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White Smoke


Well-Known Member
Local time
1:59 AM
Jan 23, 2015
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Hi guys,
My 73 Road Runner back fired so I went to restart her to suck the flame back into the engine where it belongs-and the new electric fuel pump kept pumping fuel and in less than a minute my new $7k
Paint job was done!
After cleaning up the fire damage I replaced the head gaskets. Before replacing them I took the 340 X Heads to a machine shop to lap and magna flux the heads- a two hour job at best which took them more than 3 weeks WoW-
When I picked them up I was told that during the time spent there something fell and broke off a corner of one of my heads and they sent it out and had it repaired by way of a weld-
I bought the recommended gaskets and being extremely cautious I put the heads in place and torqued them down in sequence and in succession per Mopars instructions.
Everything was fine for about 10 days and she started to smoke white on the right bank only, the same head they welded.
I re-torqued the head to no avail-Also, the same corner smoked leaking smoke fumes in the engine bay and into the passenger compartment.
I called the machine shop and they said my rings were bad!
My bird has 120,000 original miles and the rebuild engine has less than 30k-
So why are the rings bad? I think the rings are bad because they don’t want to replace the heads?
How would you handle this situation?
Please be as frank as possible as what I want to do is not cool-
Dropped off the bench... A replacement head would have been sourced if it was my work.
I think you'll need to pull that head off to give it an inspection.
Certainly their screw up. Apparently the repair wasn't done right or couldn't actually be fixed.
You need to pull that head and determine the problem with it. I say that it's more than just something that was broken off. That shop needs to replace that head. White smoke isn't bad rings. Water is getting into the combustion chamber.
Poster needs to do some diagnostics. To many Ifs here. Fire raw gas dumping causing a fire. Seems odd a supposed 30,000 mile rebuild has the heads pulled. Why was this needed.
1-Cooling system pressure leak. Is it loosing coolant? If so where? Bubbles in the system? Do a chemical test for combustion in the cooling system.
2-Compression test
3-Leak down test.
I know when I had the heads done for mine. And seen smoke. It was a grey blue. Telling me I should of done the rings.

White color would indicate either a bad gasket or cracked head.
Smoke and steam are different things. Steam will just fade into nothing like your breath in cold weather. Smoke lingers in the air awhile longer.
A damaged head that allows coolant into a cylinder will push steam like a locomotive. The spark plug in that cylinder will be especially clean as well.
Could be as simple as a coolant leak at the manifold's studs leaking coolant.
First thought was needle and seats blowing fuel in the motor, then second thought was if it's doing that for long, bye bye rings.
But yeah, need to decide why the smoke, and what kind of smoke.
Like pnora said, exhaust bolts pushing coolant
More to the story here that we haven't heard. Backfires with flames is a problem in it self. Recent under hood mods ?? One of the jobs of the air filter assembly is to prevent under hood fires. Under hood insulation is not just for noise, it is also fire retardant. Is your fuel pump wired to your ignition key?
As said before, excess fuel can wash the rings on even a brand new engine and ruin them. Do a leak down test to determine ring seal first before you take it apart.
And what is the rest of the story?
I read it that the fire occurred some time ago which in turn resulted in him pulling the heads for refreshment and now he has this issue... Like far too many threads, this is a bit confusing.
Have you pulled the plugs? Do they tell you anything? White smoke and the events leading up to it sound likely it's related to the head in question. A good whiff of the exhaust usually tells me what the white smoke is. Coolant out of an exhaust pipe is unmistakable IMO.
It would be nice if when someone started a thread they would check on it and address the issues they started...
I'm confused, as thought the posting was by Biomedtechguy. I see his avatar a lot...