P306 = External HG leak?

pinkytoe69

pinkytoe69

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Jan 14, 2012
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2004 D2

Long story short...

- 1 block from home and get loud ticking noise and blinking CEL for P0306
- Put new wire on #6 and swap plug with plug from #4. Original #6 plug is wet and black. Still Loud tick and blinking P0306
- Put new coil pack in, still loud tick and blinking P0306
- CEL does not blink when idling or revving. Only under load
- at cold start, noticed exhaust coming from somewhere in the passenger exhaust manifold area.

% chance the HG is blown out the side of #6?
 
p m

p m

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That was a 14CUX truck - so it may have caused misfiring (I am sure it did), but no Check Engine was thrown or any codes stored.
Obvious was the "pffft" sound when the engine was shut off. You may try listening to the engine when somebody shuts the ignition off.
 
pinkytoe69

pinkytoe69

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Ok, Ill give that a shot.

Can you get the deflation sound just by running for 10 sec when cold, or is it best to get to temp first?
 
rovercanus

rovercanus

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Apr 24, 2004
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Had an exhaust leak on my 2000 that was coming out of the head gasket. Truck ran like a champ and never through a code.
 
jymmiejamz

jymmiejamz

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Do you feel any air coming out around that cylinder? Is it possible that something fell into that cylinder like a dowel pin from the plenum?
 
pinkytoe69

pinkytoe69

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jymmiejamz said:
Do you feel any air coming out around that cylinder?
Click to expand...

Ill try and see.

Is it possible that something fell into that cylinder like a dowel pin from the plenum?
Click to expand...

Extremely doubtful. This started right at the end of the 30 min drive home from work. Get to the last light, and all of a sudden the CEL starts blinking and I hear the tapping. Before that, it had been running fine for 30k since doing the head gaskets and block sealer.

Dont know if this means anything, but...

When I took the intake off to do the coil pack, there was a small puddle of brownish liquid in the throttle body. Looked kinda like if you sprayed a bunch of cleaner in it and let it drip down to pool at the bottom. Didnt have a strong smell...oil-ish with maybe a hint of gas.
 
jymmiejamz

jymmiejamz

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pinkytoe69 said:
When I took the intake off to do the coil pack, there was a small puddle of brownish liquid in the throttle body. Looked kinda like if you sprayed a bunch of cleaner in it and let it drip down to pool at the bottom. Didnt have a strong smell...oil-ish with maybe a hint of gas.
Click to expand...

That's oil from the crank case breather in the valve cover. Without hearing it, I'm going to guess head gasket, but if you already did that, its doubtful that the head gasket is the issue unless you used studs or did something wrong.
 
singingcamel

singingcamel

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External leak , you should be able to isolate it , from my experience it sound more like a puffing sound then a tick and you should be able to fill the pressure with your hand, usually between # 4 and # 6 passenger side.
Suck some seafoam thru the intake and it will tell you were the leak is .
 
pinkytoe69

pinkytoe69

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jymmiejamz said:
That's oil from the crank case breather in the valve cover. Without hearing it, I'm going to guess head gasket, but if you already did that, its doubtful that the head gasket is the issue unless you used studs or did something wrong.
Click to expand...

I did use studs. I was contemplating tightening the outer ones by the cylinder a little just for kicks.

It is entirely possible I fucked something up when doing the HGs, but I think assembly idiocy woulda popped up well before the 30k mile mark.

singingcamel said:
External leak , you should be able to isolate it , from my experience it sound more like a puffing sound then a tick and you should be able to fill the pressure with your hand, usually between # 4 and # 6 passenger side.
Suck some seafoam thru the intake and it will tell you were the leak is .
Click to expand...

Yeah, I didnt tighten the y-pipe-to-manifold nuts enough on the D1 when I welded in the muffler and it sounded like a choo choo train. This is not like that. Had I not seen misty stuff around the passenger manifold while trying to diagnose, I wouldnt have thought exhaust leak at all.

Not that anyone gives a shit, but in case anyone is wondering why I havent actually tried out any of this advice yet...my mom has been in town and my wife ended her maternity leave today, so garage time has been scarce. I wont be able to really dig in till at least thursday, but Ill try to get a vid at least tomorrow.
 
pinkytoe69

pinkytoe69

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Here is a short video before I took the intake off again. I dont know what the high-pitched sound is...didnt hear it while filming.

https://youtu.be/7pTcQes-HfY

<iframe width="420" height="315" src="https://www.youtube.com/embed/7pTcQes-HfY" frameborder="0" allowfullscreen></iframe>

I will at least get the valve cover off tonight and see if that reveals anything.
 
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