Power loss
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Joined: Jun 2019
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Power loss
1992 f150 5.0 v8 auto transmission
I left my truck running while I ran in somewhere, came out and the check engine light came on, had to limp it home, it wouldn't go over 25 mph, I backed out of my spot fine, no issue, but when I went to go forward it was accelerating extremely slow, and I noticed a knocking feeling near my feet. I noticed that when I would let off the gas the rpms would go up a little as if it was running normal and the harder I pressed the gas it seemed the more it would knock, it's not an engine knock. It wasn't a continuous knock, seemed more random but it was happening quite often. When I was almost back, the check engine light turned off and it shot into second gear and then wouldn't shift up anymore. I haven't messed with it since cause I got it home and I can't afford to have to get it towed, any idea what it could be? Hoping it's not a bad transmission, but I'm not sure, never heard of a knocking sound like that from a bad transmission and the whole way home it was in the correct gear, just couldn't go faster than 25 unless it was downhill. It ran fine at idle although the rpms seemed to be about 100 higher than usual, but no knocking sound unless I was pressing the gas pedal. Any help would be appreciated because I'm lost.
Edit, I just went out to start it, and it would go forward perfectly fine, seems maybe it runs better when cooled off?
I left my truck running while I ran in somewhere, came out and the check engine light came on, had to limp it home, it wouldn't go over 25 mph, I backed out of my spot fine, no issue, but when I went to go forward it was accelerating extremely slow, and I noticed a knocking feeling near my feet. I noticed that when I would let off the gas the rpms would go up a little as if it was running normal and the harder I pressed the gas it seemed the more it would knock, it's not an engine knock. It wasn't a continuous knock, seemed more random but it was happening quite often. When I was almost back, the check engine light turned off and it shot into second gear and then wouldn't shift up anymore. I haven't messed with it since cause I got it home and I can't afford to have to get it towed, any idea what it could be? Hoping it's not a bad transmission, but I'm not sure, never heard of a knocking sound like that from a bad transmission and the whole way home it was in the correct gear, just couldn't go faster than 25 unless it was downhill. It ran fine at idle although the rpms seemed to be about 100 higher than usual, but no knocking sound unless I was pressing the gas pedal. Any help would be appreciated because I'm lost.
Edit, I just went out to start it, and it would go forward perfectly fine, seems maybe it runs better when cooled off?
Last edited by Ether Felix; Jun 6, 2019 at 06:40 PM.
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Joined: Jan 2018
Posts: 11,256
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From: Memphis, TN, Earth, Milky Way
To really help you diagnose it, we need to see ALL the truck's details in your signature:
(phone app link)
...and all its maintenance & repair history in your post. Read this caption, too (a few times if necessary), and post each code number with its COMPLETE definition:
(phone app link)
You should invest in a Haynes manual, and read it cover-to-cover at least once:
(phone app link)
You'll need any decent digital multimeter to test (NOT replace) each sensor & actuator:
(phone app link)
(phone app link)
Try to disturb as LITTLE as possible so you don't create any new problems that would confuse this diagnosis.
(phone app link)
...and all its maintenance & repair history in your post. Read this caption, too (a few times if necessary), and post each code number with its COMPLETE definition:
(phone app link)
You should invest in a Haynes manual, and read it cover-to-cover at least once:
(phone app link)
You'll need any decent digital multimeter to test (NOT replace) each sensor & actuator:
(phone app link)
(phone app link)
Try to disturb as LITTLE as possible so you don't create any new problems that would confuse this diagnosis.
