: V6 Doesn't always start on first attempt

12-27-12, 12:37 AM
2006 STS V6, 73k miles.

About 25% of the time, when I start the car, it cranks for a couple seconds, then I interrupt the ignition. When I try again, it starts up immediately. Any idea what could be causing this? It doesn't seem to be getting any better or any worse over the past couple months.


12-27-12, 07:38 AM
This happened to my wife's 07 sts4 just a month ago. Over 2 months prior to the car finally not turning over at all he would get the same symptoms as you are describing. I ended up changing out the battery and everything seems to be working fine now. Starts first time every time. No other issues going on and trust me, she'd let me know.

Have you ha the battery tested?

Cadillac Cust Svc
12-27-12, 09:33 AM
Kschwed, would you consider bringing your STS to your Cadillac dealership for a diagnosis? I'm happy to contact your dealer anytime on your behalf, so please keep us posted on your progress. And if you would like any further assistance, please don't hesitate to email me at Katie_Lucille@gmexpert.com!


Cadillac Customer Service

12-27-12, 09:56 AM
That's the kind of thing that isn't going to get better on it's own! ;)

I'd find out what's going on before you get stuck...

12-27-12, 12:49 PM
@ Cadillac Cust Svc - I appreciate it, but the dealership is always my last option. I'm more of a DIY guy, and the dealership also tends to be very expensive. I am always pleased with the quality of work and customer service I receive there though.

@ Zapconj - I haven't had the battery tested, but it is only a year and a half old. It's also an Optima Red Top. I doubt it's already failing, but I suppose anything could happen.

12-28-12, 09:44 AM
Take some of the money you'll be saving taking it into the dealership and buy an AutoEnginuity (GM Enhanced) diagnostic scanner. Learn how to use it, monitor the sensors as it starts to find out what's not doing what it's "supposed to", when you're having trouble starting. You could take a snap shot of each start and review them for comparison later.

Be that DIY guy! :D

12-28-12, 01:43 PM
@ Batu - That's not a bad idea, but I may rule out some less expensive fixes first.

Could it be a dirty/clogged component of my fuel system? I've never used any fuel cleaners or anything in this car. Is there one you could recommend?


12-29-12, 09:09 AM
Don't think so...

Fuel delivery requirements are at their lowest when starting. Restrictions, like "clogs" & filters, first show-up on the highway or at higher rpm.

More likely, one of the Many engine control sensors are giving a false reading to the ECM (computer) when stone-cold.

12-29-12, 03:23 PM
The only time I have experienced those symptoms was on my wife'e 2000 Camaro. The problem was the pick up coil and plug wires. Had new plugs installed too. Started right up after that. The car never missed or hesitated but the the starting was just like you described. Some days it started right up. Other days it didn't.

12-29-12, 05:30 PM
How involved is the process to replace the pickup coil? And which plug wires are you talking about? Spark plug wires?

12-29-12, 06:19 PM
I don't know how involved the process is. Dealer did the work. Yes spark plug wires. I hope this helps you.

12-30-12, 12:03 PM
I would start with a new fuel filter....
Yeah, a battery should be replaced every 4 years anyway.

02-01-13, 01:44 AM
My battery is a Red Top and only two years old.

So I noticed something today when I was filling up gas. EVERY time I fill up, it won't start immediately after, but always on the second attempt. It's seemingly random all other times, but without fail, it wont start immediately after getting gas. I feel like I'm getting closer to something here.

Anyone have any suggestions?

02-01-13, 09:57 PM
Do you 'top off' after the pump shuts off?

My wife does. I don't. Neither of us have had issues.

At least one member messed up his fuel system charcoal canister by over-filling his tank (after running out of gas!)

02-12-13, 11:00 AM
I had this exact problem every time I fuel I'll get embarrassed because I knew my car wouldn't crank right up soon as I was done

1st I replaced the fuel cap I thought it wasn't snapping on properly (didn't fix it )

2nd then I put some fuel injector cleaner (didn't fix it )

My engine light wasn't on so no codes I finally Ended up with a engine light on my dash board took it to the shop gonna type this directly from my work order

Dtc p0496 intermittently open
Replaced purge solenoid per doc # 2414429. T5740

Since my car still under 80k miles they said the replacement is free

So I got that replaced my car been working fine for 3 weeks. Now they also suggested that I have a few other things done So I'm gonna put it in the shop tomorrow just to be on the safe side

Air filter& fuel filter $118

Injector cleaning $150

Throttle body cleaning $125

Carbon treatment $150

Power steering oil service $99.95

A/c cleaning $125

I know a couple of those things don't. Relate but I hope. This helps you an at least u will have something to see how much ur looking. At price wise

02-12-13, 07:26 PM
Throttle body cleaning is worthwhile. Most of the rest could be done cheaper or skipped entirely, in my opinion. Opinions vary.

I hope it continues to perform to your expectations.