About three days ago I noticed my car (2001 Buick Regal) was acting a bit sluggish when accelerating on the highway, the engine would rev up a bunch and the CEL flashed, but otherwise the car still drove fine. A day later I took the car for a drive and noticed very poor acceleration, but it was still drivable, on the way back home it got much worse, it would take a minute or two to get up to 60mph and it was sputtering a lot. Today I took it for a drive around the neighborhood to see how bad it was - it's to the point where it barely accelerates at all, I can barely make it up any hills, and I noticed this clanking sound even at low speeds.

I disconnected the MAF sensor and took it for a short ride, that seemed to improve it a little bit but not much. After that, I reconnected the MAF then disconnected the TPS sensor and that just made it worse.

The check engine light is not illuminated, I tried pulling codes using an OBD reader but there were no codes to pull.

Does anyone have any suggestions on what to try next?

  • If you have the 3.1L motor it is not uncommon for the rocker arm studs to pull out of the head. If the stud is partially out it may it may run as if the valves are out of adjustment.
    – mikes
    Jun 28, 2019 at 0:43
  • @mikes I just drove it around the parking lot and it shakes vigorously even driving 5mph and there’s a trail of oil where I drove it. :(
    – William L.
    Jun 30, 2019 at 16:15
  • have you tried cleaning the throttle body? Jul 12, 2022 at 2:55
  • Sounds like serious misfire but it could be caused by many things. "Trail of oil" is not a good sign. You have a 3800 Series II engine which is a good engine, but bad intake manifold gaskets were very common which I believe could cause excessive oil consumption. How does the oil look on the dipstick and on the underside of the oil cap? How does the coolant look? Pulling plugs and inspecting them is also a good next step. A bad PCV valve or excessive blowby (ring wear) can also cause high oil consumption. Aug 7, 2023 at 23:20

2 Answers 2


A 2001 model year means it's OBD-II. The car may be putting itself into a limited-power limp mode as a method of self preservation, which may be masking what the real problem is. Once a car has failed in this way, diagnostics by way of "try this and see what happens" become tough because you may not be able to separate the actual issue from the computer's response to the issue. It will be even harder for us to try to diagnose the problem remotely.

The good news is, you can get an OBD-II reader online these days for cheap - under $50 for a standalone unit, or as cheap as $15 - $20 for a bluetooth unit to use with your phone. Or, you can take it to a car parts store and ask them to read it, most will do it for free (with the hopes that you'll then buy parts from them to fix whatever the problem is).

Once you know what codes it's throwing, you can update your question here, or do some googling to determine next steps.

  • I did try pulling the codes with my OBD-II reader, but there were no codes to be pulled and the check engine light is off.
    – William L.
    Jun 27, 2019 at 20:00
  • When you hook up a gauge to the fuel lines shader valve does the needle rise slowly ? does it fluctuate alot at idle, or at 2k rev... Does it stay positioned at roughly 50 PSI, If you cut off air to the fuel line, Does the needle rise ?
    – user38183
    Jul 28, 2019 at 11:57

Having the same problem with my 2001 buick regal ls the codes the came up were o2 sensor and crankshaft sensor had both fixed still having the same problem the shop reset my engine light now its back on again waiting to take it back to the shop.

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