P-0307; the final repair bill

Moral of the story: Never take a misfire code P030(x) for granted. Aka keyswitch "code 43" The fix can be as simple as rerouting the plug wires
so they don't arc between them (TSB 18-48-98), or it can be difficult and very-very expensive.
For those who recall me fighting a P0307 (cyl #7 misfire) code on my 97 Ram 1500 (80k miles) for the past 19 months, I got the truck back and it is finally fixed, albeit $1946.71 later - and that's in U.S. dollars for any of you Canucks who may be wondering :-)
Actually the grand total is at least $350 more than that if we factor in all of the prior diagnosing and "attempts" over the past 19 months by independent shops and my own shadetree work. Alas none of these efforts had any long-lasting effect. After many frustrating months of trying this and trying that, and the problem always coming back, the bottom line was it had to go to the dealer.
Though far cheaper than a new truck, it was a tad expensive, but a couple hundred less than the original estimate.
The fix: Two complete -new- fully assembled cylinder heads @ $353 apiece Top-end overhaul gasket set $144 (for gaskets? Holy tomatoe!) both O2 sensors at $102 each (! again - kinda proud of these) New cap, rotor, plugs, ignition wire set, T-stat, coolant, oil, etcetera, etcetera, etcetera, etcetera and ETCETERA Total parts $1275.21 total labor $ 671.50 (8 hrs @ $79) 12-mos/12,000 mi warranty on the parts & labor (yes both, I did ask) Free loaner car for 4 days
Nice to have "ole Nelliebelle" back home.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

So you are saying the ignition system and the heads were bad? Kinda odd coincidence. Why new o2 sensors? I have been fighting a p0302 for 2 years (cyl 2 misfire) and have replaced all the ignition components and am thinking it may be the head as well. It damn sure wasnt the ignition stuff.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

An earlier compression test conducted not quite 2 years ago, when the problem first began, revealed only minor, seemingly insignificant variances. What I did not realize is a 10 lb variance is considered "significant" when you're chasing misfire problems.
Also my symptoms were a little misleading. The misfires were occurring only at low idle, i.e., sitting at a light idling in gear. As long as you could maintain the idle at or above 1000 rpm, the misfire would not occur. Fuel pressure was good (52 psi)
Before the dealer tore it down another compression test indicated 15 lbs low on #7 and 10 lbs low on #2 and 5 lbs low on #8. Thus both heads were assumed to be "involved". I had recently had a couple instances of P0302 and P0300 though the primary problem from day one had always been P0307.
A combustion leak test also revealed #2, #5 and #7 sucking air past the intake manifold gasket during the intake stroke. Bad intake gaskets? Improper torque? Who can say.
Teardown revealed a cracked cylinder head with the crack appearing across the face of the #7 intake valve seat (not repairable without replacing the head). Replacing the other head vs sending it out for a valve job was close enough to a push (factoring in the labor) that we decided not to risk it and opted to just replace both heads. The tech suspected a hairline crack in the right bank around #2 as well but said only the machine shop would be able to say for sure.
Aside from the plugs, which got pretty badly trashed from the combustion chamber cleaner, the rest of the ignition parts (wires, cap, rotor) were done for thoroughness. The O2 sensors were at my option and no addt'l labor, parts cost only, although they were considerably more costly than I had anticipated. They gave me a 12/12 warranty on all parts and labor, which is 9 months longer than anyone else was offering and a free loaner car which no one else was offering.
Inarguably I probably paid to much and had some unnecessary stuff done, but bottom line is it's fixed, guaranteed to be fixed and I didn't have to get my hands dirty. When you get 5 months away from turning 60, major projects like this seem to lose a lot of the glow they once had ;-) Hell, I stopped changing my own oil 6 years ago.
If you've done all the obvious ignition stuff, the TSB, etc and still having the problem, something in the valve train is a strong possibility. Try the idle trick. Clear the code and then drive for a day or two holding a fast idle on it when you come to a stop. How many miles do you have on it? My problems began around 75k.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My Truck(1997 5.2, 75000 miles) is doing the same thing. Rough Idle and rough at 40-45mph with overdrive on. Although I'm not getting a check engine light. I have replaced intake plenum gasket, TPS, cap, rotor,plugs, wires, cat, exhaust and it still runs rough. Maybe time for a compression check? I'm at my wits end $900 into it so far.
snipped-for-privacy@dodgecity.cc wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Well, for what it's worth the one I just spent almost $2 grand on was a '97 5.2 with 83k on it. Problems started around 75k or so. Have you tried running some Mopar combustion chamber cleaner through it?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@dodgecity.cc wrote:

Yep, sounds like a factory trained technician changing parts till he hit the right one.
JAM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If you mean the "shotgun" approach, yes, that occurred to me, but the evidence of low compression kind of indicates they were sniffing around in the right place. The cracked valve seat, altho an unusual place to see cylinder head damage, was the problem and was evident to the naked eye once it was apart and cleaned up a little.
The question is whether or not they should have replaced the opposite head. Lets ask this group, when you do a valve job wouldn't it be logical to do both heads? I think the answer to that would be yes. The additional cylinder head (completely assembled) was $353. Can you get the valves & seats done on one head then reassembled w/new springs, etc for $353. The labor to R&R both heads was already there, wasn't it? So for $353 apiece we get all brand new heads, valves, springs, rockers & keepers vs buying only 1 new head and hauling the other one to the machine shop.
I think we did the right thing here. Likely didn't need the O2 sensors.
Question: Does a cracked cyl. head have any core value other than as scrap iron?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Put it on eBay. Advertise it as a "1997 Dodge Ram Cracked Cylinder Head/Small Boat Anchor". Be sure to tell the whole story and explain how you are trying to recoup some of the repair bill. You never know what people will bid on. Even if it doesn't get any bids it won't cost you anything.
--
Ken



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Jay Leno's occasional segment "Stuff we found on eBay" is living proof that some people will bid on anything and a fool & his money are soon parted. Jeeze, just imagine what that thing would cost to ship. The mailman would be wearing a truss.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, the shipping would cost more than it's worth as scrap iron but someone still might bid on it. Something like that could make it on The Tonight Show.
--
Ken



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.