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Valve seals? Blowing oil?


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Okay so as I have posted recently, my car has been randomly dying and then i have to sit there and try to restart it for a good 10-30 min. When I am doing this, it will catch and rev up then die again. Usually a couple times. (my only thought on this is that the carb and jetting are way off for the high elevation i live at) That is why I am going to be doing a weber carb swap in the next month most likely.

 

Buttttttt I noticed a lot of black around the end of my muffler and black specks behind the muffler on the snow like they shot out. Then today someone told me my valve seals are probably bad and I am blowing oil. They told me to do a compression test, and get the stock numbers for what the compression should be. and they said that this could be a huge factor for why I get bad gas mileage.

 

So Ultimate Subaru, give me the low down. What am I looking at? What do I do? What do I need? How much will it cost? Can I replace the seals myself?

 

Oh and today I drove up to the mountain, higher elevation then where I live (i live at like 6,500 ft, and the resort is at almost 8,000 i believe.) and the car would not start to come back down. Had to get a ride from a friend! WHAT SHOULD I DO?!?!?!

 

 

Is this what I need? http://www.rockauto.com/catalog/moreinfo.php?pk=2154590

Edited by Moosen
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If both the idle and jetting is set for sea level, an over rich mixture will cause it to run like crap, and you will get the dark sooty splatters out of the tailpipe, and your mileage will be terrible.

I wouldn't suspect valve seals just yet. I could be wrong with subaru specifics...but typically valve seals and bad guides will cause smoke upon startup, and then dissipate.

 

on my weber swap, I changed the main jets to 25s, and it runs really well, and I'm around the same elevation as you (well kinda, I go between 6000ft-8000ft daily).

my advice would be to do that swap to eliminate carb problems, then see what problems are left after that

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If both the idle and jetting is set for sea level, an over rich mixture will cause it to run like crap, and you will get the dark sooty splatters out of the tailpipe, and your mileage will be terrible.

I wouldn't suspect valve seals just yet. I could be wrong with subaru specifics...but typically valve seals and bad guides will cause smoke upon startup, and then dissipate.

 

on my weber swap, I changed the main jets to 25s, and it runs really well, and I'm around the same elevation as you (well kinda, I go between 6000ft-8000ft daily).

my advice would be to do that swap to eliminate carb problems, then see what problems are left after that

 

Sweet thank you for this. So you think i need 25 for jets? are jets easy to swap?

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In regard to valve seals, you will see blue smoke when decelerating, such as letting off the gas and coasting in gear.

 

The valve springs have to come out to change them. generally you have to remove the heads and you will want to use a clamp style valve spring compressor.

 

The other way to do it with heads on-car is to gert an air fitting that threads into the sparkplug to pressurize the cylinder and hold the valve in place, and use a normal style valvre spring compressor. With my experience, the tool has a hard time fitting around the double spring to get the keepers out.

 

You could also stuff a rag in the cylinder through the spark plug hole to pack the cylinder and keep the valves from falling through.

 

This is a somewhat difficult operation based on using tool effectively, or by removing the heads, but is easier with the clamp style if you already have the heads off for other reasons.

 

Black soot on the tailpipe is more conducive to the carb jetting and the altitude. Look n the emissions sticker under the hood to see if the car is eqipped with a high altitude kit. MY experience with a high altitude carb is the single barrel carter-weber which is different than the standard hitachi.

 

The tailpipe would be more oily if you were burning oil, and you would smell it readily.

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In regard to valve seals, you will see blue smoke when decelerating, such as letting off the gas and coasting in gear.

 

The valve springs have to come out to change them. generally you have to remove the heads and you will want to use a clamp style valve spring compressor.

 

The other way to do it with heads on-car is to gert an air fitting that threads into the sparkplug to pressurize the cylinder and hold the valve in place, and use a normal style valvre spring compressor. With my experience, the tool has a hard time fitting around the double spring to get the keepers out.

 

You could also stuff a rag in the cylinder through the spark plug hole to pack the cylinder and keep the valves from falling through.

 

This is a somewhat difficult operation based on using tool effectively, or by removing the heads, but is easier with the clamp style if you already have the heads off for other reasons.

 

Black soot on the tailpipe is more conducive to the carb jetting and the altitude. Look n the emissions sticker under the hood to see if the car is eqipped with a high altitude kit. MY experience with a high altitude carb is the single barrel carter-weber which is different than the standard hitachi.

 

The tailpipe would be more oily if you were burning oil, and you would smell it readily.

 

Alright scratch everything I said then. Getting a weber asap!

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  • 2 weeks later...

Update.

 

my boss tonight said he would bet me his diesel chevy truck, lifted 20XX truck for my suby. If i went out and started it, that in 3 minutes there would be smoke coming out the tailpipe if i revved it and that i need to redo the seals.

 

I said okay, then he backed out hahaha. But he still thinks it is.

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  • 11 months later...

its iceing up freezing the carb carb +cold + elavation + mosture+ velocity = ice put a heat riser on it a good one and a carb coolant heater of some kind we had this problem when we ran the SU carbs on the ea81 it took two coolant heaters and a hot air riser to keep the SU carbed turbo ea81 from freezing up. The oil burning is caused by the carb being frozen shut and pulling on the pcv syestem to try and get air is sucking the oil out of bottom end. Have leaned thiss the hard way many tril and error carbed turbo years

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I can't remember seeing any Subarus around here that showed worn intake valve seals, and if any of the hundreds around here had that problem I would have noticed.  I also don't recall anyone on the board mentioning seal issues in the past.  The engine design tends to have the oil flow away from the seals instead of onto them like most engines, so even if they were worn you might not notice.

 

But regardless, they are only oil seals.  If someone tells you to do a compression test to check them, you might want to discount their advice.

 

Have you removed your spark plugs and looked at them yet?  Ingesting oil will make the plugs look oily and usually you will have deposits caked around the electrode.  If, instead, you see a flat black soot, then you probably have too rich of a fuel mixture.

 

Even if you do have oily plugs, look to the PCV system first.  MUCH more likely to pull oil through that.

 

Regarding the need to change to a Weber: this is coming from a flatlander, but in concept the stock ECU-controlled carb (or FI) will be better able to handle changes in elevation than will a non-ECU-controlled carb like a Weber.  The Weber has no ability to compensate for elevation changes.  You can certainly get it jetted properly for an elevation, but it will only be optimized for that elevation.

 

Good luck sorting things out. :)

Edited by NorthWet
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