The Car Care Clinic with the Dr John

98 Chrysler Concorde - Miss in the 5th cylinder

Eric from Darlington

Question

My 98 Chrysler Concorde was running great with only 70,000 miles. Then the check engine light came on. The reading showed a miss in the 5th cylinder. My mechanic has replaced and checked everything, including the computer module that "talks" to the 5th cylinder, but the miss is still there. He says that replacing the intake gasket is the only thing left to try. Have you heard of this problem before Doc?

Answer

How about, trying something else? Prove that the repair is needed. My point is Sam that before you go through the expense of replacing the intake manifold gasket, prove that it is a needed repair. There are several ways to prove if an intake manifold gasket is leaking. It just depends on the equipment available. My favorite is a smoke machine. This machine pumps out a dense smoke that pressurizes the intake manifold. If a gasket, o-ring or vacuum hose is leaking it doesn’t take long for the smoke to roll out of the affected area. Another way is using metered shop air which can be used along with a spray bottle of soapy water. The air escaping will cause a nice pile of bubbles when the soapy water hits. These are just a couple of the many ways that possible intake gasket leaks can be proven before performing the repair.

Intake manifold gaskets do fail and they can cause a misfire code to be set by the computer. All I’m suggesting is have your technician take a ½ hour or so to be sure the repair is the one that is needed.

Good Luck!
Dr. John