Timing chain tensioner problem

Hi, I love your show! I listen nearly every Saturday … and sometimes other days, as I have an internet radio. Anyway, here’s one I haven’t heard yet. I’m replacing the timing parts … gears, chain, and tensioner … on my 1999 2.2l Chevy S-10. When I’m done with that, I have to replace the water pump, cylinder head, radiator, thermostat, and hoses. I have the manufacturer’s manual and a pretty good set of tools and I don’t mind the work. But here’s the problem I have encountered. The tensioner is hels on by just 2 bolts. One is an 11mm metric hex head … no big deal. The other one, just unfer the upper sprocket, is a torx … I can see it using a mirror and a flashlight. Anyway that’s also what the computer calls out at the dealerships … but it doesn’t specify a size. I first tried a T40 and it was way too big. A T30 goes in but “skips” when I turn it, almost as if it weren’t seating all the way into the socket. A T25 and T27 are both too small, so I’m pretty sure it has to be the T30. The service people at the dealerships all shrug their shoulders when I ask about this. Meanwhile the leaves are falling and it’s starting to get cold in the driveway! I can’t believe I’m the only idiot who attempts this kind of job, but now I’m beginning to re-examine my belief!! Seriously, I need to get this job done, so any help you could give me would be just great!!



This Isn’t The Radio Show
This is a site with people like you with leaves falling on them in the driveway and also a handful of professional techs as well.

I see the the bolt and they talk about it being Torx, but I don’t know what size either, sorry. Maybe it will help if someone clicks the link below.


This seems pretty simple, but are you sure there’s no gunk in the screw? You might try reaming it out with a needle or an awl or something to make sure the screw is completely clean. You also might try applying a little bit of degreaser to the screw, since when the screw’s oily, the tool will want to jump out.

I suppose there is the possibility that the screw is stripped, but I’ve never seen a stripped Torx before. I assume that all the little points need to still be sharp and not rounded off, so I’d closely examine the condition of the screw.

Are You Sure That Torx Screw Head Is Clean?

You might have to use a tool or fashion a little “L” shaped hook out of stiff wire and clean the head of the screw out with it. Your Torx bit has to go in there and bottom out. Sometimes they “crud up.” Be nice to it until you find out for sure that it’s T-30.

A good old impact driver and hammer could help, but there probably is no room for that. I have one from my motorcycle days and it’s worth it’s weight in gold.

You mentioned the tensioner is held on by two bolts but the Autozone repair guide says it is held on by 3 bolts on the side of the unit. Their manual could be wrong but you might want to check it out.

Cleaning out the torx head is a good idea from common sense answer.

This seems unlikely but could the fastener be a tamper resistant torx?

Is this torx fastener part of the assembly itself and not an attaching fastener?

One last possibility I can think of: Perhaps it is a T35 torx. See here: etoolsrus.com
It’s a very unusual size and doesn’t seem to be commonly available but it wouldn’t be the first time that GM decided to be “cutting edge” and used an unusual size for no particular good reason. The bit I linked to is too long for your use but it seems the size does exist.

I agree with the other folks about cleaning the screw(s) first. I would then douse it with PB Blaster. Also, i’d go to a different dealership and find someone who knows what holds on that tensioner. Someone has had to remove one at a dealership at some point, or will have the service guide for that year/model.