Dodge Hemi running bad

[Blk88GT]

It would seem that way, but I'm no expert on Dodge stuff.

 

[Farmwithjunk]

Are you running regular grade or mid grade gas? When I ran regular in my 03 Hemi 1500, it ran like crap and threw a couple of check engine lights. I filled up with high test to bring up the octane of the gas that was left and only ran mid-grade since.

These engines are very high compression (hence, dual plugs) and need higher octane than regular. They also use a speed density air monitoring system as opposed to mass air flow that most vehicles use. This is due mostly to the fact that they use so much more air than most and at a higher velocity. If that little sensor in the intake is dirty, the vehicle will run like crap. You can get some electric sensor spray and spray it into the intake to clean the sensor.

Also, in the future if you want to check any codes that come up just use the "key trick" to get them. This is only valid on Dodge, Chrysler, Jeep, vehicles. With the truck off and all doors shut, take the key from the off position and quickly turn it to the on position and back off three times (on-off-on-off-on) and leave it in the on position (not start). The codes will show up on the odometer display and you can reset them by holding the trip reset button.

And once you reset all the codes, reset your PCM (powertrain control module) also. Just pull the #23 fuse and turn your key to the on position. Wait for the chime to ring three times and put the fuse back in before starting it. You can just unhook the battery for a while but this way you don't lose your radio settings, etc...

Good Luck!

I'll do the #23 fuse thing in the AM. I posted on the Hemi forum (from earlier post) and got the "unhook the neg cable" trick, but that fuse sounds even better.

I use the cheapest gas I can get. And funny you should mention that. I filled up a couple days ago. After that I heard "spark knock" for the first time since I bought the truck (4 years/75,000 miles ago) When the truck started running bad this morning, the first words out of my mouth were "I think I got some bad gas".

 

[Farmwithjunk]

Found the problem.... Engine was built in late '03. "03 Hemis had weak valve springs. Broken valve spring on #1 cylinder. Ouch....

 

[wushaw]

Your hearing must be going if you couldn't hear a broken valve spring tapping
It's an easy fix if you have an air compressor with a big tank, a compresson testor with air hose fitting and a valve spring compressor that just slides over and gets just the spring. You will need new spring handy when preforming this operation

 

[Farmwithjunk]

Your hearing must be going if you couldn't hear a broken valve spring tapping
It's an easy fix if you have an air compressor with a big tank, a compresson testor with air hose fitting and a valve spring compressor that just slides over and gets just the spring. You will need new spring handy when preforming this operation

What'd ya say.....? This truck has had a clicking sound for most of it's life. It sounded more like a slight exhaust leak. With the extreme heat lately, it's been windows up and air conditioning on. Not much engine sound.

 

[wushaw]

Yea it would be kinda hard to hear with the A/C running, radio half cranked up, leaf hung up in the blower motor
That dead cylinder is the true tell tale sign something has gone arry...

 

[Farmwithjunk]

Yea it would be kinda hard to hear with the A/C running, radio half cranked up, leaf hung up in the blower motor
That dead cylinder is the true tell tale sign something has gone arry...

Kinda funny you should mention the leaf hung up in the blower motor! Actually, it's a small piece of paper....LOL!

Driving the '03 Cummins Dodge 'till the Hemi is back in business. It's got the leaf in the blower.

Radio is usually 3/4 cranked up too. Almost 40 years of marriage and I've learned to shut out almost any sort of unpleasant noise too.

 

[Z-Michigan]

Driving the '03 Cummins Dodge 'till the Hemi is back in business. It's got the leaf in the blower.

Just curious - why are you ever driving the hemi if you have an 03 Cummins Ram? Seems like you'd be saving near 50% on fuel costs to just drive the diesel all the time. (I'm not asking to stir trouble, I'm asking because I may learn something...)

 

[RobertN]

I would have thought the same. But...

I checked fuel locally today. 76 and Chevron have regular at $2.65 but diesel is $3.19 That's a $0.54 difference!

We've really been getting raked out here. In '01 when I got my '01 Ram-CTD, diesel was a little less than regular. Then it was more expensive. This last winter and spring, diesel stayed stable, while gas went higher. Now, gas is $0.54 a gallon cheaper.

It's more expensive to run the diesel pickup right now, at least here. I know when you get down in the valley, the truck stops are cheaper. But not a whole lot...

Just curious - why are you ever driving the hemi if you have an 03 Cummins Ram? Seems like you'd be saving near 50% on fuel costs to just drive the diesel all the time. (I'm not asking to stir trouble, I'm asking because I may learn something...)

 

[Farmwithjunk]

Just curious - why are you ever driving the hemi if you have an 03 Cummins Ram? Seems like you'd be saving near 50% on fuel costs to just drive the diesel all the time. (I'm not asking to stir trouble, I'm asking because I may learn something...)

Company I work for has a gas pump at the shop. I fill up free. Diesel I pay for. So, I drive a gasser to and from work.