[Zander]

I'm having troubles with my Subaru Outback stalling intermittently.

They Symptoms of my car is:
- It stalls on idle
- It stalls while driving with no warning
- While driving I can feel the engine loose power (revs drop) theres no response from accelerator and it cuts out OR pressing the accelerator makes the engine pulsate from no power to some response from the throttle a couple of times before either stalling or it goes back to normal.
- Theres a humming/whistling noise coming from the air intake area, it doesn't start making the noise untill about a minute after I've started the car
- No Check Engine Light has come on
- No codes come up when scanned
- As soon as it cuts out, it starts straight back up. Sometimes after the car cuts out it starts then cuts out staright away etc a couple of times before it starts and doesn't cut out. While this is happening I rev the car and it's as if the engine is trying to clear something?? Maybe.

These symptoms don't always happen. I can drive 100km and its absolutely fine and other times it just cuts out again and again. (The humming/whistling noise always seems to be there though)

Work done on car to try and fix the problem:
- Air Flow Meter has been replaced
- Fuel Pump has been replaced
- Fuel Filter has been replaced
- Throttle body has been cleaned
- IACV has been cleaned
- PCV has been cleaned
- 2 small vacuum hoses around the IACV have been replaced
- Pressure test done on car to rule out it being a blocked catalyic converter

Any ideas on what it could be?

Thanks

 

[Zander]

Also I have been reading that a clogged/sticky EGR valve could cause stalling problems (based on how dirty and clogged my IACV and PCV were I was thinking theres a good chance this could be clogged too) but have no idea where it's located. Have tried googling it but can't find a good diagram/photo of where it's located in a Subaru Outback.

Could this cause my problems and could anyone tell me/show me in a picture where the EGR valve is located?

Thanks

 

[CNY_Dave]

Also could be cracked intake plumbing or something improperly seated.

Year? Engine?

 

[Zander]

When I was cleaning the throttle body etc. all the air intake hoses looked good except for the two I replaced which were cracked.

It a 1997 OB engine is a ej25

 

[Zander]

Has done 260,000kms.

 

[nipper]

Check to make sure all the intake plumbing hoses are connected, this sounds like a huge vac leak. There is one hose we all miss in the snorkus assembly one time or another that can cause this.

 

[digdah]

Check to make sure all the intake plumbing hoses are connected, this sounds like a huge vac leak. There is one hose we all miss in the snorkus assembly one time or another that can cause this.

I second this. I have to admit it was not a Subaru but I have experienced something just like the OP's experience in a different vehicle (make and model) that I spent loads of money and time chasing. Replaced loads of different hardware but it ended up being a vac leak that was remedied by a simple reseating of existing hardware.

I'd check that first then move on.

 

[Zander]

I've thoroughly checked the hoses etc for leaks and can't find any. Think I might just replace all the hoses with brand new ones.

A couple of mechanics I've been talking to say it could be the crank angle sensor being faulty. Does any one know anything about that? Could that be the cause of my stalling issues?

 

[subiesailor]

Even just the buckle down cover over the air filter box can cause this. Miss getting the lid lined up and bingo you have your self a leak in the system that can throw off sensors and yes it makes the car loud too.

 

[subiesailor]

If you crack the exhaust on the exhaust side of the program this can also result in what your describing. One of the places you can do this and make it hard to spot is right at the "Y" in the Y pipe that joins all 4 of the exhaust ports to the single exhaust line. If the leak is big enough the back pressure can cause the car to run funny and even stall if its having issues sorting out what fuel vs air mixture to use etc.

 

[nipper]

That was going to be my next guess. I just wanted to try the obvious first because of the noise you said it made.

 

[subiesailor]

The lack of proper exhaust pressure on the exhaust side of the program can impact the systems managing the engine fuel and air ratio also. So vac leaks on the front end or goofy intake with a leak some place - or exhaust leak on the other end of the program causing confusion for the systems in the fuel air management - both can have similar results.

 

[Zander]

Over the last couple of weeks the crank angle sensor has been replaced but the problem of cutting out and the humming/whistling noise still continues. Have taken my car to another mechanic today who said they checked for vacuum leaks and didn't find any. They said it could be anything.

My thoughts are still thats it's to do with a vacuum leak. When I squeeze the hose that goes to the IACV the noise goes quieter so that indicates it air related doesn't it?

Does anyone know a good way to check for vacuum leaks?

 

[Zander]

Also... not sure if this is related to my problems but since I bought my car second hand the ABS light goes on and off at random. When the ABS light is on my brakes work fine and when the ABS light is off my brakes shudder. Not sure if this is related to stalling issue? Does any one know if it might be?

And I think the last few times my engines stalled the AT oil temp has come on first before all the other lights on my dash come up. Could the auto transmission fliud being too hot cause stalling problems?

 

[1 Lucky Texan]

in 'the old days' folks would use a trickle of gas from a propane tank to locate a vacuum leak. Probably need to unscrew the burner head and put some flexible hose on to move around the engine compartment. personally, I might try it before the fans come on when the engine is cold. Uh - use appropriate caution!

I think some other spray-type substances can be used too as long as they are flammable and won't attack/dissolve any plastics or paint etc.

you just listen for a change in idle as you introduce the gas around the hoses, intake manifold, etc.

 

[cardoc]

Also... not sure if this is related to my problems but since I bought my car second hand the ABS light goes on and off at random. When the ABS light is on my brakes work fine and when the ABS light is off my brakes shudder. Not sure if this is related to stalling issue? Does any one know if it might be?

And I think the last few times my engines stalled the AT oil temp has come on first before all the other lights on my dash come up. Could the auto transmission fliud being too hot cause stalling problems?

On the ABS, It will need to be scanned for error codes with a scan tool that will communicate with the ABS module.

Or:

1.Take out ABS diagnosis connector from side of driver's seat heater unit.
2.Turn ignition switch OFF.
3.Connect ABS diagnosis connector terminal 6 only, to diagnosis terminal (B81 grounds). Either diagnostic terminal is a ground point.
4.Turn ignition switch ON.
5.ABS warning light is set in the diagnostic mode and blinks to identify trouble code.
6.After the start code (11) is shown, the trouble codes will be shown in order of the last information first. These repeat for a maximum of 5 minutes

I have attached pics to help with this.

Write the codes down and post them.

On the AT Temp light: That is always the first light to come on in a stall situation before all the others light back up. When the car stalls, its like having the key on without the engine running and all the cluster warning lights come on.

 

[Attachebaghdad]

Zander:

I wonder if you ever found out what was wrong with your Outback with the 2.5 Litre engine. I have the same engine in my 98 Outback, and I am having the exact same issues.

Like you, I see the most likely source of the problem as vaccumb issues. As a result, I have done most of the things you have done - in particular cleaning the throttle body checking all the hoses, and ensuring there are no bad hoses or related hardware.

However, all this has been to no avial, and the Subaru Dealer here in the Philippines does not have the parts or equipment for further work on my behalf.

Did you ever get your car working right? Did you ever find out what was the problem?

Thanks,