I was driving my impreza that I have had a few weeks on the motorway last week, accelerated & it started juddering, done it again when accelerating, came straight off motorway & struggled to get home, in the few weeks I have owned it I had used different 95/97/99 ron due to whatever location at time, was serviced two weeks ago & number 4 plug was fouled, white to suggest running lean. Fast forward a week & thats when I blew the valve.

After a compression test found there was no compression there I have a hole in a exhaust valve the width of ballpoint pen, bad times, also the bore/piston & other valves are really clean, due to wash with the unburnt fuel?

I am getting 2 new exhaust valves & the headwork done, new head gasket that side etc.

My question is there is no obvious explanation to the running lean or how long it had been, not sure if the other cylinders are ok but all other plugs were ok when removed. This car has been a complete money pit & been a constant hassle although I did love having it for a few days.

The day before it was on a diagnostic & there was no knock, running sainsburys super unleaded & nothing to say there was a problem just a stutter before boosting so put the oe dump valve on. With the work being done do you think I am asking for further problems engine wise, should I only run 99, because the comression was weak in bore 4 will it cause the engine to have problems in other areas?

Sorry about all the questions just really need some help/guidance from the people in the know!!!

The only mods are magnecors & a stainless back box. Baileys dump valve is now off & hks mushroom filter binned.

Cheers in advance

 

Bttt!!!

 

Have you had the injectors flow tested mate?

 

"Beware the judder man, when the car is hot." See what I did there?

Seriously, is it a MY99/00 STi, WRX or UK car?

 

Car was serviced by a subaru mechanic so he is doing the work, he said injectors were fairly noisy as standard but it could be a possible cause, its a my99 with 121k.

 

Sorry uk car as well.

 

I'd have a flow test done mate,wouldn't be advisable to do the work without finding the cause first as you could end up in the same boat!!

 

Is that expensive? The bill is shooting up as it is!!!

 

Not really fella well under £100.

 

Will look into it, any other thoughts?

 

i had my injectors cleaned and flow tested by these, very quick turnaround and were the cheapest by a long shot.

http://cgi.ebay.co.uk/ULTRASONIC-FUE...item587e1889c6

 

coincidental that it happened just after you bought it. have you spoken to the the previous owner?

 

I have tried to a few times, it was stood still for 5 months, looking back on it that was a good indicator but he had a new car so took it that he would obviously use that, any other thoughts what could cause it to run lean & will getting it fixed run the risk of other failures, i.e big end etc?

 

Former owner reported no known problems, any other ideas of replacing the valve, refacing & replacing the head gasket will cause further problems???