Volvo 240 Tips, Troubleshooting and Common Part Numbers

I've owned over a hundred Volvos and I remember the 240 cars with special fondness. I hate to see these sturdy little cars suffering neglect.

Let's begin with the most common areas of neglect that create problems.

Volvo 240 corroded fuses.

It takes just a few minutes to clean the contacts and replacing the corroded fuses. Scrape away any corrosion and coat the contact area with a dab of vaseline.

Under the hood you will find a 25 amp spade fuse to the rear of the battery. Make sure the fuse is good with no corrosion and the wires to the battery are good. Many puzzling problems develop from corrosion or faulty connection at the battery.

Next on the list is to oil the hood and door hinges. DO NOT use WD40 as it washes away what oil is there and when it evaporates you have even less lubrication. Use a little light oil such as motor oil. Many hoods have buckled from binding hood hinges.

Volvo 240 flame trap service

Probably the most neglected under-the-hood service is the flame trap. If it plugs up the pressure builds in the crankcase and blows oil seals or gaskets. The parts are inexpensive but a bit of a pain. That's why they usually don't get serviced. When buying parts like this it's best to use the OEM part numbers. You find lots of choices on eBay and other sites.

Flame trap: 1389657 (newer plastic type)
FT nipple '81-87 1336681
FT hose '81-87 1336682
FT nipple '88 up 3501707
FT hose '88 up 3501708
NOTE: No flame trap on turbo models.

(Will upload some pics of flame trap, oil seal and drain plug seal, also my kit.)

CLICK HERE to check out EuroPartsHouse fuses and kits

Volvo 240 oil cap seal

The oil cap seal often becomes hard, cracked and leaking when non-Volvo technician's don't change it because they don't know where to get one. Part number is 940096.

Use good oil filters when changing oil such as the Mann W917, Volvo part #3517857. The oil drain plug seal is part # 18818.

Volvo 240 defroster not working

Usually a simple fix as the vacuum hose is split at the intake manifold. It affects the driver side defroster first, then as it cracks you lose both sides.

Volvo 240 fuel pump relay - how to make the fuel pump run

Most Volvo 240 owners eventually have fuel pump relay issues. On '85 up models you can use a jumper wire between #4 and #6 fuses to make the fuel pump run. Below shows a straightened paper clip to jump the pump circuit to see if the pump will run. You need more than a paper clip to drive it as the clip would get hot. But you get the idea, if you jump it and you hear the fuel pump when it didn't before you know you probably have a problem with the relay.

On '85 up cars the relay is above where the front passenger's feet would be. It's a white rectangular relay part number 1347603. Typically the points get burned but can be cleaned with a pocket knife. Best to replace it with a new one if you have one but if you don't you can clean the points.

The points that carry the load get burned. A sharp knife will remove the burned up material on the points. Clean both halves.

Volvo 240 most common won’t start problems

This is my estimate after a couple decades of servicing these cars from the most common to the less common.

1989-93
Fuel pump relay
Corroded or defective ceramic fuses
Failed air mass meter (scroll down)
Dead battery due to failed alternator
Magnetic pickup crankshaft position sensor / rpm sensor (scroll down to picture)
Failed ECU for fuel injection front passenger side behind right kick panel
Corrosion somewhere in the 25 amp fuse line from battery
Power stage (just forward of battery)
Misc ignition issues such as faulty cap or rotor, bad coil wire
Broken timing belt
Defective main fuel pump
Serious engine damage such as blown head gasket from overheating
Other less common reasons: fuel pressure regulator, wiring, temperature sensor for fuel injection under intake manifold towards rear of the cylinder head, ignition control unit. If after an engine or transmission change: damage to the flex plate or flex plate incorrectly installed.

Many of the 1989-93 240's came out with fuel injection ecu's that didn't last long. Some were changed under warranty but eventually most were changed. So in a sense they became better cars as they got older because the faulty ecu's were mostly replaced. More detail on this later but the fuel injection ecu's with colored labels were the early ones. Some had a red or pink part number label. The replacements had a white label. So if I'm looking for a used fuel injection ecu in a wrecking yard I only buy those with the white label.

The only crankshaft position sensor I use is the original Bougicord 271949. They cost a little more than the cheaper made-in-you-know-where ones that lack the quality control.

November 20, 2016: Will be expanding this section soon.

1985-88
Fuel pump relay
Corroded or defective ceramic fuses
Failed air mass meter (scroll down)
Dead battery due to failed alternator
Corrosion somewhere in the 25 amp fuse line from battery
Misc ignition issues such as faulty cap or rotor, bad coil wire
Broken timing belt
Defective main fuel pump
Serious engine damage such as blown head gasket from overheating
Other less common reasons: fuel pressure regulator, wiring, temperature sensor for fuel injection under intake manifold towards rear of the cylinder head, ignition control unit

1983-84
Failed air mass meter (scroll down)
Ignition pickup, those models with Chrysler ignition
Corroded or defective ceramic fuses
Corrosion somewhere in the 25 amp fuse line from battery
Dead battery due to failed alternator
Misc ignition issues such as faulty cap or rotor, bad coil wire
Serious engine damage such as blown head gasket from overheating

1982
Ignition pickup, those models with Chrysler ignition
Corroded or defective ceramic fuses
Dead battery due to failed alternator
Intake hose popped off due to a backfire
Misc ignition issues such as faulty cap or rotor, bad coil wire
Serious engine damage such as blown head gasket from overheating

1976-81
Fuel pump relay
Corroded or defective ceramic fuses
Dead battery due to failed alternator
Intake hose popped off due to a backfire
Misc ignition issues such as faulty cap or rotor, bad coil wire
Faulty warmup regulator
Faulty check valve in main fuel pump creating hot start problems
Serious engine damage such as blown head gasket from overheating

Volvo 240 limp home mode

The picture below shows where to unplug the air mass meter. NEVER plug-in or unplug the air mass meter unless the ignition switch is OFF.

With the air mass meter unplugged it's in "Limp Home Mode" so you can get it off the road. If it only runs with the air mass meter unplugged it indicates a failed air mass meter.

Volvo 240 crankshaft position sensor / rpm sensor

It's tricky replacing the Volvo cps / rpm sensor between the back of the engine and the firewall but it's just one screw.

The crankshaft position sensor aka rpm sensor is held on with a M6 screw with a 10mm hex head. I use a long 3/8 drive extension with a 1/4 drive wobble socket. 1988 and earlier models didn't use crank sensor.

Volvo 240 alternator troubleshooting

Before considering alternator issues be sure you have a skidplate aka belly pan under the engine. Part # 1254390. If not expect to have your alternator ruined when you hit a major water puddle.

Aside from the above, the most common problem with Volvo 240 alternators is that the brushes wear down. When this happens there will be no charge light with the ignition switch on. It's easy to check by simply unplugging the small red wire on the back of the alternator (the one with the slip on spade connector) and grounding it. Does the charge light come on with the wire grounded? If so the problem is almost always with the brushes and/or slip rings.

Here is a link to our replacement voltage regulator brush pack.

November 16, 2016: Will expand on this article in the next few days so bookmark it and come back soon. Will expand on the charging system and other electrical issues. This site will gradually fill up with technical pages.

Charles Risen / EuroPartsHouse.com

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