Engine: T5: 850 T-5 Stalling at idle and low revs HELP!

[DrewSommerville]

Hi Guys, needing some help here!

My volvo 850 T-5 recently packed in. It will stall after 10 - 15 seconds after I start the engine. I can fix this by applying some revs through the throttle. But if im driving and slow down to a junction or come to a stop as soon as the revs drop it will cut out and stall.

I have taken it to Volvo Sighthill Edinburgh, they failed to do a diagnostic, changed the crank sensor on 'intuition' as well as the idle air control valve. Nothing worked, I took my volvo back from them as it cost £550 and I couldnt afford to let them continue mindlessly rip my car to bits.

If anyone has had a similar problem or any ideas on a solution i would appreciate it! I will list all issues with the car below new and old

Ive been driving it since purchase for 6 months and no issues have occured with the following known faults

-Rev counter not working
- Temperature gauge not working
- odometer not working
- abs light on
- engine electrical fault (intermittent light)

After the car was returned from volvo garage

- Speedometer not working
- engine electrical fault (constant light)
- Fuel gauge playing up

Cheers
Drew

[Luxobarge]

You say "engine electrical fault" - light constantly on. This is the engine management light, you need to read the codes to see what the fault is, without this you're just guessing, which is (as you have found out) time consuming and expensive.

[acshortt5]

To me those faults on the dash point to the electrical part of the ignition switch being faulty. When these faults are happening try gently turning the key in either direction to see if anything alters. My other thought is you've got a poor earth connection somewhere.

The stalling at idle could be a number of things, as suggested gabove get the codes read and go from there. You could try disconnecting the maf sensor to see if that improves things but disconnecting it will through a fault code (just so you know).

[JohnM 855 T5R]

As above, you really need to read the fault codes. Nearly all 850's have an onboard diagnostic reader found just in front of the coolant tank. This can be used without any specialist kit.

Only the last of the 850's moved over to what's known as OBD II for which you would need a plug in reader.

Here is a link to tell you how to read codes and what they mean.

https://www.matthewsvolvosite.com/read-codes-volvo-850/

Regards
John

[DrewSommerville]

I’ve had a couple people try and read the codes from the obd2 port - Volvo garage failed to do this, and a friend of mine managed to get it on motronic 4.3 but couldn’t read any codes. I’ll keep trying to locate someone with the equipment to read the codes and will let you guys know what codes flag up.

I’ll try disconnecting the MAF sensor in the meantime and yes one of the two earth connection on the back of the engine has broken off so that might be flagging up a fault.

Cheers
Drew

[4x4]

The OBDII on the 850 is more like OBD1.5 and therefore very little if any readers will work


What you need is an Android phone then go to Google Play and buy the the 850 OBDII app for less than a couple of pounds, then go to eBaY and purchase this dongle which is known to work on the 850 (most others don't)


The app doesn't work on Apple phones...

[Mkengineering]

Originally Posted by 4x4

The OBDII on the 850 is more like OBD1.5 and therefore very little if any readers will work


What you need is an Android phone then go to Google Play and buy the the 850 OBDII app for less than a couple of pounds, then go to eBaY and purchase this dongle which is known to work on the 850 (most others don't)


The app doesn't work on Apple phones...

What he said.

Or try to download a program called VOL-FCR and also order a VAG com obd2 cable.

Life saver this program is

[tomodan]

Hi.

I had very similar symptoms and no faults were showing on the 850 android app code reader. After getting a local specialist to read the codes with their reader it was diagnosed as a faulty MAF. Replaced with an aftermarket one from GSF with a hefty online discount (original Bosch ones no longer available) and fault instantly gone.

FYI I tried the “unplug MAF to see if it made a difference” check and it did a bit so I wrongly assumed it was ok for ages before getting the codes read.