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5.4 triton constant popping in exhaust

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Tiny108

Structural
Dec 14, 2009
8
when i start the SUV the popping in prominent as it warms up it quietens slightly , fuel mileage has went to the (CRAPPER).. dealership service cant narrow it down scoped says (bank 1 sensor 2 lean).. all O2 sensors are new , new coils and plugs , octane makes no difference .. anyone have any idea to how i can fix this problem it would be greatly appreciated ..... ( PLEASE )

Tiny108
 
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I'm guessing an air leak into the intake manifold, e.g. a failed gasket or a cracked or disconnected hose.

Open the hood and listen for a hiss at idle.



Mike Halloran
Pembroke Pines, FL, USA
 
thank you for your incite any ideas are appreciated ..i have done a vac test on hole vacuum system all hold pressure no leaks ..
 
Many years ago in my past life as an auto mechanic, popping in the intake meant lean and popping in the exhaust meant rich. This is/was typical for engines when the carburetor mixture was way off spec (note that there are a lot of other things that can cause popping). For popping out of the exhaust as you described, there needs to be unburned fuel entering the exhaust.

How is the compression? I know that if the dealership scoped the vehicle, they should have picked up a compression problem while monitoring the cranking amps. Perhaps one of the folks that is more up to speed than me might be able to correct my memory if the following statement is wrong. Measuring cranking amperage to determine the relative cranking compression can sometimes miss a head gasket failure between cylinders.

I would start with a compression check with all the plugs out and/or a leak down check. It sounds like someone has been replacing parts like mad trying to correct the problem and I assume that there is no way to mix up the coil wiring on your engine.

Next I would ensure that the valve train is in good shape: (1) no rounded lobes on the cam (2) no broken or weak valve springs (3) no lifters that are not bleeding down properly.

Tiny, are you positive your engine is in good mechanical condition? If the engine is mechanically sound, then start looking for some condition that would allow unburned fuel into the exhaust
 
I am having the compression checked today somewhere other than the dam dealer <----(RIPOFF) .. My trucks been in 3 different dealer service departments and after hundreds of dollars spent I still have the same problem ... As for mixing plug wires can't I have an individual coil per cylinder .. As for mechanized internal parts cant answer that if I open the engine I void my warranty .. I would have assumed the dealer would have noticed anything like that but this day and time its hard to get an honest mechanic even at a dealer (no disrespect ment) ..
 
"As for mechanized internal parts cant answer that if I open the engine I void my warranty"

??? What kind of a warranty is that? Goes against Federal law, if I'm not mistaken.
 
Well just went to shop and the compression test told it all .. Cylinders 2 and 3 r blown between either head gasket or head , but considering its been drove with this prob that aluminum head is toast .. HAAHAA now I am taking it to the dealership for either a new head or a new engine .. By the way thank you folks for all the ideas you were a great help .. I did learn 1 thing from this all tho DON'T TRUST MY DEALER SERVICE DEPARTMENT !!!!!
 
I will Keep you posted on the results ...
 
Some people call dealerships stealerships for a reason.

I always thought they are trained to train your car to return regularly, kind of like a homing pigeon.

If I buy a new car, from the day I take delivery, it never goes to a dealership again unless it is for replacement of parts under warranty. I take it where I can do my own service and get it signed off by a licensed mechanic.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
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well i was there and seen them remove the head and low and behold the is a rut between cylinders 2 and 3 ... When he took the head over to there junk bend he dropped it like 2 feet and it broke in half lol...
 
2 feet and it broke? Wow, not good. Must be one of those import casting jobs.
 
I once dropped a cylinder head two foot onto my foot and it broke.

The foot that is. ;-)

Only other time I ever managed a breakage by dropping a cylinder head was when I had ported the head until it was quite thin, like 2mm thick or less. It only cracked the local thin area after a direct impact on that area.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
for site rules
 
well i bet the foot hurt for sometime .. i am curious if when i put it in shot for an exhaust manifold replacement if they didn't cause this somehow .?.?.? but who noes anythings possible ....
 
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