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| PCV Mod | |
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| Tweet Topic Started: Feb 13 2009, 05:19 PM (5,912 Views) | |
| leaky | May 27 2009, 02:45 PM Post #16 |
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Leaky
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My 91 metro w/145k miles was blowing oil into the air cleaner,too.I made a baffle for inside the valve cover,out of ...a piece of aluninum rain downspout.It happens to fit inside the cover,and I cut it to where it goes down each side of the cam as far as the valve cover .It runs from the cam cap on the front of the head,to just past the one side of the oil fill cap.You can still see the cam with the oil cap off and the end of the new baffle.the clearance between the valve cover and cam caps is just enough to hold the baffle secure.Make sure to bend the sides of new baffle out towards valve cover,to prevent any baffle-cam lobe contact.200 + miles,no blowby reaching the air cleaner! |
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| redpepe | May 28 2009, 08:57 AM Post #17 |
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hi folks, the ongoing saga ... and there seem to be many threads where these issues are being considered. mine is a '91 just rebuilt 1.0. and i've been battling oil pharts from the installation .... never did it in 326k previously. yesterday i bypassed the pcv and drove 25 miles at 65mph. i only get the oil flow and emissions problems at that speed or above. the result was a catch can with 3/4 of a quart of oil in 25 miles! a friend and i did some more tests. we watched the clear hose as i ran the stationary engine at equivalent high rpm .... no oil flow from the valve cover. we raised the drive wheels and ran the engine and 'drove' at 65mph and above ...... no oil flow from the valve cover. we then added a long clear hose and ran it to the passenger seat where we held the catch can. when we got to 65mph on the freeway, the tube started to carry lots of oil out from the valve cover. this indicates to me 2 things .... the events are throttle / load related ..... and primarily, that the valve cover / baffle area is collecting too much oil. i think i've tested all the external possibilities for the problem and that leaves the head gasket and restrictor as probable causes. it could also be a really poor fit for the lifters or a bad cam carrier fit allowing inordinate oil flow but the rebuild observations make that unlikely. anticipating head removal ...... |
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| Robertwb70 | Jun 5 2009, 10:34 PM Post #18 |
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Advanced Member
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Sounds a lot like what my car is doing and I'm quite sure that it's worn valve guides on mine. |
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| Johnny Mullet | Jun 6 2009, 06:30 AM Post #19 |
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Fear the Mullet
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Some of these head gaskets like Apex have incorrectly cut holes for the oil return. This is what is causing your problem. |
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| redpepe | Jun 6 2009, 07:17 AM Post #20 |
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from my rebuild thread .... quick update on the rebuild. i replaced the new head gasket and 'check valve / restrictor' yesterday and there's significant improvement in the 'oil pharting'. some more miles may help the still significant blowby but at least the pooling of oil in the valve cover baffle seems to have lessened.even above 65mph the emission seems to be only collected oil vapors ... mixed with some water vapors from blowby i think. i opened the 2 upper gasket holes to match the porting. hope to post some photos soon. ---------------------------------------------------------------------- the improvement continues. i reattached the pcv to the air cleaner but still catch the vapors from the valve cover. they seem to be mostly water with some emulsified oil .... about a tablespoon or 2 for some hundreds of miles. changing / enlarging the holes in the head gasket seems to have been the initial solution for the oil clouds .... though it could have been replacing the check valve too. i'll observe the blowby for a while before reconnecting the valve cover to the pcv system. with the pcv blocked off i got 37 mpg. reconnecting it brought it back to mid 40s. will need to take it to the desert to see how the cooling system handles the heat and the ac load ..... and some hills. ---------------------------------------------------------------------- .... and the mileage builds on friday. it seems steady now. the catch can gets a few tablespoons of watery oil mix in a hundred miles. i think the pcv could easily handle that quantity when i hook it up again. a new head gasket with 2 enlarged upper oil return holes seems to be the fix for my engine. we ordered 4 new head gaskets to compare them and they were all cut the same. not sure why some folks using these new head gaskets for their rebuilds are not getting the same oil pharting symptoms? also still not sure why my original gasket worked fine for so many miles and was unmodified and cut the same as the new replacement gaskets? i'll be doing more compression and leakdown tests after more miles because i want to see if there's more ring 'seating' happening. the pcv collections and filtering systems are neat but the head gasket modification and replacement on the 3 cyl is worth the effort to remove the oil problem imho. Edited by redpepe, Jun 6 2009, 07:20 AM.
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| mwebb | Jun 8 2009, 11:34 PM Post #21 |
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FOG
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you can actually measure blowby pressure - a vacuum gauge on the oil dipstick will do it . try to find a specification .... VW / Audi claims a max of +.43psi for the 1.8 turbo engines when power braked at 1600 rpm is the max allowed , try that with a standard transmission ? or use a pressure transducer in the oil stick while under way. all pulses must be the same , sync to 2ndary spark, larger pulse values indicate cylinders with larger blowby values . |
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| redpepe | Jun 9 2009, 06:13 AM Post #22 |
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thanks mwebb. in frustration i was considering a dry sump and that might have been the oil return. curiosity will always get the best of me and i'll do a test when i get a chance. if i'm understanding correctly, one is actually measuring the rpm dependent, differential pressures between the blowby source and the escape through the pcv / air cleaner .... flow pressure. in considering this problem, i started thinking about how pcv capacity was designed. it's also a controlled vacuum 'leak' which has substantial impact on performance. there's so little restriction for the blowby that to build even .5 psi would intuitively indicate a huge flow. in one of the tests we could feel some steady pulses and a small flow when we had the long clear hose attached to the valve cover at speed. update ... i switched back to rotella 15-40 and some 20-50 .... and now the catch can appears just about dry. at a bit over 1000miles, i'm thinking i still have some 'break in' to go. |
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| mwebb | Jun 9 2009, 09:28 PM Post #23 |
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FOG
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"..... if i'm understanding correctly, one is actually measuring the rpm dependent, differential pressures between the blowby source and the escape through the pcv / air cleaner .... flow pressure. in considering this problem, i started thinking about how pcv capacity was designed. it's also a controlled vacuum 'leak' which has substantial impact on performance. there's so little restriction for the blowby that to build even .5 psi would intuitively indicate a huge flow. in one of the tests we could feel some steady pulses and a small flow when we had the long clear hose attached to the valve cover at speed. ..... ============================================== yes the value may increase with rpm but if there is a problem , it will increase more under load - you can actually measure blowby pressure per cylinder using pressure transducers on the oil stick . the value should be zero , it never is , but all pulses should be the same . i have some images from a corrola with frozen rings due to lack of oil changes |
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| Woodie | Jun 10 2009, 06:29 AM Post #24 |
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With that oil you won't have oil pharts very long, the exhaust valves will be done in 10K miles or so. The recommended oil for Suzuki G engines is 5W-30 anywhere, anytime. 10W-30 is okay IF the temperature never goes below freezing, but 5W-30 is preferred. They originally said that 10W-40 was okay but later decided that it was too thick and caused burned valves. You're talking about something much thicker than that. Get rid of it. |
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| redpepe | Jun 10 2009, 07:20 AM Post #25 |
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right mwebb ...... when we tried to get the oil blast in a stationary run up test we couldn't ..... even when using the brakes as a 'dyno'. it took the loads of actual driving to duplicate the load and throttle openings / flows. my tractor pulling buddy would have the entire metro wired with transducers everywhere if i didn't have better? things to do. i think i'll put a special plate and grommet in the firewall for test lines and instrumentation. thanks woodie. i was using the rotella for the initial break in and returned to the 5-30 that i usually use to see if it changed the oil plumes ..... which it did not change. as my engine had aged, maybe after 250k, i'd started using heavier oil and it did well enough for the last 75k. i'll use it for a while and watch the emissions and any further changes. i'll probably try synthetic eventually, but the normal 5-30 worked just fine and i plan to return sometime in the next quick changes. btw .... that tractor puller is also a diy pilot and we considered breaking in on pure mineral oil. not enough time to do all the experiments. Edited by redpepe, Jun 10 2009, 07:26 AM.
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| Dallas | Jun 10 2009, 10:41 AM Post #26 |
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im currently on 20weight full synthetic on mine. at idle I get as low as 9-10psi oil pressure when hot (still like 40 when cold though) with 30 weight id have 15psi at idle, and ive never used anything thicker than that. I dont leak or burn a drop though, so maybe its different since my motor is brand new. on my tired 3banger I was using 40weight dino oil and it slowed the oil consumption. I wouldnt go higher than 40 though, thats already twice as thick as what ive got now |
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| Dallas | Jun 10 2009, 10:43 AM Post #27 |
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also, you should plug the ports on the intake that suck the pcv fumes in, and ditch the pcv and run your breather to a catch can then open air, or just run a hose to the ground off the valve cover... lol thats how mine is now, but I puke zero oil, so it depends. id use a catch can and of the two nipples that should be on there, one will be fed from valve cover, the other one would have a valve cover breather filter thing on it. I used that exact setup for a while before, then I just removed it and put it to the ground |
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| redpepe | Jun 11 2009, 06:30 AM Post #28 |
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thanks fyredaug, the modified head gasket replacement has cured the oil pharts on the new engine. i'm still running the catch can but have the pcv hooked to the air clnr / thrtl bdy intake as normal. switching to the heavy oil has reduced the 'catch' to a very small amount of water vapor and i will reattach the valve cover port soon. i can actually smell the uncollected emissions .... oil vapor contained in the water vapor while idling at stop lights! my car never burned more than half a quart between changes in 326k. |
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| hotrodfeguy | Jan 26 2010, 11:05 PM Post #29 |
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Elite Member
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This is awesome, thats my car :0) Yea I did that cause I was getting serious oil up through the VC. By flipping the tube it allowed the PCV side to suck away the fumes and not the oil. It did work but then after about another 60K i pulled the cover and found it was going right past the baffle. Pulled out the baffle and filled it up with Steel wool and drilled and tapped the baffle back on. Still controlling the oil puke. I think its just alot of blowby. When I first bought the car a was getting 60 now she is down to about 52-55MPG I am at about 200K now on stock engine. This is a awesome forum and learning even more.
Edited by hotrodfeguy, Jan 26 2010, 11:09 PM.
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| starscream5000 | Jan 27 2010, 12:38 AM Post #30 |
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Got 70 MPG?
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Guys, why aren't you hooking the second port to your catch cans back up to the intake manifolds where the PCV valve is? This is how a proper PCV system is supposed to be setup. Those of you who are just slapping on an air breather meant for a valve cover are doing it wrong and you'll end up damaging your motor in the long run. You need the vacuum generated from the running engine so you can suck the oil vapor out of the valve cover and the bottom end of the motor (the crankshaft case, thus meaning of positive crankcase ventalation). If the vacuum is not applied, you will have excessive windage and you can build up pressure in your crankshaft case, which will take the route of least resistance (front and rear mains, and/or camshaft oil seals). To do it right you'll need to do this: New hose going from valve cover to catch can inlet. (A baffled catch can is preferable) New hose from catch can outlet towards the throttle body injection hat and pcv valve. A tee going into the end of the new hose that just came from the catch can outlet. One short piece of new hose going from the tee to the TBI hat. (where the factory PCV hose went to) One short piece of smaller hose from open end of tee into a NEW PCV valve. (You can find this special sized tee at autozone) That's it, fairly simple and effective. You'll get the vacuum needed for the crankcase, and you'll never have worry about oil vapors getting back into your intake and motor, causing even more carbon buildup issues. (Assuming you baffled the catch can and dump it before it gets full) Edited by starscream5000, Jan 27 2010, 12:42 AM.
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