High (circa 1500 rpm) idle, D5 185.

[Lancee]

V70 D5 2005 facelift, 185 engine. (Also posted in the general section).
When started the idle speed sits steady at around 1500 rpm, accelerator pedal when pressed works beyond the usual relative 1500 rpm position (possible to rev higher).

I have discovered that when at (1500) idle, if the brake pedal is pressed and held down repeatedly the revs will gradually reduce to the correct normal idle level, removing foot from brake pedal and the idle revs gradually increase back to 1500, it is possible to briefly use accelerator across the complete usual range (if quick enough before revs creep back up!).

I have also discovered that disconnection of the brake pedal position sensor (on the back of the servo) results in the correct steady idle speed, but the accelerator pedal does not then respond at all.

The car has previously had a replacement throttle pedal position sensor fitted.

As a layman I am suspecting a vacuum issue. The following are all related;
1=vacuum pump
2=power brake booster
3=VNT governor
4=engine pads
5=solenoid valve
6=engine speed (rpm) sensor
7=engine control module
8=brake control module

I have checked (felt suction with my finger!) for vacuum at usual idle revs by removing the front engine mount pad vacuum pipe, the vacuum (correctly) disappears at this point when the revs rise again (back to 1500).

I do fortunately have a ppc code reader, there are never any relevant codes found. (I do have a faulty reversing sensor, nearside door mirror and air quality sensor, these are the only codes that ever show up).

I hope this all makes sense, perhaps someone of the "CLANmeisters" ilk can shed some light ! Thanks in anticipation!

[5cilinder]

I had the high idle after hard braking with ABS correction only to dissappear after shutting down for a while
At first it was every time after braking with ABS now its becoming rare
Vacuum seems to be ok (guessing because of working mounts )

[5cilinder]

I had the high idle after hard braking with ABS correction only to dissappear after shutting down for a while
At first it was every time after braking with ABS now its becoming rare
Vacuum seems to be ok (guessing because of working mounts )

[Lancee]

Originally Posted by Lancee

V70 D5 2005 facelift, 185 engine. (Also posted in the general section).
When started the idle speed sits steady at around 1500 rpm, accelerator pedal when pressed works beyond the usual relative 1500 rpm position (possible to rev higher).

I have discovered that when at (1500) idle, if the brake pedal is pressed and held down repeatedly the revs will gradually reduce to the correct normal idle level, removing foot from brake pedal and the idle revs gradually increase back to 1500, it is possible to briefly use accelerator across the complete usual range (if quick enough before revs creep back up!).

I have also discovered that disconnection of the brake pedal position sensor (on the back of the servo) results in the correct steady idle speed, but the accelerator pedal does not then respond at all.

The car has previously had a replacement throttle pedal position sensor fitted.

As a layman I am suspecting a vacuum issue. The following are all related;
1=vacuum pump
2=power brake booster
3=VNT governor
4=engine pads
5=solenoid valve
6=engine speed (rpm) sensor
7=engine control module
8=brake control module

I have checked (felt suction with my finger!) for vacuum at usual idle revs by removing the front engine mount pad vacuum pipe, the vacuum (correctly) disappears at this point when the revs rise again (back to 1500).

I do fortunately have a ppc code reader, there are never any relevant codes found. (I do have a faulty reversing sensor, nearside door mirror and air quality sensor, these are the only codes that ever show up).

I hope this all makes sense, perhaps someone of the "CLANmeisters" ilk can shed some light ! Thanks in anticipation!

FURTHER TO THE ABOVE, I now notice that the electric cooling fan runs immediately at high speed after the engine starts (from both stone cold and hot starts) under all of the above conditions.

[5cilinder]

Can be 2 different causes
If the engine is shut off very hot and is running the fan and abruptly shut off it sometimes completes a cyclus by running after starting

Also if the aircon pressure is on the low side it can cause the fan to start up after starting even if the aircon is not on

[Tapani]

Hi, I would start with reseting all DTCs and after a while reading the new ones in order to get a hint where to look at.
As You write it migth be a vacum issue, to my understanding pressing the brakes down influence the engine mounting vacum? control. Engine mountings are a known weak point in these as they get more miles.
br Tapsa

[Hurm0s]

Have you found out what is the problem?

My D5 is having exactly the same issues.

[jvcooper]

Mine did exactly the same today after having to brake v hard. After stopping with engine off for 20mins started ok and ran alright, be really keen to know the likely cause due for a service soon

[ppj]

Could be a dodgy coolant temp sensor, if the sensor has failed in such a way that the engine ECU thinks the engine is too hot it can cause all sorts of funny things to happen like fans coming on, unusual fueling causing high idle, the dash sensor will be different to the engine sensor so it wont look like a hot condition to the driver, worth plugging it into VIDA and check what temp the ecu thinks the engine is at. Does the glow plug lamp come on when engine is cold? If not then it may think the engine is too hot.

[cheshired5]

Pretty certain there's only one coolant temp sensor which can be found in the thermostat housing where the radiator top hose meets the engine.
If you don't have Vida, don't worry because it's not a Volvo specific problem and as it is, it's easier and quicker to test with basic equipment like a multimeter or a £5 diagnostic dongle.