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Ex-VPC Headbanger
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I replaced the pcv valve several months ago. I used a Fram valve. It looked fairly well made. I had a valve job about two years ago, so that is a less likely source, though I wonder about the seals.

The car does comsume a bit of oil (1qt every 1000 miles or so). I still can't picture in my mind how a bad turbo is going to cause this problem. If you can provide a more detailed explaination of the plumming that could cause this it would be appreciated.

[This message has been edited by David_J (edited January 06, 2000).]
 

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If the car consumes 1 qt. of oil every 1000 miles, and you have oil in the breather line dripping, you seem to be getting "blow by"..You will need to fix this problem by replacing the rings and re-honing the block, but if the block is out of spec (need to Mic. it), then you will need to bore it to the next oversize, install new pistons, and rings. The oil is NOT due to the valve seals, this has nothing to do with it, as the valve seals prevent oil from passing the valve guide into the combustion chamber.. It IS normal to have a "little" oil in the rear intake tube leading to the rear turbo as the crankcase ventilation system runs through here and is connected to the rear valve cover. If you did not have a crankcase ventilation system you would build up excessive crankcase pressure and blow every oil seal..The PCV valve will not affect this as it is connected to the intake manifold (lower), just look at the hose where connects from the front valve cover (pcv valve), to the lower intake manifold nipple. If the PCV was bad, it would send oil into the chambers, and you would see it...
 

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Ex-VPC Headbanger
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Discussion Starter #3
I have "wet" oil on both ends of my breather hose. That's the hose on the right back of the front valve cover on the DOHC engine. The nipple that the far end of the hose connects to under the intercooler hard pipe has a new oil drip and oil deposits around its base.

Is this normal or do I have a valve seal issue?
 

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Curmudgeon
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It could be worn valves, or it could just be that you need a new PCV valve. How old is the one in there, and is it a good quality one? I'd stay away from those Duschebag ones from the local chain store...
 

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BFA
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I have the same problem. The oil is most likely coming from your one or both of your turbos. I asked the dealer about this, and they said that after awhile, the seals in the turbos get a little worn, and they start sucking in oil from the vacuum they create. $1200 for a new stock turbo or $800 for some internal parts you could replace if the casing is good. I'm not going to pay for either. I'm just gonna save up for some upgraded turbos. It's not the end of the world, but it'll use up a little oil. Also, it'll probably start getting oil in the cylinders, and the engine will misfire everyonce in awhile. Not really a good thing, but I can live with it for a little longer if it means saving $1200.

Jason
92 Stealth R/T TT
 

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Curmudgeon
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A quick note here, last time I looked in the catalog Fram did NOT list a PCV valve for our cars. A couple of months ago someone here (Andrew?) mentioned the Fram they got was working backwards, the one-way valve was "sucking" in the wrong direction!
The Purolator PV1043 works like the stock one, with the threads to your lips you should be able to blow out through the valve but not suck back in.
I don't have the turbos, I missed that last night. Brian and the rest can tell you more about that, but I though the Fram thing was worth mentioning.
 

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If this is anything like the Talon/Eclipse problem...and I would bet it is, there is a breather hose going from the valve cover to the intake tract.

When you are revving at high RPMs this valve is used to breath off any excess built up air (ie. blowby). Of course, along with this air comes oil.

Is your engine high mileage? Is your boost turned up? These things usually adds to the blowby.

Look for a gummy sticky film inside the intake tract. Also, if you clean your intercoolers with gasoline, it should come out black, due to all the deposited oil, the first time.

One solution is to clean out the oil and put a breather filter on the valve cover.

The better solution is to get a catchcan filter for the breather valve.

The DSM FAQ for this is at: http://www.vfaq.com/index-main.html

Click on:

Valve cover
filter/catchcan
(PRINT Version)

I have been through this on my DSM. I haven't checked by Stealth TT yet.

Finally, it's not really that big a deal. If you don't notice you losing any oil, I wouldn't worry about it.

I hope this kind of helps
.
 

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The problem is greatly magnified by running higher than stock boost. That's because of the increased vacuum effect caused by the incoming air (from your air cleaners to the turbo compressor inlets). When this air rushes by the fitting to which the tube to the rear valve cover is attached, the vacuum that is created causes the oil to literally get "sucked" out of your valve covers. Over time (read: 1000 miles), you could easily lose a quart of oil.

In 8th grade science class, we used to "boil" water at room temperature by attaching a hose with a "tee" fitting to a faucet. On the tee part, a tube was attached through a rubber stopper into a beaker with about 1/4" of water. The vacuum created by the water rushing by the tee would lower the pressure inside of the beaker and the water would begin to boil since the lower pressure would enable the water molecules to exceed its surface tension.

Our vacuum isn't quite so pronounced, nor is it countinuous. But it is enough to extract a considerable amount of oil out of the valve covers. The best way to fix this is to install a catch can and block off that fitting that leads to the rear turbo. I did and it is amazing how the problem disappeared.
 

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You cannot easily lose a quart of oil!! If this was true, then the catch cans would have to be dumped every week!! I have only had to dump a catch can every two-three months, and even then, there is not much in there..
 

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Ring blowby certainly is part of the problem, but turbos definitely suck oil out of the valve covers. The fact that there's a tube from the rear valve cover to the turbo inlets was no accident on the part of Mitsubishi design engineers.

Exactly how much oil is lost depends on how one drives. In my case, almost every mile I drive is under some sort of boost -- either stoplight-to-stoplight or out on the back roads. This car is for sheer pleasure, not transportation. Therefore I run the piss out of it at all times, since, I know that if I blow it up, I can always rebuild it. (Comes with the territory). The more boost I run, the more oil I lose. I find a portion of it in my intercoolers whenever I clean them out.

Prior to installing the catch can I was losing oil at a rate of about 1 quart every 1000 miles just like the original poster complained. I put a Summit catch can in place, made no other changes whatsoever to the car and suddenly my oil consumption ompletely stopped. I would have to conclude that the catch can has something to do with it.

If blowby-induced oil loss wasn't such a problem, why would companies like Cusco and Summit make catch cans in the first place?
 
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