1987 GMC Jimmy
Automobile Hoarder
- Joined
- Jan 23, 2016
- Posts
- 5,848
- Reaction score
- 2,387
- Location
- Mississippi
- First Name
- Jesse
- Truck Year
- 1987
- Truck Model
- V1500 Jimmy
- Engine Size
- 350
The title gives it away, but the noise is strange and unpredictable. I thought it was the catalytic converter not having been punched correctly because it's like a rattling, tapping, ticky noise that varies with engine RPM, but it was further up than that. I stuck a vacuum wand in the tailpipe and found only a tiny leak at the front of the passenger side exhaust manifold, which I was already aware of its existence. I pulled the flexplate cover, and the noise made itself more apparent. It's always there, but sometimes it's a really soft click that you can barely hear, and the loudest it's gotten is a clattering/grinding sound. It will usually present itself after parking on an incline or driving up or down a steep incline, and it gets loud when it's warm and very rarely when cold. The loudness, when it decided to get loud, while driving can be controlled by how much I'm accelerating. If I let off, it'll taper back, and after I'm done accelerating, it'll almost go away. The torque converter and the flexplate spin true, and the converter bolts are all tight. I looked at the flexplate bolts the best I could and saw nothing out of the ordinary, but the sound is almost definitely coming from there. Engine runs great (20-22 MPG on the highway depending on how fast I'm going), and it has no top end ticking, besides the fairly tame exhaust leak, or bottom end issues. It's a 700R4 with 248,000 miles on it, never rebuilt. Fluid is good and doesn't look anything out of the ordinary. TV adjustment is good, and the transmission still shifts very nice and smooth. I feel like I missed something with the flexplate bolts, granted I did the best I could, or my torque converter is on its way out. I'm not saying that it couldn't be something like low oil pressure, and that's causing a clatter, but the jeez the engine only has 82,000 miles on it. Plus, the noise is right there at the torque converter and flexplate. I know the transmission doesn't have a ton of life left, even if it's going well now, but for what it is, how worn it is, and how old it is, it does extremely well be it in the country or big city traffic.
