P0174 on Jaguar: How to Diagnose & Fix
System Too Lean (Bank 2)
1 Jaguar model · 1 documented issue · $400-$1,200 repair
P0174 on Jaguar by model: symptoms, diagnosis and fix
The crankcase ventilation (PCV) valve on AJ-V8 engines fails, causing excessive oil consumption, oil leaks from gaskets under positive crankcase pressure, and rough idle. The valve diaphragm tears, disrupting crankcase pressure management.
Common Symptoms
- Excessive oil consumption between changes
- Oil leaks from valve cover or front main seal
- Rough idle
- Whistling noise from engine
- Check engine light for lean codes
How to Fix
Replace the crankcase ventilation valve assembly. On the 5.0L, the pressure control valve is built into the right-hand camshaft cover; Jaguar bulletin SSM74375 now supplies a lower-level kit (C2D60163) with the rubber diaphragm and valve cover as an alternative to replacing the complete camshaft cover.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine AJ89074-type crankcase breather valve for the 4.2L branchOEMAJ89074 / W0133-1785056
Confirmed stuck/leaking crankcase vent valve on a 2009-2010 XF 4.2L V8 Fitment/availability: The genuine W0133-1785056 listing is specifically fit for 2009-2010 XF 4.2L and corresponds to the AJ89074 breather-valve family. Confirm VIN an…
- Genuine Jaguar C2D60163 PCV diaphragm-and-cap service kit for the 5.0L AJ133 branchOEMC2D60163
Confirmed torn or leaking PCV diaphragm on a compatible 2010-2015 XF 5.0L AJ133 Fitment/availability: C2D60163 is the factory diaphragm-and-cap service kit cataloged for AJ133 applications. Confirm VIN and inspect the breather housing/ho…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipIf your V8 XF is consuming more than 1 quart per 3,000 miles, check the PCV valve before chasing other oil consumption causes. It is the most common culprit.
Sources for this issue (1)
P0174 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0174 mean on a Jaguar?
P0174 stands for "System Too Lean (Bank 2)." P0174 means the engine computer detected that the air-fuel mixture on Bank 2 (the side of the engine that does not contain cylinder 1) is running too lean — too much air relative to fuel. The computer monitors this through the oxygen/air-fuel sensors and fuel trims; when it has to add a large amount of extra fuel to compensate and still can't reach the target, it flags the mixture as too lean. A lean condition can cause rough idle, hesitation, or misfires, and over time can raise combustion temperatures. Because it's Bank 2 specific, an unmetered air leak on that bank or a fuel delivery shortfall is typical. On Jaguar it is documented across 1 model: XF.
What are the most common causes of P0174?
The most common causes of P0174 are: Vacuum or intake air leak (hoses, gaskets, PCV), Dirty or failing mass airflow (MAF) sensor, Weak fuel pump or restricted fuel filter (low fuel pressure), Clogged or underperforming fuel injectors, Leaking intake manifold or throttle body gasket, Faulty or contaminated oxygen / air-fuel sensor, Exhaust leak upstream of the oxygen sensor, Stuck-open EGR valve. The specific cause varies by vehicle.
How much does it cost to fix P0174 on a Jaguar?
Published repair estimates on Jaguar range from $400 to $1,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0174 on a different make?
View P0174 across all makes →Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.