With a low milage car receiving a P052E positive crankcase ventilation regulator valve performance issue.
2017 Mercedes-Benz GLC-Class engine problems
moderate 23 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Complaints
23
Recalls
0
Avg fix
$3,100
1fire
When does it fail?
Of the 23 engine complaints filed for the 2017 Mercedes-Benz GLC-Class, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Among the 7 model years of Mercedes-Benz GLC-Class in our records for engine problems, this one ranks #2 by owner-complaint volume.
Engine accounts for 20% of all owner complaints filed against this vehicle, across 9 categories tracked.
The failure pattern owners describe
Buyer takeaway: The 2017 GLC-Class has a history of serious engine defects, most commonly PCV regulator valve failure (code P052E) and piston cracking, often occurring before 90,000 miles. Budget $2,000–$3,000+ for PCV repair out of warranty, or face potential engine replacement ($5,000–$9,700+) if piston failure occurs.
Owners of 2017 GLC-Class vehicles report two dominant engine failures.
PCV regulator valve (P052E) problems show up repeatedly: check engine light comes on—sometimes intermittently, sometimes for good—starting as early as 13,700 miles. The code links to Positive Crankcase Ventilation Regulator Valve Performance. Dealers quote $2,000–$2,500 or higher to replace it; one shop demanded $9,700+. The part is sometimes backordered. Several owners note a recall covered some C-Class and GLC-Class models with the same engine, but their vehicles were excluded. One owner's vehicle caught fire at 9,000 miles.
Piston cracking is the second major failure: owners report pistons fracturing and detaching inside the engine, often without warning. Loss of acceleration at highway speeds, white smoke from the tailpipe, and stalling follow. Mileage at failure ranges from 47,000 to 88,000 miles. Dealers and independent shops confirm via camera inspection or teardown that the piston is fractured. Engine replacement is the only fix, running well over $5,000. One owner's turbo was also destroyed by metal filings from the failing piston.
Three owners report misfire, camshaft/adjuster failures, and blocked crankcase vents requiring extreme labor (6–8 hours with engine removal) out of proportion to part cost. All issues occur out of warranty, leaving owners unprotected.
Same Mercedes-Benz GLC-Class engine reports on nearby years: 2016 · 2018 · 2020
Failure modes owners describe
Cracked or failed piston
Piston fracture and detachment inside the engine, often in cylinder #2, causing immediate loss of power and white smoke from exhaust. Multiple owners report catastrophic engine failure requiring full engine replacement.
When: 47,000–88,000 miles; one case at 9,000 miles (vehicle fire)
Symptoms owners cite: Loss of acceleration or inability to accelerate on highway; Engine shaking or severe vibration; White smoke from tailpipes; Slow acceleration delays prior to failure; Engine stall or refusal to start
Codes mentioned: Visual inspection by dealer (camera showed fractured piston)
Repairs/costs cited: Engine replacement required; one case cited turbo failure due to metal filings from piston damage; repairs exceed $5,000–$9,700+
Recalls/TSBs owners mention: No recall identified for piston defect; one owner noted similar issues discussed on forums with other C-Class and GLC-Class vehicles; manufacturer contacted but no assistance provided in some cases
Positive Crankcase Ventilation (PCV) regulator valve failure
PCV harness or regulator valve malfunction causing check engine light and, in some cases, inability to accelerate or stall while driving. Owners report this is a recurring design issue across multiple model years. One owner notes a recall existed for some C-Class and GLC-Class vehicles with the same engine, but their VIN was excluded.
When: Before 50,000 miles warranty expiration; 13,700 miles; onset varies, some intermittent before persistent failure
Symptoms owners cite: Check engine light (comes on and off intermittently, or remains on); Unwillingness to accelerate or stall risk on highway; Slow or hesitant acceleration; Gas smell from under hood
Codes mentioned: P052E (Positive Crankcase Ventilation Regulator Valve Performance)
Repairs/costs cited: Parts cost $300–part costs vary; labor 6–8 hours at dealer, totaling $2,000–$2,500 or more; one case quoted $9,700+; part reportedly backordered at some dealers with no estimated arrival
Recalls/TSBs owners mention: Partial recall for C-Class and GLC-Class (same engine) covered some vehicles; affected VINs not included in recall; owners argue this is an emission control device under state/federal warranty; Mercedes extended warranty covers diesel engines but not gasoline for this issue
Crankcase vent valve blockage
Blocked crankcase vent valve requiring engine removal for replacement, flagged as a design defect due to extreme labor intensity. Owners report dealer hesitation to address under warranty.
When: After warranty expiration
Symptoms owners cite: Engine efficiency loss; SMOG test failure risk
Repairs/costs cited: Part cost $300; labor 6–7 hours with full engine removal, costing ~$1,800, totaling ~$2,100; flagged as design flaw because labor cost is 6 times higher than part cost
Recalls/TSBs owners mention: None mentioned; dealers did not identify problem during warranty period
Engine misfire with persistent failure after rebuild
Engine misfire affecting spark plugs and cylinders; one owner reported engine was rebuilt twice but misfire persisted, indicating underlying defect not resolved by standard rebuild.
When: <UNKNOWN>
Symptoms owners cite: Engine misfire; Check engine light illuminated
Repairs/costs cited: Engine rebuilt twice without resolution
Camshaft and adjuster failure
Intake and exhaust camshaft and adjuster failure causing loss of acceleration and stall starts, with safety risk on highway. Technician opinion: should not occur at this mileage.
When: 83,000 miles
Symptoms owners cite: Vehicle will not accelerate; Stalled starts; Loss of power on highway
Repairs/costs cited: Repair cost over $5,000; vehicle out of warranty, no manufacturer recourse
Recalls/TSBs owners mention: None
Vehicle fire while parked
Vehicle caught fire while parked in driveway at very low mileage, reported as manufacturer defect. Fire department contacted and police report filed.
When: 9,000 miles
Symptoms owners cite: Vehicle ignition while parked
Repairs/costs cited: Vehicle not repaired or towed
Recalls/TSBs owners mention: Manufacturer notified; no further details on response
Synthesized from 23 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
My car has P052E code with a message of Positive Crankcase Ventilation Regulator Valve Performance. My car mileage is only 13,700 as of today. I think this is a cause of a deflective part and this should be a recall item. FYI, Wen I contact a Mercedes dealership and they asked me a cost of $2,500 to fix this issue. Thank you,
The contact owns a 2017 Mercedes-Benz GLC300. The contact stated that while driving approximately 55 MPH, she detected white smoke coming from the tailpipes. There were no warning lights illuminated. The contact was able to pull over. The vehicle was towed to the local dealer who placed a camera inside the engine and noticed that the piston had fractured and detached inside the engine. The…
Had engine trouble with your 2017 Mercedes-Benz GLC-Class?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2017 Mercedes-Benz GLC-Class?
It's a documented issue but not catastrophic. 23 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 23 complaints filed, engine issues most often appear around 52,333 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2017/Mercedes-Benz/GLC-Class.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.