A couple of days ago, I read on the board about holes developing on the intake hoses on b230ft engines. My 740 hasn't been performing like I have wanted it to. I was told my turbo has gone 'bad'. Well, low and behold on the underneath side of my intake hose immediately after the connection strap was a thumb size hole! Well, needless to say, a little duct tape goes a long way for a temp fix and performance. What a difference!! now this is the car I wanted to buy!!
Yeah, I know there is a bigger problem to why the hose developed the hole. I think its oil? from the turbo? I guess i'll have to replace all the hoses on my turbo and intercooler (when i get the money for those hoses...ouch!!)

Just wanted to share my story!! :)

Typically, the inlet hose to the turbo gets mushy, for lack of a better term, at the underside of the hose due to heat and the oil which comes from the breather hose across the top of the engine. I went through three of them, one original, one new and a used one. Call around to various junk yards and get a used one. It will be much cheaper than a new one.
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Warren Bain - '99 V70GLT G-Valve > 70K mi, '96 965 >110Kmi Wifemobile near Manassas Va.. Check the 700/900 FAQ via the 'features' pull down menu.

I had the SAME EXACT PROBLEM!

the hole in my hose though was so large that it actually confused the engine, negating the AMM and started sending the computer into a fail safe limp home mode. Got it fixed, recovered MPG and HP.

Glad to hear you got it working!

Glad you found the problem. I have a question. What was your boost guage doing before patching the hole? Did the needle ever go into the yellow (orange) range?

Thanks,
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Erwin in Memphis, '88 745t 183,000 miles, '95 855t For Sale

Even at WOT it would just barely touch the yellow. Extremely poor acceleration and a rough idle.

Yeah, that's what the problem sounded like... real common on all these cars.
There is a drain on the bottom of the intercooler - you may find quite a bit of oil in it. It's pretty well accepted that turbos use a bit more oil than normal models... you can't get good lubrication of a unit spinning so fast without losing a little bit. So it just builds up over time in the intake. The rubber hoses usually seem to rot from the inside out, so it's definitely entrained oil in the air intake. The turbo could be on it's way out- they don't usually live much past 160K-170K. But a rebuild is not too expensive when you're willing to do the work yourself- could be in the $400 range. If the turbo actually damages itself due to wornout bearings, it could be closer to $900. I'd keep an eye on oil usage. Don't worry about it unless it gets over 1qt per 1000 miles.
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Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K

Any recommendations on the best way to clean the intercooler out? How about detaching inlet and outlet hoses opening that drain plug and flushing out with water? maybe a degreaser to get all the oil out? what do ya' think?

remove it from the car (about 5 mins if you go slow!) and lay it flat, pour in degreaser, swish around some...pour out degreaser, then repeat with water (nb do the degreaser until your happy prior to water...refit....

You might want to consider a premature oilchange,
since you got all dust and unfiltered junk
into the engine.

Ah-you had a turbo. Did not read that.
More overpressure on the intake.
But isn't there also under some conditions
a underpressure on the intake, which gets
false air in through the hole?
Just asking?

The intake of a turbo engine is going to fluctuate between positive pressure and vacuum depending on throttle position. So yes, some particulate matter from unfiltered air has gotten in. But it's not something I'd be overly concerned about. It's not ideal, but I don't think that it'll kill an engine outright as long as it's caught within a reasonable period of time. But I agree on the early oil change. It's a cheap way to prevent further damage.

Tim
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Tim Smith '85 745GLE M46 w/90k. Also in the family: 94 854T w/120K.

The hose on the discharge side of the intercooler (isn't that where your problem is?) is only about $12 list at the Volvo dealer.

Yeah, on the discharge side, thanks! I haven't taken all the hoses off yet, but I'm pretty sure I've got oil in all hose both sides of the intercooler. One indication is the oil all over the hoses just after the turbo. $12, huh...well, that doesn't sound too bad. thanks, again.

The oil you see was probably sucked into the intake side of the turbo from the "Crankase ventilation hose" longstanding problem with this engine !! Doubt there is any problem with that turbo .