3oostdmstng
Well-Known Member
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- #1
Hey people! I am a happy (sometimes) owner of a '16 mustang eco...
I bought it CPO with only 10k in it...
The car was perfect until about 27k mi (I put miles quite fast since I commute to work quite a bit), anyway, first thing I noticed was a slight rpm drop WHILE driving, usually city driving. Say I am going 45 mph at a constant speed and suddenly there is this little surge and the rpms drop and get back up. The rpm drop while driving can happen 3x within 30 -45 min of wach other OR not happen at all in a given day. I took it in to my dealer to get it checked. Told me nothing is wrong. Fine.
Fast forward a couple of miles, about 32k, mind you with the random rpm drops still happening, but it got worse at around 32k. I fueled up one night and I pulled out of the gas station and was at the light waiting to change. Well, in that time the car's rpm dropped so low that it felt like the car was going to stall. Fortunately THAT night it did not, however, the following day it did. ( will post clip). I was a Wendy's drive through and noticed my air/fuel ratio acting funny and eventually car did stall that night.
Following day I took it to my same local dealer with that concern. The sales advisor opened the hood and he witnessed the car shuddering and wanting to stall but it didnt, he wrote it down on the report, however.
I left the car with them thinking it might take them the whole day to diagnose. Nope. 2 hours later the guy calls me back to tell me that I have an after market DROP IN air filter and that airbox was not clipped properly and thus the root of the problem. Even on the phone I told him that did not make sense because, first of all, they were the last ones to check on my air filter for maintenance purposes when I take it in...long story short, he tells me they will clean the throttle body intake and that it should fix the problem. Ok, great.
I get the car back. Everything is perfect. The issue went away but only for about 5k miles.
Now I am back to square one in which the car is dropping rpms while driving (only notice it while city driving - meaning 45-55 mph). I drive highway and never does it going higher speeds. And the same problem after fueling up, It acts funny like it wants to stall (if I am not mistaken while you're at a stop on D, the air/fuel ratio should be steady at 13.8-14.2, mine drops ALL the way down to 11's shoots back up to 15's) when I am at a stop but then once I start driving it goes away eventually....
I just once more dropped it off at the dealer I bought it from and the one I bought my extended warranty from as well for them to diagnose it. I get a feeling they will call me and tell me they cannot find the problem. Unfortunately, for some reason, the car does not throw a CEL.
I have been reading about people changing their low side pressure sensors, and/or the purge valve.
Does anyone here heard/experience this problem in which clearly there is an issue (evap/emission/air&fuel) one but NO CEL? Any input would be greatly appreciated.
Will post clips soon.
I bought it CPO with only 10k in it...
The car was perfect until about 27k mi (I put miles quite fast since I commute to work quite a bit), anyway, first thing I noticed was a slight rpm drop WHILE driving, usually city driving. Say I am going 45 mph at a constant speed and suddenly there is this little surge and the rpms drop and get back up. The rpm drop while driving can happen 3x within 30 -45 min of wach other OR not happen at all in a given day. I took it in to my dealer to get it checked. Told me nothing is wrong. Fine.
Fast forward a couple of miles, about 32k, mind you with the random rpm drops still happening, but it got worse at around 32k. I fueled up one night and I pulled out of the gas station and was at the light waiting to change. Well, in that time the car's rpm dropped so low that it felt like the car was going to stall. Fortunately THAT night it did not, however, the following day it did. ( will post clip). I was a Wendy's drive through and noticed my air/fuel ratio acting funny and eventually car did stall that night.
Following day I took it to my same local dealer with that concern. The sales advisor opened the hood and he witnessed the car shuddering and wanting to stall but it didnt, he wrote it down on the report, however.
I left the car with them thinking it might take them the whole day to diagnose. Nope. 2 hours later the guy calls me back to tell me that I have an after market DROP IN air filter and that airbox was not clipped properly and thus the root of the problem. Even on the phone I told him that did not make sense because, first of all, they were the last ones to check on my air filter for maintenance purposes when I take it in...long story short, he tells me they will clean the throttle body intake and that it should fix the problem. Ok, great.
I get the car back. Everything is perfect. The issue went away but only for about 5k miles.
Now I am back to square one in which the car is dropping rpms while driving (only notice it while city driving - meaning 45-55 mph). I drive highway and never does it going higher speeds. And the same problem after fueling up, It acts funny like it wants to stall (if I am not mistaken while you're at a stop on D, the air/fuel ratio should be steady at 13.8-14.2, mine drops ALL the way down to 11's shoots back up to 15's) when I am at a stop but then once I start driving it goes away eventually....
I just once more dropped it off at the dealer I bought it from and the one I bought my extended warranty from as well for them to diagnose it. I get a feeling they will call me and tell me they cannot find the problem. Unfortunately, for some reason, the car does not throw a CEL.
I have been reading about people changing their low side pressure sensors, and/or the purge valve.
Does anyone here heard/experience this problem in which clearly there is an issue (evap/emission/air&fuel) one but NO CEL? Any input would be greatly appreciated.
Will post clips soon.
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