howards11 Posted May 23, 2009 Author Share Posted May 23, 2009 (edited) Saturday.........................the Forester hesitated several times and it backfired once. It also started something new. It shakes sometimes waiting for a light. Still no CEL. My podiatrist did mention to me that this problem could be a valve hanging up. I don't even want to think about that. ~Howard Edited May 23, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 24, 2009 Share Posted May 24, 2009 If you haven't cleaned the MAF sensor I would try that first before replacing anything. Quote Link to comment Share on other sites More sharing options...
howards11 Posted May 24, 2009 Author Share Posted May 24, 2009 (edited) If you haven't cleaned the MAF sensor I would try that first before replacing anything. COUGAR: I ran the Forester last evening on one of our expressways. It performed OK and there were no problems driving through the city streets after leaving the expressway. Coming back from dinner, I think I heard another backfire ("pre-ignition" ?) but the radio was on so I could not really tell. After I got off on the city streets again there was no problems. I'm keeping a check on things this weekend and if the problems still exist Tuesday I will be contacting a local dealer. There is a PM waiting for you. ~Howard Edited May 25, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
howards11 Posted May 30, 2009 Author Share Posted May 30, 2009 (edited) My problems with the Forester still have not stopped. It still hesitates and backfires. Both problems are intermittent. It seems however after the backfire the problems go away for a while. It like it has to (please excuse this) pass gas and then it "feels better". Still no CEL ! ~Howard Edited May 30, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
howards11 Posted May 31, 2009 Author Share Posted May 31, 2009 (edited) I turned the radio off today and it addition to the other problems mentioned before I now think I hear pinging. This seems to happen when the engine is under stress like with the AC on and going up a hill. WHAT A MESS !! I'm leaving the car at my mechanic on Monday for one last shot from him on the problems. ~Howard Edited May 31, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
Qman Posted May 31, 2009 Share Posted May 31, 2009 I turned the radio off today and it addition to the other problems mentioned before I now think I hear pinging. This seems to happen when the engine is under stress like with the AC on and going up a hill. WHAT A MESS !! I'm leaving the car at my mechanic on Monday for one last shot from him on the problems. ~Howard Sounds like the beginning stages of a bad MAF. I have had two go bad in the last year. They all gave similar symptoms before they went bad. The last one had pinging, rough idle and missing. Assumed the knock sensor to be the culprit. Not the case though. The MAF finally threw a code right before it completely crapped out. You might try cleaning it but it sounds like replacement is needed. Throwing parts at it is very frustrating. Definitely not the way to go. Do you have a friend or board member that lives near you? Better to try a known good one before buying a new one. Though, I believe yours may only be around $50-75.00. Good luck, this type of thing can be very frustrating. Don't give up on it though. Quote Link to comment Share on other sites More sharing options...
howards11 Posted June 1, 2009 Author Share Posted June 1, 2009 (edited) Sounds like the beginning stages of a bad MAF. I have had two go bad in the last year. They all gave similar symptoms before they went bad. The last one had pinging, rough idle and missing. Assumed the knock sensor to be the culprit. Not the case though. The MAF finally threw a code right before it completely crapped out. You might try cleaning it but it sounds like replacement is needed. Throwing parts at it is very frustrating. Definitely not the way to go. Do you have a friend or board member that lives near you? Better to try a known good one before buying a new one. Though, I believe yours may only be around $50-75.00. Good luck, this type of thing can be very frustrating. Don't give up on it though. QMAN: Thanks for the info. I've passed it along to my mechanic. When he calls me I am going to ask him to clean the MAF and we'll go from there. I priced the part on-line and we're looking at around $60.00. I might just have him replace it. ~Howard Edited June 1, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
howards11 Posted June 2, 2009 Author Share Posted June 2, 2009 The car did not misbehave for my mechanic. He does not just want to throw parts at it which I understand. He suggested a local dealer and I am going there once the problems start up again. ~Howard Quote Link to comment Share on other sites More sharing options...
howards11 Posted June 6, 2009 Author Share Posted June 6, 2009 (edited) Here's the latest development. I think I've pinpointed the problem to something in my gas tank. The problems start again when the gas drops to 1/2 tank and below. A friend suggested letting the tank almost run to almost empty which would burn up any crud left in it. Then add some fuel system cleaner and refill. Other than that I think I'm going to wait for the engine to throw a code before I go to the dealer. Otherwise I think I'm just throwing out my money. Comments please. ~Howard Edited June 6, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
Cougar Posted June 6, 2009 Share Posted June 6, 2009 I am a little skepticle about that idea unless there is a high vacuum in the tank when the level drops. Do you hear a relief of vacuum when you open the gas cap when the fuel level has dropped to about half way in the tank? If so, then the venting/purge control for the fuel system may be faulty and relieving the vacuum by opening the cap should clear the trouble for the rest of the tank of gas. Quote Link to comment Share on other sites More sharing options...
Hondasucks Posted June 6, 2009 Share Posted June 6, 2009 I'm going to suggest the reflash as well, your vehicle is under the mileage for the emissions system warranty, so they should be able to do it for free. (I know we would at my dealership...) Even if it's not, it should only be a half hour (it takes about 20 minutes at most) so it'd cost ya ~$50 depending on what your local dealer's shop rate is. I try to reflash any car that comes in that has one available, if it's under warranty. (Warranty pays .6!) I had one guy come in with a V6 Camry that had a hesitation under moderate throttle, he had been to an aftermarket shop and had dropped quite a bit of money replacing plugs, having the injectors cleaned, etc.. All to no avail. Brought it to us, I plugged the laptop in, saw there was a reflash available that covered his exact condition, and it was still under the emissions warranty, so it didn't cost him anything. He totally wished he had come to us first! Quote Link to comment Share on other sites More sharing options...
howards11 Posted June 7, 2009 Author Share Posted June 7, 2009 (edited) I am a little skepticle about that idea unless there is a high vacuum in the tank when the level drops. Do you hear a relief of vacuum when you open the gas cap when the fuel level has dropped to about half way in the tank? If so, then the venting/purge control for the fuel system may be faulty and relieving the vacuum by opening the cap should clear the trouble for the rest of the tank of gas. COUGAR: I do hear a relief of vacuum when I open the gas tank cap when it's half full. But isn't that normal ? Tonight on the way to dinner with the tank almost to the half full point, the engine hesitated and then backfired. On the way back from dinner the engine ran fine. What I'm trying to avoid is taking this to a dealer and spending a lot of $$ with no answers. Should I just wait until the damm thing throws a code ? I am really confused at this point. ~Howard Edited June 7, 2009 by howards11 Quote Link to comment Share on other sites More sharing options...
ron917 Posted June 7, 2009 Share Posted June 7, 2009 It may never throw a code. Don't rely on codes alone. Not every problem will throw a code. Not every code points to the root cause of the problem . If your dealer mechanic claims "no code means no problem", find another mechanic. On the 1/2 tank issue: I'm not very familiar with what's in the tank of a Subaru, especially a Forester. But I've seen issues on other vehicles I've owned when the fuel drops below a certain level. On a VW, the in-tank fuel pump would seize when the fuel got low. The in-tank pumps are cooled by the fuel surrounding them. When the level dropped enough to expose the pump, it would get too hot and seize. When the problem first started, the pump didn't seize completely, but it slowed down enough to cause problems. On a Volvo, the tube leading from the fuel intake strainer on the bottom of the tank cracked. When the level got below the crack, it would suck air. So something like that could be a problem in your car. Also, I believe that the evaporation emissions checks run when the fuel is at a certain level. Maybe something to do with that? Quote Link to comment Share on other sites More sharing options...
Cougar Posted June 7, 2009 Share Posted June 7, 2009 COUGAR:I do hear a relief of vacuum when I open the gas tank cap when it's half full. But isn't that normal ? Tonight on the way to dinner with the tank almost to the half full point, the engine hesitated and then backfired. On the way back from dinner the engine ran fine. I don't think having a vacuum in the tank is normal but I am not positive on that. What I think should happen is the tank gets vented to the air through the charcoal filter at certain points and pressure adjusts inside the tank then. This is controlled through the purge valve I believe. There may be a problem with it opening. The circuit may be good to it and if so you would not see a code until it did have a problem electrically. You wouldn't know about a mechanical problem except for signs like you are having. To see if this idea is correct you could try opening the gas cap after the fuel level drops to a level before you start having the misfire problems. If the misfiring goes away then I would say you should have the vent system checked for some sort of a blockage. It may be the valve itself has a mechanical problem and air to the tank isn't venting like it should be. Quote Link to comment Share on other sites More sharing options...
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