Another Comp Cam & Lifter Failure?? - Help me please
Posted: March 9th, 2023, 6:44 pm
Hello All,
So heres where I’m at. 1992 Jeep XJ w/ 4.2 mini Stroker via Russ / aw4 , np231
Silvolite PN#2229 Bored .06 over
Comp Cams 4x4 Extreme - PN# 68-232-4 w/ nitride coating
Comp Cams High Energy Hydraulic Lifters - PN# 822-12
Melling m81 - Standard Oil Pump
Stock length pushrods (Melling)
Was running a new set of stock rockers all this time but as you will find in the novel below I just switched to HS Roller Rockers because they are pretty.
Engine was broken in with comp cams break in oil and run @ 2000rpm standard procedure replaced the oil then replaced again @ 500 miles and then again @ 1500 miles. Was running Lucas 10w-30 Hot Rod oil for the first 3000 then switched to 15w-40.
Russ provided all of the parts and did all of the machine work. I did all of the assembly. Project went on for years and finally a couple of years ago got it done and have been driving the Jeep for about 4,000 miles or so on the new motor. Had a ton of annoying electrical gremlins, went through about 8 Cps sensors and a few distributors. They don’t make the original molar Cps for early models. Finally figured all that out.
The Jeep has been running really good up until this week when I pulled off the highway and heard loud tapping noises. Pulled over and opened the hood while idling and it was very loud. Shut her down and got the Jeep home.
- Took the valve cover off and found that the #6 cylinder rockers had enough play in them to wiggle them back and forth easily by hand. So I checked all of the rockers and made sure they were torqued to spec.
- Changed the oil and filter to a lighter weight 5w30 (was running 15w-40) Oil that I dumped was clean, no metallic flakes or anything unusual
- Changed the spark plugs to a one step colder set which I had been planning to do. The plugs that were in for the last few thousand looked good. Grayish proper color.
- Started her back up with the valve cover off. Tapping was still there. Rockers were getting oil at idle and made a little mess when given any throttle.
- Removed the rockers push rods and inspected them. Some of the pushrods were a little worn on the very tips. Holes were basically misshapen just a bit on the rocker side. Lifter side the rods were all fine. No bent rods.
- Had a set of Harland Sharp roller rockers that I have been too lazy to install so I decided to throw them on with a full new set of push rods just to see if that alleviated the tapping at all.
- Checked that the pushrods were correct length and that the lash was within spec. Basically all of the rockers torqued down to spec from zero lash within 1 full turn of the bolt. Most were right at 3/4 turn. Some were in between that and a 1/2 turn.
- Felt all of the rockers for play after torquing and rotating the engine and they felt solid.
- Started the engine up again with cover off and they got oil just as before. All of pushrods spun as they went through the motions.
- Still have very loud tapping! Let the motor warm up to see if that would help and it did no so I shut her off.
- Once again, I grabbed all of the rockers to check for play and found that #5 exhaust was slightly loose and #1 intake was slightly loose. Waited for things to cool down a little and checked again and #5 exhaust pushrod can be pushed down by hand and feels totally spongy which brings me to my questions…
Does this means my lifter is collapsed? Also, could the lifter just have bled down quickly from the oil being 5w-30? (its what I had in the garage) Either way I assume it’s not supposed to do that so quickly.
There is a little play in a few other lifters as well (although not near as bad as #5) which makes me think I have multiple collapsed lifters and most likely flattened cam lobes…
I am planning to tear the head off as it clearly can’t be helped I assume but in the meantime, please let me know your thoughts so I can move forward and try to get this thing running like it should!
My other questions would be, what cam and lifter set should I run next? I was looking at Clay Smith potentially depending on cost. Made in America and all that. Or should I go back to a stock cam and lifter setup to keep things reliable?
I daily drive the Jeep and really don’t abuse it although its fun to smash the pedal every now and then. Really, performance wise I did the mini stroker in hopes of having a mild motor that was fun and reliable.
Thanks for you time!
-Zach
So heres where I’m at. 1992 Jeep XJ w/ 4.2 mini Stroker via Russ / aw4 , np231
Silvolite PN#2229 Bored .06 over
Comp Cams 4x4 Extreme - PN# 68-232-4 w/ nitride coating
Comp Cams High Energy Hydraulic Lifters - PN# 822-12
Melling m81 - Standard Oil Pump
Stock length pushrods (Melling)
Was running a new set of stock rockers all this time but as you will find in the novel below I just switched to HS Roller Rockers because they are pretty.
Engine was broken in with comp cams break in oil and run @ 2000rpm standard procedure replaced the oil then replaced again @ 500 miles and then again @ 1500 miles. Was running Lucas 10w-30 Hot Rod oil for the first 3000 then switched to 15w-40.
Russ provided all of the parts and did all of the machine work. I did all of the assembly. Project went on for years and finally a couple of years ago got it done and have been driving the Jeep for about 4,000 miles or so on the new motor. Had a ton of annoying electrical gremlins, went through about 8 Cps sensors and a few distributors. They don’t make the original molar Cps for early models. Finally figured all that out.
The Jeep has been running really good up until this week when I pulled off the highway and heard loud tapping noises. Pulled over and opened the hood while idling and it was very loud. Shut her down and got the Jeep home.
- Took the valve cover off and found that the #6 cylinder rockers had enough play in them to wiggle them back and forth easily by hand. So I checked all of the rockers and made sure they were torqued to spec.
- Changed the oil and filter to a lighter weight 5w30 (was running 15w-40) Oil that I dumped was clean, no metallic flakes or anything unusual
- Changed the spark plugs to a one step colder set which I had been planning to do. The plugs that were in for the last few thousand looked good. Grayish proper color.
- Started her back up with the valve cover off. Tapping was still there. Rockers were getting oil at idle and made a little mess when given any throttle.
- Removed the rockers push rods and inspected them. Some of the pushrods were a little worn on the very tips. Holes were basically misshapen just a bit on the rocker side. Lifter side the rods were all fine. No bent rods.
- Had a set of Harland Sharp roller rockers that I have been too lazy to install so I decided to throw them on with a full new set of push rods just to see if that alleviated the tapping at all.
- Checked that the pushrods were correct length and that the lash was within spec. Basically all of the rockers torqued down to spec from zero lash within 1 full turn of the bolt. Most were right at 3/4 turn. Some were in between that and a 1/2 turn.
- Felt all of the rockers for play after torquing and rotating the engine and they felt solid.
- Started the engine up again with cover off and they got oil just as before. All of pushrods spun as they went through the motions.
- Still have very loud tapping! Let the motor warm up to see if that would help and it did no so I shut her off.
- Once again, I grabbed all of the rockers to check for play and found that #5 exhaust was slightly loose and #1 intake was slightly loose. Waited for things to cool down a little and checked again and #5 exhaust pushrod can be pushed down by hand and feels totally spongy which brings me to my questions…
Does this means my lifter is collapsed? Also, could the lifter just have bled down quickly from the oil being 5w-30? (its what I had in the garage) Either way I assume it’s not supposed to do that so quickly.
There is a little play in a few other lifters as well (although not near as bad as #5) which makes me think I have multiple collapsed lifters and most likely flattened cam lobes…
I am planning to tear the head off as it clearly can’t be helped I assume but in the meantime, please let me know your thoughts so I can move forward and try to get this thing running like it should!
My other questions would be, what cam and lifter set should I run next? I was looking at Clay Smith potentially depending on cost. Made in America and all that. Or should I go back to a stock cam and lifter setup to keep things reliable?
I daily drive the Jeep and really don’t abuse it although its fun to smash the pedal every now and then. Really, performance wise I did the mini stroker in hopes of having a mild motor that was fun and reliable.
Thanks for you time!
-Zach