Tag: CBV

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1999 V70 T5 – Reflections On Servicing Turbo CBV

I’m in the middle of PCV service and replacing the last hoses on my 1999 before it goes to college.

Working behind the motor is tough and it’s tough to get your hands down into the area. Many operations require two hands …more to come.

Approaching the beast…turbo pipe, cooling hoses removed

Here is the winter of your disconnect….

Bolt number one, 10mm wrenches off easy..you are 1/3 done and sitting pretty.

Bolt number 2, at the bottom, you go underneath since your hand won’t fit from top. Note the shiny part of the turbo coolant return pipe. You guessed it…the bolt will not clear the pipe with it installed, so plan on replacing that hose for this job. From below, left hand to start the threads, it is tough moving cover to align but it must be done. Tension bolt number one so that the cover moves but stays in place.

Turbo S80 TCV & Vacuum Line Routing

The pressure from the outlet of the turbo presses on the wastegate diaphragm to keep it closed. When the ECU decides there is enough boost, it stops allowing the air from the turbo outlet from going to the wastegate actuator and allows it to go to the compressor inlet tube. The system is a pulse width modulated system meaning it is never “always on”, but instead cycled on for longer periods of time to increase boost, and shorter to decrease boost. When the TCV is off, air from the compressor is dumped to the compressor inlet, and the spring pressure in the wastegate is what regulates compressor outlet pressure.

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CBV Install on AWD P80 Volvos DIY

“Yes this first rate individual designed the CBV bottom bolt to be virtually un-accessible due to the cooling pipe running off the back of the engine. He could have allowed at least 3mm more clearance on the pipe to make it easy as I see the pipe has plenty of clearance in the surrounding area for at least 1 addition inch of clearance in there.

The sharp edges of the trans wiring hardness and other edge makes for a scene from the Van Damme movie Blood sport when he is punches a bowl of glass with his hands for training.”