1987 760 Turbo, automatic trans:

Yesterday, while trying to merge into traffic on the freeway I noticed an acceleration problem with my car. When trying to accelerate fast (when using the turbo) the turbo would "whir" (much LOUDER than ever before) and it would whir and whir and whir and not shift gears. I had to let up on the gas, as the car was NOT ACCELERATING AT ALL and i was afraid to burn up the engine. It was only over a long time and a great distance and without using the turbo that i finally got up to speed with the traffic. While trying to accelerate with the turbo engaged i also noticed small amounts of BLACK SMOKE in addition to the very loud WHIRRING (it has always whirred a little and it has always worked, but not now). Also, while driving on surface streets where i don't have to use the turbo, the car shifts gears fine. I am not low in ATF or oil. I DO have loose bushings at my gear selector, though i don't think this has anything to do with the problem.
if anyone has any ideas as to the cause of this problem (i guess you'd call it a long long long hestitation to shift when using the turbo) let me know. also if you need me to explain more, let me know and i'll write back.
thank you so much
trina

You probably have a vacuum leak somewhere along your hoses leading to your intake manifold. Since the car doesn't move fast, it won't shift gears. The vacuum leak will cause your car to run very rich when the turbo should be engaged. This is because the air mass meter sees an large intake of air when the turbo kicks in and orders more gas to the cylinders. The air ends up leaving through the air leak some where and the fuel burns up rich.
Check for a leak in a critical area such as the hose leading to and away from the intercooler.
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-Brandon at FSU '88 744ti 150k miles

This is exactly right- you'll probably find a leak on the bottom side of either the short hose on the driver's side of the intercooler (about 3 inch diameter, about 3-inch long), OR in the L-shaped molded hose that goes into the intake manifold (basically right next to the left front strut).
Oil in the system rots the rubber right away. Any pinhole air leak will cause this exact situation. If removing these hoses shows any evidence of "missing" rubber or exposed white cord reinforcement in the hose, you've got rubber rot- replace the hoses. Try FCP Groton or your local Volvo dealer.
The short one's cheap- the big one's are not.

As for driving it around... duct tape works remarkably well at sealing those leaks for a short while. Seriously.
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Rob Bareiss, New London, CT 86 244, 87 244, 88 744