Any transmission experts?
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Joined: Jan 2017
Posts: 1
Any transmission experts?
Hello Everyone!
A week ago I picked up a 2002 Monte with the 3.4 engine. It has 122,000 miles on it. I have started to notice some odd behavior from the transmission. When I am going anywhere from 25 mph to 40 mph with very light throttle application, just enough to maintain speed on flat ground, the RPMs will drop from 1500 RPM down to 1000 and it sounds like the engine is lugging. With the slightest increase in throttle, or sometimes without any, the RPMs shoot back to anywhere between 1500 and 2000. It seems like to me the torque converter is constantly locking and unlocking. Should there be lockup at such low speeds? There are no warning lights on, nor codes in the computer. The transmission is NOT slipping, it makes nice normal shifts. I haven't been able to check the fluid yet, but was wondering if anyone knows what I'm talking about based on this info alone. I've read that a simple dirty MAF sensor can mess with these transmissions. Is this true? I'm curious as to the most likely cause, and am hoping it doesn't involve a new transmission.
Thanks a lot in advance for any advice everyone!
A week ago I picked up a 2002 Monte with the 3.4 engine. It has 122,000 miles on it. I have started to notice some odd behavior from the transmission. When I am going anywhere from 25 mph to 40 mph with very light throttle application, just enough to maintain speed on flat ground, the RPMs will drop from 1500 RPM down to 1000 and it sounds like the engine is lugging. With the slightest increase in throttle, or sometimes without any, the RPMs shoot back to anywhere between 1500 and 2000. It seems like to me the torque converter is constantly locking and unlocking. Should there be lockup at such low speeds? There are no warning lights on, nor codes in the computer. The transmission is NOT slipping, it makes nice normal shifts. I haven't been able to check the fluid yet, but was wondering if anyone knows what I'm talking about based on this info alone. I've read that a simple dirty MAF sensor can mess with these transmissions. Is this true? I'm curious as to the most likely cause, and am hoping it doesn't involve a new transmission.
Thanks a lot in advance for any advice everyone!
Joined: Dec 2013
Posts: 24
From: Philadelphia, PA
I'm gonna take a guess here and say this might be close to normal behavior. Driving on a flat surface at similar speeds with no acceleration and light throttle application, my 01 SS will sometimes run at a very low RPM (around 1200, probably running in 4th gear), which is well below the lock point on the torque converter. It doesn't really sound like it's "lugging" but I do have a partial aftermarket exhaust on my car so it's hard to tell. When giving it just a little more gas, the car will downshift and the RPM will go up to 1500+, which is around the torque converter stall RPM. A dirty MAF or failing torque converter can cause random RPM fluctuation and a rusty exhaust can cause excess noise, but I highly doubt this is a transmission problem. If the car feels like it's shuddering or running rough, check those things, but I don't think it's too serious.
MOTM Mod
Joined: May 2013
Posts: 5,498
From: Nebraska
Hello Everyone!
A week ago I picked up a 2002 Monte with the 3.4 engine. It has 122,000 miles on it. I have started to notice some odd behavior from the transmission. When I am going anywhere from 25 mph to 40 mph with very light throttle application, just enough to maintain speed on flat ground, the RPMs will drop from 1500 RPM down to 1000 and it sounds like the engine is lugging. With the slightest increase in throttle, or sometimes without any, the RPMs shoot back to anywhere between 1500 and 2000. It seems like to me the torque converter is constantly locking and unlocking. Should there be lockup at such low speeds? There are no warning lights on, nor codes in the computer. The transmission is NOT slipping, it makes nice normal shifts. I haven't been able to check the fluid yet, but was wondering if anyone knows what I'm talking about based on this info alone. I've read that a simple dirty MAF sensor can mess with these transmissions. Is this true? I'm curious as to the most likely cause, and am hoping it doesn't involve a new transmission.
Thanks a lot in advance for any advice everyone!
A week ago I picked up a 2002 Monte with the 3.4 engine. It has 122,000 miles on it. I have started to notice some odd behavior from the transmission. When I am going anywhere from 25 mph to 40 mph with very light throttle application, just enough to maintain speed on flat ground, the RPMs will drop from 1500 RPM down to 1000 and it sounds like the engine is lugging. With the slightest increase in throttle, or sometimes without any, the RPMs shoot back to anywhere between 1500 and 2000. It seems like to me the torque converter is constantly locking and unlocking. Should there be lockup at such low speeds? There are no warning lights on, nor codes in the computer. The transmission is NOT slipping, it makes nice normal shifts. I haven't been able to check the fluid yet, but was wondering if anyone knows what I'm talking about based on this info alone. I've read that a simple dirty MAF sensor can mess with these transmissions. Is this true? I'm curious as to the most likely cause, and am hoping it doesn't involve a new transmission.
Thanks a lot in advance for any advice everyone!
Check your Trans fluid for color you should want it to be Bright Red and not a dirty Brown. If it is you may want to consider a change.
The other thing I would recommend if you have this on the shifter selector Use the Normal D and not the OD for driving around. Some times it will tell you this in the owners manual also. What I have been told is that the car shifts into OD somewhere near 45mph so if in OD it could be shifting up and down like that. But in regular D it may not.
