Are new coils needed ?

Ryd2live · Oct 1, 2013

I recently purchased a 2004 5.7l 4X4 2500 Ram Truck. I really have no idea what sort do maintenance (if any) has been performed on this vehicle. So without knowing what has or has not been done I am performing multiple things on this truck. Ie. ... Trans filters, brakes, rotors turned, air filter, oil change,shocks etc,etc.
I am going to perform a "tune-up" this weekend. Ie.... Plugs & plug wires. The dealership recommends replacing the coils as well. Is this necessary ? I really do not mind doing this if needed since I am going to have everything taken off anyway. They are rather pricey I would prefer not to replace them if it is not necessary. Any thoughts comments or suggestions would be appreciated. Thanks

MegaMouseGW · Oct 1, 2013

Depending upon the mileage the coils should be replaced. Everything else seems like you hit the nail on the head. Depending upon the state of the rotors you may need to replace them also. Not too expensive but worth the peace of mind.

Ryd2live · Oct 1, 2013

The truck has 151k miles. I had the rotors turned they were within spec. Previous owner had the exhausts made into true duals. I am having both cat converters replaced ( really bad welding job) dodge dealer could not/ would tell me which one was bad. Replacing both upstream O2 sensors since they showed to be bad as well. They also mentioned minor exhaust manifold leaks. Seems like the list never ends. I did not pay much for truck TG. How significant is the exhaust leak related to mpg's and possible future damage to engine ?Ultimately I want get better than 10.5 mpg.

hemihustlin · Oct 1, 2013

Leaks at the manifold, aside from sounding bad, will decrease your mpg because the o2s will see extra oxygen in the gases so to compensate it will inject extra fuel. Hemis dont normally break ( the exhaust manifolds) it should just be a couple of loose or broken bolts that will need to be replaced along with the gaskets.

MegaMouseGW · Oct 2, 2013

As Hemihustlin said Exhaust leaks are bad for the mpg. Replace the gaskets with a good aftermarket set, and replace the studs and nuts with some locking ones.
One other thing that will decrease your mpg is the true dual exhaust. Have a muffler shop install a crossover pipe behind the cats. That will allow proper scavenging of the cylinders and better airflow overall.

Ryd2live · Oct 4, 2013

Just had the cats changed today with a crossover. The engine light had been on since I bought the truck. Now after driving a few mies the engine light went out. I was told previously that I had bad O2 sensors. Now I am thinking not so much. The guy who did the repair showed me the seriously bad welds that had huge holes in them. The big surprise was that he showed me the cats that came off were completely hollowed out. So now that my check engine is now now out does that mean the problem is resolved as far as the O2 sensors ? I have narrowed down the exhaust manifold leak and that is next on my list of to dos. Figure I can do that myself after reading up on it and having the mechanic at the dodge dealership give some helpful hints.

MegaMouseGW · Oct 4, 2013

Sounds like you fixed one issue with the crossover pipe. Cool. Now I would still change out the header gaskets and bolts like I stated in an earlier post just to get those pesky leaks out of the way. Problem with Exhaust leaks is that they can introduce carbon Monoxide into the trucks cab. Which is a very bad situation.

hemihustlin · Oct 4, 2013

And yes, if your check engine turned itself off after installing good cats then i would belive the o2s are good, because if the pcm is always preformong cat efficiency test as you run/roll (fords and gms are different, gms do 1 test per trip and i forget fords procedure lol

) so all things indicate a good running system. You will get an o2 preformance code if the pcm detects it often out of range but sometimes replacing the o2s even with no code will improve the mpgs

KGBIGCOUNTRY · Oct 5, 2013

The poor welds will also cause codes for the o2s. The front o2's just reads the mixture for the motor and the rear ones just make sure the cats are working. If a leak is infront of either it will cause a light, or in your case leaks and gutted cats will cause issues.

Are new coils needed ?

Ryd2live

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