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Sedans Nissan Altima Nissan Altima Engine Failures
497 messages, Last post on Nov 21, 2009 at 8:01 PM
You are in the Nissan Altima Forum. Your Hosts are pat & karens
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Replying to: laura19 (Jan 30, 2008 12:25 pm) "Initially, plug 3 was oil fowled due to a minor leak through the valve cover gasket". I am not aware of any way that a valve cover gasket leaking could allow oil to get into any cylinder or combustion chamber. They are simply not related. I assume the mechanic just switched the ignition coils between cylinders #3 & #4 and the same problem occured? The problem may be the primary circuit feeding the coil, which comes from the computer. It could be the connector is bad, or the wiring is bad, or an input to the computer is bad, or the computer could be bad, in that order. HOWEVER, I would be sure to test the output of each coil first, just like I said in my previous messege. If the coil is putting out a weak spark, whether it is the coil, wiring, or computer, it will show up in the coil output voltage test. You can compare the relative voltage output of each coil by the maximum length of the spark it makes. Here is how I do it.: To test the coil output voltage, you test one coil at a time. The engine is going to run on 3 cylinders while you test the fourth coil. Remove the small bolt that holds the coil in place. Unplug the connector from the coil and pull the coil up off the spark plug and out of the valve cover. Plug the coil back into the connector. Place a good insulator under the coil to hold it up off the engine (like a dry block of wood). Make sure the coil has the long boot on it that goes down to the spark plug. Get a good flexible test wire with an alligator clip on each end. securely fasten one alligator clip to a GOOD Ground in the engine compartment. Be sure that it won't come off. If it comes off while you are doing this test, you will recieve a tremendous shock! So be sure it stays on. At the bottom of the coil boot, insert a piece of wire or rod or screw that when in place will connect to the metal inside the boot and act as a conductor protruding a short distance out the end of the boot. Clip the other end of the alligator clip test wire to this metal. When all set, have an assistant start the car, keep yourself and wires away from moving parts. The motor will run a little rough since it is running on 3 cylinders. Carefully loosen the alligator clip from the metal protruding from the coil boot, and slowly withdraw the alligator clip away from the metal. It will draw an arc, should be bluish-white with some some tinges of red or orange color. Continue to slowly draw the arc longer and longer, noting how long it is before the arc starts to fail. Measure with a WOOD ruler if you need to. Clip the aligator clip back on the metal and have the assistant shut off the engine. Write down the arc length and cyinder number. Remove the test wire and metal and assemble the coil and plug back into the original correct position and install the small coil bolt. Do this same procedure on the other coils and compare the arc lengths. The longer the length, the higher the voltage. they should all be about the same are length. Any coils found with short arc lengths should be investigated for weak coils or problems in the primary circuit. What's this about a remote starter? I had not heard you mention that before. Did your engine have all the sensor recalls done to it? Good Luck, E.D. in Sunny Florida |
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The car has almost 106,000 miles on it. It is burning all five quarts within driving 200-300 miles. I've never seen anything like it before. When I changed the pcv valve there was no noticeable blowby, but I will double check by pulling off the pcv hose and vent hose. When you say vent hose, are you talking about the other hose on the valve cover? I haven't checked the compression yet either. My intentions are to rebuild if possible or to buy another engine, but in doing this should we expect the same problems in the next 100,000 miles. Has Nissan done anything about the top cat, or should we all expect it to malfunction again. If not, it seems a fresh rebuild or new engine would be a complete waste of time and money.
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Replying to: southerncomf (Jan 31, 2008 6:08 am) The crankcase vent hose (the hose that carries clean intake air into the engine crankcase) on the drivers side end of the valve cover, is shown in photos #07364, 07365 & 07366. Remove the spring clamp as shown, and pull the hose loose from the valve cover. You might have to take the other end of the hose loose, to get enough slack to pull it off the valve cover. The PVC suction hose (the hose that carries the dirty air, fumes or smoke from the engine crankcase to the intake plenium) connects on the back of the valve cover, is shown in photo #06958, you loosen that spring clamp and pull that line off the backside of the valve cover. When you pull the hose off, the hose should have suction when you start the engine, plug the hose. Look to see if any smoke comes out where you unplugged the hose from the valve cover. Having both hoses disconnected will expose the crankcase to atmospheric pressure, and it any smoke or pressure is created by blowby, it will come out one or both of the openings. A very small amount of blowby is acceptable, but a large amount is not. Having someone rev the engine may increase the smoke, if any is visible. If you do get a lot of blowby gas coming out the valve cover opening, it is an indicator that the piston rings are worn out, but confirm with a compression test. You can also do a vacuum test, but the clyinder compression test give more reliable results. I would not tear into or rebuild the engine without making a thorough diagnosis first, to be sure of what is wrong with it. If you are going to rebuild the engine, you will have to remove the engine from the car. It may be best to buy a remanufactured engine and put one in. A remanufactured engine from Jasper Engines with a 3 year warrenty is $3,411.00. You said "My intentions are to rebuild if possible or to buy another engine, but in doing this should we expect the same problems in the next 100,000 miles. Has Nissan done anything about the top cat, or should we all expect it to malfunction again. If not, it seems a fresh rebuild or new engine would be a complete waste of time and money", and you are right, you will have the same problems again, because the problem is NOT the engine, the engine is a fairly good engine, The problem IS the PRE CATALYIC CONVERTER failing and contaminating and destroying a perfectly good engine. Nissan has not done anything about the pre-cat as far as I know. Listen closely, read all the messeges in this forum so that you know what is going on. If you are really looking at spending that much money and that much inconvenience, it is certainly worth doing a days worth of research so that you can avoid this problem in the future. I gave you the solution in messege #190, read the BOLD TEXT again, and this time read between the lines. The catalytic convertors are required by law, so I can't legally tell you to change, alter or modify them. I can only tell you what I did. What you do is up to you. But I have permanently solved the catalytic converter problem on my daughters 2002 Nissan Altima 2.5S. It is running perfectly fine now. She has drove it about 1500 miles since I put the engine back together, and it is smooth as silk, no smoke, not using hardly any oil (she said the oil was barely down from full on the stick). Also, it is important to go back and read messege #75, and pay special attention to the part that says: "When I felt the 2nd catalytic converter, it was still cold, even after the engine ran for several minutes. That means it was plugged up! I unbolted the pipe and 2nd catalytic converter and took it off and unplugged it, put it back on, and the car ran perfect again." I fixed the converters, and I don't expect to have any converter problems or oil burning problems with it. Her converter problems were not as bad as yours, and I caught the problem in time BEFORE it destroyed the engine. Her car was starting to use about 1 quart in 1500 miles, but now it seems a lot better, will know by next oil change. I was fortunate that the Cat Plugged up the exhaust system, which brought the problem to my attention. I then unplugged the cats and the problem is gone. The reason her engine had to come apart was because the head warped and the head gasket began to leak. I removed the head, did a valve job on the head, milled the head flat, put on a new head gasket and put it back together. Take a look at the pictures of the pre-cat, photos # 06930, 06931,06932, 06933 & 06934. The inside of the pre-cat are gone, they blew down the exhaust pipe to the second cat and plugged it up. She is taking the 2002 Altima 2.5S on a 400 mile trip tomorrow, mostly interstate driving, so I will see how it did when she gets back. The following link is to the album on the photo site that has the photos of how the cat (second cat, the one under the car right before the muffler) was unplugged: http://www2.snapfish.com/thumbnailshare/AlbumID=215914481/a=85874609_85874609/t_- =85874609 Photo #06065 shows the the second cat, the one under the car, the one that plugged up. Photo 06064 shows it in front of the muffler. Photos 06068 & 06069 show a lot of water draining out of the muffler, it was FULL of water because barely any exhaust gas went through the converter, and what little did condensed into water in the muffler, because the muffler never warmed up. Photo 06082 shows a close up of the second cat off the car. Photo 06087 shows the inside of the second cat before it was unplugged. Photos 06096 & 06097 show the stuff that came out of the cat when it was unplugged. Photos 06098, 06099 & 06100 show the inside of the second cat after it was unplugged. I have gone into a lot of detail in explaining these problems, because in this open forum setting, many others will read these messeges and hopefully many will benefit from them. Good Luck, E.D. in Sunny Florida |
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Replying to: electricdesign (Jan 31, 2008 7:12 pm) 
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Replying to: pat (Feb 01, 2008 4:54 am)
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Replying to: mpd2434 (Feb 01, 2008 4:54 pm) If I were you, I wouldn't worry about it. Though the problem does exist, its not affecting anywhere near a majority of altima's. The chances of lightning striking twice would seem pretty rare to me. but, if your not comfortable with it, I'd sell now rather than waiting. |
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Replying to: kannadiga (Jan 11, 2008 8:46 am)
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Replying to: powerfulbag (Feb 02, 2008 11:48 am) |
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Replying to: southerncomf (Jan 31, 2008 6:08 am) |
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Replying to: pure_hp (Feb 11, 2008 8:20 pm) I also am somewhat anxious about some of the posts written here but of the millions of Nissans on the road, I think it is worth the gamble to buy the vehicle. We are reading about such a small cross section of Nissan owners that the number may well be well under .01%. The car drives great, fuel economy promises to be very good, the seven year warranty we purchased should pick up most of the problems, and you will look good in the car. Check out all the threads involving the Altima and then go look at them at the dealers with any questions you have. Also check out the reviews on the 2008 Altima just to the right on this page. Lots of info there. Hope this helps and good luck in whatever you purchase.
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