'87 944 Engine Noise (Not the usual rattle...)
08-12-2018, 12:49 PM
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'87 944 Engine Noise (Not the usual rattle...)
I just got my 944 back on the road yesterday after having it on jack stands for a couple weeks, and I'm noticing a distinct noise coming from the center of the engine. (I should note that it isn't a new sound; I'm just noticing it more now that I haven't driven it in a little while.) I'd describe it as sounding like something rotating consistently but seeming to be rubbing on something equally consistently, like one rough metal surface oscillating against another. At first I thought it was simply the oil level getting low and something was losing its lubrication, but the oil level and pressure are both where they should be. Just in case, I added maybe 1/3 of a quart of oil to see if that made any difference and it didn't.
It doesn't seem to be better or worse if the engine is warm or cold. I admit, I don't know a lot about the car's history because I purchased it in July. I did take a video of the engine bay after a 20-minute drive this morning but unfortunately it's the wrong format to upload with this post.
I'd be more than happy to field any questions or clarify anything that would help in the diagnosis. I'm taking it into my local garage to have something else looked at and I'll be mentioning this to them, but I wanted to see if there was anything obvious that may cause this.
Thanks as always!
It doesn't seem to be better or worse if the engine is warm or cold. I admit, I don't know a lot about the car's history because I purchased it in July. I did take a video of the engine bay after a 20-minute drive this morning but unfortunately it's the wrong format to upload with this post.
I'd be more than happy to field any questions or clarify anything that would help in the diagnosis. I'm taking it into my local garage to have something else looked at and I'll be mentioning this to them, but I wanted to see if there was anything obvious that may cause this.
Thanks as always!
08-14-2018, 02:29 PM
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Is it possibly a bearing or pulley that's worn out, or maybe even a gasket that's spinning? Is there any vibration associated with the noise? Does it get louder with higher RPM? Is it a grinding noise or more of a scraping noise? Grinding would tend to indicate bearings, scraping would tend to indicate something no longer in its correct position or something that got inside when it shouldn't have
08-14-2018, 03:54 PM
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Toasty, your instincts are on-point. A gearhead friend and I poked around and tested a few things that evening. There has been a moderate rattle from the front driver's side also but I thought the two were unrelated. Turns out that and the oscillating noise were symptoms of the same issue: the A/C compressor. The rattle was the clutch slowly going out, and the sudden appearance of the other noise was the bearing following its example. We pulled the belt free of the compressor pulley, started it and ran it for a few seconds, and the noises were gone.
Replacement parts are ordered and en route. I'm not overly concerned about the A/C working (since it currently doesn't and I'm not in desperate need to have A/C in a project car), but it seems easier to replace the worn parts than to create a bypass/workaround to go around the compressor.
Replacement parts are ordered and en route. I'm not overly concerned about the A/C working (since it currently doesn't and I'm not in desperate need to have A/C in a project car), but it seems easier to replace the worn parts than to create a bypass/workaround to go around the compressor.
08-14-2018, 04:20 PM
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Excellent! That's much better than some of the things I was imagining. Just be careful not to put too much tension on that belt, and keep the pivot bolt on the compressor a tad loose while you're adjusting the tensioner arm so the pivot doesn't bind and crack.
08-14-2018, 04:33 PM
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Will do! Part of me would prefer to just remove the compressor and save myself from having to possibly repair it again down the road. I really don't have any intentions of bringing the A/C back to working order, but the bearing and clutch replacement should be straightforward enough and will be easier than figuring out a workaround.
08-14-2018, 05:23 PM
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I agree. There are a/c delete kits that keep the belt position and tensioning arm in place, but unless you're trying to keep weight down, I'd just leave the a/c system in place for a quick solution now and in case you change your mind and want it working later.
05-31-2023, 10:48 AM
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'87 NA Engine compartment noise
Viking3467,
Was it a rhythmic dry sound, like a skier making turns? I'm having that sort of sound and am trying to find the source. It's not an internal engine sound that's in sync with rpms, like valves, or injectors.
Was it a rhythmic dry sound, like a skier making turns? I'm having that sort of sound and am trying to find the source. It's not an internal engine sound that's in sync with rpms, like valves, or injectors.
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06-20-2023, 05:50 PM
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Rattling noise from rear of valve cover
My 1987, 944 has 37,000 original miles had rattle very loud at the back of the valve cover. Also vibrating noise underneath car and in center under tunnel. Turned out to be multiple things cracked heat shield mounting just underneath exhaust manifold. Also weird, vibrating floor sound turned out to be rocks and debris between the catalytic converter shield and the tunnel shield. After I replaced The fuel injectors I noticed that there was the most rear nut on. The manifold was missing, and then the next one towards the front of the car was very loose. Fixed all of those problems. Car sounds a lot better but now I can hear a different rattle lol high pitch on deceleration.