Helping son with 2000 Jag V8 4.0L problem. 105K miles. Had into shop to have rebuilt tranny installed. Shop (AAMCO) noticed no exhaust from passenger side exhaust. First time out on freeway several days later at about 60mph, car starts billowing lots of white smoke. He pulls over within a half mile. Had not overheated (I don't believe). Had towed to Midas. They said its probably a head gasket caused by the passenger side catalytic converter probably being shot (plugged) and causing sufficient backpressure to cause headgasket failure. This diagnosis was based solely on son's description of events, etc. No tests were performed. Son says engine had overheated briefly athe day before during city driving.

Since he is unemployed, we scratched our heads a bit for an inexpensive solution, and decided to try a head gasket repair kit called K-Seal. Due to perceived excess backpressure due to the plugged catalytic converter, and advice from K-Seal, we decided to remove the upstream 02 sensor to create a quarter-size pressure relief hole before starting the K-Seal repair which involves putting K-Seal fluid in the coolant header tank and letting the car heat-up to operating temperature when supposedly the headgasket would become sealed again (if it worked) and the white smoke would stop billowing out the drivers-side exhaust.

At the outset of the repair, there was lots of white smoke and some fluid that seemed to be coolant (watery but slightly slippery, but not looking like oil) dripping out the tailpipe. That stopped within several a minute or two, but the white smoke continued. White smoke also started coming up along the firewall, and/or from under the engine, but stopped after awhile. Engine heat gage went a short ways past center for awhile but went back to center. All-in-all it idled for about an hour (with some slight racing of the engine by my son) and the white smoke may have subsided a bit, but still a significant problem.

While the engine was running (and smoking thru exhaust) my son was puzzled as to why when he tried to check for air in the cooling system he could not get any coolant to come out the bleeder valve??? near the header tank where you put coolant in. Also, the oil was very hot and was perhaps a half-quart or so above the max mark on the dipstick when we started the repair and was still at about the same mark at the end of the repair attempt.

Not sure of what we might try next. And what could be concluded from what we have experienced so far?

Does anyone have some good advice here?

Thanks

 

Even if the gasket fix worked, you still would not be able to drive with the first problem. I hate to say it but at this point you either need to do a real repair, or take it in. If your smooking coolent, and the "gasket" fix didn't work, then you need to replace your gasket or blow a oil ring, or compression ring, if not already. Many more problems can follow this. Please don't try anymore magic quick fixes. You have a sick kitty that needs real help.

 

Thanks SchultzLD, and I hear you. If the gasket fix worked the next thing we were going to do was to immediately replace the apparently failed catalytic converter on the passenger side. Hopefully we could confirm it is shot by seeing if there was any air flow from the output end of the converter by examing for air flow at the output end's 02 sensor hole.