Russ in CT
Well-Known Member
- Joined
- November 11, 2002
- Messages
- 176
- Reaction score
- 0
- City, State
- Milford, CT
- Year, Model & Trim Level
- '99 XLT
'99 Explorer - 4.0 SOHC - 4x4 - 180K miles
I was getting both the rattle on startup as well as the 2K-3K rpm 'pinging' that signal timing chain issues. This was going on since I got the truck with less than 100K on in, but I didn't know about the SOHC timing chain issues then. The startup noise wasn't that bad, and I thought the 2K-3K noise was actual pinging.
So having found out about the chain issues, I just recently took it in to have it fixed. I brought it to the mechanic that works on my Audi. He is the only guy I trust to work on my vehicles besides myself (I didn’t have the time nor inclination to tackle this one myself). He replaced the front tensioner (with the complete 00M12 kit), as well as the jackshaft tensioner and guide. I had told him while he was in there to replace anything that was suspect. When he got it apart he found the jackshaft tensioner was just hanging there, almost ready to fall apart, but no missing pieces to worry about having fallen into the pan. After he got it back together there was still some noise at startup, and so the rear tensioner was replaced as well, which cured 90% of the remaining startup clatter. All the chains themselves were within spec as far as ‘stretching’ goes, so none of them were replaced.
Interestingly, the front tensioner had already been replaced with the updated one with the reservoir, but the restrictor that prevents oil drain back was never installed. I believe the PO had 00M12 done at the dealer, but they apparently neglected to do the whole job.
Anyway, I get the truck back, and its smoother than ever, no noise. Great. However after driving it a few days suddenly I notice this clacking noise while driving home on the highway. From inside the cabin it kinda sounds like maybe a lifter tick, but more pronounced. So I pull into a well lit parking lot, and from under the hood it sounds much worse. You can hear it at idle (barely), but get it up around 3K rpm’s and it makes a hell of a racket. Its coming from the front of the engine (at least its not the rear cassette), but its difficult to tell if its upper or lower. Even later with a stethoscope I couldn’t tell just where. It’s a sort of clacking noise, definitely not a rod, more like a chain noise, you hear a successive series of clacks like maybe a chain rubbing on something.
I gingerly drove it back to the shop, put the key in the drop box, and got a ride home. The shop has heard the noise, but they aren’t sure where its coming from either. They are going to open it back up and do some exploratory surgery. In the meantime I’m looking for suggestions about where to have them look.
An obvious place to start is the stuff they just replaced, is it all still intact and working? I was also thinking balance shaft. They didn’t mess with it, but I understand its tensioner is rather fragile, maybe it got damaged while the other work nearby was done? If they take it apart to look at the work they already did, should be easy enough to check balance stuff out at the same time. Any other suggestions?
It never made this much noise before, and it was fine for a few days after the repair, so whatever it is isn’t something that was already shot before but just missed, it has to be something new. Either something that was just replaced that didn’t hold together, or something that was damaged during the recent repairs. Or maybe something that was on its way out, whose death was exacerbated by all the shiny, new, stronger bits that were just replaced, I just don’t have an idea what might fall into that category.
Any ideas?
I was getting both the rattle on startup as well as the 2K-3K rpm 'pinging' that signal timing chain issues. This was going on since I got the truck with less than 100K on in, but I didn't know about the SOHC timing chain issues then. The startup noise wasn't that bad, and I thought the 2K-3K noise was actual pinging.
So having found out about the chain issues, I just recently took it in to have it fixed. I brought it to the mechanic that works on my Audi. He is the only guy I trust to work on my vehicles besides myself (I didn’t have the time nor inclination to tackle this one myself). He replaced the front tensioner (with the complete 00M12 kit), as well as the jackshaft tensioner and guide. I had told him while he was in there to replace anything that was suspect. When he got it apart he found the jackshaft tensioner was just hanging there, almost ready to fall apart, but no missing pieces to worry about having fallen into the pan. After he got it back together there was still some noise at startup, and so the rear tensioner was replaced as well, which cured 90% of the remaining startup clatter. All the chains themselves were within spec as far as ‘stretching’ goes, so none of them were replaced.
Interestingly, the front tensioner had already been replaced with the updated one with the reservoir, but the restrictor that prevents oil drain back was never installed. I believe the PO had 00M12 done at the dealer, but they apparently neglected to do the whole job.
Anyway, I get the truck back, and its smoother than ever, no noise. Great. However after driving it a few days suddenly I notice this clacking noise while driving home on the highway. From inside the cabin it kinda sounds like maybe a lifter tick, but more pronounced. So I pull into a well lit parking lot, and from under the hood it sounds much worse. You can hear it at idle (barely), but get it up around 3K rpm’s and it makes a hell of a racket. Its coming from the front of the engine (at least its not the rear cassette), but its difficult to tell if its upper or lower. Even later with a stethoscope I couldn’t tell just where. It’s a sort of clacking noise, definitely not a rod, more like a chain noise, you hear a successive series of clacks like maybe a chain rubbing on something.
I gingerly drove it back to the shop, put the key in the drop box, and got a ride home. The shop has heard the noise, but they aren’t sure where its coming from either. They are going to open it back up and do some exploratory surgery. In the meantime I’m looking for suggestions about where to have them look.
An obvious place to start is the stuff they just replaced, is it all still intact and working? I was also thinking balance shaft. They didn’t mess with it, but I understand its tensioner is rather fragile, maybe it got damaged while the other work nearby was done? If they take it apart to look at the work they already did, should be easy enough to check balance stuff out at the same time. Any other suggestions?
It never made this much noise before, and it was fine for a few days after the repair, so whatever it is isn’t something that was already shot before but just missed, it has to be something new. Either something that was just replaced that didn’t hold together, or something that was damaged during the recent repairs. Or maybe something that was on its way out, whose death was exacerbated by all the shiny, new, stronger bits that were just replaced, I just don’t have an idea what might fall into that category.
Any ideas?
