smoke from the engine compartment - transmission ?

[BlackBart]

In addition, crankcase pressure can force oil through an old, hard seal on the oil filler cap - top of the engine. The oil eventually runs off the top of the cylinder head (towards the back of the car), runs down the backside of the block, and all over the exhaust and turbo, making a terrible cloud of smoke.

[850forum]

The PTC is a small heater unit on the cold air intake from the air-box to turbo. It has a little plastic pipe that a small rubber hose connects to. It is there to try to stop the crankcase oil fumes from freezing in colder climates. With age, the small hole through them can block and needs to be cleaned or it will pressurize the crankcase as it can't vent into the turbo intake.

The pipe/nipple can get broken off if care is not taken fitting or removing the pipe.

That same turbo cold air intake pipe can start to break up or split with age as the plastic goes hard where it connects to the turbo.

Neil.

OK, but what does the abbreviation PTC stand for?
Is it located behind the engine, at the low point of the air intake where the downcomer pipe turns 90 deg inboard?

[850forum]

HOW DO I FILL THE ENGINE WITH COOLANT TO THE MAXIMUM?
This leak amounts to possibly draining the entire coolant system, so I should follow the procedure for refilling the whole system from empty.

Um, what is it? I've never done that myself on THIS car, and not for decades on any other.

Where is the air bleed at the high point?

Since I am not running the car as I fill it, to open the thermostat, I suppose I should remove the thermostat so I can fill the whole engine with liquid? So where is it & I think I have some black seal-a-gasket lying around for a temporary seal.

I could even pour liquid directly into that opening, to fill the block ?

Is the coolant tank sufficiently higher than the bleed valve, so the weight of cold liquid forces the air out?
Also, I have to look, is it sufficiently higher than where the bottom radiator hardpipe goes over the engine, so cold water will rise & flow over the engine & fall down the back?

Driving the 1/2 mile to my mechanic without a thermostat will keep the engine block cooler too, since there will be more liqud flowing, right away, thru the radiator.

Maybe I should fix that blown gasket too. Dunno if liquid will leak out or only under pressure.

Probably can fill it mostly with water for that short distance? Air temp is around 70-75 degrees still.

Capacity is 7.4 quarts, so I have added about 6 qts. Does that addition correspond to filling the radiator up to the thermostat, minus the air bubble at the top? Dunno what fraction is radiator + hoses vs engine block itself.

Remind me which way the coolant flows. Hot from engine into top hose into radiator & down ?

Multiple edits, its 3AM and I woke up with this on my mind, very fragmented right now.

[abscate]

You can run pure water for a <10 miles as long as you are well above freezing and not in high temperatures. Antifreeze is also anti boil, it protects coolant at both ends of the temperature scale.

Just idle the engine, stick a hose in the reservoir and fill it until it overflows. Tip a bit out to make space, then run it to garage. It will burp about one liter of air from the engine so you might see the coolant low light come on , during the short trip

[scot850]

As abscate says. Carry some water with you. But if you are filling with anti-freeze mix, use a mix to top up.

I have found more success with having the front raised off the ground on stands when filling. I still can get burps from the car but less than filling on the flat or downhill facing.

Neil.

[abscate]

OK, but what does the abbreviation PTC stand for?

Positive Temperature Coefficient Nipple

It is not a valve of any kind, it is just an orfice that is heated by electrical current to prevent the chunkies from condensing in your snorkel. It is a source of vacuum for the crankcase ventilation system.

Volvo says it clean it every 50,000 miles/5 years - on high mileage cars 2 years/24,000 miles is recommended

[850forum]

My wife took it to town this morning.
Didn't get smoke from the vents until she was almost home.

Still want to know where the air bleed screw & thermostat are.

[scot850]

If you are looking for an air bleed screw for the coolant there is none! If it is for fuel it is on the fuel rail for the injectors. RH end when standing in front of engine. There is a Schraeder valve.

Thermostat is in a housing on the block where the top radiator hose is connected. There are 2 Torx screws to remove that can be a devil if not used in a long time.

Neil.

[850forum]

Just idle the engine, stick a hose in the reservoir and fill it until it overflows.

Did that.

[abscate]

There is a bleed screw way in the back of the engine ( technically the right side of the engine) but that’s on the suction side of the water pump so no one uses it. Too hard to get too. Top off, short trip, top off, run hard, top off final.