Suby Club

Hey all, I've been experiencing a bit of a issue when I first start my 05 Impreza GX in the morning.

Now this has been happening for a while but it's only just started to happen a bit more lately.

 

Now what happens is when I first start the car it goes up to 2000rpm then drops gradually like normal to around 1200rpm until warm which happens when the car doesn't play up but lately it's been going from 2000rpm then dropping below idle (Around 400rpm) then jumping back up and continuing to drop down every few seconds or so until I hit the accelerator then it will act like normal.

 

Any idea what could be causing that?

 

Thanks in advance.

Check the Vac line connecting to the fuel pressure Reg.. mine came off and did that back in the 2.5

Ok I checked that and it's still connected and tightly I might add. Their are no visible cracks but I'll check it again when It's cold.

Maybe the oil grade is too thick for cold winter morning starts.

Full synthetic oil is a lot better for cold starts.

Certainly sounds like it could be a vacuum leak somewhere. When was the last time you ran upper engine cleaner through it? IACV or throttle body might need a good clean too

Maybe the oil grade is too thick for cold winter morning starts.

Full synthetic oil is a lot better for cold starts.

The car currently has Penrite 10w30 in it I think (Don't quote me on that the last time I checked the paperwork was when I got the car)

Certainly sounds like it could be a vacuum leak somewhere. When was the last time you ran upper engine cleaner through it? IACV or throttle body might need a good clean too

Well I tried looking for a leak ages ago but since this is my first Subaru I'm still working out where everything is. Never I bought the car just a little under 2 months ago and when I got it it had a service done to it 1000kms before but I'm pretty sure nothing like that was done.

 

I was thinking maybe the IACV or throttle body might need a clean like you said so I'm probably going to try that.

Wont be oil.. My money is on vac related problem.. be it IACV or maybe even PCV but deffs a Vac prob.

 

 

Also check the Lines going to the charcoal canister.

Wont be oil.. My money is on vac related problem.. be it IACV or maybe even PCV but deffs a Vac prob.

 

 

Also check the Lines going to the charcoal canister.

Ok will do.

 

I found a manual online for my car and it doesn't seem to have a IACV unless they changed it to IACS since on my car it seems to be a solenoid not a valve.

 

It would be great if I had friends that knew about Subaru's haha, One of them owns one but doesn't know anything about mechanics I don't think he even knows how to check the oil....

Just a can of Upper engine cleaner will do wonders.. regardless of which idle control unit it has.

Wont be oil.. 

This.......

 

Just a can of Upper engine cleaner will do wonders.. regardless of which idle control unit it has.

...................and this.