Jump to content
LegacyGT.com

compression--leak down question


Recommended Posts

Though I am planning to do a compression+leak down tests for my car due to what happened to us a while ago (see here), is it possible to have compression/leak issues with all the following conditions met:

1. 25.5 MPG fuel economy highway

2. hitting 13.6 psi max on stock tune/turbo

3. no idling issues

4. no problem starting the car

5. apparently no weird sounds. Just the regular subie tick.

6. Car appears to pull the same as always.

7. No noticeable excessive oil consumption

 

Interested to see what you guys think.

Link to comment
Share on other sites

  • Replies 85
  • Created
  • Last Reply
you're probably fine

 

That's what I like to hear instead :). On a serious note though, there must be some symptoms that one could track or notice. Would any logging parameters such as timing advance, etc... would act a bit funny?

Link to comment
Share on other sites

  • 2 weeks later...
bump for some more feedback. I'd have to admit that my subie tick is pretty loud, to my taste, when engine is cold and under load below 1200 rpms. I need and will post a sound clip of it. I've only noticed it now that it is warm where we live and I can put the windows down. Have never put the windows down for the two previous years...
Link to comment
Share on other sites

prolly cracked ringland and burnt valve

 

 

 

;)

 

^:ohhh:

 

Seriously though, can a cracked ringland and/or burnt valve still have the engine meet all the conditions mentioned above? I don't want to have to carry a spare shortblock in my trunk if you know what I mean ;).

Link to comment
Share on other sites

  • 6 months later...
Though I am planning to do a compression+leak down tests for my car due to what happened to us a while ago, is it possible to have compression/leak issues with all the following conditions met:

1. 25.5 MPG fuel economy highway

2. hitting 13.6 psi max on stock tune/turbo

3. no idling issues

4. no problem starting the car

5. apparently no weird sounds. Just the regular subie tick.

6. Car appears to pull the same as always.

7. No noticeable excessive oil consumption

 

Interested to see what you guys think.

 

Reviving my old thread :rolleyes:. Well, about 10000 miles after this happened to me, the above list no longer holds true :(. All seven points are still fine except 3. I am getting idling issues with misfires. Got 2 misfires on 4 so far while idling (after driving the car for 5mn). And today, I even got a pending misfire code for cylinder 2 but it never popped. I kept driving with the CEL on and still got full power.

I still have not done compression/leakdown tests yet. I will do it for sure as soon as I can.

 

In any case, why do you all think I am getting these misfires? Remember that all 7 points still hold true except point 3. Note that I've been getting these misfires and rough idling in cold and damp weather conditions (35-50F and 80% humidity).

 

Could be

1. injectors (don't think so)

2. spark plugs (don't think so)

3. coil packs (don't think so)

3. broken ringland (maybe but I am 'only' burning a quart of oil per OCI)

4. valves (could be especially knowing that my TB tensioner failed as I was driving)

5. o-rings at the intake to TGV's (maybe--I kina hope so)

 

 

Note that rough idle mostly occurs within the first 15mn of a given drive. After a while, it appears to be fine.

Link to comment
Share on other sites

I've decided today (instead of doing a swap) to change my injector on #4 since I had a brand new OEM one already. Here is some close-up pics of the old injector. What do you guys think? Is this considered dirty?

 

btw, I've gone for a 35 mile drive (mixture of highway and city traffic). So far so good. No CEL. The cold idle was not that great. But then again, the ECU was reset. When warm, idle appeared fine. Car is pulling pretty good in any gear.

 

Next, I plan to change all my spark plugs since it is time.

 

NOTE: click on the pictures to see them full-size.

FLS_7277.thumb.JPG.1de4d75da5c473f5e21c0eebf5216a36.JPG

FLS_7278.thumb.JPG.2486b3d311c775ad0603f64506404109.JPG

FLS_7280.thumb.JPG.67a9408a13f3da1a9995b49ff0efc253.JPG

FLS_7282.thumb.JPG.eac9f487a6f9fc3e4bf3625388966a22.JPG

FLS_7283.thumb.JPG.c7d526bb99a162010e6350eddd6708a3.JPG

Link to comment
Share on other sites

really? I have to say that my white balance settings on my camera were on 'warm' (5000k). So it may look like rust but looks more like dirt to me. I need to check the net for pictures of dirty injectors to compare with. Drove an extra 30 miles. So far so good.

 

I think I am done with el cheapo gasoline (from supermarkets).

Link to comment
Share on other sites

I thought I had a picture of it 'dirty' but the only one I have is after it was cleaned. Wasn't that much of a change. Since you already have a new one you know what they look like but I thought I'd post this up for others to see the difference between clean and dirty.

 

http://legacygt.com/forums/picture.php?albumid=1534&pictureid=7886

 

http://legacygt.com/forums/picture.php?albumid=1534&pictureid=7887

Link to comment
Share on other sites

Misfire came back while idling after being barely semi warm :mad:. Though when fully warmed up, my idle is pretty stable around 750 rpm with a bit of cabin shake but not too bad (I always had some 'cabin shake' since I've owned the car). Car responds well too when I push on it. So, basically I am :confused:. Until I can find a place to get a compression test, my next steps are change spark plugs and find some carb cleaner to spread on the intake manifold gasket area. And cross fingers that the rpm will fluctuate when I spray some :redface:.
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.




×
×
  • Create New...

Important Information

Terms of Use