My 5600 has a ticking sound coming from under the valve cover. Not too loud. 1) should I be concerned? 2) if I take the valve cover off, what do I look for?
Probably valve adjustment, also known as adjusting the valve clearance, or sometimes called "tappet adjustment" or "valve lash" . If doesn't really matter if that is the problem or not, because to diagnose a tick from the upper end you start by doing a valve clearance adjustment. Clearance between valve stem and rocker is normally in the .004" to .012" range for most water-cooled engines and you will find the proper spec. for your engine in the shop manual. You will need feeler gauges and a set of wrenches, plus some way to turn the engine to the right positon for setting each valve. More on that below. With this one adjustment of each valve you are setting the clearance of that valves entire valve train. For a 4 cylinder engine you will do all 8 valves, rotating the engine slightly for each new valve. Normally, you will find it easy to get the the adjustment within a thou or two and that will suffice. If way too loose the valve will always make a ticking or clacking noise, but that is better than being too tight because too little clearance can cause a valve to be held open which can burn a valve's seating surface. I think you will find it easier to do than to read about.
Start by taking off the valve cover and just see if one of the rockers is way out of adjustment. You may even be able to tell one that is really out of adjustment with your fingers. Then set all the valves back to nominal with a feeler gauge. There is a right and wrong way to go about this, so read up.
I'll give you some hints. Rotate the engine very slowly with the fuel OFF! by using a socket wrench on the front engine pulley. Slowly, slowly....You don't want it to fire! If the compression is too high to be able to rotate the engine accurately, either sneak up on it slowly or in extreme cases it will help to pull (remove) the injectors to eliminate the engine compression. Some engines have hash marks on the front pulley or through some inspection port that will tell you when the crankshaft is in the right position to set the valves. That's in the shop manual again.
But finding those registration or hash marks isn't strictly necessary since the valves on all engines can be set by using and understanding the following: For each cylinder, set that cylinder's intake valve when the exhaust valve is just starting to open, and set the exhaust valve clearance when the intake valve has just closed. Doing it that way is always correct because it absolutely takes into account the overlap and quieting curves that are part of the geometry of modern camshafts.
Alternately, if you have removed the injectors and can see the piston, you can set both valves when the piston is at the Top Of The Compression Stroke or TDC. But only if you are sure you are on the compression stroke.
Remember that in any 4 stroke engine the piston also comes up to the top of the cylinder when the engine is on the exhaust stroke; it's up to you to know which stroke it's on. you do not want to set the valves at the top of the exhaust stroke by mistake.
It's really not difficult. Do it once and the valve setting mystery is solved forever.
good luck,
rScotty
