Shops quote $3,200–$4,500 for this one, and the quote usually isn't the ripoff, the job really is that big. Here's what's actually failing, what the correct repair involves, and the honest part: this is not a job I do in a driveway.
GM's 3.6L LLT V6, found across the Traverse, Acadia, Enclave, SRX and CTS, doesn't use one timing chain, it uses three: a primary chain and two secondary chains, one per cylinder bank. The design's weak point is oil maintenance sensitivity: extended oil-change intervals let the oil shear down, the chains' pin-and-link joints wear, and all three chains stretch. At the same time, the plastic chain guides go brittle and crack, and the hydraulic tensioners bleed down overnight, which is why the racket is worst on cold start, before oil pressure pumps the tensioners back up.
The computer sees the stretch before your ears do. Codes P0008 (engine position system performance), P0016 and P0017 (crank/cam correlation) mean the camshafts are no longer where the crankshaft expects them to be, the chains have lengthened enough to throw off valve timing. That's what causes the rough idle and lazy throttle response that comes with the rattle.
There's no partial fix here. Replacing one stretched chain and leaving two equally worn ones in place is throwing labour away, the engine has to come apart the same amount either way. The correct repair is the complete set: three chains, all guides, all tensioners, both cam actuator sprockets checked, new front cover seals. Done right once, it's done for the life of the engine.
If your GM is doing any of these, this is the likely cause:
Not certain that's what you're dealing with? Match the symptom in plain English first:
Or describe it to the AI mechanic, it'll tell you the likely cause for your exact GM in seconds, free.
See how that range compares across Mississauga, Oakville, Milton, Brampton and Etobicoke in the GTA Repair Price Index, honest shop & dealer ranges for the jobs people actually get done.
Complete Timing Chain Set Replacement (All 3 Chains) is on my published list of jobs I turn down. It needs a hoist, a press or a machine shop, and I work out of driveways with hand tools. That list is public on my trust page. I'd rather lose the job than learn it on your engine, and you should be suspicious of anyone who says yes to this over the phone.
So here's what I can genuinely do for you, holding a $3,200–$4,500 quote. Both are real, both are flat-priced, and both are worth more than a bad yes.
Before you spend $3,200–$4,500, have someone independent confirm that's actually what's wrong. This is a diagnosis, not the repair, no hoist, no lift, nothing comes apart. I scan it, test it, look at it with you, and tell you straight whether their diagnosis holds up. If it does, I say so and you go pay them with confidence.
Book the second opinion →At $3,200–$4,500 on a car that might be worth not much more, plenty of people replace instead of repair, that's a completely reasonable call. If that's where you're heading, get the next car measured before you hand over money: 150 published points, at the seller's location, written report the same day.
Book a pre-purchase inspection →Tell me what you've been quoted and what the car is doing. $100–$250 flat, at your location, and you get a straight answer either way.
Rather just have the quote read? The free quote check tells you whether the number is in line, no visit needed.
Jobs on this car that ARE mine:
Not so you can do it yourself, so you can tell whether the shop quoting you understands the job:
That's the job. It's why this one belongs on a hoist instead of in a driveway, and it's why $3,200–$4,500 usually isn't a ripoff, it's a big repair honestly priced. What's worth checking is whether that's really what your car needs.
Get the diagnosis confirmed firstPlain version: Complete Timing Chain Set Replacement (All 3 Chains) needs equipment a driveway doesn't have, a hoist to get under it properly, a press or a machine shop for the parts that come out, and a controlled space for an engine or gearbox that's in pieces for days. I work out of driveways with hand tools. That's not false modesty, it's the published limit of what I take on, and it's listed on my trust page alongside the warranty.
What that means for you: this page is here to tell you what's failing and what it should cost, so you walk into a shop knowing the job instead of nodding at a number. And if you want that number checked before you pay it, that part I can do, $100–$250 flat, at your location.
Stretched chains don't fail gracefully. The tensioners run out of travel, the cracked guides shed pieces into the oil pan, and eventually a chain jumps teeth, at which point valve timing is gone and you're talking bent valves and a head job on top of the timing set. The cold-start rattle stage is the affordable stage. The no-start-with-bent-valves stage is not.
Mechanically yes, practically no. All three chains wore in the same oil for the same kilometres, replace one and the other two will have you paying for the same teardown again within a year or two. The complete set is the only version of this job worth doing.
Oil changes. This engine punishes stretched intervals, keep it to regular changes with the correct spec oil and the updated chain components will outlast the rest of the vehicle. We'll set you up with the right interval before we leave.
No. Complete Timing Chain Set Replacement (All 3 Chains) is on my published list of jobs I turn down, it needs a hoist, a press or a machine shop, and I work out of driveways with hand tools. I'd rather lose the job than learn it on your engine.
Two things, and both are real. A second-opinion diagnostic at your car, $100–$250 flat, at your location, so somebody independent confirms that's actually what's wrong before you commit to a $3,200–$4,500 repair. And if you're weighing replacing the car instead of fixing it, a pre-purchase inspection on the replacement, $149–$399 flat, at the seller's location.
Because the useful part isn't the wrench. It's knowing what's actually failing, what the correct repair involves, and that shops quote $3,200–$4,500 for it, so you walk in knowing the job instead of nodding at a number. If you want that number checked before you pay it, that part I can do.
Send it over for a free second opinion. I'll tell you straight what the job actually involves, and if their quote is fair, I'll tell you that too.
Get a Free Second OpinionOther makes:
I'm not the guy who does this repair. I'm the guy who tells you whether you actually need it, before you spend $3,200–$4,500. Second opinion at your car, $100–$250 flat, in Mississauga, Oakville, Milton, Brampton and Etobicoke.
Book a Second Opinion Inspect a Replacement CarYour options on this one