Volvo 940 TD Auto - Turbo Probs

Hi, well here goes, I got a 940 TD auto and love this car 2 bits, however
when I boot or accelerate sharply, the turbo light comes on and get a
sooking noise (louder than usual). Runs like a dream other than that. I
think its a 1992 / 1994 model. Anyone any suggestions ?

Davie

 

I'm not very familiar with the diesel turbos, but it sounds like your boost
is going too high, you should look at the wastegate and whatever controls it
in that car, is it a simple pneumatic solenoid, or does it have electronic
control?

 

Left unresolved this will quickly toast your turbo as it did mine.

Also from my experience, if the mecahnic says, "That just happens
sometimes. Sometimes the Turbo runs into the red and the turbo light
comes on" then he's an idiot and a liar and you shouldn't trust him

Been there, paid that.

blurp.

 

Well, actually on a 240 Turbo that originally wasn't intercooled had a
gauge with a red section that the needle would go into when the
intercooler kit was installed. This would also turn the light on, part
of the intercooler kit installation was removing the turbo warning light
on the dash.

 

Yeah but that's different, that's a modification that allows you to run
higher boost. The factory intercooled models had a different boost guage
with a larger yellow section and no connection for the warning light. Of
course even with that guage mine goes into the red

Still it's different with a gasoline engine than a diesel, turning up the
boost on a gas (petrol) engine gives more power provided the fuel system can
keep up, on a diesel you have to turn up the fuel to match whatever boost
you're running.

 

Speaking of 940 Turbodiesels there is only one reason why the light comes on.
There is no gauge so the guy cannot truthfully say that the turbo runs into the
red. So the problem is that the engine is tricked into either overboost or into
thinking that an overboost condition has been achieved. If there is no EGR, then
there is just one overboost switch which operates if there is excessive manifold
pressure to put the light on. If the wastegate operating arm is sticking in the
closed position then overboost can be readily achieved. So check the small pipe
from the turbo output to the small pressure actuator. It may be split or
punctured or even missing, or the actuator may well have seized.

Cheers, Peter.

: blurp wrote:
: >
: > Left unresolved this will quickly toast your turbo as it did mine.
: >
: > Also from my experience, if the mecahnic says, "That just happens
: > sometimes. Sometimes the Turbo runs into the red and the turbo light
: > comes on" then he's an idiot and a liar and you shouldn't trust him
: >
: > Been there, paid that.
: >
: > blurp.
: >
:
: Well, actually on a 240 Turbo that originally wasn't intercooled had a
: gauge with a red section that the needle would go into when the
: intercooler kit was installed. This would also turn the light on, part
: of the intercooler kit installation was removing the turbo warning light
: on the dash.
:
: --
: Mike F.
: Thornhill (near Toronto), Ont.
:
: Change cant to ca and remove parentheses to email me directly.

 

I was speaking specifically to blurp, who I know from past posts has a
240 Turbo that my statements would apply directly to. He's had some
problems with his mechanic who he feels has mislead him, so I was just
pointing out that maybe he's not being mislead with this overboost
statement.

None of this applies to a Volvo turbo diesel.

 

Don't worry Mike, I wasn't referring to your message to blurp. I was answering
the first poster as he said it was about a 940 TD. Having got one myself, and
what a very good machine it is too, I thought I could throw some light on his
problem. I should have made it clearer and for that I am sorry.

Cheers, Peter.

: James Sweet wrote:
: >
: > > >
: > >
: > > Well, actually on a 240 Turbo that originally wasn't intercooled had a
: > > gauge with a red section that the needle would go into when the
: > > intercooler kit was installed. This would also turn the light on, part
: > > of the intercooler kit installation was removing the turbo warning light
: > > on the dash.
: > >
: > > --
: >
: > Yeah but that's different, that's a modification that allows you to run
: > higher boost. The factory intercooled models had a different boost guage
: > with a larger yellow section and no connection for the warning light. Of
: > course even with that guage mine goes into the red
: >
: > Still it's different with a gasoline engine than a diesel, turning up the
: > boost on a gas (petrol) engine gives more power provided the fuel system can
: > keep up, on a diesel you have to turn up the fuel to match whatever boost
: > you're running.
:
: I was speaking specifically to blurp, who I know from past posts has a
: 240 Turbo that my statements would apply directly to. He's had some
: problems with his mechanic who he feels has mislead him, so I was just
: pointing out that maybe he's not being mislead with this overboost
: statement.
:
: None of this applies to a Volvo turbo diesel.
:
: --
: Mike F.
: Thornhill (near Toronto), Ont.
:
: Change cant to ca and remove parentheses to email me directly.