Buick Frustrations

Originally Published 10-01-2007

Had planned to roll out the new <un-named> distro in a few weeks, but I have spent too many weekends repairing the Buick. In a past life someone who will remain nameless drove this car two miles from home to church and back twice a week for about twelve years. As a sometimes used car salesman / buyer / dealer person you really want to find these cars, with maybe 60K miles, put a couple cans of sea foam engine cleaner in the guy, and sell it or a quick and hopefully large profit. If you fall in love with the car, plan on replacing the fuel system and the emissions package. So if you thought you were getting a bargain think again. Labor Day weekend it was first an O2 sensor, then a hose fitting which broke off, followed by a failed alternator, and a throttle position sensor switch. So after the car was stranded in Alabama for a week, I fixed it and got it home. More starting problems and leaks required new plenum gaskets all the way around, plus a knock sensor. Weekend before last, I decided to check out the fuel system, replace the fuel filter, etc. Ended up replacing four of six injectors, and lost a day of paying work. I suspect I will have to replace the other two soon. Hopefully the fuel pump and pressure regulator are ok. Both take a bit to get, and the fuel pump is in the tank, so that may require a shop. This past weekend I invested in a fuel pressure gauge which appears to show the fuel pump is ok, but raises questions about the fuel pressure regulator. Next I guess is cleaning or replacing the EGR valve, maybe replacing the idle speed control valve, since it is somewhat less expensive. The main problem is starting cold. It takes a couple minutes for the engine to actually become functional, and this car will not allow you to change to Drive unless the engine has proper RPM or something. Sounds like a massive vacuum leak, until the process stabilizes, but what is causing it is not obvious. Sounds like it is in the air cleaner, but there is no way. Either the EGR or the idle control device. The other problem seems to be missing under load, a hint of knocking, all of which improved with the injector replacement and other emissions repairs.

After much fiddling about with the buick systematically replacing failing parts including the exhaust doughnut and the mass air flow sensor which is more expensive than necessary, I finally isolated the problem while working on the EGR valve.  This particluar model has a offset mount for the EGR, a flex tube from the exhaust manifold, and a flex tube from the top of the mount bracket to the intake manifold – which by the way is hard plastic.  At the point where the flex tube attaches to the EGR bracket there is a single bolt clamp / retainer to hold it to the mount.  Under this bracket I found what appears to have been a small presumably high temp o-ring gasket, which was brittle, and shattered, through which air was pulled into the vaccumn of the intake mainfold, making havoc with all the engine settings.  This part is not listed so its a matter of finding a hightemp gasket making compound or material to replace it.  Once this part was replaced, the EGR cleaned and its gasket replaced , the buick met expectations.

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