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Ford 5.4 Triton no spark at #5 coil

Well good deal. You are making good progress. If the error code for coil E really means the 5th cylinder that sure would make sense since that is where the trouble was at. Is the code active? It might take several starts for the code to clear after the problem was fixed.

The code is still there and I took it to a local mechanic and he says it has a burnt valve. It surprises me because of all the electrical issues it has had and how the miss in the engine started suddenly. He seemed pretty sure about his diagnosis and all but I haven’t committed to having him tear into it yet. He said he did a compression test and that’s how he came up with his diagnosis. Do you know if I can have the PCM checked? He didn’t think I could. $1000 to repair the burnt valve doesn’t sound bad but I would hate to do that if it in fact had a bad PCM. Thanks again for all the great info…I appreciate it very much!

Check the resistance to ground of #5 coil wire when it is disconnected from the coil and while the ignition is turned off. Use the diode function of the meter to do that. Then compare that results with a different coil. Hopefully they are close to the same reading and if so I would think the PCM and coil wiring is okay.

It seems strange that there is an exhaust valve problem if the plug wasn’t firing. It sounds like the tech is right on track with his testing. It would be nice to know what the number results of the testing was.

I will try to get that done tomorrow and will post results. Thank you.

Old blue

So the mechanic says you have a burned valve, and he arrived at this diagnosis via a compression test, correct?

I take it the #5 compression was extremely low?

If so, what was the compression?

How many psi?

Did he also perform a cylinder leakdown test to confirm his suspicions?

If so, what % leakage?

I don’t know what the numbers were. I do trust this mechanic but I am hesitant to have the repair done until I have a second opinion. If it is a burnt valve I am thinking of either buying new heads because I have had #3 spark plug pop out on the other side and repaired already. I may also consider finding a low mileage used engine. Not sure yet but the truck is in real good shape and I feel its worth repairing.

If the valve truly is bad and this was my truck I would just have the head repaired. New heads would cost you a lot more and repairing yours would be more cost effective in my opinion. If the other side hasn’t been a problem after the other repair I would leave it alone. The mileage on the vehicle really isn’t that high considering the age of it and should have a significant amount of good service life left, saving you money over the cost of a new one.

Thanks for all the tips! I probably will just go with having the burnt valve fixed after looking into used engines. New ones are out of the question and if I can get a few more years out of this truck, I will be happy. I haven’t had any problems with the plug repair and I think its been 2 years or better. Thanks again.

You’re welcome for the help. From the sounds of it you should have a lot of life left in the truck without much trouble. Keep up with the recommended period for the fluid changes and other things. You should be able to get top dollar for the truck when it comes time to sell it.

Your mechanic should have all compression numbers written down and a follow-up wet test on the compression should have been done; just in case it was not. One does not want to spend X dollars on the cylinder head only to discover a piston ring problem.

I would also hope that any valve job would mean both heads. With multiple cylinder heads you never do one side only when it comes to head gaskets, valve jobs, and so on.
The price sounds a bit on the cheap side for both heads.

I am going to ask him to break down everything for me on the numbers. He did ball joints and new lock out hubs for me in the past and did good work and was done in good time. He also stays busy and has a great reputation here. I am just ready to get it fixed and get back on the road. I will ask him about pulling both heads and just going through both of them. I am going to see when he can get to it and I will put an update on here when its done. Thanks to everyone for the good advice and suggestions.

If you get the work done you should also ask him about other things that could be done at the same time but may not be a problem at this point in time. Like the water pump for instance.

That’s a really good idea. Looks like the water pump would be a job to fix after the fact. I am going back to the shop tomorrow and talk with the mechanic and get some finals costs. Hope to have it fixed and back within a couple weeks depending on his work load.

Changing the timing chain might be another thing to look into also.

F250 update…my mechanic kept putting me off so I bought a compression tester for the Triton and pulled all the plugs and had between 135-140 on all cylinders and did a wet test at number 5 and yielded 200lbs. I was shocked because I just took his word on the truck having a burnt valve. Well, new plugs and I ordered Accel coils from Amazon for $185 and it runs perfectly fine. I am thrilled that the mechanic is backed up and it forced me to do a compression test. Thanks to everyone for their comments and advice, it was all helpful!

Thanks for the update . . . and congratulations!

Great news. Glad you solved the trouble at a reasonable price and thanks for the update. I have to wonder why the mechanic gave you that information about the cylinder. Did he really even take time to make the test? It might be time to find another one that could help you better on the next issue. At least you have us here to refer to if needed and we don’t charge for the information, whether it’s good or bad.

Thanks to all you guys again! I will definitely post on here again when I have issues…its nice to have a tool like this forum!

Your truck still has a problem. Those 135-140 numbers are too low and the fact that they jump up to 200 during a wet test means there’s a worn piston ring problem.

Note my comment on Page 3 of this discussion.

ok4450,
I thank you for the heads up but the truck is running good with no miss at all at the moment. If it acts up again I will post another update…