4HK Injector Problems – Symptoms, Causes & Fixes

Engine: 4HK 1 compatible injectors From £100

Common Injector Failures on the 4HK

The 4HK engine uses high-pressure common rail diesel injection. Over time, injector nozzles wear, seals degrade, and internal components lose calibration. This leads to a range of drivability symptoms that worsen if left unaddressed. We stock 1 tested replacement injectors for this engine from Bosch.

Vehicles fitted with the 4HK include models from Ford. If you are experiencing any of the symptoms below, your injectors may need testing or replacement.

Symptoms of Injector Failure

Related Fault Codes

P0201 P0202 P0203 P0204 P0263 P0266 P0269 P0087 P0089 P0300

How to Test 4HK Injectors

Leak-off test: Connect clear hoses to the injector return lines and compare fuel volumes at idle. The injector returning the most fuel is likely worn.

Correction values: Use a scan tool to read injector correction (IMA) values. Readings beyond ±3 mg/stroke indicate wear.

Resistance check: Measure resistance across the injector connector pins with a multimeter. Compare to manufacturer specs.

Complete Testing Guide Leak-Off Test Guide

4HK Injector Replacement Cost

Parts (per injector)

£100–£100

Labour

£150–£400

Total (per injector)

£250–£500

Full replacement cost guide

Compatible Injectors for the 4HK1 found

0445115025Bosch

£100.00

Most Common Injector Part Numbers for 4HK Engine

0445115025Bosch

£100.001 vehicle

Related Cross Reference Numbers for 4HK

0445115025 0445115092 0986435351 0986435450

Vehicles Using the 4HK Engine

Ford S-MAX4HK

Related Engine Codes

4HN 4HP 4HR 4HS 4HT CVRA

Frequently Asked Questions

What are common injector problems on the 4HK engine?

The 4HK engine commonly suffers from injector seal failure, nozzle wear causing poor spray patterns, and back-leak issues. Symptoms include rough idle, black or white exhaust smoke, hard starting, and increased fuel consumption. These issues typically appear after 100,000–150,000 miles.

How much does it cost to replace injectors on a 4HK engine?

A remanufactured injector for the 4HK engine typically costs £100–£100 per injector. Labour adds £150–£400 depending on accessibility. We found 1 compatible injectors for this engine.

Which vehicles use the 4HK engine?

The 4HK engine is found in vehicles from Ford. Common models include Ford S-MAX.

How do I test the injectors on a 4HK engine?

Perform a leak-off test by connecting clear hoses to each injector return line and comparing fuel volumes at idle. You can also check injector correction values with a diagnostic scan tool or measure electrical resistance with a multimeter.

Injector Compatibility Checker

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Need a Replacement 4HK Injector?

We stock 1 tested replacement injectors for the 4HK engine. All remanufactured, bench-tested, and supplied with a 12-month warranty.

View All Injectors Replacement Cost Guide Call 020 3355 6581