- 2,699
- 118
- Sep 4, 2004
-
Eau Claire,
Michigan
Sorry for the long post but bear with me as this it makes more sense as a whole stort.
Hey all, 2 months ago my buddy bought a 92 awd 6 bolt. Basically he doesn't know much about cars and I am his DSM guru/ mechanic. I have done every bit of work and maintenance on the car. I have also been his guiding light with his purchases as well. The car does have ECMlink V3.
Anyways, he calls me about 2 weeks ago and says the car died while driving and he had to push it home about a mile. He honestly thought it died because he accidentally filled it up with 87 octane vs. 93.
I come over the next day and hook up my laptop (Yes I do all the tuning to the car as well, he doesn't have a laptop either). I check to see if there are any DTC's and sure enough it has a Crank/Cam sensor malfuntion DTC. I pop the hood, notice that the Cam/crank sensor came unplugged, and plugged it back in (no clip). I clear the DTC and then start the car. I let the car run for about 10-15 seconds and shut it off. The car ran and sounded perfectly fine.
Immediately after this, I wired in a new 02 sensor for him as his was bad. After installation I start the car up preparing to make a log.
Upon startup, the car started making a loud clunking or knocking sound, as well as a "chirp" sound. It sounded as if it were coming from the lower timing side of the engine. I shut it off and started to rotate the engine over with a 17mm wrench on the intake cam gear bolt. As I rotate it by hand the timing belt skips a tooth, but I wasn't sure at the time if it did. Rotated it some more by hand, and it skipped another tooth. I then told my friend, somethings very wrong and it needs work.
So we began working on the car in my shop, and I tore into the timing belt side of the engine. First thing I notice is that the balance shaft belt had stripped half of its teeth. Next I noticed that the timing tensioner pulley was actually loose and the tensioner itself was fully extended. This made sense as to why the belt skipped while rotating by hand. I was just hoping that no valves were bent.
So I spun the balance shafts by hand, and they did not bind, or have any tight spots. However, I decided it was still a good idea to remove the shafts, so I did. The old balance bearings looked perfect and could have been easily reused. While having the oil pan off I grabbed the rods by hand and they had no excessive play, etc. Also the pan was clean and I did not see any metal shavings, etc.
I put the engine back together with no balance shafts, and installed new timing components for good measure. Pulled the MPI fuse and went to crank the car to prime it. Upon cranking I could hear that same clunking/knocking sound that I heard while it was running for that short time a few weeks ago.
It definately sounds like its coming from the bottom half, and surely doesn't sound like valves. At first I thought it sounded like a loose flywheel, crawled under the car, removed the inspection plate and checked, no dice. Starting pulling plugs one by one while cranking but the noise never changed until all the plugs were out, then the noise stopped. Put the plugs back in and cranked it over while holding in the clutch, THE NOISE STOPPED again. So if the clutch is held in while cranking, it will not make the knocking sound.
I also checked the crank end play and its moving very slightly, but to me it seems normal and not excessive. Also with the crank pulley bolted to the crank, while turning over, it looks like the pulley is wobbling, as if the crankshaft was bent or something to that matter, but I don't know. I've never seen or heard of a 4G63 crank bending.
So before I rip this engine apart, anyone have insight as to what might be making or causing this knocking sound, and that it doesn't make the sound if the clutch is held in? It just doesn't make sense to me that ran perfectly after I plugged the CAS back in, then 20 minutes later its knocking like crazy.
Thanks, Dan
Hey all, 2 months ago my buddy bought a 92 awd 6 bolt. Basically he doesn't know much about cars and I am his DSM guru/ mechanic. I have done every bit of work and maintenance on the car. I have also been his guiding light with his purchases as well. The car does have ECMlink V3.
Anyways, he calls me about 2 weeks ago and says the car died while driving and he had to push it home about a mile. He honestly thought it died because he accidentally filled it up with 87 octane vs. 93.
I come over the next day and hook up my laptop (Yes I do all the tuning to the car as well, he doesn't have a laptop either). I check to see if there are any DTC's and sure enough it has a Crank/Cam sensor malfuntion DTC. I pop the hood, notice that the Cam/crank sensor came unplugged, and plugged it back in (no clip). I clear the DTC and then start the car. I let the car run for about 10-15 seconds and shut it off. The car ran and sounded perfectly fine.
Immediately after this, I wired in a new 02 sensor for him as his was bad. After installation I start the car up preparing to make a log.
Upon startup, the car started making a loud clunking or knocking sound, as well as a "chirp" sound. It sounded as if it were coming from the lower timing side of the engine. I shut it off and started to rotate the engine over with a 17mm wrench on the intake cam gear bolt. As I rotate it by hand the timing belt skips a tooth, but I wasn't sure at the time if it did. Rotated it some more by hand, and it skipped another tooth. I then told my friend, somethings very wrong and it needs work.
So we began working on the car in my shop, and I tore into the timing belt side of the engine. First thing I notice is that the balance shaft belt had stripped half of its teeth. Next I noticed that the timing tensioner pulley was actually loose and the tensioner itself was fully extended. This made sense as to why the belt skipped while rotating by hand. I was just hoping that no valves were bent.
So I spun the balance shafts by hand, and they did not bind, or have any tight spots. However, I decided it was still a good idea to remove the shafts, so I did. The old balance bearings looked perfect and could have been easily reused. While having the oil pan off I grabbed the rods by hand and they had no excessive play, etc. Also the pan was clean and I did not see any metal shavings, etc.
I put the engine back together with no balance shafts, and installed new timing components for good measure. Pulled the MPI fuse and went to crank the car to prime it. Upon cranking I could hear that same clunking/knocking sound that I heard while it was running for that short time a few weeks ago.
It definately sounds like its coming from the bottom half, and surely doesn't sound like valves. At first I thought it sounded like a loose flywheel, crawled under the car, removed the inspection plate and checked, no dice. Starting pulling plugs one by one while cranking but the noise never changed until all the plugs were out, then the noise stopped. Put the plugs back in and cranked it over while holding in the clutch, THE NOISE STOPPED again. So if the clutch is held in while cranking, it will not make the knocking sound.
I also checked the crank end play and its moving very slightly, but to me it seems normal and not excessive. Also with the crank pulley bolted to the crank, while turning over, it looks like the pulley is wobbling, as if the crankshaft was bent or something to that matter, but I don't know. I've never seen or heard of a 4G63 crank bending.
So before I rip this engine apart, anyone have insight as to what might be making or causing this knocking sound, and that it doesn't make the sound if the clutch is held in? It just doesn't make sense to me that ran perfectly after I plugged the CAS back in, then 20 minutes later its knocking like crazy.
Thanks, Dan
