The front brake rotors can warp and cause a vibration when braking. The rotors will need to be machined or in cases where they are worn to thin, replaced to correct this issue.
Resources for the Repair and Maintenance of your 1990 Honda Civic Si
1990 Honda Civic Si
1990 Honda Civic Si Problems
Plugged moon roof drains can cause a water leak inside the car, usually over the head of the driver or passengers head when turning a corner. Cleaning the drains will fix this problem.
Certain models can leak oil externally or allow coolant into the combustion chamber due to a faulty head gasket. The head gasket needs to be replaced to correct this problem.
Rear trailing arm bushings crack and break. The trailing arm bushings will need to be replaced when they break.
Leaking tail light gaskets can allow water into the tail light assembly and inside the vehicle. Replacing the tail light gaskets will commonly correct this issue.
1990 Honda Civic Si Questions and Answers
the rear hatch light ajar light in dash will not go out even though the hatch is locked and closed....any suggestions
1990 Honda Civic Si Reviews
My 90 has 286,000 and counting. Bought in new and it still brings major smiles all the time. It's been my everyday car to work and for fun from day one and I dunno what to say except I think Soichiro Honda made a deal with supernatural forces on behalf of the CRX because it's excellence has not diminished in the 20 plus years of driving it.