Weird rattling noise

[Belen]

Hello, my Tercel has been making a weird noise since this afternoon. I think it could be something related to the alternator belt.

Here is the video:
https://youtu.be/Ejqm6Shy69Y

As usual, thanks in advance!

[xirdneh]

If you think its alt belt related, take the belt off and start the engine to see if noise goes away, just do not let it run very long cause it will overheat. Radiators do not make noise unless something is hitting it.

[rer233]

If you think its alt belt related, take the belt off and start the engine to see if noise goes away, just do not let it run very long cause it will overheat. Radiators do not make noise unless something is hitting it.

I agree, but it doesn't sound like an alternator problem to me. Sounds more like a valve train problem. Does the noise seem to be coming from the top of the engine? Has it been run low on oil recently?

[Belen]

Thank you! I will look at it today. I will post an update as soon as I know what it was.
The oil level seems to be ok.

[dlb]

i agree that it sounds like valves. try letting the engine run, then removing one spark plug wire at a time. if the sound changes or goes away when you remove a wire, the problem lies in that cylinder.

removing the belts to determine if it's a belt issue is also a good idea.

[Gottolovem]

Sounds like a valve to me as well.
Get a piece of wood like a hammer handle put it to your ear and move around the top of the valve cover with the other end when you find the source of the noise you will know

[Petros]

that sounds rather obnoxious, almost sounds external like a bad alternator. Could be something wrong with one of the valves, if the noise sounds like it is coming form inside the top of the engine you might take the valve cover off and carefully inspect all of the rocker arm, valve springs, etc.

I have also seen it where really badly worn connecting rod bearings allow the piston to strike the head surface. also, if the timing belt is worn out and skipped a few teeth on the cam sprocket it could allow an open valve to strike a piston top (not likely but an easy check). So when you take the valve cover off you might also remove the upper timing belt cover, line up the timing mark on the font pulley and verify that the sprocket timing marks line up on the front of the head (see the service manual for what the timing marks look like).

There is a small chance that an exhaust leak at the gasket can make a sound like that, the sudden blast of exhaust popping out at each combustion cycle can often sound like a mechanical impact. you put your hands around the exhaust manifold, over and under, and you will likely feel the intermittent blast of air when you find the leak. Careful you do not burn yourself, all those parts will be hot.

There is a small chance an exhaust valve broke a piece off and it stuck in the top of the piston, causing it to bang into the head face. do a compression test, if the exhaust valve is broken there will be one cylinder with little to no compression. If that is the case the head has to come off, likely it can be repaired without pulling the whole engine, but it will have to get new valves and a head gasket. If that is the case likely you should have a head rebuilt at a machine shop. This is a big job, but it is not as bad as must other cars, and not too costly to do yourself. There is a headgasket replacement thread over in the repair guilds section with everything you need to know about doing the job yourself.

But do not pull the engine apart until you diagnose the problem first, you may not fix the problem and just spend a lot of time and money not fixing it.

good luck.

[Belen]

Hi again, and thanks everybody for your help. Here is an update on my Tercel's status. I had a mechanic look at it and he said it was an O-ring inside the motor (I think O-ring was the term), and it was just as expensive to open the motor and repair it, as installing another motor. In spite of what I thought, the oil level was too low and apparently that is what caused the malfunctioning.

I had a motor installed, and now the car works fine, but now there is a problem shifting into first gear. I called the garage to complain about this, and they said that they haven't replaced it, but this is something that didn't happen before. They want to make me pay 400 USD for a new transmissiona and this just makes me so angry

[gnarnold]

Do not pay rip -n-gougers just get.a new clutch cable .that will fix her up.worked for me Unless a fork in the tranny is busted ..drop the tranny its easy. Wait. ........400 for a new tranny ?!!# where is this place ???.Shang ri La !!!?

But seriously .is your clutch pedal an auto adjusting one perhaps? If so some times the little teeth on the plastic cheese wedge piece don't touch or just barely touch the other teeth .and a new cable will fix that hopefully .grease the new one .

[gnarnold]

Unless a fork in the tranny is busted ..drop the tranny its easy
But as far as the noise.goes that noise is a familiar one indeed .that is the same sound that my first engine made right before I shattered a piston about 60miles from home .needless to.say the car will do 75-80 miles an hour on three pistons .loud. ...yes .ruined my day yes .was it the last trip for that engine ....yes .did I give up ......no

[gnarnold]

Just get used to the smell of gear oil .it's an aquired kinda thing.

[dlb]

it sounds like the mechanic said a piston ring was damaged, which could lead to damaging the cylinder, which could mean replacing the block. this could be caused by running it low on oil so that part sounds plausible to me.

as for difficulty shifting into 1st gear, can you elaborate? does it grind when you try to put it in first, do you have to force it, does it not go in at all? once it's in first, does it stay in that gear and drive fine? these details will help determine whether the problem is in the transmission or the clutch. the clutch is the part that essentially connect the engine and transmission. when a clutch wears out, it can be difficult to get into some gears. you might also experience 'slipping,' where you are in gear and the engine RPM are rising but the speed of the vehicle is not increasing.

it's possible your clutch was marginal already and something about the way it sits in the new engine just makes it more obvious, but if it was that worn than the mechanic should certainly have noticed it when they swapped it to the new engine.

give us some more details on the shifting problem and we'll go from there.

[Petros]

sometimes just a clutch at the end of its life will act like this, the auto adjuster on pedal lever arm can not travel enough to disengage the clutch when the clutch is worn out. Though the clutch cable is an easy and inexpensive fix to try first.

It seems the mechanic should have inspected the clutch when he had it out to swap it out on to the new motor. If the clutch was good, than either he did not install the cable and lever arm properly, or it is coincidence that the clutch cable stretched enough at the same time to not allow disengagement.

The trans is likely okay, it is the clutch not fully disengaging that does not allow it to shift into first.

[Belen]

Here is a video taken with my phone: https://www.youtube.com/watch?v=5C9bgl9lk2E

I will take a look at the cable this weekend. Thanks!

[dlb]

hmmm. popping out of gear does point to internal transmission issues, rather than the clutch.

a few guys here are better versed in trans specifics so i'll let them pipe up.