Had milkshake for oil. Of course, coolant was mixing with oil. Heads were not cracked or warped. (checked at shop). No obvious problems or damage with the gaskets. Found a 1/8 inch hole in one of the freeze plugs. Now i'm putting it back together and having trouble with the timing chain. dotted the I's and crossed the T's and it seems the passenger side chain is intermittently slack when I manually turn the crank. No resistance. Any thoughts ?

 

Take a screwdriver and place the end under the chain guide right next to the tensioner. Now pry up slightly just to allow the tensioner to extend. You don't want much pressure just a little. The tensioner will extend when you start the engine and oil pressure rises. I used to do this so as not to risk jumping a link in the timing chain on initial startup. I know some are going to dispute this but I've done it hundreds/thousands of times. If the tensioner seems frozen then loosen the two bolts and retorque to 20-30 Nm. Sometimes they will distort and not pop out as designed. Just make sure you don't have something blocking the tensioner oil supply hole behind the tensioner, such as an allen plug...If the tensioner will not extend then you may want to replace it. Good luck.

 

The tensioners work under oil pressure, so that manual turning will cause the chain to go slack every now and then. Completely normal, don't fret.

 

Yep. My only concern is that the piston is free and not stuck in the bore. That's why I would sometimes test with the screwdriver to be sure it is free before I replaced the front cover. Would find some stuck (from distortion) until the bolts were loosened and they would pop out. Especially since oil /coolant snot got into the system. I always hate second guessing after the engine is back together. Take care.

 

Thanks for your input Dynotec and bigbronc. I have taken the tensioners out, cleaned them and checked the oil holes. All seems well with them. I am far from getting it back together to start it though. The thing is i'm worried that I screwed something up by not having the camshaft and crankshaft positioning tools ( could'nt find them anywhere) however, i jury rigged something to hold them in place while i did the remainder of the work.

 

Oh I should mention that everything does stay lined up as I crank despite the intermittent slacking

 

If you suspect you bent a valve then perform a leakdown test right now. It beats getting it together and having to tear it back down to fix a valve. If you have to remove the chains again then first rotate the crank so it's keyway is at 12:00. Now leave the crank in this position until you have the timing chains off and back on with the tensioners released. This way you can rotate the cams by hand to remove the chains and reinstall them without worry of bending a valve and no cam retaining tools are needed. The pistons are below the deck far enough with the crank in this position so no valves can get bent. Actually at every 90deg the crank will have pistons low enough. But I always used 12:00 as a standard that worked well. I applogize as I'm pretty sure I could teardown and rebuild one of these engines blindfolded but sometimes I'm not very good at explaining how to do it. Bigbronc, jbrew, matts ford, and others here are very knowledable regarding these engines. If you get in trouble I'm sure one of us will try and help you out. Take care.

 

Well, not sure what a leakdown test is. Might of did it once when I used to drink, I don't think it's the same. I will check my manual to see what I need to do. By the way, I fully understand your great directions otherwise. Thanks again. Ill keep you informed.

 

Well, leakdown test not feasible, or at least not until I get it running enough to warm it up, according to what I read. I like bigbroncs theory on the oil pressure taking the slack out once it is running. I do notice the tensioner piston is sticking out further on the side where the intermittent slacking occurs. Could there be some stretch on the chain ?. It has 170,000 miles. Gears look good as do the chains otherwise. Any thoughts

 

Left tensioner on the left side and Right tensioner........ You are only turning the crank in a clockwise direction?

 

Yes and yes. replaced guides and r tensioner

 

replaced the chains and one tesioner and the guides. Double, triple and quadruple checked the links and turned over the crank about a hundred times by hand to make sure the timing was right. Put it all back together and it started right up. Musta done something right. Runs like a champ. No more mixing of oil and coolant. I guess the small hole in the freeze plug was the problem after all. I think the intermittent slackening of the chain was related to backyard mechanic error which fortunately i rectified before I put it together. Thanks for your help