Was riding my 400 in colder weather. She started up fine let it warm up and went for a ride. After about 2 miles it starts sputtering like it was running out of fuel. It started a louder ticking rattling noise than normal and then died. It would turn over but would not start. Towed it into a heated shop. After sitting all day it started right up but then had the very loud ticking noise when idling, like the valves were out of adjustment.

So I changed the plug, and added some fuel dryer as I thought I had picked up some water. Checked the valves which were within specs and tried it again. Still very loud ticking noise. I then took in back into the shop and changed the oil. Found fine metal shavings stuck to the magnet on the drain plug. got me curious so I rechecked the valves again. When I started it back up it still had the loud ticking noise at idle. It is still there at higher rpm's but not as noticiable.

Took it for a ride. Ticking is getting louder. It sounds like its on the top end around the vavles. So I took the access plate off for adjusting the valves and started it and let it idle to make sure oil was getting up there (which it was) and that is was working correctly (which it was) and you could really hear the ticking sound.


I was thinking about checking the compression, draining the oil again to check for metal shavings a second time and then possibly removing the head? I am stumped.

Anyone have other suggestions?

Oh almost forgot, its a 2003 400i with just over 3600miles.

SJ

 

Could the cam chain adjuster have gotten broken, or loosened up?
Its not an exhaust leak?

 

I am going to try an run a compression test tonight, but last night I was looking through the valve adjusting port and I was able to grab the intake rocker arm and wiggle it side to side quite easily but could not do that with the exhaust rocker arm. Engine was at TDC. It could be it but wouldn't explain the why?

I really want to figure out the what and why before tearing into it so I make sure I fix the problem the first time.

If I take the head off I will look at the timing chain and its adjuster as it could be broken or the chain slapping against it.

SJ

 

I would take a long screwdriver or rod stock (or stethescope) and placing it against the engine in different places, and while it is running see if you can find where the noise is coming from, before you rip it apart. Also, cut the filter open carefully with a chisel and see if there is much metal in the paper element, cut it off the spool and lay it out on the bench, run a magnet over it. I would also take the drained oil and filter it thru a coffee filter, dilute it with some kerosene or other solvent and see how much metal there is. Sounds like valve adjustment, tho. But that shouldn't have made it not want to restart. Best of luck.

 

Drop some SeaFoam in there too, I know that gas you get out there in the bush of Alaska is crap, I had problems with it all the time when we were in Dillingham. However it does sound like you have a internal issue. On another note, I remember my 400 always having a natural ticking sound to it too. Keep us updated swampy.

 

Take the center bolt out of the auto tensioner then remove the two bolts that holds the tensioner on. Once you have it off place your thumb nail at the last rachet mark where the dog is engaged, then with your orther hand pull the tensioner. If the push rod is extended out all the way it's time for a new timing chain. If this is what it is and you replace the chain your self make sure you get the timing marks correct, the auto compression release on the exhaust side of the cam is really picky. By any chance, had a valve adjustment been done on it just before it started ticking ?

 

I did a compression check which came back a little high on compression range. (it was over about 8) So I rechecked the valve adjustments. They were a little tight but still within the correct ranges so I adjusted them out some.. It was during this I noticed the intake rocker arm was very loose. I can even wiggle it some when it has the intake springs compressed. The exhaust valve rocker arm has almost zero wiggle at any time. So I think the ticking could be the loose intake rocker arm.

The ticking sound is still present but not as noticeable. I am not sure if its back to what it was and I am just being super sensitive to it or if somethin gis still wrong.

I still suspect the intake rocker arm is worn, but if the intake rocker arm is worn wouldn't the compression test come back high?And why would it start and run so easily? you would think it wasn't getting the propper air/fuel mixture?

With your guys help I am heading in the right direction but, darned if I don't just keep scratching my head on this one.

Wilburnga, No I had not adjusted the valves prior to the ticking starting. But I have done it 3 times since it started. The ticking sound I can hear is definitely coming from higher up on the motor than where the timing chain adjuster is located.

Sj

 

It could be that the valve guides are very worn. Are you burning any oil?

 

Valve guides could be worn. But I just changed the oil and haven't put but 10miles on it since. The compression test also was high

In fact it has been sitting for a few days and I started it up and rode it this morning and the ticking was really loud at first until it had ran a few seconds and the oil must have made it up there to the top end as it quited way down. I let it warm up about 15 minutes then rode it. Ticking was still present but not what it used to be. No blue smoke so if its burning oil it is not very much.

I am going to ride it some more today and then change the oil and look for metal shavings. If I do not find any I will just keep riding it and see how it does. Ticking noise right now could be normal except I am sensitive to it and listening for it. It is running as well as it ever has. Starts easy (even cold -8 degrees), idles smooth, runs and shifts well at all speeds and gears.

I think I could be trying to fix something that is not broke! Maybe the AC synthetic oil is too thick? and not getting to the top end fast enough OR Maybe its too thin and is not staying on the top end for start-ups? Anyone know of a way of thickening or thinning AC sythetic oil W/O messing up the wet clutch OR switching to dino oil?

Maybe I can get my wife to spring for an oil heater? OR better yet a heated garage!

SJ

 

Not to scare you but i had the same symptoms when a wrist pin clip came out and the wrist pin walked out and the piston was smackin the head [img]i/expressions/face-icon-small-shocked.gif[/img]