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Old 05-13-2010, 09:09 PM   #1
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Default I think i need a rebuild

So i was seeing some oil smoke coming from the exhaust. I thought that it was coming from the turbo from that time that i accidental kinked the drain line. No such luck, here are the number from my compression test: 166,159,156,167

then i put a tbsp of oil in each cylinder and i got this: 186,177,175,190

I think the rings are just about shot.
So, how much have i screwed up this 78k mile engine?
Is this now a ticking time bomb?
How much longer will this thing last?
Should i just drive at super low boost (WG wired open)till i can afford a new bottom end?

Suggestions?
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Old 05-13-2010, 09:24 PM   #2
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I don't know, those numbers don't look super horrible to me. Like how much smoke are we talking about? Are you 100% sure it's not your turbo letting oil through?
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Old 05-13-2010, 09:26 PM   #3
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Originally Posted by swimming108 View Post
So i was seeing some oil smoke coming from the exhaust. I thought that it was coming from the turbo from that time that i accidental kinked the drain line. No such luck, here are the number from my compression test: 166,159,156,167

then i put a tbsp of oil in each cylinder and i got this: 186,177,175,190

I think the rings are just about shot.
So, how much have i screwed up this 78k mile engine?
Is this now a ticking time bomb?
How much longer will this thing last?
Should i just drive at super low boost (WG wired open)till i can afford a new bottom end?

Suggestions?
Yes that sounds like rings but as a machinist I know always says, you never know the whole story till you open it up.

Those aren't terribly "out of spec" numbers and they are fairly consistent. I know new is ~190psi but I recall acceptable being as low as 140psi (correct me if I'm wrong). Is there much oil burned? It's only going to get worse and you'll rapidly accelerate the problem with the application of boost.
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Old 05-13-2010, 09:36 PM   #4
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it is roughly 1/4 to 1/2 qt every thousand miles. I noticed it today quite a bit when decelerating off of the interstate. The smoke might be a combination of rings and turbo. How would you suggest i go about checking to see if the turbo is the issue?
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Old 05-13-2010, 09:40 PM   #5
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I doubt its the rings. I had a freind with 90 psi comp on all cylinders and it still did not smoke. I test drove a NA last July and it had 110-138 on all and it did not smoke.

My guess is valve train related. I would not tear it down just yet.
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Old 05-13-2010, 09:41 PM   #6
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I don't know, those numbers don't look super horrible to me. Like how much smoke are we talking about? Are you 100% sure it's not your turbo letting oil through?
i see gray puffs in the mirror now and again. sometimes it happens at idle. but definitely not consistent.
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Old 05-13-2010, 10:39 PM   #7
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I doubt its the rings. I had a freind with 90 psi comp on all cylinders and it still did not smoke. I test drove a NA last July and it had 110-138 on all and it did not smoke.

My guess is valve train related. I would not tear it down just yet.
How can the oil be coming from the valvetrain? Would a catchcan help?
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Old 05-13-2010, 10:42 PM   #8
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How can the oil be coming from the valvetrain? Would a catchcan help?
Worn valve stem seals/valve guides will make the car smoke. A catch can is never a bad idea. I ditch the PCV system entirely on all of my cars.
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Old 05-13-2010, 10:54 PM   #9
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tell us about the oil restrictor for your journal bearing turbo. I don't know what size you need for a journal bearing turbo, but you probably need one. PM Jkav and post the answer.
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Old 05-13-2010, 11:08 PM   #10
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tell us about the oil restrictor for your journal bearing turbo. I don't know what size you need for a journal bearing turbo, but you probably need one. PM Jkav and post the answer.
unless one is designed into the turbo, i don't have one. I would have thought that BEGI would have already thought this one through?
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Old 05-13-2010, 11:09 PM   #11
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So, are we in agreement that my compression numbers are not too bad. Or should i take it easy and plan a rebuild in the near future?
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Old 05-14-2010, 09:07 AM   #12
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So, are we in agreement that my compression numbers are not too bad. Or should i take it easy and plan a rebuild in the near future?
Was that hot or cold, and with the throttle wide open or shut?

Even if the motor was warm, and throttle wide open, then those numbers are still decent, low side to me, but nothing drastic.
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Old 05-14-2010, 09:21 AM   #13
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The engine definitely has wear but is acceptable. I'm my experience valve guides only show their leakage after sitting for a while (overnight) not constantly, you never know though.

If you have a complete begi kit installed it should have any required restrictor included. This is not to say the turbo isn't leaking oil.

I'm on the stock pcv system and have had 0 oil burn in 3000km, I'm planning to make a catch can but haven't gotten around to it.

If you have the means and a spare car or engine I'd look into a rebuild but that's me not wanting to possibly destroy a rebuildable engine. People do drive Chrysler's and Honda's with them smoking, I just don't know for how long.
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Old 05-14-2010, 02:37 PM   #14
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this test was with the motor just below operating temp and with the throttle open. And i did each cylinder twice before recording the number.

And no, i do not have a spare car or motor. this is also my only vehicle. Yes, i know i am an idiot...
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Old 05-14-2010, 02:40 PM   #15
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So, are we in agreement that my compression numbers are not too bad. Or should i take it easy and plan a rebuild in the near future?

It'd be worrisome if the numbers were high at first and then stayed the same with oil. since they all went up more or less evenly across the board, I'd say they are okay.
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Old 05-14-2010, 07:04 PM   #16
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this test was with the motor just below operating temp and with the throttle open. And i did each cylinder twice before recording the number.

And no, i do not have a spare car or motor. this is also my only vehicle. Yes, i know i am an idiot...
I'd say drive it then, as long as your not being an asshat all the time you should be fine.

Stupid is me having to pass emissions, think they'll care if I swap ecu's and injectors in the parking lot?
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Old 05-15-2010, 02:38 AM   #17
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I'd say drive it then, as long as your not being an asshat all the time you should be fine.
Ya, that is the problem. When i autox, i do drive like a hooligan. Mysterious oil leak aside, can this motor handle a couple autocross sessions?
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Old 05-15-2010, 02:40 AM   #18
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Originally Posted by hustler View Post
tell us about the oil restrictor for your journal bearing turbo. I don't know what size you need for a journal bearing turbo, but you probably need one. PM Jkav and post the answer.
JKav responded that he doesn't know...
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Old 05-15-2010, 08:57 AM   #19
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Ya, that is the problem. When i autox, i do drive like a hooligan. Mysterious oil leak aside, can this motor handle a couple autocross sessions?
I wouldn't, but 5-6 years ago I blew a couple bp's running at the ragged edge so I'm more cautious now.

Unless someone, who knows what their doing, can drive it and see the engine operate they are just giving an opinion. Even seeing it run it's an opinion (better than over the internet though), I don't think it's ever a good idea to beat on / drive an (shall we say) injured engine but it's your car.

Anyone you know that could take a look?
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Old 05-15-2010, 08:13 PM   #20
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what would be a good way to trace this oil leak?
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