2000 Cadillac Seville

[sadillac]

I am driving along and my voltage is 14.5V, without warning, the voltage drops to 12.8 or 13.5V for 2-3 seconds. If my foot is not on the gas the car shuts off. It is like the car bogs down but I have been driving without any radio, ac..no draw other than the engine. New battery, cleaned throttle body, fuel filter, fuel treatment, air filter, only 93 octane. Any ideas?

[caddydaddy]

How many miles? It sounds like a voltage regulator problem, maybe the alternator or a bad connection somewhere.

Also all 2000-up Northstar engines were designed to run on 87 octane. Under extreme driving, 89 is best, but your engine will very rarely have the need for 93 octane. You are just wasting your money. I have a 2000 STS and I drive it very hard and it runs great on 89 octane. Just a thought!

[mcnu]

I dont know if you know this or not, but in 2000, cadillac made the northstars so they can run on regular 87 octane.

[caddydaddy]

Originally Posted by mcnu

I dont know if you know this or not, but in 2000, cadillac made the northstars so they can run on regular 87 octane.

Yes, that's what I said! But for optimum performance if you drive the car hard, 89 is the best to use!

[TAG781]

What about the 99?? I still have to use super??

Originally Posted by caddydaddy

Yes, that's what I said! But for optimum performance if you drive the car hard, 89 is the best to use!

[caddydaddy]

Originally Posted by TAG781

What about the 99?? I still have to use super??

If you use less than premium in a 1999 or earlier Northstar, the PCM may cut back ignition timing if it detects knock. This would reduce power of course. I've heard of people using 89 and even 87 and doing fine. And I'm sure it is if you're just a cruiser. But if you drive your STS like it was meant to be driven (fast and hard), then low octane gas isn't going to be the best choice.

[SickDaytona]

Originally Posted by TAG781

What about the 99?? I still have to use super??

Just thought that I would let you know that I use 89 octane on my 99' SLS and have no issues. All good here.

[caddydaddy]

Originally Posted by SickDaytona

Just thought that I would let you know that I use 89 octane on my 99' SLS and have no issues. All good here.

And that's probably fine for most driving. But if you run it hard, the engine will probably cut back some ignition timing, so you'd have a slight power loss.

[butch h]

You may have a momentary electrical shorting situation.

[butch h]

You may have a momentary electrical shorting situation.