2008 Saturn Aura
130,000 miles
GM 3.5L High Value V6 - Pushrod w/ VVT
GM 4T45E transmission
I really like this car; looks good, underrated performance, and drives well. At least, it used to... Lately I've been having some issues which I would like to fix the right way without just throwing parts at it. Car doesn't have any codes stored and no CEL. Still drives, but definitely has some problems. If it's a minor fix, I'm definitely willing to keep the car going, but something major and I'll just defer the decision to repair until something actually breaks for real or starts throwing codes.
Symptoms:
1) Hard shifting. 2-3 is the worst, 1-2 and 3-4 can be bad too. This seems to point me to typical GM 4T45e transmission woes. I'm not opposed to eventually putting a reman transmission in the car, but I'm not sure that's actually the problem with the car because of the other symptoms.
2) Occasional hesitation and poor acceleration. Pretty straightforward here, car sometimes doesn't like to get up and go. Other times, press the pedal and it feels like when it was a brand new quick V6 with nothing wrong. I'm thinking this could be MAF or MAP sensor. MAF was cleaned 6 months ago with MAF cleaner.
3) RPM fluctuations. This makes the car really annoying to drive. RPMs like to move around and make the car feel like its lugging and jerking. Even on the highway sometimes the RPMs will move around like the torque converter isn't locked, but then it will "lock up" and RPMs will stay still. Torque converter/transmission problem?
What I know:
Throttle body was cleaned a year ago which fixed a rough idle.
MAF sensor was cleaned 6 months ago with MAF cleaner. It was a long shot attempt to fix some of the symptoms I described without throwing parts at the car.
Engine Vacuum doesn't seem right. Using Torque app I see that my vacuum is around 18 "Hg at idle but drops to around 5 "Hg when driving...and rarely comes back up unless I fully take my foot off the throttle. Normally, I thought the vacuum was supposed to come back up after the initial drop upon acceleration as everything "evens out." This might be a slightly clogged exhaust?
-----
Any thoughts on what may be causing these problems? I don't have a ton of time right now to be troubleshooting and fixing things, but I would like to know what is going on so I can get around to fixing it if possible. Like I mentioned, car still drives and doesn't have a CEL, so I'm not panicked about any of these symptoms yet. I'm moderately handy, can do routine repairs and even some moderately complex ones if you give me a good set of detailed instructions. If it's transmission, I'll be taking it to a transmission shop though.
130,000 miles
GM 3.5L High Value V6 - Pushrod w/ VVT
GM 4T45E transmission
I really like this car; looks good, underrated performance, and drives well. At least, it used to... Lately I've been having some issues which I would like to fix the right way without just throwing parts at it. Car doesn't have any codes stored and no CEL. Still drives, but definitely has some problems. If it's a minor fix, I'm definitely willing to keep the car going, but something major and I'll just defer the decision to repair until something actually breaks for real or starts throwing codes.
Symptoms:
1) Hard shifting. 2-3 is the worst, 1-2 and 3-4 can be bad too. This seems to point me to typical GM 4T45e transmission woes. I'm not opposed to eventually putting a reman transmission in the car, but I'm not sure that's actually the problem with the car because of the other symptoms.
2) Occasional hesitation and poor acceleration. Pretty straightforward here, car sometimes doesn't like to get up and go. Other times, press the pedal and it feels like when it was a brand new quick V6 with nothing wrong. I'm thinking this could be MAF or MAP sensor. MAF was cleaned 6 months ago with MAF cleaner.
3) RPM fluctuations. This makes the car really annoying to drive. RPMs like to move around and make the car feel like its lugging and jerking. Even on the highway sometimes the RPMs will move around like the torque converter isn't locked, but then it will "lock up" and RPMs will stay still. Torque converter/transmission problem?
What I know:
Throttle body was cleaned a year ago which fixed a rough idle.
MAF sensor was cleaned 6 months ago with MAF cleaner. It was a long shot attempt to fix some of the symptoms I described without throwing parts at the car.
Engine Vacuum doesn't seem right. Using Torque app I see that my vacuum is around 18 "Hg at idle but drops to around 5 "Hg when driving...and rarely comes back up unless I fully take my foot off the throttle. Normally, I thought the vacuum was supposed to come back up after the initial drop upon acceleration as everything "evens out." This might be a slightly clogged exhaust?
-----
Any thoughts on what may be causing these problems? I don't have a ton of time right now to be troubleshooting and fixing things, but I would like to know what is going on so I can get around to fixing it if possible. Like I mentioned, car still drives and doesn't have a CEL, so I'm not panicked about any of these symptoms yet. I'm moderately handy, can do routine repairs and even some moderately complex ones if you give me a good set of detailed instructions. If it's transmission, I'll be taking it to a transmission shop though.