I have a 2004 Ram 1500 with a Hemi. It's got about 75,000 miles on it. Last winter when ever the temps dipped below 40 I would have a hell of time starting it in the morning. It would crank but the engine just wouldn't turn or fire. Kind of like I was out of fuel.
Then it threw the codes p0340 and p0335 Cam and crank position sensors.
I replaced the crank sensor and the light never came back on. By this time winter was almost over it was warming up out and the truck began to start fine again.
Well this morning it was 45 out and the truck didn't want to start for about 5 minutes then It finally did and the same 2 codes came up.
Anyone else have this issue? I did buy the cam sensor lastyear just never put it in. Why would the crank sensor be throwing codes again now?
Thanks for your help
Mike

Not a mopar but my friends cars ran fine when is was warm out but when it got below freezing the car wouldn`t start. He took it to the dealer and they replaced the pcm. To prove it, they took the pcm out when the car was warm and still ran fine. They put it in a freezer overnight reinstalled and the car wouldn`t start.

Interesting. I don't think it's that because it was like 46 this morning when it happened.

I wonder if it has something to do with the gas tank? This is a different problem but...My wife's Sebring with fill just fine in the summer. When it gets cold, gas spits back out the fill tube when full. We replaced a couple valves in the fuel system but it still does it. The only other pieces to replace aren't available separately. They come attached to a new gas tank. I know Chrysler has had problems with filling for a while. Maybe something in the tank...or a valve attached to the tank is causing the no start issue when cold?

Any hard starting issues I've ever had have usually been ignition related, but they ususally don't crop up until you get into single digit temps (Fahrenheit). Last one was a Sunfire that was a hard starter when it got around 5 Fahrenheit. Checked the plugs and they had about .125" of gap. Replaced them and it was fine, it'll now start in -30F no sweat. Have you ever changed the plugs? Supposed to every 30K

Plugs are stock. Supposedly good till 100k. I should probably look into that though.

Our 05 hemi plugs in our durango are only good for 32K MILES, I've changed ours twice now so far, all 16 of the ba$tards.

You want to monitor the voltage when your cranking...if it low it won't start. Always start there unless the car/truck needs a tune up.

Good luck getting those plugs out...

This is possible, imo.

We did get a whole new gas tank in our 05 durango under a recall. Cost us nothing and we were second owners. It did just what you said no matter how slow you went at the end year round, every time split gas out. My wife will not put up with that.

(thinking after the fact, maybe that's why it was on the dealers lot as a trade in with 46K miles on it?) Otherwise the vehicles has been great.

Then I read on moparts about a recall on them. I called the dealer and they knew nothing about it.

I called back about a month later and they knew all about it then and scheduled it in. Took one day and we had a whole new gas tank. I was surprised it took a whole tank to fix it?

The wife fills the thing up and it fills great, no problem. She goes to work and the durango is leaking gas all over the parking lot at her work! She calls me and I swing by to look at it and it is leaking down from the top of the new tank. Call the dealer and they come pick it up with a roll back truck. The plastic fittings on top of the new tank got cracked when they installed the new tank, I was told. So we got a second new tank and alot less gas but they got it right the second time. Been fine for 5 years now.
What a stupid thing to have to deal with.

What Challenger1 Said

The 04 Hemi left the factory with standard copper plugs good for only 30,000 miles

At 75,000 miles - I am not saying that's your issue , but a good place to start - No pun intended

Aluminum Heads - 11 Years - Original Plugs =

Reminds me , I should look into my 2011 now that I think about it

Not the gas tank because even when spaying starter fluid it wouldn't fire up. So I don't think it's a fuel issue.

You're probably right.

Your plugs are trashed and wires/boots and?,IMO. Especially if your spraying that in there.

When you change your plugs pull all the coils off and spray some penetrating oil down the tubes and let it sit overnight. I changed mine when I bought the truck with 65K on it and it was no big deal to get them out (I doubt they'd been changed before that).

Just did it again today and it's 52 outside. This morning it fired up quicker than normal even and just now in left work and it took me 4 tries to start. Barely fired then died out 3 times.

Cam and cranks sensors should be replaced in pairs and use genuine Mopar only, lots of problems using aftermarket sensors.

My 05 had intermittent crank/no start events when the crank position sensor started to fail. Use an OEM one.

I also agree you need to change your plugs, but it likely isn't the issue.

I always use oem. I have the cam sensor just need to put it in.

When it isn't starting, do you get a reading on the tach? Does the check engine light stay on or go out? On lots of vehicles if the check engine light stays on during crank it isn't seeing an rpm signal from the crank position sensor. I think I remember when mine acted up the check engine light stayed on when it was attempting to start.

The tach will hover around 600-700 rpm when it's struggling to fire. I believe the check engine light is on during this.

A bad cam sensor can set a crank sensor code on these. I would throw that on a see what happens. If you have access to a scope you can check patterns and see what is happening. Last time I had Hemi ram with crank code it wouldn't act up with the scope on it , just put both sensors on it and it was fine.

How difficult is the cam sensor to replace?

I agree with the plug change. When I pulled the plugs on my Hemi truck they were had twice the gap they should and were at 90,000. That 100,000 mile change is way too long. You will be surprised at how much easier it will start and an increase in gas mileage when you swap new plugs in.

It is a bolt in deal like the crank sensor , bolts in the timing cover on the passenger side behind the thermostat.

Thank you