need help diagnosing power loss issue.
03-14-2014, 10:33 AM
#81
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Posts: 290
Its good to hear there's life returning to your car. I tend to be a bit wary of aggressive internal engine cleaners. They may do alot of cleaning now, but in the long term they may do more harm than good. For example seafoam is an alcohol based cleanser. internal parts of your car, like the intake manifold, are coated with a plastic film to reduce the buildup of carbon inside the car. Seafoam may have cleaned everything AND washed that film away. So your car which is clean now, may build up carbon more quickly in the internal parts now.
Here's one raging discussion about it;
http://www.bobistheoilguy.com/forums...pics/1870422/1
Arguments on both sides with no clear winner. Who knows
I prefer to err on the side of caution. I intend to be one of those guys with 400K or more miles on my original motor. Instead of seafoam, I would look into TCW3. It does all that seafoam does but it's a harmless oil, and you put in so little;
http://forums.maxima.org/fluids-lubr...itive-new.html
As for the dirty debris in your fuel, keep in mind that the fule filter has a sock on it. After that first filter, the fuel passes thru the fuel filter in the engine bay, then it finally reaches the injectors. I don't think that much dirt is getting through, but hey
Here's one raging discussion about it;
http://www.bobistheoilguy.com/forums...pics/1870422/1
Arguments on both sides with no clear winner. Who knows
I prefer to err on the side of caution. I intend to be one of those guys with 400K or more miles on my original motor. Instead of seafoam, I would look into TCW3. It does all that seafoam does but it's a harmless oil, and you put in so little;
http://forums.maxima.org/fluids-lubr...itive-new.html
As for the dirty debris in your fuel, keep in mind that the fule filter has a sock on it. After that first filter, the fuel passes thru the fuel filter in the engine bay, then it finally reaches the injectors. I don't think that much dirt is getting through, but hey
I honestly don't think that much dirt/rust was making past the filters. Maybe it was moisture. When I changed the fuel filter rusty gas came out the bottom of the filter the gas in the rail looked clean. But IMHO It only takes a tiny bit of debris to mess up an injectors spray pattern
03-14-2014, 10:36 AM
#82
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03-24-2014, 05:52 PM
#83
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OK I know I've said this before but I'm sure now. The problem is mostly because of my MAF and or wiring. Dennis's guess was right, it just took time for the maf to show signs of a true bad maf. The can is occasionally stalling now, sometimes I can't Rev above 2k rpm. And its running really rich now. When I wiggle the connector it will cause the car to run rough, stall, or Rev up. So I need some help with testing the harness and grounds to make sure its not a wiring issue, before I go buy a new maf.
03-25-2014, 11:59 AM
#84
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OK well I had a bad ground on my MAF so I added a new one and the car.ran much better. But wasn't perfect. So I tapped on the maf while the car was running and it shut right off. Mystery solved the MAF is bad. So I guess its time to shop for a good used MAF.
03-27-2014, 12:59 PM
#87
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Join Date: Apr 2006
Location: Oakland, CA
Posts: 704
There's a thread on here somewhere about going into the MAF and re-soldering a few connections. It worked for me. I thought I saved the link but I can't find it now.
03-27-2014, 01:36 PM
#88
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Join Date: Jan 2011
Location: Central AR
Posts: 3,041
Dwapenyi's advice below is about as good as it gets. I'm on my 3rd DSC4. I usually buy them with 150,000 miles. The previous owner was selling the car due to lost performance, poor mileage, and a couple of CEL codes like KS and O2. Steps that always cause a used DSC4 to spring back to good performance.
1) Replace Lazy Upstream O2 sensors -- they start to get lazy over 100,000 miles.
2) FPR - another maintenance item to be replaced over 100,000 miles.
3) Clean the MAF -- which you have done. It appears you need a replacement.. I get mine from salvage yards for about $30 each. I keep a couple of spares (that I test as soon as I get) on hand for when I need one.
4) New filters.
5) Premium Fuel.
Surprisingly the KS code will disappear after I replace the lazy O2 sensors.. At some point in the future I usually replace the KS with a SMP or BWD brand I get from eBay for a sweet deal.. Replacing lazy O2 sensors has always made the best performance improvement.
1) Replace Lazy Upstream O2 sensors -- they start to get lazy over 100,000 miles.
2) FPR - another maintenance item to be replaced over 100,000 miles.
3) Clean the MAF -- which you have done. It appears you need a replacement.. I get mine from salvage yards for about $30 each. I keep a couple of spares (that I test as soon as I get) on hand for when I need one.
4) New filters.
5) Premium Fuel.
Surprisingly the KS code will disappear after I replace the lazy O2 sensors.. At some point in the future I usually replace the KS with a SMP or BWD brand I get from eBay for a sweet deal.. Replacing lazy O2 sensors has always made the best performance improvement.
Tired O2s are not dead O2s. Tired O2s dont throw codes and you will get readings that look OK from them. When the O2s are working properly, they rapidly change readings. Tired O2s are slower to respond to changes......your car winds up feeling sluggish because of it. Again, tired O2s dont give codes. If you know that the primary O2s on your car are more than 5 years old, you should change them. You can replace just 1, the front primary. I did that on my car and my friends 99 I30. Both cars noticed a liveliness that had gone missing before.
You will find that coils are bit of a vague science. Its good that your CEL told u cylinder 5. Just replace that one. Other times, however, you may a find a coil that is kinda sortof bad. It works fine when cold but acts up when warm or hot. Only thing you can do is replace one at a time with some used OEM ones until your car acts better. The tests u will run will be inconclusive unfortunately. Been there done that
I would replace the fpr too. Chances are your car has oem from factory. How does the car start? When u turn the key does it jump to life or does it take a few turns for the car to come alive? That could be a symptom of a tired FPR. My FPR was so bad that on the highway, if I decided to floor it while in 5th gear, sometimes I would get a backfire. All gone with the new FPR. And it starts like a champ now.
You will find that coils are bit of a vague science. Its good that your CEL told u cylinder 5. Just replace that one. Other times, however, you may a find a coil that is kinda sortof bad. It works fine when cold but acts up when warm or hot. Only thing you can do is replace one at a time with some used OEM ones until your car acts better. The tests u will run will be inconclusive unfortunately. Been there done that
I would replace the fpr too. Chances are your car has oem from factory. How does the car start? When u turn the key does it jump to life or does it take a few turns for the car to come alive? That could be a symptom of a tired FPR. My FPR was so bad that on the highway, if I decided to floor it while in 5th gear, sometimes I would get a backfire. All gone with the new FPR. And it starts like a champ now.
03-27-2014, 11:51 PM
#93
03-30-2014, 05:25 AM
#94
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05-06-2014, 10:28 AM
#97
Take off the radiator cap. Warm the engine. Top off the coolant. Rev the engine. The coolant should suck down. If it shoots up or boils out, you have a blown head gasket. I have exact same power loss issues and thought it was everything else. My car is not overheating or leaking or white smoke. I detached the cat and driving like that so the antifreeze won't blow through. A mobile mechanic (while I was at AutoZone checking codes) looked at the car and checked the dip stick and said possible water or antifreeze in oil. Then did the rev check with radiator and said blown head gasket. That explains why nothing else works. I tried maf sensor, throttle body and sensors, intake manifold gasket, so it's time for a new engine or car most likely.
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