Is this the clutch going bad or what?

LearningAsIGo

New Member
Supporting Member
Joined
Nov 5, 2022
Messages
9
Location
Flower Mound, Texas
Hey guys, got a weird problem and I'm wondering if it's a sensor problem or maybe the clutch going out. I have a 1997 jeep tj 4.0 manual with 126000 miles on it. A few weeks ago I started having some problems with the keep lurching/ intermittent loss of power. Normally last for about a second or so and usually when I'm accelerating. I think it also seems to happen more while I'm letting out the clutch when changing gears but not exclusively then. The weird part as whenever it happens my tachometer spikes at the same time by a few hundred RPMs or so but it doesn't sound like the engine is revving up at all, more so like it's bogging down/ cutting out. First seemed to happen only when I was shifting from second to third but now can happen at anytime. Shifting at higher RPMs seems to help and pressing down more on the throttle also seems to help. Planning on checking the trans fluid level this weekend just to see if that's the problem but other than that not quite sure. Haven't had to deal with clutch/ transmission problems before so don't know much about them. It doesn't seem to matter if the engine is cold or warm, no engine codes or anything else abnormal. It also doesn't seem to happen when idling or adding throttle while in neutral. Last side note is that I'm in north Texas and we've been having consistent 100-105+ degree days over the same time period. Not sure if it's at all related, could just be coincidental but thought I'd mention that too. Any advice would be much appreciated! Lmk if you have any questions.
 
With the tach spiking the clutch may be slipping which is why you don’t feel like you have any power.
 
I agree, sounds like the clutch, AX15 transmission in that year. Although I would have thought you'd feel it starting in 1st before 2nd gear? The transmission works off a friction disc between flywheel and transmission. It's similar looking to brake pad material. Once it wears down it starts slipping due to loss of friction until it finally grabs. It progressively gets worse fairly quick.
 
It doesn't sound like a clutch problem to me, not to mention the OE clutch can easily make it to 200k miles. A couple initial suspicions include a bad crankshaft position sensor or bad upstream O2 sensor.
 
  • Like
Reactions: skrelnik
Hey guys, got a weird problem and I'm wondering if it's a sensor problem or maybe the clutch going out. I have a 1997 jeep tj 4.0 manual with 126000 miles on it. A few weeks ago I started having some problems with the keep lurching/ intermittent loss of power. Normally last for about a second or so and usually when I'm accelerating. I think it also seems to happen more while I'm letting out the clutch when changing gears but not exclusively then. The weird part as whenever it happens my tachometer spikes at the same time by a few hundred RPMs or so but it doesn't sound like the engine is revving up at all, more so like it's bogging down/ cutting out. First seemed to happen only when I was shifting from second to third but now can happen at anytime. Shifting at higher RPMs seems to help and pressing down more on the throttle also seems to help. Planning on checking the trans fluid level this weekend just to see if that's the problem but other than that not quite sure. Haven't had to deal with clutch/ transmission problems before so don't know much about them. It doesn't seem to matter if the engine is cold or warm, no engine codes or anything else abnormal. It also doesn't seem to happen when idling or adding throttle while in neutral. Last side note is that I'm in north Texas and we've been having consistent 100-105+ degree days over the same time period. Not sure if it's at all related, could just be coincidental but thought I'd mention that too. Any advice would be much appreciated! Lmk if you have any questions.

I will say if its not the clutch, i had a similar issue at first it only happened on hot day 110+ so i didnt worry about it. Then it got worse i isolated it to the tps because i was able to let the clutch out and the rpms wouldnt spike as long as i didnt touch the gas peddle. If you dont touch the gas when letting out the clutch does the issue presist? This would be more from a red light vs shifting gears.
 
I haven't had a chance to really look at the sensors yet, but here's a video of what it's doing. I feel like the outside temperature might have something to do with it. It seems to happen less often in the morning or at night than it does in the middle of the day when it's 105+ out.
 
I haven't had a chance to really look at the sensors yet, but here's a video of what it's doing. I feel like the outside temperature might have something to do with it. It seems to happen less often in the morning or at night than it does in the middle of the day when it's 105+ out.
 
Mine was doing that and it was the crank position sensor.

I just finally got a code P0340 saying "Camshaft position sensor A circuit bank 1 or single sensor" so I'm guessing that's my problem. Going to take a look at it tomorrow to see if there any obvious signs of it failing (like corrosion, frayed wiring, ect...) and go from there. I believe they both exhibit similar symptoms when failing though.
 
Like I said in a response above, I'm getting a P0340 code saying "Camshaft position sensor A circuit bank 1 or single sensor." From what I remember after having a problem with one of the two sensor in the past (I think I just replaced them both and the problem was solved) the crankshaft position sensor and camshaft position sensor can exhibit similar symptoms. Not sure if that's true, or the the failing of one could trigger a code for the other or if there's possibly a third component that could be playing a role as well. I do enjoy the detective work, which is probably simple to any trained mechanic, but as an untrained pseudo mechanic that's enrolled in the 'keeping a 26 year old jeep running without having the money or willingness to pay an actual mechanic so I got to figure it out myself University,' it's always teaching me something. Side note that no one will care about *IF YOU DON'T CARE, YOU CAN STOP READING NOW*, but I'll write it up anyways. I'm a premed student, and have for years been calling mechanics "car doctors" because it's pretty much the same process in my mind, albeit from my admittedly incomplete understanding of either occupations, but I have enough experience in both to draw this conclusion, which I think is an accurate one. The pertinent questions are: What are the symptoms, what could be the underlying problems, what could be the confounding factors, what if there are multiple problems simultaneously presenting symptoms that could make the diagnosis more difficult and finally what is the best methodology to go about determining or at least narrowing down the probable causes, and then treating/fixing the problem by testing targeted treatments until the symptoms resolve. Idk, it's just always seemed like a similar process to me, I'm sure engineering is the same and I'm also sure that this is nothing that is meant to be discussed on this forum so I apologize for distracting from the real reason we are all here; to make our jeeps run lol. I'll update this after I do some more investigating and post whatever ends up working.
 
I agree...basic troubleshooting techniques and procedures are more or less the same be it a computer, body or a camshaft sensor.

You might want to verify if you have 5v on the pin that powers the sensor. I recall reading some posts about that. Good indicator or whether or not you have a larger wiring issue.

-Mac
 
So I took some CRC electronic cleaner and cleaned the connections for the crankshaft and camshaft position sensors and that seems to have fixed my problem. I also noticed my air intake filter had come off so put that back on. Not sure how long it was like that, or if that might have had anything to do with it but it's running a lot better now and I haven't had that problem since.