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On cold start XJ "clicks"

alexgalexg

NAXJA Forum User
Location
Connecticut
1998 XJ 4wd Auto AMC 242 240,000 miles Lifted 3.5 inches



Hi all, been a long time since I have posted here. Having a confusing issue I have been trying to track down. Often times when cold starting my xj once it starts it makes this awful click click click noise (not the typical connecting rod bearing light diesel noise they are known for getting.)


If you give the gas a tap to try to make the noise stop the engine stumbles a bit (no backfire). It either clears up on its own or I have to shut off and restart the vehicle. Otherwise it runs fine and gives me no problems.



Until recently I worked in automotive restoration and would try to diagnose it on my hour here and there, only thing I found less than perfect was that it seemed to have slightly low vacuum but no leak. It also seems to ping a bit at low rpm under lode in 4th unless using premium.



Tune up is recent, all new seals, replaced 0630 head in 2017.



Explaining the noise almost sounds like a failing lifter. I will try to get a recording of the noise if possible but for now I will leave it at this. Before I throw parts at a problem I haven't fully diagnosed I was hoping someone else may have some helpful input.
 
Definitely check the valve train, probably checking the lifter pre-load will tell the most/fastest.
 
Definitely check the valve train, probably checking the lifter pre-load will tell the most/fastest.


Hmm, for the sake of new lifters being an easy $25 or more each that might be worth my time. I do not have the dial to measure preload do you recommend any specific one? Or should I just browse for one that seems like it will work with amc's non adjustable rocker and pushrod setup.
 
I have horrible lifter clatter until warm, I would replace them, except you have to pull the head to do it; and another member has cited issues of new lifters rounding off old cams. It almost sounds like you may have a lobe rounding off as it is though.
 
Hmm, for the sake of new lifters being an easy $25 or more each that might be worth my time. I do not have the dial to measure preload do you recommend any specific one? Or should I just browse for one that seems like it will work with amc's non adjustable rocker and pushrod setup.

The issue there is you have to pull the head to replace the lifters and I would also do the cam at that point! For a dial indicator the most important parting is the accessories for mounting.
https://www.amazon.com/Magnetic-Adjustment-Indicator-Anvile-0-0005/dp/B01K6KYHZW/ref=asc_df_B01K6KYHZW/?tag=hyprod-20&linkCode=df0&hvadid=312139641063&hvpos=&hvnetw=g&hvrand=11763420382691169365&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029983&hvtargid=pla-566905294710&psc=1&tag=&ref=&adgrpid=61496776229&hvpone=&hvptwo=&hvadid=312139641063&hvpos=&hvnetw=g&hvrand=11763420382691169365&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029983&hvtargid=pla-566905294710
 
Oh why must nothing ever be inexpensive or simple :banghead:This will be a lot of fun to deal with along with the trans replacement on my list to do this spring. I suppose for the winter it will have to just click, clack, tap and cough on cold starts. I will have to keep the road trips to VT at a minimum this winter
 
I would at least want to know what's going on, it could lead to a much more expensive repair later, or it could be as simple as new rockers and pivots.
 
I would at least want to know what's going on, it could lead to a much more expensive repair later, or it could be as simple as new rockers and pivots.
Agreed, the winter buys me time to do more testing. Pivots are original but the rockers and rods I replaced when I did the head in 2017.
 
My guess would be a collapsed lifter too. Ive had three Jeeps over the years and they've all had a lifter tick. I replaced the lifters in two of them and they cleared right up. One way to think about it in a positive light is although its a royal pain to remove everything to change the lifters out, you'll be refreshing all your top end seals that may or may not be in good shape. Especially the notoriously leaky valve cover gasket. I usually take this time to clean and paint my head and valve cover just for show.
One trick i use is to soak them in oil first for a day or so (overnight would be fine I'm sure). Clean out an old coffee can and sit them in there so they're up-and-down like they'd sit in the engine and fill it up with new oil or trans fluid. I used atf cause its thinner and will get into the lifters easier. The little bit of atf mixing with the engine oil when installed shouldnt cause any negative effects (ever put Marvel Mystery Oil in your engine?). Im sure someone will tell me this is a bad idea though.
 
My guess would be a collapsed lifter too. Ive had three Jeeps over the years and they've all had a lifter tick. I replaced the lifters in two of them and they cleared right up. One way to think about it in a positive light is although its a royal pain to remove everything to change the lifters out, you'll be refreshing all your top end seals that may or may not be in good shape. Especially the notoriously leaky valve cover gasket. I usually take this time to clean and paint my head and valve cover just for show.
One trick i use is to soak them in oil first for a day or so (overnight would be fine I'm sure). Clean out an old coffee can and sit them in there so they're up-and-down like they'd sit in the engine and fill it up with new oil or trans fluid. I used atf cause its thinner and will get into the lifters easier. The little bit of atf mixing with the engine oil when installed shouldnt cause any negative effects (ever put Marvel Mystery Oil in your engine?). Im sure someone will tell me this is a bad idea though.


Did you replace the cam as well? Toying with just getting a kit from mopar since I cant get anything from AMC and aftermarket is usually out of spec. Thinking I will just bang out everything thats been bothering me all at once. Replace the trans, lifters and cam (if further diagnosis suggests this is the issue), replace the fuel pump that has an iffy sending unit and undercoat the jeep again (did it a long time ago and its getting due). This would be a good late spring project.



Maybe while im at it a new high flow manifold, downpipe and cat will magically appear since my high flow setup is currently only a cat back :rtm:
 
You can see by the work I've put into it that it's a bit too nice no not fix now
2a2e36c5ae1c233aa37891f9ed8c45af.jpg


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Wow. That's definitely a keeper. What a beauty.
 
That's a beauty, but why stick with a stock cam, get something that will put a little step in it!
 
That's a beauty, but why stick with a stock cam, get something that will put a little step in it!


Well yes, that sounds great! But quite frankly I dont know how to pick the right cam for the job, especially one that wont work AGAINST the torque converter making it slower. Then theres the question of what else needs to be adjusted or replaced to make it all work. These are skills I have yet to confidently master :repair:
 
Did you replace the cam as well? Toying with just getting a kit from mopar since I cant get anything from AMC and aftermarket is usually out of spec.
:rtm:

I hadn't done a cam on any of my Jeeps but I drive pretty conservatively so i never needed anything more than stock performance. My most recent Jeep I pyt in annew timing set and radiator all at the same time as the lifters so that really would have been the best time for me to do a cam upgrade in it. I will definitely be doing one in the longblock that I'm building out of the Jeep this spring
 
Did you replace the cam as well? Toying with just getting a kit from mopar since I cant get anything from AMC and aftermarket is usually out of spec.
:rtm:

I hadn't done a cam on any of my Jeeps but I drive pretty conservatively so i never needed anything more than stock performance. My most recent Jeep I put in a new timing set and radiator all at the same time as the lifters so that really would have been the best time for me to do a cam upgrade in it. I will definitely be doing one in the longblock that I'm building out of the Jeep this spring
 
I hadn't done a cam on any of my Jeeps but I drive pretty conservatively so i never needed anything more than stock performance. My most recent Jeep I put in a new timing set and radiator all at the same time as the lifters so that really would have been the best time for me to do a cam upgrade in it. I will definitely be doing one in the longblock that I'm building out of the Jeep this spring
Thinking about doing an upgrade this spring. I need to do more research into it first and make sure I buy the right cam for the job. I have a fairly light foot as well but I still cant complain about more power. Especially since I have the automatic 4 speed which robs me of power on steep highways. Really wish the auto was a 5 speed like the manual

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