I tried starting my 1996 bonneville and it made a quick "dunk" sound each time i turned the key to start it but wouldnt start.....i finally got it to start and pure WHITE smoke came out the exhaust....i checked under hood and i had NO engine coolant in tank.....my mechanic told me and an uncle of mine comfirmed that the intake manifold (hope i got the name right) is made out of plastic and it leaked coolant into pistons and thats why it made "dunk" sound cause the pistons were fighting against the excessive coolant amounts inside the shafts...and the white smoke was coolant burning................is it really made out of PLASTIC? and is it true this is a common problem on bonnevilles like my mechanic said? he told me it will cost round 400-500$. THANKS GUYS FOR YOUR HELP

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http://www.bonnevilleclub.com/forum/...e=article&k=38


Then go out and drain your oil immediately.
You can do all the work for between 200-250.