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#31 | |||
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#32 |
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Super User
Join Date: Oct 2006
Location: Orange, Cal
Posts: 7,225
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I don't see the benefit of more than about a teaspoon of atf or whatever penetrating oil. I tend to use Marvel Mystery oil for that sort of thing, at least it smells nice.
Running funny and dying doesn't sound like low compression, so multiple things are wrong. |
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#33 | |
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Rennlist Small Business Partner Join Date: Mar 2005
Location: Anaheim
Posts: 4,352
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Quote:
It had a similar issue that you are describing. The car suddenly would not start and had terrible compression. If they added oil into the combustion chambers, it ran, but only at higher rpms. smoked like crazy. It would die and not restart unless more oil was added into the combustion chambers. I took it apart and something had turned the normally "hard" carbon/oil that collects in the rings soft and gummy. Super sticky gummy. The rings were stuck at the bottom of all the ring lands and most didn't even touch the cylinders. I cleaned everything up, bought new rings and put it back together. No problems. I've thought about that car, over the years, wondering if something would have "removed" that gummy crap with the engine together...never have figured it out, but I'd sure as hell try, if it was my engine. The downside to running an Alusil engine without the rings contacting the bores is that the pistons are going to contact the bores a hell a lot more than they normally do...until the rings free up. This could screw up the bores. I'd quit running it. until I tried something to "loosen up" the rings. Here's what I'd try... Fill the entire engine with diesel fuel...which is a pretty good solvent and pretty cheap. When I say fill...I mean fill. I'd want to see the pistons completely "floating" in diesel fuel. Obviously, remove the plugs and fill the cylinders. Fill the crankcase. Remove one of the cam carrier plugs (from each side) and fill it completely full, with a funnel. Let it sit. Turn it over, by hand, after a couple of days. Sure, some diesel fuel is going to come out of the spark plug holes...but you can refill it after you are done turning it over. Keep doing this, for a week or two. Then drain it, put oil in it, crank it over with the plugs out. Put the plugs in and try running it. I'd plan on changing the oil again, fairly quickly, if this works. |
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#34 |
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Rennlist Member Join Date: Oct 2009
Location: Alberta, Canada
Posts: 2,469
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There may be other problems as others have suggested, I have not followed along fully and do not know your car and assume you have done proper diagnoses.
If it has been sitting a long time, filling the cylinders and allowing lots of trans oil to soak past the rings may help loosen any corrosion. Running it with no load at 2g to get everything good and hot will help the rings relax if there is any life left in them. Remember some of the pistons would have been at the top of the cylinders where it is smaller and the rings would have been compressed, over that period that it did not run. This is why it is always good to roll the engine over every few months I would not let my engine bearings sit in diesel fuel and any o-rings that the diesel soaks into will destroy them.
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89 928 Left hand drive brought in from Japan vin#WPOZZZ92ZKS842476 Cat delete, tec-4GT engine management, mild porting and gasket matched to intake. RMB in 2012 and sounds awesome Brads Photo-bucket pictures Tire Smoke Video Brad W. Haugen 928OC Alberta Chapter http://forums.928oc.org |
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#35 |
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User
Join Date: Jan 2009
Location: Adelaide South Australia'79 5spd twin turbo
Posts: 249
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Greetings all
Brad ang Greg are on the right track, I believe. I had an experience with a 302 windsor years ago that had sat for a very long time. The pistons that were at the bottom of the bore that were not soaked in sump oil ( engine had no flywheel or flex plate on it and the sump bulge was at the front so the rear pistons at the bottom of the bores were fine) those at the front that had sat at the bottom of the bore had little compression pressure due to the rings being stuck in the ring grooves. This engine started and ran but not on 8, it didn't pick up the other cylinders with use, and we pulled it down and put a set of rings in it. If this is the presumed scenario then I would opt to soak the offending cylinders in Auto trans fluid, as Brad has suggested. For some reason Auto trans fluid does seem to clean things in this situation, some diesel operators swear that a little in the fuel tank keeps injectors clean? Best Wishes Gunar, you have put a power of work into that car and we all are hoping that you get your just rewards in due course. Cheers Roy |
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#36 |
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Rennlist Member Join Date: Oct 2004
Location: Atlanta
Posts: 1,334
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just recenlty, i put a 3.4L 996 engine into my boxster. the engine hadn't been started in 8 years. i added a bit of oil to the cylinders & rotated the motor by hand a lot during a minor refresh (seals, IMS bearing, etc). i did a compression check & it was terrible. my working theory was that some crap in the engine formed over the years that prevented the valves from seating properly.
at any rate, when i started it, TONS of smoke, wouldn't really rev, wouldn't idle right, sounded like total crap. i worked on diagnosis, but ultimately, the problem solved itself. after maybe 25min of run time, the idle smoothed out and it started to rev nicely. i've since put 1000 miles on it & it keeps getting stronger and stronger. for those who are interested, here is an oil analysis from blackstone. the right column shows the oil that sat in the engine for 8yrs. the left column shows my 1000 mile 'break-in' oil that i used to wash out all the crap. my next oil change should show normal.
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#37 |
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Rennlist Member Rennlist Site Sponsor Join Date: Jun 2001
Location: Acworth, GA
Posts: 5,691
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Time for a "Hail Mary".
In your situation, I would definitely not tear the engine down until I had exhausted all other approaches. While each of us has his/her own favorite "mouse milk" miracle approaches, and most of the approaches that have been suggested have some chance of helping, I prefer to start simple, cheap and easy, and escalate as necessary. There appears to be some chance that the rings may be stuck. It seems to be worth trying some non-destructive chemical approaches. My choice of approaches would be to put two quarts of Rislone (not sealer, but just the standard old solvent) in the crankcase and run the engine until warm, let it cool, run until warm, let it cool, and repeat as long as your patience holds out. The next step would be to try GM Top Engine Cleaner. This is basically butyl cellosolve (a powerful solvent, but not one that is "hot" or aggressive like MEK or lacquer thinner) that is added thru the intake of a warm, running engine. I would not put it thru a hot-wire MAF sensor! Follow the directions exactly. Warning - this will generate clouds of very pungent, very visible smoke. If neither of these helped noticeably, I might try Greg's approach. One final suggestion - I would adjust the idle speed or block the throttle so that I didn't have to hold the throttle open and risk it dying.
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Wally Plumley 928 SPECIALISTS ONLINE STORE 30,000+ Parts Online! Search for 928 Parts by Your Model Type! 928 OC Charter Member |
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#38 | |
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Rest in Peace
Rennlist Member Join Date: May 2006
Location: Bird lover in Sharpsburg
Posts: 9,942
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Quote:
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87 928S4, needs work and money, lots of money. 928 forums resident racist (ricist). Greg at Greg's Garage Sharpsburg Georgia |
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#39 |
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Super User
Join Date: Jul 2001
Location: New York
Posts: 4,728
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#40 |
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Rest in Peace
Rennlist Member Join Date: May 2006
Location: Bird lover in Sharpsburg
Posts: 9,942
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Or bearings, or that the tops of a cylinder were smaller.
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87 928S4, needs work and money, lots of money. 928 forums resident racist (ricist). Greg at Greg's Garage Sharpsburg Georgia |
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#41 |
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Rennlist Member Rennlist Site Sponsor Join Date: Jun 2001
Location: Acworth, GA
Posts: 5,691
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I have seen engines where the bottom of the cylinder was smaller...
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Wally Plumley 928 SPECIALISTS ONLINE STORE 30,000+ Parts Online! Search for 928 Parts by Your Model Type! 928 OC Charter Member |
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#42 |
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Super User
Join Date: Jun 2003
Location: southern new england
Posts: 2,404
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bit of oil, diesel fuel, rislone, Rislone Compression Repair with Ring Seal, some non-synthetic oil, GM Top Engine Cleaner, dexron, Auto trans fluid, and marvel mystery oil are most of the suggestions for inserting into the cylinders from above to help loosen the piston rings.
Would it be possible to pick 1 winner from these for all engine sitting situations to avoid Greg's "Super sticky gummy" mess? It would have to be one of the above that lubricates, dissolves crap, and burns off or makes it's way into the sump leaving no residue. |
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#43 |
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Rest in Peace
Rennlist Member Join Date: May 2006
Location: Bird lover in Sharpsburg
Posts: 9,942
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After they have been ran, yea.
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87 928S4, needs work and money, lots of money. 928 forums resident racist (ricist). Greg at Greg's Garage Sharpsburg Georgia |
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#44 |
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User
Join Date: Nov 2008
Location: Arlington Texas
Posts: 1,424
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On post #10 there seems to be some kind of water and soap solution seating in the valve reliefs on the piston crown. What did you use to clean the pistons?
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#45 |
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| Tags |
| 8years, 928, engine, fix, gm, loosen, piston, rings, rislone, seating, starting, stuck, top, washed, water |
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