Engine randomly shuts off

abtx · Dec 27th, 2017, 15:40

On my S40, I recently got my alternator replaced and have an SRS service urgent message (not checked yet, but I thought I'd give this for context just in case).

So the car does this completely at random: usually when engine is running idle in neutral (parking, or traffic lights) it will shut off. I can't start it until about a minute and a half later.

It also does something else (sometimes when driving in gear) it will turn itself off momentarily for split second and gets back on.

What might be the cause of this? It's different to throttle body clog (cleaned just over a year ago) which prevented it from starting at all.

Did this happen to you before?

EDIT: I don't drive a lot (5k/year), it happens occasionally and there's not evident pattern to it. My girlfriend was driving couple days ago and it misfired 3 times, once dying completely, two times over speed bumps(!?). It misfired few times when I was driving, once completely on a junction, but was driving couple hours around the city today and it was fine

Sysyphus · Dec 27th, 2017, 17:13

An engine needs three things to run: fuel, spark and compresssion... this sounds most likely a fuel issue to me, pump perhaps, injectors possibly... but it’s all shooting in the dark really until you hook it up to Vida and read the codes, which should narrow it down significantly.

dme123 · Dec 27th, 2017, 18:32

Quote:

Originally Posted by Sysyphus

An engine needs three things to run: fuel, spark and compresssion... this sounds most likely a fuel issue to me, pump perhaps, injectors possibly... but it’s all shooting in the dark really until you hook it up to Vida and read the codes, which should narrow it down significantly.

This one is diesel, so it only needs compression and fuel!

Well worth getting the VIDA codes read. Have you changed the fuel filter recently? A dirty diesel fuel filter often causes poor running and so on.

My colleague also had a similar problem with a LR Freelander II that he always ran on supermarket diesel. It had big miles on it, but a few tanks of Shell Nitro whatever it's called diesel cleaned it out and fixed it. Blocked injectors most probably, but not blocked enough that a bit of GTL fuel and detergents couldn't sort them out.

Sysyphus · Dec 27th, 2017, 18:38

Quote:

Originally Posted by dme123

This one is diesel, so it only needs compression and fuel!
.

Oh yeah, just noticed the D in his sig

Makes fuel issue an almost certain bet then

abtx · Dec 27th, 2017, 20:51

Oil and filter changed end of September. I do run on cheap diesel 99% of time. Will try running on premium for a while. I ordered a OBD2 reader so hope will get some insight into the problems. Will keep the post updated as soon as I find what's going on and experiment with premium fuel (still got this whole tank to go). It's 125k miles on the clock btw. I'm also changing the oil every 9 months since I do only 5k a year.

dme123 · Dec 27th, 2017, 22:01

Quote:

Originally Posted by abtx

Oil and filter changed end of September. I do run on cheap diesel 99% of time. Will try running on premium for a while. I ordered a OBD2 reader so hope will get some insight into the problems. Will keep the post updated as soon as I find what's going on and experiment with premium fuel (still got this whole tank to go). It's 125k miles on the clock btw. I'm also changing the oil every 9 months since I do only 5k a year.

I think your car will have something like 1 year / 16k service intervals, that's a lot of synthetic oil being thrown away very early if you're changing it ever 9 months and 4k!

If it only does short journeys it may well do it the world of good to give it a tank of premium diesel and/or a bottle of injector cleaner and drive it like you stole it for half a tank. Do you drive it gently, keep the revs down and short journeys only?

abtx · Dec 27th, 2017, 22:43

I occasionally take it out to the bypass at night and do 100mph when there's no traffic. Most of its life it's 90% short and gentle city trips and 70mph on cruise motorway trips. There's nothing stopping me to use better fuel, I didn't know using sub-par one like supermarket one would make that much difference in the engine. I red opinions I should change oil more often if I take short trips and drive low miles as this is considered extreme use?

Dec 27th, 2017, 15:40	#1
abtx Junior Member Last Online: Dec 29th, 2023 21:05 Join Date: Dec 2015 Location: Edinburgh	Engine randomly shuts off On my S40, I recently got my alternator replaced and have an SRS service urgent message (not checked yet, but I thought I'd give this for context just in case). So the car does this completely at random: usually when engine is running idle in neutral (parking, or traffic lights) it will shut off. I can't start it until about a minute and a half later. It also does something else (sometimes when driving in gear) it will turn itself off momentarily for split second and gets back on. What might be the cause of this? It's different to throttle body clog (cleaned just over a year ago) which prevented it from starting at all. Did this happen to you before? EDIT: I don't drive a lot (5k/year), it happens occasionally and there's not evident pattern to it. My girlfriend was driving couple days ago and it misfired 3 times, once dying completely, two times over speed bumps(!?). It misfired few times when I was driving, once completely on a junction, but was driving couple hours around the city today and it was fine __________________ Moby Brick 940 2.3 LPT Last edited by abtx; Dec 27th, 2017 at 16:35.

Dec 27th, 2017, 20:51	#5
abtx Junior Member Last Online: Dec 29th, 2023 21:05 Join Date: Dec 2015 Location: Edinburgh	Oil and filter changed end of September. I do run on cheap diesel 99% of time. Will try running on premium for a while. I ordered a OBD2 reader so hope will get some insight into the problems. Will keep the post updated as soon as I find what's going on and experiment with premium fuel (still got this whole tank to go). It's 125k miles on the clock btw. I'm also changing the oil every 9 months since I do only 5k a year. __________________ Moby Brick 940 2.3 LPT

Dec 27th, 2017, 22:43	#7
abtx Junior Member Last Online: Dec 29th, 2023 21:05 Join Date: Dec 2015 Location: Edinburgh	I occasionally take it out to the bypass at night and do 100mph when there's no traffic. Most of its life it's 90% short and gentle city trips and 70mph on cruise motorway trips. There's nothing stopping me to use better fuel, I didn't know using sub-par one like supermarket one would make that much difference in the engine. I red opinions I should change oil more often if I take short trips and drive low miles as this is considered extreme use? __________________ Moby Brick 940 2.3 LPT

Dec 27th, 2017, 17:13	#2
Sysyphus Senior Member Last Online: Yesterday 02:05 Join Date: Dec 2016 Location: Suburban Philly	An engine needs three things to run: fuel, spark and compresssion... this sounds most likely a fuel issue to me, pump perhaps, injectors possibly... but it’s all shooting in the dark really until you hook it up to Vida and read the codes, which should narrow it down significantly.

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