1997 Volvo 960 Problems: 5 Known Issues

How to Fix

Replace the heater core, which requires significant dashboard removal. Flush the cooling system and use only Volvo-approved coolant. Install an inline coolant filter to protect the new heater core from debris.

Owner tips & cautions

• WarningNever mix coolant types - electrolysis from mixed coolant accelerates heater core failure
• TipAn inline coolant filter on the heater hose can extend the life of a new heater core

How to Fix

1. Check the pressure cap first. If it is the old grey cap or shows hairline cracks in the threads, replace it with the current green 150 kPa (22 psi) Volvo cap or an equivalent. A bad cap usually shows up as hot coolant leaking from the cap, or as hoses that collapse while the engine cools. 2. Pressure-test the cooling system. A shop can do it, or you can make a tester that fits the reservoir neck. Pressurize to the cap rating, 150 kPa (22 psi). The pressure should not drop noticeably within three minutes. A slow drop with no visible drip points to a leak that only shows under heat and pressure. 3. With the system pressurized, check these spots: the U-pipe joint at the back of the water pump housing, the coolant return pipe under the front of the exhaust manifold, the expansion tank (especially its lower outlet and the hose there), the plastic necks on the radiator, and the heater hoses at the back of the engine. 4. U-pipe or return-pipe leak: replace the O-ring. To pull the U-pipe you remove the exhaust manifold heat shield, move the secondary air pump out of the way and unbolt a bracket under the rear manifold next to cylinder 5. One owner used a 39 mm OD Buna-N O-ring with a small amount of RTV as lubricant. If the pipe itself has to come out for repair or replacement, the exhaust manifolds must come off. 5. Cracked or brittle expansion tank: replace it. Don't just tighten the clamp. Volvo Club editors treat the tank as a wear item and suggest replacing it about every eight years, along with the radiator. If you replace the radiator on a 960, use an OEM-type aluminum and plastic unit, not an all-metal one. Don't overtighten the hose clamps on its plastic necks. 6. Weep directly beneath the exhaust manifold with every other source ruled out: suspect the porous-block defect, mainly on early 1992 engines. Owners report mixed results. Careful epoxy (JB Weld) repairs have held on small leaks for some, but you have to pull the exhaust manifold or drop the subframe to reach the area, and welding has had very little success. Replacing the block is the sure fix. 7. Afterward, refill with Volvo coolant mixed 50/50 with distilled water and change it about every three years. A Volvo Club contributor also suggests replacing the thermostat about every 60,000 miles, because a thermostat that sticks closed can overheat the engine and warp the head. I found no recall, warranty extension or service bulletin that covers these leaks.

How to Fix

Replace the timing belt, tensioner, all idler pulleys, and water pump as a kit at the interval in the owner's manual for your model year (70,000 miles on 1996 cars). Use OEM-quality components. Do not extend the service interval.

How to Fix

Replace the leaking component — pump, hose, or rack seals. Flush the power steering system. Use the power steering fluid specified in the owner's manual (ATF on the 960; do not mix fluid types). Address all leaks to prevent pump damage from low fluid.

How to Fix

1. Read the codes first. On pre-1996 (OBD-I) 960s you can flash the codes at the diagnostic unit: insert the test lead into socket 1, turn the key to position 2 with the engine off, and press the button for 1-3 seconds. Code 1-1-1 means no faults. Code 3-1-3 means a bad gear position sensor (PNP switch) signal. 1-1-2, 1-2-1 and 1-2-2 point to the No. 1 shift solenoid circuit, 2-1-2, 2-2-1 and 2-2-2 to the No. 2 shift solenoid, 1-3-1 to the line-pressure solenoid, 3-3-x to the lock-up solenoid, and 2-3-5 to high fluid temperature. 2. If the code points to the PNP switch, try shifting slowly from P to L and back a few times. Owners say this can restore contact for a while. The service manual's Test Mode 2 confirms the fault: response code 2-4-3 means the gear position sensor is faulty. Check the 8-pin gear position sensor connector, which is the middle of the three connectors at the front of the transmission. The plugs are tight and crack easily, so use penetrating spray and take care. If the switch is bad, replace it. Owners say cleaning the old one does not work. Align the new switch when you fit it (owners line it up so the backup lights work in R and the engine cranks in P and N), and torque the sensor bolt to 62 in-lb (7 Nm). Clear the codes afterward. Owners report pulling fuse 14 to reset the transmission light, while the check-engine light needs a scan tool. 3. If the connectors are corroded, which owners report especially on the large plugs at the upper left of the transmission on early 1992 cars, unplug them, spray them with electrical contact cleaner, let them dry, and reconnect them with silicone dielectric grease. Disconnect the battery before you unplug transmission connectors. 4. If a solenoid code comes back, measure the solenoid resistance. Per the service manual, the No. 1, No. 2 and lock-up solenoids should read 10-15 ohms and the line-pressure solenoid 2-6 ohms. A reading out of range points to the solenoid or its wiring. On a 1992 960 that shudders before the converter unlocks, bulletin DCS43-02-1194 calls for replacing the lock-up solenoid. Until the fault is fixed, start off in L, as the service manual advises, and do not drive far while stuck in 3rd, because the fluid can overheat. The only recall the Volvo Club FAQ mentions is a 1996 recall for the shift-lock microswitch in the shifter console, which is a different part. Costs reported by owners: a PNP switch costs about $110 for the part, $300-400 fitted by a dealer, and about $32 to have a shop clear the codes. A lock-up solenoid costs about $250 for the part.