It sounds like a bean in an insulated can being shaken around - the weird thing is... when the car's warm - the sound only comes on when I apply an electrical load (turn on the headlights, power windows up even though the windows are already up, etc.)
The sound does vary with RPM (it follows it - AKA, rpm increases... the bean is shaken faster).
Someone mentioned that it would seem to be electrical... but - what could this be?
And when the car's cold... it's there all the time.
With the noise appearing at operating temp when electrical load is applied, would something inside the engine really be worth checking?
Given the description of the sound, yes, that makes perfect sense...but the addition of the electrical input makes me wonder if there's an issue outside the engine...with the belt tensioner setup, perhaps.
My '94 made a horrible racket for a day or so that made me wonder about a rod issue...until I noticed the tensioner bolt on the alternator had somehow slipped from it's metal bracket and was flapping around.
I'll try to get a video up. thanks for the responses btw. Would the timing belt being off result in loss of power - or is that only when the belt is off in the "retarded" way? - - - too advanced... possibly.
If the timing belt were to be off the cams your car would not be running at all. If your timing belt was put on wrong as in it skipped a tooth your timing would be retarded.
Get/borrow/rent a timing light and check it. Adjusting the CAS is a 1 bolt deal, though having 2 people makes it easier. I doubt you would have jumped teeth on the actual gears.
If it's a light ticking it most likely means you need to do something about the oil. Change it, or add about a quart. I know mine burns through it like a rotary. If it's a louder knocking that is heard at certain RPM's then it's probably a busted rod bearing. So if you feel like being under the car for six hours. Get the $30 kit from FlyinMiata, and get your crank shaft looked at. It can get chewed up if that happens. My rod bearings went this weekend, and I'm dropping in a rebuild 1.8 next weekend. cost the same as a full rebuild. Good luck
video fail... took a video with my phone...uploaded it... no sound. :-/ i'll try again with an actual camera this time! I took off the valve cover and the upper timing belt cover to see if the noise was coming from there...... still inconclusive :-/
engine's toast. :-/ took another look and the crank has a mad wobble. Now it's... swap in a 1.8 and ride for a while..... swap in a 1.6 and sell the miata for a better price than without an engine and look for another miata... or look for another car in general (mazda 3... wrx wagon... civic hatch...lol)
^+1 mine had the "knock". Took the crank pulley off, inspected every thing, cleaned it all up real well, put some loc-tite on the woodrufd key and the bolt and torqued it to spec. Mine also had the wobble. The best thing you can do is pull it apart and check it all.
Yep. The noise was horrendous. Luckily enough it came apart pretty easy, got it all put back together and it was happy. Just make sure every thing is clean and you use a GOOD torque wrench. Do you have a short or a long nose crank?
Christian, yes, sometimes the crank bolt can back out, like what happened to Dustin. His keyway was fine. That's why some people put blue loctite on that bolt.
yeah - jbguillo did the timing belt crank nut + locktite thing a while back when he offered his services. the car's currently at pitgarage. the FM kit sounds like it's going to come in around Monday. There's a part of me that wants to take the car back - try it out - and then get the engine swapped out if it doesn't work...
wtf? aw mannnnnn - Now that I think of it... I was trying to make the accessory belt a little less noisy...so I tightened it up. Maybe it was too tight then?
If I went back to the car...what am I supposed to do then? Just unbolt the crank bolt...and retorque with locktite?
Oh yeah...... mine came out by hand. The best thing I can figure that happened, was that it started to back out but not enough to cause a problem. Increasing the belt tension was enough to show the wobble of the loose bolt and finished loosening it up. If you drove it for a while you could have trashed the key way though.
Ick. Can you wiggle the pulley by hand? If So does just the outer portion move or does the whole assembly. It may help to releive the tension on your accessory belts to check this properly. Also by tight, did you put a torque wrench on it? Could just seem tight.
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