P0340 and P1336 2004 Exp 4.6

[whagen]

I have looked around on this forum and other and have not seen a most likely cause for both of these codes to come up at the same time.

It's a 2004 Explorer, 4wd, 4.6L, with about 150K on it. Nothing done to it lately, or ever really. it's been a reliable truck. other than the fresh air intake box crapping out twice so far.

The truck runs ok. It's not smooth at idle in or out of gear. Off idle it seems fine, if it's not running right then it's not off by much.

My plan is to replace the Cam Position Sensor since it's a cheap part and not to much of pain to change.

Mainly because it seems to run fine when moving, i am thinking it's not mechanical.

Anyone else run into this and have a solution?

 

[Number4]

I'm lazy today, can you post what the codes are?

Cam sensor isn't easy to get to.

 

[whagen]

P1336 Ford - Crankshaft Position Or Camshaft Position Sensor Input Signal Error
P0340 Ford - Camshaft Position Sensor Circuit Bank 1 Sensor 1

 

[Number4]

Has it had any noise at start up? Chain rattle?

You have to remove the power steering pulley, pump and braket in order to get to the cam sensor. Not too big a deal.

 

[whagen]

There has been some noise when starting up and cold. I was thinking it was the lifters cold and leaking down. Or maybe piston slap till they warm up. Once it warms up its quiet. Oil usage is about a quart every 3000 miles. No smoke on start up.

 

[Number4]

The drivers side tensioner tends to fail. Passenger could too. They quit holding oil pressure after sitting due to bad seals. This allows chain slack which could also allow the cam gears to jump a link.

 

[whagen]

Being off a tooth it would still run fine? Power is fine. Milage is the same. Just not smooth at idle.

The noise at start up has been there for a while, and more pprevalent when cold.

It does have 150k so i can understand things wearing out.

 

[whagen]

Is there anyway to tell if the tension is the issue without getting to it?

Also was a faulty cam position cause a poor idle, from what I have read it's just used on startup to figure out what position the cam is in relative to the crank.

Also clearing the code didn't anything, still rough idle and the code come back on the next start.

 

[whagen]

Well it looks like it's the timing chain adjuster that is shot and that the chain has jumped a tooth. Now it's just crossing my fingers that it doesn't completely fail before it gets fixed.

Anyone have a recommendation on timing kit? Ones to go with or to stay away from?

I would attempt it but working out in the cold (below freezing) isn't enticing me.

 

[Number4]

If the chain has jumped, it'll do it again. You may get away with one tooth, but anymore and you will most likely be buying an engine.

You need to stop driving until it's fixed.

Not sure how you know it's the tensioner, but to test, remove the valve covers and see if the chains have slack. Do so after the car has not been driven for some time, like over night.

 

[whagen]

Basing it on a trusted mechanic's experience , codes, sound, and basic testing. Sensors are fine and so is wiring. So electrically it's working as It should. Doesn't appear to have a vacuum leak. throttle body is clean. So milage, symptoms and typical engine failures are pointing toward it.

I could see if compression is different on each bank. Ill see if the o2 sensors read different or if one is hotter.

I am guessing the cam sprocket is the one that jumps or would if be the crank?