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View Full Version : Got myself into a real bind, 2.8L, valves cams and timing....



Ryanic
12-05-2014, 02:19 PM
So started out trying to do a pretty straight forward cam chain tensioner replacement on my passenger side head. First mistake I made was not putting it at TDC, so when I tried to put the cam chain tensioner tool on and tighten the tensioner down it didn't compress the tensioner... The tool binded up and almost broke so I decided to try to loosen the tool to remove it. For some unknown reason now the tool wouldn't come off. It just keeps spinning and spinning and spinning like it's stripped. But I tried every trick in the book to get it out nothing.

So next thing I tried to do was to just go ahead and try to get the tensioner out as it is. First I manually cranked the crank over so I had the chain slack at the top of the tensioner. Then I loosened up the intake side of the cam caps so I could try to lift the cam up a little to get more room with the chain and the tensioner clearing the back of the cylinder head. No luck.

Called it a day and then today I forgot to tighten back down the cam caps on the intake side. I went to manually crank over the crank again to get it to TDC but after I cranked a couple times I realized what I just did. Stupid me accidentally manually cranked over the engine while I had the intake side of my passenger head cam caps loose so the intake cam didn't push on the valves and what not when the exhaust cam did. (Both cams spun because the cam chain was still on and in perfect timing, but the cam just lifted up and spun without pushing on the valves because of the loose caps).

So where am I at...... I'm in way over my head..

bhusted
12-05-2014, 02:45 PM
You need to get the head back into correct time. It's okay that the engine spun and the intake valves did not open. Staying open would be bad, though I don't know if you could turn the engine over by hand and bend valves.

Start out by loosely installing the cam caps for the intake cam so that it's not flopping around. Rotate the crank so that the mark lines up on the timing cover. Check that the large holes on the cam keys point inward and directly at each other. If not, do another full rotation. You are now at TDC. You can check by pulling the spark plug in #3 (driver's side closest to firewall) and inserting a dowel or something else appropriate. The exhaust cam should also line up with a mark on the cam cap nearest the chain. You'll see a small arrow pointing to the keyway for the sprocket. If the intake cam is still in the correct place it should also line up with the mark. You can also count the links of chain between the marks. There should be 16 links for the passenger side and 15 for the driver side. I like to mark the chain and cam sprockets with a paint marker to make it easier to line up on re-installation.

Now compress the tensioner. Go slow with this. It is full of oil and takes a bit for the oil to drain out. If you're doing it correctly, it should not take much force at all to compress. Think 1/4" ratchet and a couple of fingers...Once the tensioner is compressed, remove the cam caps once again, keeping them in the correct order/orientation. Remove the bolts holding the tensioner (5 or 6 T30). Lift the intake cam and swing it clear of the chain. You should now be able to remove the tensioner. With the tensioner removed, clean the mating surfaces and install a new half moon seal and steel gasket. Slide in the new unit. Put some assembly lube on the cam journals. Line up the paint marks on the chain/sprockets and set the intake cam in place. Count the links and check the marks to verify correct timing. Once you are sure that you have the timing set correctly, put some more assembly lube on the cam caps and torque everything down. There is a specific order for torquing the cam caps. Once you get everything reassembled, rotate the engine by hand for several revolutions to be sure everything is set.

b5a4erik
12-06-2014, 06:25 PM
^ awesome.