Volvo S40 - Recent Questions, Troubleshooting & Support - Page 6

Well, did you do the next thing and check for spark? Coil?

This occurred to me the other day. They thought it was the alternator and battery, but nothing. What was the problem with her car. Please help, I'm going nuts trying to figure this out!

Time to change the thermostat if you not already have done so. This is the cause of most overheating problems, although a good radiator flush may solve the problem also. The fan will stay running until the engine coolant reaches the proper parameters and then shut off.

this should help you How To Replace an Alternator on 2006 Volvo S40 T5 Part 1 Removal as long as its the same engine but it will be the same to the alternator, and ac pump will be fine just remove the belt and put back on after its not a major part changing the belt.

Cannot figure out what that part is, but it has a vacuum line connected. Therefore, it should not be functioning unless the engine is running. I would have to guess there is a wire crossed in the key cylinder. The presence of the key should activate the warning system and perhaps deactivate the security system. However, the engine system wiring comes in proximity to the warning wiring behind the ignition switch near the contact reel. It's possible you have a short in that area. I am posting access instructions from autozone.com. CAUTION Models equipped with a Supplemental Restraint System (SRS), use an inflatable air bag. Whenever working near any of the SRS components, such as the impact sensors, the air bag module, steering column, and instrument panel, disable the SRS.

1. Before servicing the vehicle, refer to the Precautions Section.
2. Disconnect battery cable.
3. Remove steering wheel and air bag module. Refer to Steering Wheel removal and installation.
4. Remove steering column covers. Remove or disconnect the following: Screws from lower coverClip mounting between the upper and lower coversLower steering column coverUpper steering column cover
5. Remove the contact reel:
   1. Disconnect the left connector.
   2. Remove the screws.
   3. Remove the contact reel. Fig. Removing the contact reel from steering column Removing the contact reel from steering column
6. Remove the ignition switch:
   1. Disconnect the electrical connector.
   2. Remove the screws.
   3. Remove the ignition switch. Fig. Ignition switch removal Ignition switch removal

To install:

1. Install the ignition switch:
   1. Position the ignition switch and tighten the screws.
   2. Connect the electrical connector.
2. Install the contact reel. Tighten the M5 screws to 44 inch lbs. (5 Nm).
3. Install the upper and lower steering column covers. Tighten the screws.
4. Install the air bag and steering wheel. Refer to Steering Wheel removal and installation.
5. Connect the negative battery cable.

The dealer should have a part number for the complete wiring that you need, but it may be a main harness which may require many hours to replace.

Sounds like you could have a tire out of balance. Try to see if you can locate where the sound is coming from.

it could be one of 2 things the cam sensor or the co sensor on the exhaust, both of these when warmed up will set off an eml light and confusing error codes. as when engine is stopped they reset themselves. but codes will be logged and they need to be warmed up again. cam sensor faults is when the resistance in the sensor become erratic. as it has volts on the sensor will go up and down. co sensor can be the heater as it has to heat the sensor to make the sensor reliable. it takes a few seconds for the sensor to read. if it fails and come up on eml light but then turn engine off and then start it again it can be this cam and crank sensors work the same way they can over heat them selfs of time and will both need replacing, i found its best to replace both at the same time.