Back firing part 2

[bearsden]

Don't just blindly replace all the lifters, esp. if you are on a budget.

Just how loose is it? It could be as simple as a really worn rocker/fulcrum - a very common issue on these engines, esp. engines with one piece fulcrums, and very cheap/simple to replace if that's the case.

Lifters often don't "fail" - they just get dirty and stuck. You can often free them by running the motor w/ the valve cover off and tap the affected rocker w/ a soft mallet right above where the pushrod meets it. Don't be afraid to give it more than a tap but don't go full ape poopie on it either.

If that seems to help I would run a quart of ATL in lieu of 1 qt. of oil for a while and keep an eye on the filter. That should really help clean things up inside the motor.

thank you Jdarg i think i will give that a go before tearing into it. It was not loose when i took it apart to fix the freeze plugs in the head and it actually ran fine just leaked antifreeze,so i think i'll try what you said before taking all that apart again!

 

[jdarg]

Good luck. Another trick is swapping the rockers and fulcrums from one cylinder to another. See if the looseness stays with the same cylinder or moves with the parts.

Be careful loosening the fulcrums - you need to do each side very evenly to avoid bending or cracking the bridge.

 

[bearsden]

you are very correct on that.I had to replace a couple taking the head off the first time. I'll let you know what happens.Thanks again!!!!

 

[bearsden]

Good luck. Another trick is swapping the rockers and fulcrums from one cylinder to another. See if the looseness stays with the same cylinder or moves with the parts.

Be careful loosening the fulcrums - you need to do each side very evenly to avoid bending or cracking the bridge.

okay ,so I took the valve cover off and tapped the rocker arm and no luck.So i took the head off and removed the lifter.It " looks" fine with little or no wear on the bottom.Is there away to check the cam other than pulling it all out? also I got a lifter from the local auto zone just to compare with and the one they gave me is smaller than the one i have in there.same diameter ,different in height ???

 

[Torxhead]

The cam lobes can be checked with a travel indicator. You did check the push rod height as a comparsion?

 

[bearsden]

The cam lobes can be checked with a travel indicator. You did check the push rod height as a comparsion?

yes i did check the push rod height ,but didn't know about how to check the cam lobes. And i would definitely like to check that one i'm having the issue with.tell me more.......

 

[Torxhead]

yes i did check the push rod height ,but didn't know about how to check the cam lobes. And i would definitely like to check that one i'm having the issue with.tell me more.......

To check the lobes like I suggested would require using precision measuring equipment, What I had in mind would be something like a dial indicator set up to measure the high and low position of each cam lobe. Using a magnetic base to hold it in position. Got any friends that work in a machine shop? You problem could have started from a clogged oil passage not filling up the lifter. Using a high detergent oil like a Shell Rotella T would help.

 

[bearsden]

To check the lobes like I suggested would require using precision measuring equipment, What I had in mind would be something like a dial indicator set up to measure the high and low position of each cam lobe. Using a magnetic base to hold it in position. Got any friends that work in a machine shop? You problem could have started from a clogged oil passage not filling up the lifter. Using a high detergent oil like a Shell Rotella T would help.

so i'm guessing i should replace all the lifters while i got it apart and then should I put the rotella 15w40 in for startup? Or should i use something else ? I don't really know anyone that would have a dial indicator so i suppose I'll have to go with it. Is there anything else i should do when I'm putting this back together ? I'm hoping this does it,i bought this thing in february and have only driven it once.Also the lifters i got were smaller in height than what was in there ??? I was just going to change the bad one but now with the different height i'm changing them all. The new ones mic'd at 1.82 and the old one micd at 1.90 ?

 

[hole]

Just stick with the 15-40 from here on out

 

[NorthwestCJer]

before putting this back together, lets see a couple pics. Bottom side of head and the cylinders. ???
Did you ever do a compression test on each cylinder?

 

[jdarg]

What did the rockers/fulcrums end up looking like too? IMHO those are way more likely to be the issue than your lifters, esp. if you pulled the lifters and they work fine.

The .008 slightly shorter lifters may only make any existing issues with worn rockers/fulcrums worse.