TURBOCHARGER REPLACEMENT PROCEDURE APPLIED ENGINES: VR30DDTT IF YOU CONFIRM One or both turbochargers require replacement. ACTION 1. Replace the affected turbocharger(s). Refer to the SERVICE PROCEDURE in this bulletin for the updated procedure. IMPORTANT: You MUST closely follow the entire SERVICE PROCEDURE as it contains information that is essential to successfully completing this repair. 2. Refer to step 212 in the SERVICE PROCEDURE to confirm if the ECM needs to be reprogrammed. 2016-2024 Q50 and 2017-2021 Q60 will require ECM reprogramming at the end of this SERVICE PROCEDURE. 3. If the ECM part number is in Table A (page 61 and 63), reprogram the ECM. IMPORTANT: The purpose of ACT
full bulletin at NHTSA ↗2018 INFINITI Q50 engine problems
severe Owners of the 2018 INFINITI Q50 have filed 11 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
11
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2016 Q50 | 7 |
| 2017 Q50 | 9 |
| 2018 Q50 (this page) | 11 |
| 2019 Q50 | 7 |
1fire
When does it fail?
Of the 11 engine complaints filed for the 2018 INFINITI Q50, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 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
Of the 4 model years of INFINITI Q50 we track for engine problems, this one carries the most owner complaints on file — 11.
Engine accounts for 26% of all owner complaints filed against this vehicle, across 4 categories tracked.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
MIL ON WITH DTC(S) STORED IN THE ECM This bulletin is no longer active. Please discard previous versions of ITB17-050.
full bulletin at NHTSA ↗***** Retailer Announcement ***** INFINITI is committed to providing the highest levels of product quality and customer satisfaction. Therefore, INFINITI is conducting a warranty extension to Full Useful Life (FUL) of 10 years or 120,000 miles, whichever occurs first, if white smoke or oil leak occurs with MIL-On condition that requires replacement of the turbocharger assembly on model year 2016-2018 Q50 and model year 2017-2018 Q60. All other warranty terms, limitations, and conditions remain unchanged. On some model year 2016-2018 INFINITI Q50 and 2017-2018 Q60 vehicles there is a possibility that the turbocharger bearing may leak engine oil internally due to premature wear. The internal t
full bulletin at NHTSA ↗ENGINE ROOM SUB-HARNESS IF YOU CONFIRM DTC P06DA-00 for “ENGINE OIL PRESSURE CONTROL” is stored as current (active) with CONSULT-III plus (C-III plus). ACTION Replace the engine room sub-harness. Refer to the SERVICE PROCEDURE in this bulletin. IMPORTANT: The purpose of ACTION (above) is to give you a quick idea of the work you will be performing. You MUST closely follow the entire SERVICE PROCEDURE as it contains information that is essential to successfully completing this repair.
full bulletin at NHTSA ↗MIL ON WITH DTC(S) STORED IN THE ECM This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners describe serious engine problems affecting 2018 Q50s across multiple failure categories. The most severe is catastrophic internal engine failure: one owner at 75,000 miles experienced sudden total engine seizure on a highway after earlier misdiagnosis of a Mass Air Flow Sensor issue. Inspection revealed debris and a disintegrating camshaft in the oil pan. The engine replacement cost $32,000, with warranty covering only $21,000 of fair market value. Another owner at 107,000 miles got a timing chain failure diagnosis. Multiple owners report porous engine blocks as the root cause of failure, with inconsistent manufacturer treatment across VR30DDTT-equipped vehicles.
Serpentine belt failure occurred at 28,660 miles when the belt shredded during light acceleration under 30 mph. The failure knocked loose a coolant hose, overheated the engine, and damaged the water pump and A/C compressor. The dealer noted this is a documented issue in Infiniti Service Bulletins. One owner also reports recurring belt noise and potential tensioner pulley problems.
Coolant system troubles include persistent reservoir emptying with suspected internal leakage leading to rod failure. Additional complaints mention turbo oil leaks creating exhaust smoke, antifreeze consumption, engine-start noise, and one report of an engine fire that destroyed the vehicle completely.
Failure modes owners describe
Catastrophic Engine Seizure / Block Failure
Engine failure from internal component breakdown, with debris and disintegrating camshaft found in oil pan. One owner reported complete engine failure requiring replacement; another reported porous block leading to engine failure.
When: 28,660–107,000 miles
Symptoms owners cite: Increased RPMs with loss of power and stalling; Intermittent stalling that progressed to complete engine shutdown; Engine would not run at all; Abnormally loud engine noise at startup; Low oil pressure warning light illuminated; 'Low Oil Pressure - STOP' message displayed
Codes mentioned: Low oil pressure warning
Repairs/costs cited: One owner faced $32,000 engine replacement cost with warranty coverage capped at $21,000 fair market value; timing chain failure diagnosed in another case; porous block reported by multiple owners; debris and disintegrating camshaft found in oil pan
Recalls/TSBs owners mention: Infiniti initially misdiagnosed issue as Mass Air Flow Sensor (electrical, not covered under extended warranty); factory warranty covered repair to 75,000 miles; case opened and owner referred to NHTSA Hotline; some owners report other VR30DDTT engine-equipped vehicles receiving replacements while others denied
Serpentine Belt Shredding / Drive Belt Failure
Drive belt shredded while driving at low speed, causing secondary failures in coolant system, water pump, and compressor. One narrative also reports recurring serpentine belt noise and tensioner pulley concern.
When: 28,660 miles and recurrently thereafter
Symptoms owners cite: Battery light illuminated on instrument cluster; Check engine light; White smoke from engine; Engine overheating; Consistent serpentine belt noise in all weather types; Squeaking noise during acceleration
Repairs/costs cited: Pulley tensioner assembly, serpentine belt, water pump, and A/C compressor replaced under manufacturer's warranty; repair took three weeks; belt replacement performed once with noise recurring; tensioner pulley suspected on second occurrence
Recalls/TSBs owners mention: Covered under manufacturer's warranty; dealer informed owner this is a known issue documented in Infiniti Service Bulletins; at 10,000 miles, dealer tightened tensioner and warned owner belt could have shredded without that service
Engine Coolant Loss / Porous Block
Coolant reservoir emptying repeatedly, leading to owner concern about internal engine coolant leak and possible rod failure. Multiple owners report porous engine block as cause of engine failure.
When: Mileage not specified; one failure at 107,000 miles
Symptoms owners cite: Coolant reservoir going empty; Engine stalling while driving at highway speed; Loss of vehicle control (all systems stopped); Coolant entering combustion chamber (suspected)
Repairs/costs cited: Radiator fan module replaced by dealer; dealer initially stated engine was not porous; inner rod failure suspected by owner due to coolant ingress; porous block confirmed as failure cause in separate complaint; vehicle not repaired in timing chain case
Recalls/TSBs owners mention: Manufacturer notified in timing chain case and case opened; owner referred to NHTSA Hotline; some owners report inconsistent treatment of porous block failures (some replacements, others denied)
Turbocharger Oil Leak
Oil leaking from turbocharger, causing oil burning and smoke from exhaust. One owner also reports turbo starting to work (unclear context) with antifreeze consumption.
When: Mileage not specified
Symptoms owners cite: Oil leaking from turbo; Oil burning; Smoke from exhaust; Antifreeze consumption (separate report)
Repairs/costs cited: No repair details provided by owners
Engine Fire
Vehicle caught fire under the hood in a parked vehicle, resulting in complete burn-up.
When: As of 12/4/2018
Symptoms owners cite: Fire under hood; Complete vehicle burn-up
Repairs/costs cited: No repair details provided
Engine Noise (Startup/Idle)
Consistent whorl or whining noise from engine during warm-up and startup.
When: Mileage not specified
Symptoms owners cite: Consistent whorl/whining noise from motor during startup and warm-up
Repairs/costs cited: No repair details provided
Synthesized from 11 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 5 most recent
Leak in the turbo causing oil to burn and create smoke from the exhaust
Turbos are starting to work and car is starting to consume anti freeze
The serpentine belt makes consistent noise in all types of weather. Already had the dealer replace it once. Noise came back and the dealer now says it could be the tensioner pulley.
From start into the warm-up, there is a consistent whoreling noise coming from the motor.
On 6/13/2020 the drive belt shredded while driving under 30mph, under light acceleration. At first, the battery light illuminated on the instrument cluster, followed the check engine light. White smoke began to come from the engine. Thankfully, I was nearby my house and made it there safely. Furthermore, the engine overheated due to a coolant hose being knocked off by the shredded belt.…
Had engine trouble with your 2018 INFINITI Q50?
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 2018 INFINITI Q50?
It's a meaningful issue. 11 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Based on the 11 complaints filed, engine issues most often appear around 35,332 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/2018/INFINITI/Q50.
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.