaks in, changed the oil after the first 500 miles, and it's now got about 750 on it. The horn and fog lights aren't working, so I was looking at the fuse/relay box under the hood one day checking if everything was good. I ran out of time, and closed the hood. When I started the car the next time, I had the RED BATTERY light on the dash, which means electrical problem. I left the car running, popped the hood, and headed to the relay box again. When I pushed down on the box, the cars idle would drop down to normal (800 rather than 1100 where it was when i first started it) and the RED light went off. When I puch down on the box, the car sounds perfect and all noise goes away. Why would this be??

Also, when I come to a red light, the rpms stay up at about 1200 and drop down to normal idle after about 5 seconds?? What would be causing this??

I know this all sounds strange, but I just don't see how these things have anything to do with each other. ANY AND ALL SUGGECTIONS ARE APPRECIATED!! Thanks.

 

What weight of oil is in the engine right now? Does it only sound weird when its cold or ANYtime you restart it?

It should be 5w-20 or 5w-30.

If it has 10w-anything or a straight weight oil, it's too thick at start up when cold and you're getting metal to metal at startup because the oil is taking too long to circulate when you first fire it up. (you're causing damage)

Actually the Red batterly light means your charging system has an issue (Alternator) The box you pushed on if it's by the battery is the main relay harness. I'm guessing you have a loose connection there.

Where is the noise coming from?

 

Only when it's cold. And unfortunately it's got 10w-30 in it.... that's what the guy who rebuilt it told me to use. I guess I'll switch to 5w tonight. Should I use Lucas stabilizer, or not??


About the battery light... I thought it was the charging system too, but the owner's manual says "Electrical System".

 

Yeah 10W-anything is too thick for this time of year especially in a rebuilt engine. I wouldn't use the stabilizer. Put the money towards semi or full synthetic oil for when you've put about 3K-5K worth of miles on the motor.

Take the alternator to a parts store like autozone and have them test it just to make sure it's fine. Then take a look at the relay box. Wiggle things around while the car is running to see if you can locate the loose relay.

 

I'm in Southern Califormia... so it's not really that cold here. But I'll still switch.

 

How much did it cost to rebuild the engine I’m having similar issues with my crankshaft. The tooth on the end is chipped off, someone suggested a machine shop repairing it.
anyone have any experience, plz let me know
1. should I atleast try to weld and fix, before I pull the engine?
2. Should I buy a used motors or just replace the crankshaft on the original motor?
how much approximately?