Volvo 940 2.o Turbo Coolant water

[TrevorL]

Hi

My VOlvo 940 has a misterious problem. It loses coolant water (at the rate
of about 1l per week) yet there is not sign of a hose leaking or a radiator
leak. Also the engine is running very smoothly and the oil looks "clean" so
i don't think its a gasket gone. The engine is using much more fuel than it
should so there is something wrong but I don't know what.

Also, although probably completely irrelavant, there is a fluid of some
discription leaking from the air inlet of the carbon cannistor. I cannot
see that this is connected to the water problem but thought it worth
mentioning.

Any ideas gratefully recieved.

 

[Michael Pardee]

Hi

My VOlvo 940 has a misterious problem. It loses coolant water (at the rate
of about 1l per week) yet there is not sign of a hose leaking or a
radiator
leak. Also the engine is running very smoothly and the oil looks "clean"
so
i don't think its a gasket gone. The engine is using much more fuel than
it
should so there is something wrong but I don't know what.

Also, although probably completely irrelavant, there is a fluid of some
discription leaking from the air inlet of the carbon cannistor. I cannot
see that this is connected to the water problem but thought it worth
mentioning.

Any ideas gratefully recieved.

My guess is the water pump. Leakage from that can be devilishly hard to see.
Look for a white deposit on the lower side of the weep hole in the water
pump - I have a hard time reminding myself coolant residue is white, not
green or whatever. Most varieties are fluorescent, so a black light is
useful for looking for leaks.

You need to identify the fluid coming from the charcoal canister. Smelling a
sample is a good start. If it is gasoline, you have a clue why the fuel
consumption is high.

Mike

 

[Rusty]

My guess is the water pump. Leakage from that can be devilishly hard to see.
Look for a white deposit on the lower side of the weep hole in the water
pump - I have a hard time reminding myself coolant residue is white, not
green or whatever. Most varieties are fluorescent, so a black light is
useful for looking for leaks.

You need to identify the fluid coming from the charcoal canister. Smelling a
sample is a good start. If it is gasoline, you have a clue why the fuel
consumption is high.

Mike

I had a hairline crack in the water jacket of my turbo. This was discovered
only after my engine blew during a long road trip. There was no sign of this
coming, the coolant just sprayed out onto the turbo and cooked away.

The crack was discovered when the turbo was removed during install of a new
(to me) engine. The coolant leaked out under pressure only after the engine
was fully hot, and the coolant would instantly vaporise on the hot exterior
surface of the turbo, leaving no smell or sign of fluid loss. It's a very
rare occurrence, but don't rule it out. Obviously, the turbo had to be
replaced, and Herman at Cherry Turbos did a stellar job.

Get a mirror, a flashlight, and have a good look all around the turbo area
for any white residue at all. If you find any, there's trouble.

Good luck.

RS

 

[Tony Stanley]

Smelling


I had a hairline crack in the water jacket of my turbo. This was discovered
only after my engine blew during a long road trip. There was no sign of this
coming, the coolant just sprayed out onto the turbo and cooked away.

The crack was discovered when the turbo was removed during install of a new
(to me) engine. The coolant leaked out under pressure only after the engine
was fully hot, and the coolant would instantly vaporise on the hot exterior
surface of the turbo, leaving no smell or sign of fluid loss. It's a very
rare occurrence, but don't rule it out. Obviously, the turbo had to be
replaced, and Herman at Cherry Turbos did a stellar job.

Get a mirror, a flashlight, and have a good look all around the turbo area
for any white residue at all. If you find any, there's trouble.

I also had turbo problems recently, see post '940 leaking turbo'.

The turbo only has a small waterway in the middle to cool the bearing, so
leaks are usually slight. Mine also leaked slowly but intermittently.
After putting up with this for a year or so the head gasket started leaking
intermittently due to the lack of coolant additive caused corrosion to
breakout a small gap between a water way and cylinder. Intermittent head
gasket leaks are very bad as the whole lot goes out the exhaust pipe very
quickly leading to complete overheat, warped head, cracked manifold, cracked
down pipe etc.

The leaking turbo was evident from residue and water lying on the turbo when
cold as the leak was on top. Get the turbo fixed/replaced before you get
cascade failure.