I have a 2004 Pontiac Bonneville SLE. Recently I had the all the lifters replaced. I, myself, replace alternator, battery, camshaft position sensor, and crankshaft position sensor. (The sensors were codes that popped up with check engine light). Original symptoms after lifters were replaced- car ran just fine for about a week or 2. Then after a 20 mile trip home from work I turned the car off for about 10 minutes then had to leave again. But this time the car just shut off, no sputtering or anything just like I turned the key off. Now anytime I start car there’s a long cranking period before it start but it does start. Then after car gets to normal driving temperature it just turns itself off. It’ll start back up right away but then turns itself off again within minutes. I drove it just to test how it felt driving and noticed that when it shifts it loses a little bit of acceleration/power. I can’t really tell which it is as none of the electrical components (radio, dash, lights) seem to lose power when this happens. It doesn’t idle rough or have any kind of needle fluctuations.

Crank and Cam sensors rarely fail at the same time. It would make more sense that the wiring harness was bad. Since those 2 sensors are the main control for spark control, I'm assuming you have an issue with that harness or the ground and you're losing spark. The harness is small and easy to replace.

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

Thanks that makes so much sense. Sorry if this is a dumb question. How can I test the harness itself?

You'd be testing for continuity on each individual wire, but if its an intermittent issue, than it might be a partial break where the circuit fails dependent on temperature or position. Easier to just replace the harness and be done with it.

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

Thanks for the input. That’s what I’ll do.

3800's will throw a Cam sensor related code (P034something) if there is a mismatch between 3x pulses signals of the crank sensor and correlated pulses of the cam sensor. I fought with this one, and it ended up being a failed crank position sensor in my case. It had already been throwing the code for the 18x signal loss for years, but once the x3 fueling signal started dropping out, it started falling apart. If you have already replaced the crank sensor, double check the wiring like Andrew said, but also check the wiring at the ICM harness that plugs in under the coil packs. I believe the crank signal also goes through the ICM, so if it's packing up it would fit the symptoms you are having. If you already have a spare ICM, I would recommend swapping it in when you check everything out. There's also ways to check it out of the car that can be found on the internet, and given it acts out when hot, you'll likely need to warm it up when you are checking it.

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~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place