The speedometer and possibly also the fuel gauge has electrolytic capacitors which may break open with age. The speedometer then will not work but the capacitors may be replaced. The electrolyte may be washed off the board with distilled water. Here are the steps. Remove the instrument cluster. Remo...

I have been the proud owner of two 1991 volvo 740 sedans. The engines are identical, standard 8 valve. One of these gets good acceleration and 25 mpg. The other is noticably slower and gets 23 mpg. It went to a shop, and they replaced the harmonic balancer and retimed. No change. I replaced the oxyg...

On two different Volvo 740 sedans (1991), the trunk always leaks in a heavy rain. The water goes in one or the other of the low areas on either side. It is not clear if the water comes in past the gasket which goes all the way around the trunk opening, or if it is coming in at the top of the tail li...

What stopped a 740 in Quanah, Texas, was a defective fuel injector relay. It had been running rough for some time, getting worse and worse. The relay is on the right side of the engine compartment on the front of the coolant reservoir. Fortunately, there are two relays there. The second one is for c...