A bit about me

 

Owned a 98 Subaru Impreza turbo for the last 14 years and still currently it got in the garage  :D. Just got my hands on a 02 forester sport love that boxer sound they make but got problem with it  :(

 

I got a misfire on cylinder 4 and a shaky engine when it is idle, any help with resolving these issues?

 

Thanks alot  :D

 

Sweeney from Surrey

Hi mate welcome to S.O.C 

A cylinder misfire can be caused by lack of spark, lack of compression or imbalance in the air/fuel mixture. Lack of spark can be caused by worn or damaged spark plugs or Coil pack, lack of compression by a blown head gasket and imbalance in the air/fuel mixture by a faulty fuel injector, fuel pump or pressure regulator. It can ultimately be a number of things so further diagnosis would be necessary to find the cause, and assess the damage and repair cost. 

I would start with the cheaper options 1st I don't think it would be a head gasket I'm sure you would know yourself if that had gone. So would start with the spark plugs then work back to the coil pack. 

And have you cleared the codes for it to return before you start ripping it to bits :D Yes I speak from  experience on that part ;) 

If you're not confident to take it on yourself I would give one of the Subaru specialists in surrey a call, Surrey Subaru Specalists or TFS racing If have used both of them myself and would recommend them. Dan at Surrey Subaru specialist is also able to provide a mobile service. Both also come highly recomended by the Surrey Scoobies Club, they do work for an awful lot of members.

nothing to add other than, wotcha and welcome to the forum - all covered above B)

Thanks for your feed back,

Subaru went in to the garage this morning and i forgot to mention that sometimes when the car is at a standstill the engine light flashes. They changed the spark plugs and put a new distributor and leads on as well as did a compression test which was fine. They cleaned the injectors but the engine still rocks and the engine light still flashes sometimes. When it is running however it runs fine and the engine light no longer flashes. 

 

Any more suggestions would be a big help, thanks

You're very welcome mate

I'd look at the MAFS and idle control valve followed by the 02 sensor in no particular order :D Would be my next steps anyway 

Yeah, defo clean the MAF. Even though it may look clean, it's probably not.its worth doing regardless and will only cost you the price of a can of "isopropyl alcohol".how old is the air filter? Also what rpm does it tick over at at normal running temprature

Could try clean it, it's I've always been told not too as it can cause more damage. But you never know :)

Hi and welcome.

With the engine running at idle, unplug the MAF. If the MAF has had it, the engine will run on without issue. If the MAF is a good one, the engine will falter and maybe even stall.

However, if the running issues are fine but the engine rocks from side to side, it's probably got a broken engine mount.

Hi thanks for help  when its hot it runs at 750rpm steady when it idling,in traffic it goes down to 500 rpm up to little over 1000 rpm.when pulling away it dips a little then its fine on the run,its never stalls but nearly has,when i say the engine shakes it  makes the hole car rocks.

I think it will be the MAF by the sounds of it. I'd do what Tlag said see change it if it need's doing and see how it goes after that  just remember to reset the ECU if you change it. If you need hand with that we have a guide some where can dig out showing you how to do that with little to no tools needed :D 

that would be a great help if you could dig out guide for us thanks for your help  :)

Here go mate. Should help :) let us know how you get on mate  

hi had a look for mafs couldn't find it got idle control valve with blue sticker on it   

Should be here mate 

thanks for your time gambit that's the same as my impreza turbo the forister air box is different may have a map or pressure sensor ? i will look in to it  

You're more than welcome 

I forgot you was on about a forester. Haha the profile picture I'm blaming that ;) 

I think the MAFS is apart of the airbox or a part of the pipe that comes off it. I don't have a picture of the engine on a 2002 but I do have a workshop manual if that would be of any help :D 

yes please anythink that you could tell me would be great thanks

I've had a drink now, school tomorrow work won't be fun :( 

I will PM a link  to download it from :) 

forester went to surrey subaru specialists bad news valve guides worn it seams to be a common problem with naturally aspirated subaru engines not so with the turbo models because cylinder 4 is the last to get oil to it will let you know what happens when its been fixed by sss   best to keep changing the oil unlike the last owner ones a year 10,000 miles 

:( not good mate but least it's in the right place thing I'm going to have to email a few Garages see if we can get them involved on here. 

Are more regular oil changes the solution or is there any merit in changing oil pumps?

I've not changed mine just filter and oil. Have me thinking now :D 

that will be good gambit. i will be asking those question jay762  when i see him in march he's got so much work at mo  

We have a few of you from that way on here and all rate SSS and be nice to have them on the list. They don't need to be active every day or anything but get there own post like what I did for Sheffield Subaru Services and get a catalogue of recommended garages here :) 

Thats my bigger picture anyway :D