ecourt

my 06 f150, 5.4 2wd supercab with 138k on it has been a great truck... absolutely no problems, til last week.

I'm out of town, and the wife drives it to a store, calls me, says it won't start, and won't turn over, and when it does, it's popping, through the intake.

I get home, look it over, everything looks ok, check battery, and it test OK.

My thought is the timing chain has slipped, but in the searching I've done, seems like it just don't happen that often.

My cam phasers have been clicking for a few miles, and was planning to do them at some point, but I'm at a loss to find anything else that would cause this. Is there anything anyone can think of ? Is there a quick way to check to see if the timing chain has slipped short of removing the valve-covers?

I don't want to continue to try cranking, as this is an interference engine, and I don't want to bend a valve or worse punch one through a piston.

Any help is appreciated.

Martian

Do some more troubleshooting yourself... "backfiring through the intake" wouldn't happen unless your timing was 180 degrees off and that's hard to do

ecourt

That's where I'm going with the post.

I know the mechanical part, and the only thing that could cause it to behave this way is the timing chain slipping. No, it wouldn't need to be 180 off to pop through the intake, just a few deg would cause it.

I'm ASKING what else can I check, and is there a easy way to tell if the timing chain has slipped without pulling the valve covers.

Martian

Well of course, start by pulling for any codes / pending codes. The crankshaft and camshaft position sensors should've had something to say about that if your timing was THAT much off.

ecourt

No codes of any kind (except p1000-ff) , but the tow truck driver removed the negative battery cable before towing. I've run all the test that can be run without the engine running. it was 3 days before I got home to look at it, so it cleared the memory.

if you don't know, p1000-ff is -- codes cleared...

Martian

Have you seen the camshafts in these engines? I'd think your timing would have to be off much more than just "a few degrees" to be popping through the intake. And if it was off that much, you would've lost an entire bank and certainly had a Check Engine light and more.

What's odd is what happened. Your wife drove to a store just fine, then when she goes to start back up, it won't go. If your timing is off THAT much, I wonder if you broke a tensioner or guide. Like, completely. Even a tensioner that's not "tensioning" will hold a chain pretty well unless its guide is totally shattered and laying in the oil pan. Ask her if she heard anything break during the first crank, because if it didn't start up again and that was the problem, it might've broken when she cranked.

That's extreme without doing small stuff first though. Have you checked for normal stuff, i.e. fuel pressure and spark?

ecourt

it won't turn over. it keeps popping, and don't want to rotate. it will turn over if you let the compression leak off, and hit it again, but I don't want to do that, as this is a interference engine, and if it's jumped enough, I don't want to bend valves, or worse, push a valve through a piston.

To be honest the wife would have heard anything unless it smacked her in the back of the head.

After thinking about it, it was turning over just a bit slower than normal a few days before. I'd bet the tensioner broke, and was wedged. I fully agree it's probably out more than a few degrees, but cam timing don't need to be off a lot to cause this type of issue.

I'm going to pull it in this weekend, and start tearing into it. pretty sure it's the timing chains. A bit disappointed in Ford on this one. I've never had a ford engine not last 200k

Martian

Eh, it's hit or miss. This really is a great engine. Damn tough. It just has a few parts (namely under the front cover and the spark plugs) that could've been designed better. Those replaced, it'll run until they're fighting over it when you're dead (with proper maintenance). Hope you post updates and pictures.

lewissa81

Maybe a fuel injector is leaking and the motor is hydro-locking. Before tearing into the timing system, I would pull the fuel rails off and check for leaking injectors.

Martian

Whoa, don't go that far yet. We haven't even checked fuel pressure.

Plug in a scanner and read your fuel pressure. If you don't have a scanner, turn your key and listen for the fuel pump. It might not stop. You could also pull plugs and listen / smell for raw gas being sprayed.