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Jwbmo replied to johnmh's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)Please! Would love to see photos. Thanks
Jwbmo replied to johnmh's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)I am curious, did you two guys by any chance get coolant in oil, but no oil in coolant? Also where and how big was the crack/cracks? Thanks
Jwbmo replied to 1999911's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)I bet it's a cracked head if no oil in coolant.
Well I have just completed a major project. I have installed the LN dual race IMS, RMS, AOS, flywheel and clutch. It was a big job but doable.
If you go with the LN bearing, the tool kit and instructions make that part of the job relatively straight forward.
I am selling the toolkit if you are interested. This is my thinking... The toolkit is expensive. I paid $350. I would like to sell it for $300. I am happy to pay $50 for the one time use of the tool and then the next person can sell it for $250 if they like and so on.
Best wishes. Let me know. Cheers Rick
Jwbmo replied to Chicagospeed996's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)2016-04-22 14.12.16.mov While I am in diagnosing a cracked head I changed out my rear mounts. Easy job, but glad I did -- '99 - 84000 miles and had developed a slight vibration right at idle - would go away slightly off idle - I hope this cures it. Video - new on left - completely shot on the right!
Thanks Ahsai! The more pictures of cracks I look at, I can envision a crack from a water jacket dumping coolant into the valve cover/oil. So my cylinder leak down might have been good, but I got the coolant stream from the exhaust this time either because I had the coolant test pressure high enough or I had the spark plugs out and coolant found its way into the cylinder through the open plug hole and exhaust from the crack. None of the spark plugs seemed steam cleaned on that bank, but next time I drive back over to work on it, I will pressurize coolant again and borescope those cylinders to possibly locate before disassembling. I feel better after seeing that link, knowing if only a head crack I have good options for repair and might not need to split the bottom end. I have been confident with the completely clean oil/filter changes and that the coolant has been completely oil free. Hopefully the water/oil milkshake that I drained out pretty quick has not allowed any corrosion damage on internals. I certainly will do an RMS and IMS along with clutch etc. while in there. I still cannot imagine how that clean coolant made its way into the intake plenum!!!
The infamous cracked head .....Finally got all the cooling system repairs finished up (new AOS, oil cooler, water pump, L & N low temp thermostat, multiple hoses, new plastic hose connectors) and pressure checked. All waterpump vanes were intact on an original pump with 85K+ ---- all looked good with a minimal leak down as I tightened up a few connections. Re pressurized to 20 and left it for 15 minutes. Came back to see a nice small stream running out of the right bank exhaust. Must be a small crack that I could not detect with the cylinder leak down test that I did with the cold engine. There was a slight leak down on one cylinder on the right bank through the exhaust. I wrongly assumed a slight valve leak or ? I still have no clue what was allowing my original cooling pressure check to be unreadable with a large loss. Anyone have any idea how clean coolant was pushed up into the intake plenum by a head crack leaking out the exhaust? The old AOS pressure checked fine. After all the PITA work with engine in -- out it comes and due to the cost versus value issue of a '99 model - this will become another long term project that I will have to learn to rebuild over the next winter myself I guess.
Thank you JFP and Ahsai. JFP -yes, before disassembling, I tried vacuum and pressure on the cooling system. It would not hold anything and blew out so fast with my little pancake compressor, I could not get a read or location at all. Now that I know where hoses go, I should have isolated the AOS and pressure tested system again. I also should have refilled system with some dye, as I was just trying to listen for the air leak location. I falsely assumed it was the AOS after seeing the puddle of coolant in the plenum and disassembled all. I did pressurize the AOS finally up to 60 PSI - no leaks -- however, after reading your post Ahsai, I did not reverse the pressure - but I am not sure that would be a factor if it is a simple diaphragm. I have not built up a good pressure test for the cooler yet except for a simple vacuum test that it passed, but I will. I will finish up everything and pressure test coolant system before I start it and while I still have the oil pan off. Thanks again.
How disheartening! I finally got time to remove the oil cooler and it checks out too! I can see no evidence of leakage between the o rings either. Does any one have any other ideas before I button up the top with new AOS, starter, oil cooler, many hoses, waterpump and cooler thermostat and just try it again before I remove the engine and send it off or salvage the car? Please see my post earlier - large dump of coolant in oil after a fresh oil change still on jacks! - NO oil in coolant --- AOS and cooler hold vacuum, cylinder leak down tests were great - slight leakage on two-one exhaust and one intake. The intake plenums had lots of clean coolant in them when disassembled - the coolant was clean even in the oil cooler that I just removed - oil was the same chocolate milkshake. I might need to put a lot more vacuum or pressure on the cooler and AOS to test properly. Only thing I can think of is my leak down tests were done with engine cold and I know cracks can open up when warm, but this fast coolant in oil dump had to have a big leak! My cooler was obviously tested cold too. So, do I have some internal case crack? Not associated with the cylinders? Thank you for your help - this is so baffling.
The AOS replacement will be a slow process with limited time, but I guess this photo inside the plenum after throttle body removal confirms the AOS dumped coolant instead of a cracked head or bad head gasket (along with the previous leakdown test). In the future with a potential AOS failure or coolant in the oil, this would be one of the first easy things I look for: pop open the throttle body and look for coolant in the plenum. So the AOS not only dumps lots of coolant into the crankcase, but also sucks it into the engine plenum. Sure would like to eliminate this from happening in the future. What problems would occur by not allowing the coolant flow through the AOS? Not a fun thing to see......
Good point! Thanks!
DBJoe996 and JFP in PA Thank you very much for the quick replies! This has been driving me nuts and very glad to confirm my AOS thoughts especially due to the volume of coolant and no opposing pressure. I was ruling out the cooler as I always thought it would create an oil in coolant or a combination with the pressure differential. I am pretty sure the AOS is original - at 17 years old, this should be a time replacement item - not for the potential AO separation failure, but for this coolant issue! Very lucky it failed where I caught it in the shop. Imagine if it slowly dumped coolant in on a long trip where it might not get noticed - water in oil for 1000 miles? I will report back with results - I will be changing out water pump, a cooler thermostat, a few choice coolant hoses, fresh coolant etc. while I am in there and flushing system with fresh oil for a short run and then fresh oil change. Thanks again!
Ok, I have spent countless hours studying this issue on multiple web sites and books trying to figure out my new coolant in oil problem. Yes, I understand it is probably my worst fear, but this occurred in such odd circumstances. 1999 C2 -87,000 mile - oil changes every 3000-4000 with Joe Gibbs oil (since 45,000 mile purchase) - I pull the oil sump off every other oil change and look around (IMS fears), inspect the filter in detail every change - always perfectly clean - almost too clean! I had the vehicle up on jacks doing other work, completed an oil/filter change - ran it on the jacks for 3-5 minutes, topped the oil off and then left the vehicle there for about 2 months while I was out of town. Came back, started car, moderate miss in one cylinder and smoke out the pipe, but it was quickly clearing up (smoke and miss) as it started to warm. Shut off, pulled vehicle off of jacks, checked oil - noticed an 1/8" high to what I know was an exact fill (jacks and ground level) Thinking I must have screwed up on fill 2 months back, I reset the mis code and restarted. Mis and smoke very light and almost gone, it did pull a mis code- let it warm up for 5 minutes - mis and smoke gone now and shut down. Checked oil - 1/2" or more high, checked coolant - yes - low and also got the coolant low light. Obviously expecting the worse case scenario, even though the vehicle was only run a very short time without load on both occasions. Performed vacuum leak check on coolant tank, it leaked so bad/fast, I could not get any location indications. Drained fresh, but now chocolate milk oil and pulled sump to look around. Drained coolant and NO evidence of oil mix! I had to leave car for a month, but got back and performed a leakdown test. 1 and 6 had a 25% leakage (still in green), but clearly one was exhaust and one intake. 2,3,4,5 were tight, virtually no leakdown. Engine was cold, so not the best test. I am totally confused. This engine dumped one to two quarts of coolant in oil in those three short 3-5 minute no load runs and yet my leakdown test seems to show no cracked head, D chunking, etc. (unless the crack did not reopen with the cold engine). Before I tear into things, is it possible that the oil cooler could do this one way leak? I understand the oil vs. coolant pressure difference. Or in all my reading, I still cannot determine if there are coolant lines on the top AOS where a diaphram might let go on this model. Could I be that lucky? I doubt it, but what am I missing here guys? Any experienced thoughts? My next call will be to Raby I guess. Thanks, Jim
Jwbmo replied to Deftones1's topic in 996 Series (Carrera, Carrera 4, Carrera 4S, Targa)53, DITTO - being accused of midlife crisis