850 Turbo, low power

Today my 1995 850 turbo would not rev over 2700. Turbo appreared to have no
boost. After running 10 miles (at 20-30 mph flat out), I let it sit for an
hour, and everything worked. Had to drive through a blizzard yesterday.
Any ideas what went wrong, and how to prevent it in the future?
Doug

 

My 91 940 did the same thing about a year ago-I inspected the intake and
found a tear in a hose and not much else. After putting it all back
together, everything was fine until last week when it occured again. This
time the turbo is seized up and I am looking at repair options. I am unsure
if this is what happened earlier (although obviously in a temporary fashion)
but perhaps check to see if anything may have become dislocated into the
turbo itself. Look for worn or torn hoses, etc. You might also check the
oil lines to the tubro for blockage.

 

I'll bet it was really cold where you are as well. Believe it or not,
enough water can get into the bottom of the intercooler and completely
block the air flowing into the engine. I can't explain why, but a clean
PCV system prevents this from happening. This consists of the oil trap
under the intake manifold and the hoses that are attached. The oil trap
isn't really cleanable, the only option is to replace it. Also make
sure the heated nipple where the hoses connect to the air intake hose at
the turbo inlet is clean. Volvo even has an expensive heated PCV system
kit to cure this problem.

To see if this is your problem, next time it happens, open the hood, rev
the engine and watch for collapsing intercooler hoses.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Mike,
Thanks for the info. You are right, I'm in North Bay, ON and it was -23C
during the night before this happened. I will go over this with the local
Volvo mechanic, as I would really like to prevent this. In fact it happened
mildly again this morning, but cleared after I drove about 2-3 miles. I
just hope that this is not a potential source for damage to the turbo or
engine!

 

On the bright side, this doesn't actually hurt anything, except maybe
your punctuality.

To prevent this, put in a new oil trap and PCV hoses. Flushing the
intercooler with solvent helps as well. Make sure the drain hole in the
bottom of the intercooler is free.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)