Mileage = 245,000+/-
Well maintained and regular oil changes every 3,500 miles with quality oil and Mobile 1 oil filter.
Automatic, 4.0L 6 cylinder original factory motor with no internal replacement parts.
Car randomly generated a misfire code on cylinder #4. Replaced coil pack and no change, computer is 1.5 years old. Took to mechanic for compression test and additional troubleshooting. Compression test results on cylinder #4 was approximately 75 psi. Factory specs are 120-150psi with allowable 30psi deviation.
We think it may be a small head gasket leak. Plug for cylinder #4 was tan in color and looks almost too clean with no residual oil.
Jeep is in very good shape and engine runs strong other than misfire. Should we consider adding Steel Seal? Our son uses the car at college and maintains the vehicle very well. We are the 2nd Owner and purchased it 18 years ago with only 43,000. Oil changes never greater than 4,000 mile.
-Joe
Should we consider adding Steel Seal?
No. "Steel Seal" and similar products are temporary bandaids at best that may well do nothing but clog your cooling system. Not something to use on a vehicle you intend to keep any length of time.
However, in this case you really need to do more diagnosis to determine the actual cause of the low compression problem before taking any action.
