Re: Over heating 940 Turbo
Thermostats fail. You can just remove it and see if the car runs too
cold. Hopefully it does. Start the car with the reservoir cap off and
see if the coolant shows signs of bubbling. That might indicate a
condition where the exhaust is leaking into the coolant- that could be
a leaking head gasket, cracked block or cracked head. it could also be
When it gets warmed up. Stop the motor and run your hand over the
radiator to feel for even heating of the core. That would show that it
is not blocked.
Depending on how badly it overheated, it could have warped the head. A
mechanic can do a leakdown test, or even use an exhaust gas analyzer
to check for CO content at the reservoir.
If it was running well with no performance problems we can
fairly-safely eliminate things like dragging brakes, timing problems,
overly-lean fuel:air mix, etc.
If it boils coolant out then it is important to completely refill the
motor. Air can get trapped in the block which can cause overheating.
For the 240s I think the book says to run the motor until warmed up
with the coolant reservoir cap off to allow the air to be purged, but
there are special tools (pressure or vacuum fillers) to pull the air
out I think.
It is also possible tha tthe water ump has a problem like the impeller
separating from the shaft, but that would be a stretch I would think.
"AlexL" <email@example.com> wrote:
>Hay glad I found this group!
>I've owned a 940 Turbo for a couple of years and it has been a great
>car. However yesterday it over heated. Had added fluid to the over
>flow that morning because it was almost dry but about 10 minutes down
>the road I noticed the temperature gauge all the way up and a fine
>spray covering the back window. Thought maybe I didn't put the
>overflow cap on tight so let it cool and added water. However same
>thing happed again. Was watching the gauge this time and it heated up
>to the right temperature and stayed there but after about 5 minutes the
>temp shot right up. Playing amateur mechanic, I decided that the fan
>clutch was bad and wasn't kicking in to cool the radiator. Obviously
>that wasn't it, over heated again! Then tightened the belt going to
>the water pump and still over heated. This time it was in my driveway,
>and when it got up to temp I noticed a small trickle of water getting
>pushed out thru the over flow cap and when I shut the car off and
>cracked the over flow cap open a bit, a sound that I can only guess as
>water boiling in the block. I keep thinking the thermostat is working
>as it heats right up to the proper temperature and only after 5 minutes
>or so does the temperature gauge start to climb.
>Thanks in advance
Randy & \ \/ /alerie's
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"