2001 V70XC - struggles to idle when coming to stop light Topic is solved

Post by **abscate** » 08 Sep 2020, 10:29

Ive found there is time saved removing each hose, covering each hole to prevent tool loss, the examining each piece of induction hose out of the car under strong light for holes, soft spots, splits, and other distress.

Short Turbo to hard pipe
Hard Pipe to hard pipe connection
Hard pipe to bottom intercooler
Intercooler to ETM pipe
pipe to ETM

(a LPT may be different than this, but check each and every hose and hose clamp.)

Post by **xHeart** » 09 Sep 2020, 11:11

abscate wrote: 08 Sep 2020, 10:29 Ive found there is time saved removing each hose, covering each hole to prevent tool loss, the examining each piece of induction hose out of the car under strong light for holes, soft spots, splits, and other distress.

Short Turbo to hard pipe
Hard Pipe to hard pipe connection
Hard pipe to bottom intercooler
Intercooler to ETM pipe
pipe to ETM

(a LPT may be different than this, but check each and every hose and hose clamp.)

HELPFULL! Intake pipe connection at turbo is separated; broke off from the clamped end..

: MVS_V70XC_1144.jpg (195.11 KiB) Viewed 1376 times

Post by **abscate** » 10 Sep 2020, 07:27

Nice...I’ll ping Erik to get the Horns back.....

Except I left that one off my list!

Post by **xHeart** » 11 Sep 2020, 06:36

abscate wrote: 10 Sep 2020, 07:27 Nice...I’ll ping Erik to get the Horns back.....

Except I left that one off my list!

😀

The parts from FCP arrived FEDEX Next Day. It is put back together -- a shade tree family mechanic event. Next, a test drive then to O'Reilly's for code check for road worthiness.

Post by **xHeart** » 12 Sep 2020, 08:34

Replaced the ambient air hose to the air box, MAF, intake hose between MAF and turbo, and the TCV. Checked the hoses and pipes for routing. It starts and runs like a champ. Acceleration is stable, but taking foot off the gas pedal has light jerk - NOT when taking pressure off the gas pedal.

It burps coming down from 1000rpm to idle, but settles to around 720rpm. Is this a new normal? O'Reilly guy said to drive away, but check the Compressor Bypass Valve function, your thoughts?

Post by **abscate** » 12 Sep 2020, 11:42

Let the adaptives relearn for a week of driving.

Post by **xHeart** » 14 Sep 2020, 08:46

abscate wrote: 12 Sep 2020, 11:42 Let the adaptives relearn for a week of driving.

I will.
What is the sensor on the intake pipe at the turbo connection, and what is it sensing and reporting?

XC70Rider · Post by **XC70Rider** » 14 Sep 2020, 14:01

xHeart wrote: 14 Sep 2020, 08:46
abscate wrote: 12 Sep 2020, 11:42 Let the adaptives relearn for a week of driving.
I will.
What is the sensor on the intake pipe at the turbo connection, and what is it sensing and reporting?

That is the PTC nipple. It heats the PCV oil to keep it from clogging.

Post by **abscate** » 15 Sep 2020, 02:03

It gets cleaned at 60k and at 30k intervals thereafter, per Volvo. At that time, inspect snorkel for wear.

Ok,I made that last part up.

Post by **vtl** » 24 Sep 2020, 13:05

Intake holes can be seen in fuel trims. Small ones will drive LTFT (long term) up, large holes will drive STFT and cause idling/driveability problems. ECM relies on front H2OS for this loop to work.

STFT/LTFT can be read with any OBD-II scanner, DiCE/VIDA setup is not necessary.

If you see fuel trim off, but can't find the hole (smoke test is strongly suggested) AND the car works fine for a few minutes after cold start - that might be a bad front H2OS sensor. It does not work properly until heated to a working temperature, ECM knows that and ignores its readings for a few minutes. The moment ECM switches to a bad oxygen sensor you'll be getting engine troubles.

If you find someone with DiCE/VIDA, you can run a ETM test and see whether it reacts to ECM commands well.

Other common problem is a coolant temperature sensor. Most of engines don't work well if this sensor lies.