Broken valve spring?

[notamechanicbrad]

2011 Expy with 270k miles.

I am getting a misfire on cylinder 8. New plug, coil and injector. I am definitely getting spark and fuel. The wiring all tests ok.
No water in the oil. No oil or bubbles in the water.

Next step...compression test. I rented the tester at OReillys but it didnt come with the adapter for Ford so I ordered 1 this afternoon for tomorrow delivery.

If I dont have good compression but have no oil/water problems...Broken valve spring or rocker arm????

 

[2016 ford expo]

possibly but I'm not positive. I have never had this problem maybe its cuz your expo has 270k. that might be part of the reason

 

[GlennSullivan]

2011 Expy with 270k miles.

I am getting a misfire on cylinder 8. New plug, coil and injector. I am definitely getting spark and fuel. The wiring all tests ok.
No water in the oil. No oil or bubbles in the water.

Next step...compression test. I rented the tester at OReillys but it didnt come with the adapter for Ford so I ordered 1 this afternoon for tomorrow delivery.

If I dont have good compression but have no oil/water problems...Broken valve spring or rocker arm????

*** EDIT ***

Start At 3 minutes and watch the remainder of the video.

Ford F-150 & Expedition 5.4L 3v Triton Engines Hard to Diagnose Misfires Fixed!

In this video we show you what to check when you have hard to diagnose misfires on this engine.These are the Parts and Kits I Recommend:2004-2014 Engines Lat...

www.youtube.com

 

[notamechanicbrad]

Thanks for the input Glenn! On both threads!

I ordered the adaptor for my compression tester but what came was the older 5.4 spark plug size. I ordered another one, hopefully the correct size, coming tomorrow.

In the meantime, yesterday afternoon, since I had no way to check compression, I pulled the valve cover and took a look at the roller followers, etc... Everything appears to be in good condition and in the right place. All the cam lobes look fine.

Then, today, we pulled the fuel rail off and checked for any blockages in the fuel injector ports. All looked good. Reinstalled that and put in another new injector, then we ran a jumper wire off the fuel injector directly to where it goes into the PCM. So, I am bypassing the wiring harness on both the coil and the injector at this point.

Interesting thing is... When we put it all back together this afternoon, at idle and just driving it down my street at 10-15mph if felt like it wasnt missing. But, once I got just a few blocks to the main road I started feeling it missing and it felt like it got worse the longer I drove it (a total of about 2 miles).

The check engine light comes on flashing when under a load...then goes off when acceleration gets lower.

Also replaced the variable valve timing solenoid since I had the valve cover removed.

I have the Forscan software but an not educated in how to use it. Ive used it to program keys but thats about it.

Ive talked to 5 "Mobile Mechanics" but only 1 has showed up and he looked over what I have done and said it all looks like it should. You really have to have someone who knows these 5.4 3v engines... Its not just installing an alternator type repair.

 

[DieselMonk]

About the parts you replaced… are they genuine Ford parts or some aftermarket chit?
Other than that, I would say:
Broken valve spring, cam shaft, bunt or bent valve, valve seats, coil, spark plug, bent rod, piston rings, scored cylinder wall, weak coil driver (PCM), fuel injector, also wouldn’t rule out a vacuum leak just yet.
Suck… squeeze… bang… blow… and off she goes!
That’s all I can come up with on the quick.

 

[notamechanicbrad]

Thanks for the post DieselMonk!

Im pretty tired of working on it at this point.

Mostly mid-grade OReillys lifetime warranty parts. Coil packs and fuel injectors thru Amazon that I have in my purchase history and have had decent luck with in the past. I put 16-1800 miles a week on these trucks so am often replacing parts. I go thru a lot of coil packs, injectors, etc... Unfortunately, I wear out the suspension and drive axles, etc in 6-12 months...so its not usually worth buying more expensive external engine parts.

Everything I could see with the valve cover off looked ok. No unusual wear on the cam. All rocker rollers in place.

No smoke from the exhaust so I think the rings are ok.

I have swapped the coil, plug and injector with different cylinders and the misfire stays on #8.

I recently had some wires going to the transmission melted against the exhaust manifold. Once repaired, I replaced the PCM as I believe some circuits were burnt do to the short in the wires. I have an extra PCM for this VIN as well. I swapped to the other PCM, reprogrammed the keys with Forscan, and get the same misfire with either PCM.

 

[DieselMonk]

Hmm… that leaves a vacuum leak in the intake manifold, a bent rod, timing, something making the valves not seal properly, scored cylinder walls and piston rings. We also cannot verify that the coil is drawing the proper amount of current and sparking at the right time. Even with parts swapped around.
You got a borescope so you can look down the spark plug hole and check the inside of the cylinder and the valves (seats)?
Maybe just cheaper to find a running 5.4L from the junk yard. They are plentyfull to be had. Maybe find a 32 valve from the Navigator?

 

[notamechanicbrad]

I ordered the gasket for the intake manifold. Ill check compression in the morning and if that looks good I will change out the gasket on the intake.

 

[DieselMonk]

Before you change the gasket, check the piston top dead center and compare it to a different cylinder (to rule out a bent rod). Also make sure the valves actually open and close.

 

[engineer1]

Just a thought from a whole different direction. My EB is a gen 2, so may not apply to your situation, but I was having a similar problem and decided to replace the coil packs. When I removed #7 I noticed it was wet on the bottom, but did not have a coolant smell. I came across a thread on this forum about the weather seal along the top of the firewall being made in 2 pieces with a joint in the middle that allowed water to drip down onto the engine. I sealed it up with silicone rubber and haven't had a problem since. May be an easy thing for you to just check.

 

[pitdexion]

Water also ingresses through the plastic clips holding the seal fyi.

 

[notamechanicbrad]

Thanks engineer1 for your suggestion. Ive been checking the well for the coil//spark plug with some long Q-tips actually...and it is always dry.

Thanks DieselMonk. The compression tester adaptor I ordered still hasnt arrived. It was supposed to be here Sunday, then Monday, now by Wednesday. If it ever gets here I will check compression. If I get good compression then I know the valves are all closing. The cam and rocker rollers look good so I think the only possible valve problem would be that 1 is stuck open. I dont know if the piston would hit it or not if always in the open position.

I will post the results when I am able to do the compression test.

 

[notamechanicbrad]

Thanks pitdexion. Yes, I am curious if I am getting any water thru that seal. The truck hasnt been on the road for a couple months or in any significant weather. But, that spark plug well is dry at the moment.

 

[Fastcar]

I ordered the gasket for the intake manifold. Ill check compression in the morning and if that looks good I will change out the gasket on the intake.

Before you change the gasket, spray a little ether on the fittings and along the intake to heads with the engine running that should show you where your leak is.

 

[DieselMonk]

Thanks engineer1 for your suggestion. Ive been checking the well for the coil//spark plug with some long Q-tips actually...and it is always dry.

Thanks DieselMonk. The compression tester adaptor I ordered still hasnt arrived. It was supposed to be here Sunday, then Monday, now by Wednesday. If it ever gets here I will check compression. If I get good compression then I know the valves are all closing. The cam and rocker rollers look good so I think the only possible valve problem would be that 1 is stuck open. I dont know if the piston would hit it or not if always in the open position.

I will post the results when I am able to do the compression test.

The valve just needs to be suck open a tiny bit, or the valve seat is buggerd up somehow, cylinder wall scored, etc.
You need air, fuel, compression, spark and that all with the correct timing. How does the engine sound at idle?

 

[notamechanicbrad]

At idle it sounds fine but you can feel a slight vibration from the misfire. No ticking or clattering or other strange noises.

A few days ago after we had done some work on it, I started it up and my helper said "I think its fixed...its idling great". We got our hopes up...but by the time we got down the long driveway and out on the street I could feel the misfire. By the time we got 1/4 mile from the house it was back to full misfire mode.

Amazon lost my compression tester adaptor so I had to order another 1. It will be 2 days before it gets here...or the original order might show up sooner. I figure its gotta be a compression issue. I will know in a couple days.

 

[notamechanicbrad]

Thanks fastcar.

What am I looking for when I spray the ether? Sounds like the start of a major fire! Im not trying to burn it to the ground...YET. Probably next week...

 

[DieselMonk]

At idle it sounds fine but you can feel a slight vibration from the misfire. No ticking or clattering or other strange noises.

A few days ago after we had done some work on it, I started it up and my helper said "I think its fixed...its idling great". We got our hopes up...but by the time we got down the long driveway and out on the street I could feel the misfire. By the time we got 1/4 mile from the house it was back to full misfire mode.

Amazon lost my compression tester adaptor so I had to order another 1. It will be 2 days before it gets here...or the original order might show up sooner. I figure its gotta be a compression issue. I will know in a couple days.

What were you guys doing or taking apart when it ran good for a few minutes?

 

[notamechanicbrad]

I believe it was due to disconnecting the battery for a couple hours. My helper said it was when we replaced the plug to the injector and bypassed the wiring harness routing it directly to the wire coming out of the PCM. I believe it was still misfining, just not as bad.

Still no compression tester adapter. Amazon shows it will be here tomorrow but it look like it just left Chicago area today and I am all the way near Ft Worth, TX. Until that gets here and I can check compression Im not spending any more money on it.

 

[notamechanicbrad]

I tested compression on the misfiring cylinder #8 today. It was 148.

I probably need to do a proper test on all cylinders. I did #5 next and it was 120. So I checked to make sure my compression tester was tight down in the spark plug hole which it was. Tested #5 again and it was 90. So...Im not doing something correctly while performing the test.

Im going to look at a 2012 Expy EL this evening. 155k miles.