Shops quote $6,000–$9,000 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.
The M273 V8 in the 2005–2008 E500, ML500, S500, and CL500 uses the same failure-prone idler gear design as the M272 V6. The gear's teeth are made of a material that simply wasn't up to the job, and they wear away with mileage. As the teeth strip, the timing relationship between the crank and cams drifts, and the computer starts logging P0016 and P0017, crankshaft-to-camshaft correlation faults.
Owners usually notice it as a vibration at idle that wasn't there before, sometimes with a rattle from the front of the engine. The codes are the giveaway: P0016/P0017 on an M273 of this vintage almost always traces back to the worn gear, not the sensors that less experienced shops keep replacing. Chasing sensors on this engine wastes money on a problem that's purely mechanical.
The repair is famous for being quoted as an engine-out job, which is where the most extreme estimates come from. With the right Mercedes-specific tooling, it can be done with the engine in the car. Either way, waiting isn't an option forever: a chain that jumps on this interference V8 puts valves into pistons, and the repair bill multiplies.
If your Mercedes-Benz is doing any of these, this is the likely cause:
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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.
Balance Shaft Idler Gear & Timing Chain Replacement 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 $6,000–$9,000 quote. Both are real, both are flat-priced, and both are worth more than a bad yes.
Before you spend $6,000–$9,000, 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 $6,000–$9,000 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 $6,000–$9,000 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: Balance Shaft Idler Gear & Timing Chain Replacement 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.
P0016/P0017 on this engine is the warning shot. The gear doesn't heal, and every drive grinds more teeth off it. The failure mode, a jumped chain on an interference V8, means bent valves and a torn-down top end at minimum. Fixing it while it's still a gear-and-chain job is dramatically cheaper than fixing it after.
On a 2005–2008 M273 with idle vibration, almost never. Those codes report a real mechanical disagreement between crank and cam position, which is exactly what a stripped idler gear causes. We verify before repairing, a scan and inspection at your home tells us for sure, but throwing sensors at this engine is the classic wasted-money move.
No, the updated part corrects the original material problem. Combined with a fresh chain, tensioner, and guides, the repaired engine is more robust in this area than it left the factory. This is a fix-it-once job.
No. Balance Shaft Idler Gear & Timing Chain Replacement 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 $6,000–$9,000 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 $6,000–$9,000 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 $6,000–$9,000. 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