Gents,

My V70 T5 has rough idle when started from cold. It takes few seconds until it stabilises.
There is no problem if the engine is already warm, or it has been started once.
Where would you recommend to start the trouble shooting: cleaning throttle body? injectors ?

Thank you, Stilian V70 T5 2001 93K km

Thank you all!

When were your spark plugs last replaced? When the engine is cold started, the ECU will purposefully enrich the mixture to ensure combustion. But, if there is a small vacuum leak you will be over-rich and plugs will foul.

BTW, use copper core plugs only in your HPT engine.

Klaus
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Proud owner of a 220S. If I had more room, I would have more Volvos.

I would start by cleaning the Idle Air Control valve. Info on the board. I have heard it's useful to give it a good coat of WD-40 when the cleaning is done to prevent water vapour from locking it up.

Always start with the intake and PCV systems for engine problems. There is info on the board on replacing vac lines and PCV lines. Vac issues can be insidious and very difficult to spot. Vac line is cheap and you're better off just replacing everything you see then trying to salvage old line. I have a habit of splitting the old line up one side and using it as a heat shield wrapping over the new line.

Check for vac leaks around intake manifold - info on the board.

Clean your throttle body with TB cleaner and a tooth brush. It would probably be worthwhile to replace the TB gasket and completely clean the TB while you have it off.

run a good injector cleaner through the gas tank. I like SeaFoam. Use half the can in ~1/8-1/4 tank, and pull the rest into the intake via vac line and then let it rest. More info on the board, along with 'water torture'.





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1998 V70 AWD->FWD Turbo 200k+