What are the symptoms of Unusual noise and metallic grinding when A/C is on in Jaguar XJS?

Weak cabin cooling. Unusual noises when A/C is turned on

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Unusual noise and metallic grinding when A/C is on

Q: How to fix Unusual noise and metallic grinding when A/C is on in Jaguar XJS?

Disassembly of the unit, alignment (grinding) of the mounting surfaces, installation of stiffer, double pressure plates (dual plates) based on a longer central screw tightened with a controlled torque (45-50 ft. lbs.) and installation of O-rings lubricated with a special adhesive (Nylog).

in Jaguar XJS (1985-1991)

Symptoms

Weak cabin cooling
Unusual noises when A/C is turned on

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Technical diagnosis (Premium)

Recognized technical fault:

Auxiliary controller voltage instability detected

Technical analysis

Detailed analysis of HVAC controller operation parameters, CAN bus data readings, and diagnostic signal waveforms. Purchase PRO access or log in to read the full fault analysis.

Confirmed solution

Complete step-by-step repair procedure including module non-volatile memory reset, sensor calibration, and correct wiring routing. Unlock the full report to see the instruction.

Parts needed

Filters ferrite anti-interference / noise suppressor
Auxiliary starting battery (depending on cell status)

Workshop hacks

Important workshop tips for mechanics regarding bypasses without expensive control module replacement and manufacturer software service bulletins.

TSB / TPI service bulletins

TSB-24-HVAC-01TPI-2068943/2

A/C Technical Specifications

(X351)

Refrigerant: R134a Amount (g): 700g Oil: JLM12260 PAO 68 lub PAG ISO 46 Oil (ml): 110ml

Standard

Refrigerant: R134a Amount (g): 900 – 950g Oil: SP 20 PAO 68 lub PAG ISO 100 Oil (ml): 120 – 150ml

See full specification

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