Symptoms
A puff of blue smoke at start-up or after a long idle, smoke on the overrun, and oil use with no external leaks. Worn valve stem seals are a known V6 complaint. One ExplorOz owner says they 'normally need replacing at 200,000 km', and another warns that when they wear out it means 'a lot of smoke or [an] expensive repair'.
The fix, step by step
- First rule out the rings: a compression and leak-down test tells you whether the cylinders are healthy.
- With the heads on, the job means removing the intake plenum and valve gear, holding each valve shut with compressed air through the spark-plug hole while you compress its spring, then pulling the old seal and pressing on a new one.
- If the heads are coming off for gaskets anyway (see the head-gasket job), have the machine shop fit new seals and check the guides at the same time.
- Follow the factory manual for cam timing and torque values on reassembly.
Tools & part numbers
- Compression and leak-down tester
- spark-plug-hole air adapter and compressor
- overhead valve-spring compressor
- seal pliers and installer
- torque wrench
- factory service manual.
Where to buy the parts
Hunting a used or discontinued part? Search eBay Motors for Mitsubishi Pajero / Montero (Second Generation) parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.