Question 1

Cooling system leaks and overheating

Accepted Answer

You'll notice the temp gauge creeping up, puddles of coolant under the car, or the heater not working properly. The engine may consume coolant without obvious external leaks. The cooling system on these PRV V6 engines is complex, with multiple hoses, a heater valve, and aging seals. Radiators corrode internally after 40 years, heater cores develop pinhole leaks, and hose connections weep. The thermostat housing can crack. Water pumps fail. Head gasket failure is possible but less common if compression is still good. Start with a pressure test of the cooling system to find leaks. Replace all coolant hoses as a matter of course if they haven't been done, they're cheap insurance. Fit a new thermostat and check the radiator for blockages or leaks. If the heater core is leaking (you'll smell coolant in the cabin), replacement is a dashboard-out job. Water pump replacement is straightforward. Use genuine Volvo coolant and bleed the system properly, air pockets will cause overheating.

Question 2

Poor starting, especially when cold (B27/B28 with K-Jetronic)

Accepted Answer

The V6 is reluctant to start when cold, runs rough for a few minutes, or won't start at all. Once warm it's usually better. The Bosch K-Jetronic continuous injection system relies on vacuum-operated components, precise fuel pressure, and a functioning cold start system. The cold start injector (a sixth injector) often fails, the thermo-time switch stops working, and the warm-up regulator sticks. Vacuum leaks are endemic on old engines. Check fuel pressure at the distributor, should be around 72-77 psi with the engine running, dropping to about 50 psi when the engine is off. Test the cold start injector by removing it and checking for spray during cranking (it should spray for a few seconds then stop). Replace the thermo-time switch if faulty. Hunt down vacuum leaks with a smoke machine or by spraying carb cleaner around suspect areas. The K-Jetronic system can be fiddly; if you're not confident, find someone who knows these systems.

Question 3

Oil leaks from everywhere

Accepted Answer

Oil spots on the driveway, oily residue on the underside of the engine, falling oil level. Every seal and gasket is four decades old. The PRV V6 is notorious for leaking from the camshaft seals, valve cover gaskets, front and rear crankshaft seals, and oil pan gasket. The cam covers are alloy and can warp slightly, making leaks worse. Systematically replace all gaskets and seals. Cam cover gaskets are easy. Camshaft seals require timing cover removal. The rear main seal is an engine-out or gearbox-out job, so do it if you're already in there. Use quality gaskets, cheap ones won't last. Clean all mating surfaces thoroughly before reassembly.

Question 4

Engine runs rough, misfires, lacks power

Accepted Answer

Uneven idle, hesitation under acceleration, flat spots, check engine light (if fitted). Ignition system faults are common. The Bosch EZ-series electronic ignition uses a distributor with a Hall effect sensor, ignition coil, and power stage module. The power stage (mounted on the inner wing) can fail. Spark plug leads perish. The distributor cap and rotor wear. The MAF sensor (on later fuel-injected models) can fail or get contaminated. Start with the basics, new spark plugs (use OEM spec), leads, cap, and rotor. Check the power stage with a multimeter (there are test procedures in the workshop manual). Inspect the distributor for wear or cracks. If fitted with an MAF sensor, clean it or replace if faulty. Check fuel pressure and injector spray pattern. Compression test to rule out mechanical issues.

Question 5

Radiator corrosion and blockages

Accepted Answer

Overheating, poor heater output, coolant looks rusty or sludgy. Original radiators are 40+ years old. Internal corrosion blocks coolant passages. Mixing coolant types or using water creates sludge. Electrolysis from poor earthing accelerates corrosion. Replace the radiator with a new or reconditioned unit. Flush the entire system thoroughly before fitting the new rad. Use the correct Volvo coolant mix (ethylene glycol-based) and distilled water. Check all earth straps, poor earthing can cause coolant to become conductive and corrode alloy components.

Question 6

Heater valve failure

Accepted Answer

No heat in the cabin, or heat all the time regardless of control position. The vacuum-operated heater valve sticks open or closed. Vacuum lines perish and leak.

Question 7

Fuel pump failure

Accepted Answer

Engine cranks but won't start, or dies suddenly. You might hear the fuel pump buzzing or clicking but not delivering fuel. Electric fuel pumps wear out. The main pump (in the tank on later models, under the car on earlier ones) eventually fails. Wiring connections corrode. The fuel pump relay sticks or fails. Check for fuel pressure at the fuel rail or distributor. If pressure is low or absent, check voltage at the pump. If voltage is present, replace the pump. Check the relay, common failure point. Clean all electrical connections.

Question 8

Clogged fuel filter and lines

Accepted Answer

Poor running, hesitation, loss of power, rough idle. Decades of crud accumulates in the tank. Fuel filters (especially inline types) clog. Rust particles from old steel tanks block injectors. Replace the fuel filter as a matter of course. If the tank is rusty inside, consider removal and professional cleaning or replacement. Blocked injectors can sometimes be cleaned ultrasonically, but replacement may be necessary.

Question 9

Intermittent or total electrical failures

Accepted Answer

Lights dim, instruments stop working, car won't start, battery goes flat. Random electrical gremlins. Age. Corroded earths, failing alternator, worn wiring, dodgy fuses, and amateur repairs all conspire against you. The 260 series uses a relatively simple electrical system by modern standards, but four decades of British weather (or wherever) takes its toll. Start with the basics, clean and tighten all earth points (especially the main engine earth strap and body earths). Check battery condition and charge state. Test the alternator output (should be around 13.8-14.4V at idle). Go through the fuse box and clean all connections. Repair or replace corroded wiring as you find it. Invest in a proper wiring diagram.

Question 10

Alternator failure

Accepted Answer

Battery warning light comes on, battery goes flat, dim lights. Brushes wear out, diodes fail, bearings seize, voltage regulator packs up. Test alternator output with a multimeter, should see 13.8-14.4V at idle. If output is low, remove the alternator and have it tested/rebuilt, or fit a reconditioned unit. Bosch alternators are rebuildable and parts are available.

Question 11

Corroded fuse and relay box

Accepted Answer

Intermittent electrical faults, accessories not working, strange behaviour. Water ingress, corrosion, decades of heat cycling. The fuse box is under the bonnet on the inner wing and exposed to the elements. Remove the fuse box cover and inspect. Clean all fuses and contacts with electrical contact cleaner. Replace any corroded fuse holders. Check relays, common failure point. Consider relocating critical relays to a drier location or fitting a waterproof relay box.

Question 12

BW55 automatic slipping or not engaging

Accepted Answer

Slipping between gears, delayed engagement from park to drive, no drive at all, harsh shifts. The BW55 is a three-speed slushbox with no overdrive. It's a simple, robust design, but after 40+ years and 200,000 miles they wear out. Clutch packs glaze, seals leak, valve body passages clog with sludge. Lack of fluid changes is the usual culprit. Check the ATF level and condition with the engine running and transmission at operating temperature. If it's dark brown or smells burnt, you're too late, the transmission needs a rebuild. If caught early, a fluid and filter change might help. Remove the sump, replace the filter, clean the sump and magnet, refill with fresh Dexron II or III ATF (about 3.5 litres for a service, more for a complete refill). If it's still slipping, budget for a rebuild or replacement.

Question 13

M46 manual gearbox issues

Accepted Answer

Difficult or noisy gear selection, especially into reverse. Crunching when changing gear. Overdrive not engaging or cutting out. Synchromesh wears out (especially on second gear). Clutch doesn't fully disengage. Overdrive solenoid or relay fails. Gearbox oil is old or incorrect spec. Check and adjust clutch pedal free play. Change the gearbox oil, use the correct grade (usually SAE 80W or ATF depending on spec). If synchros are worn, the box needs a rebuild. Overdrive issues are often electrical, check the relay, wiring, and solenoid. The overdrive can be rebuilt separately.

Question 14

Worn propshaft and diff mounts

Accepted Answer

Clunking when pulling away or changing gear. Vibration at certain speeds. Rubber mounts perish. The centre bearing support on the propshaft degrades. Diff mounts crack. Jack up the car and check for play in the propshaft centre bearing and diff mounts. Replace as necessary. The centre bearing support is a common wear item.

Question 15

Worn front suspension bushes and ball joints

Accepted Answer

Vague steering, clunking over bumps, uneven tyre wear, wandering on the road. Rubber bushes perish. Ball joints wear. Track control arm bushes fail. The MacPherson strut top mounts degrade. Jack up the front and check for play in all ball joints, bushes, and links. Replace anything worn. Poly bushes are available if you want a firmer, longer-lasting setup, but NVH increases. Fit new strut top mounts if they're original, they're a common cause of knocking. Get a four-wheel alignment done after any suspension work.

Question 16

Leaking dampers (shock absorbers)

Accepted Answer

Bouncy ride, nose-diving under braking, oil on the damper body. Dampers wear out. Seals fail. Replace in pairs (both fronts or both rears). Bilstein or Koni are good aftermarket options. OEM Volvo dampers are fine but pricey.

Question 17

Power steering leaks and heavy steering

Accepted Answer

Whining noise from the pump, heavy steering, puddles of ATF (power steering fluid), steering suddenly goes heavy. Power steering pump seals leak. Hoses perish. The rack develops leaks. Pump wear. Low fluid. Check fluid level in the reservoir (use Dexron II ATF). Top up if low and look for leaks. Common leak points are the pump, pressure hose (high-pressure rubber hose from pump to rack), and rack seals. Replace leaking components. If the pump is noisy, it's worn, replace it. Flush and bleed the system after repairs.

Question 18

Spongy brake pedal, poor braking

Accepted Answer

Pedal feels soft, long pedal travel, car takes longer to stop. Air in the brake lines, worn pads or discs, failed brake master cylinder, leaking wheel cylinders or calipers, old brake fluid. Bleed the brakes properly. If the pedal is still spongy, suspect the master cylinder or a leak. Check all brake lines and hoses for leaks or bulging. Replace pads and discs if worn (minimum thickness stamped on discs). Change brake fluid every two years, old fluid absorbs water and reduces braking efficiency.

Question 19

Seized brake calipers

Accepted Answer

Car pulls to one side, binding brakes, excessive disc wear, smell of hot brakes. Caliper pistons corrode and seize. Slider pins seize due to lack of lubrication. Remove, clean, and lubricate slider pins. If pistons are seized, rebuild or replace the calipers. Fit new pads and check discs for warping or uneven wear.

Question 20

Brake servo failure

Accepted Answer

Heavy brake pedal, requires much more effort to stop the car. Vacuum servo diaphragm splits, vacuum hose leaks, non-return valve fails. Check vacuum supply to the servo with the engine running. Listen for a hissing sound indicating a leak. Test the non-return valve. If the servo is faulty, replace it.

Question 21

Sills (rocker panels) and inner sills

Accepted Answer

Rust perforations along the lower body, structural weakness, MOT failure. Water and road salt sit in the sills. Drain holes block. The inner and outer sills corrode from the inside out. If it's surface rust, treat and paint. If perforated, the sills need cutting out and replacement sections welding in. This is a big job requiring a welder who knows what they're doing. Inner sills are load-bearing, don't bodge this.

Question 22

Rear wheel arches and spare wheel well

Accepted Answer

Rust around the rear wheelarches, bubbling paint, holes in the boot floor around the spare wheel. Water collects, mud packs in, salt accelerates corrosion. The 260 estate is particularly bad for spare wheel well rot. Cut out rotten metal and weld in new panels. Repair sections are available. Clean out all mud and treat with rust inhibitor after welding.

Question 23

Front inner wings and bulkhead

Accepted Answer

Rust around the strut tops, inner wing perforations, firewall rust near heater box. Water sits in the front scuttle panel, drains block, condensation from the heater. Clear scuttle drains. Cut out and weld repair patches if perforated. Strut top rust is structural, don't ignore it.

Question 24

Doors and bootlid

Accepted Answer

Rust along bottom edges, door hinges sag. Water sits in the door bottoms, drain holes block. Clear drain holes. Treat surface rust. Replace door skins or entire doors if necessary. Hinges can be shimmed or replaced.

Question 25

Odometer failure

Accepted Answer

The mileage counter stops working, but the speedo still operates. Plastic gears in the odometer mechanism crack and strip. Common failure on 1970s/80s Volvos. Remove the instrument cluster and replace the odometer gears. Repair kits are available, or send the cluster to a specialist. Not a hard job if you're handy.

Question 26

Cracked dashboard

Accepted Answer

Cracks appear along the top of the dashboard, especially above the instruments. UV exposure and age. The vinyl-covered foam shrinks and cracks. No perfect fix. You can cover it with a dash mat, have it professionally restored (expensive), or replace the entire dash (even more expensive and rare as hen's teeth now).

Question 27

Worn seat upholstery

Accepted Answer

Driver's seat bolster worn through, headrest covers split. 40+ years of use. Recover the seats or source used replacements in better condition. Leather wears better than cloth, but is expensive to replace.

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262 / 264 / 265 known problems