# 02 SD 5.4 Low compression in #2 after plug blew out



## TJS (Oct 22, 2003)

Ok the nightmare started last Saturday when I was plowing a parking lot. I had just finished and shut the truck off to do a walk around. I got in and started it up and bang, pow, pop pop pop. I shut it down opened the hood and #2 cyl had the COP broken with the plug hanging off. The truck has 69k on it. I bought it used with 64k on it. Anyway, limped it home and got the real time sert kit$$ and a COP. Did the repair to exact instructions as they state. I even made a nice tool to blow the chips out. I also used heavy marine grease on the tooling to catch the alum. chips. Got it all back together figuring I was all set. I also changed all the spark plugs and torqued them to 13 Ft. lbs using NO neversieze. I have read that neversize eventually causes probelms. Anyway I started truck to pull it out of the garage and it was running rough. I figured eh just some **** in there it will clear up. No dice. I unpluged injectors to find the cylinder that was not really firing. To my dismay it was #2 cylinder. I swapped injectors from #1 to #2 and even the COP. These fuel rails are so easy to make changing injectors by the way. Still the clupret was #2 when running and testing it again. Damn. THERE IS A SKIP AT IDLE.

Did some searching online and found many armchair techs to do this and that. Well to eliminate and vacuum leaks I removed the TB and IAC, cleaned everthing and removed all the vaccum lines and pressure test them. All good. While I had the TB off I pulled the #40 fuel pump fuse and did a compression test on #2 cylinder. 120PSI, hmmm seems a little low. Then I checked #1 for comparision and that registered 200PSI (now that is more like it.) So here I am pissed off at Ford once again. I have spent more money on this thing than I bought my old beater Chevy pickup for in the past 4 months. I have a buddy who works for the state police (they use Fords) as a tech and he thinks I bent a valve by pinching and aluminum chip between the valve seat and the valve. I am not sure about that but it is possible. So I took the plug out again and was able to staw feed some marvel mystery oil in there and then hook up the compression tester with valve stem removed and pressurize the cylinder to try and blow the pinched chip(s) out. Who knows but the truck does seem to run a little better but still has 120PSI compression in #2. Just at idle I can feel the roughness, right off idle and acceleration it drives normal. I do not want to take the head off just yet as we still have many snow storms to go. 
I have read somewhere about bad valveguides causing the valve not to seat and make a seal. I am thinking of pulling the cam cover and see what is going on there.

I just got through doing both exhaust manifolds and studs, all ball joints, front axle joints, rotors, pads, shocks and sway bar bushings for that wonderful clunk. Now this, this sucks.
T.J.
ps- sorry so long.


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## tim096 (Dec 24, 2007)

It most likely is a bent valve, the next step to take would get a leak down gauge and put air in the cylinder and listen for the leak. good luck


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## TJS (Oct 22, 2003)

tim096;1210214 said:


> It most likely is a bent valve, the next step to take would get a leak down gauge and put air in the cylinder and listen for the leak. good luck


I have one and I am going to do that next weekend. In the meantime I gotta run it for the next storm.
T.J.


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## John_DeereGreen (Jan 2, 2011)

I'm a little bit behind in this one...but I've got an 02 with a 5.4 as well and 186K.

It's got the same miss at idle that you describe, as well as a hissing noise coming from the top of the engine. No compression when a gauge is put on it, but anything above about 1200 RPM's and it runs PERFECT.

I've had some people tell me it's a bent valve, some people tell me it needs the typical 5.4 spark plug "fix" and some people tell me there's a hole in the piston.

I bought it used with the miss "needing a coil." So when you get yours figured out I'd appreciate hearing what it ends up being...Good luck!


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## TJS (Oct 22, 2003)

You need to find the one that is hissing because it is about to blow a plug out of that cylinder, sounds like your threads are stripped. That is what mine did but I had just did the exhaust manifolds and thought the sound was coming from there, or the Y-pipe but my bolts were tight. I even said to myself when shoveling a walk and the truck was running the noise started getting louder, “I really need to get to that noise”. Then 5 min later after I shut the truck off the plug blew out taking a COP with it.

You are saying you have zero compression on the compression tester or is it low (120psi) like mine is. If it is zero then that is not good. I know someone who is going to let me use his boreascope so we can take a look to hopefully see what is going on.

T.J.


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## Elite Property Services (Oct 28, 2008)

Have you found the problem yet?


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## TJS (Oct 22, 2003)

Elite Property Services;1228493 said:


> Have you found the problem yet?


I need to take the head off. That will not be until the spring time.
T.J.


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