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OldUsedCelica
11-15-2005, 08:20 AM
Here is one for all you pro's on the forum... I've been banging my head against the car for the last couple of days and can't seem to find my answer.

My Celica is a 1991 GT 5SFE manual with no mods and whatnot. Just recently it started to hum at me. Seriously. When I first start up the engine and it is cold, it will hum at me when I am inside the car. Outside of the car, the humming is still there but you can't really hear it, only when you are inside the car does the humming get REAL loud. The whole car shakes, rattle and roll like no tomarrow too.

I checked the muffler, some of the engine mount (I can only find 3 of them, dont know the location of all of them), all the pulleys and external accessories that are attached to the engine, and whatnot.

Although I did noticed that when I press down on the engine, the humming changed to a buzz? (the pitch of the sound changes).

Another interesting thing is that when I press the clutch to change gear, it will rev up another 200-300 RPM before it settle down. Never had that happen before either.

Is it just a old Celi or is it a sick Celi?

-Thanks guys

Morwan
11-15-2005, 03:38 PM
That's pretty standard for old Celicas. Have you checked if the heat shield or exhaust manifold are loose? Try removing the heat shield and see if it continues.

Mine.. Well, the previous owner snapped one of the bolts on the exhaust manifold, and I'm going to wait until I can get a new manifold (probably a Camry manifold) to fix it.

streetcelica3
11-15-2005, 04:30 PM
the rattle could be anything really same with the humming just something lose. but when you talk about the whole car shaking what do you mean there? like the motor rocking?

OldUsedCelica
11-15-2005, 05:02 PM
Hey strretcelica3... all the loose stuff shakes... for example I have an older kenwood deck in the car that does not have the anti-skip feature, whenever the car is cold and I am revving, it rattles enough to cause the disc to skip. The deck is mounted tightly into the DIN so... *shrug*

Oh and if anyone had ever had a muffler crack or leak at them, that is what the humming sound like. Again though, there is no leak anywhere on the exhast system. And repeat, when you are outside of the car... even with your head in the engine bay... the sound is muted. Only when you are actually inside the car will the humming be pronounce.

And if this is the way old celica sounds... that really suck ass. I have a stock 1979 Maverick that is in sever need of restoration and even when it fire up it doesn't sound like that.

Slider
11-15-2005, 08:44 PM
Mine has 190,000 miles on it and it doesn't do that, unless I'm used to it and don't realize it anymore. :hehe: It only shakes is when it's idleing at 750rpm warmed up, that's because of my old motor mounts. I'm stumped, maybe it's something is loose and is causing this, like something vibrating against the exhaust.

streetcelica3
11-15-2005, 10:42 PM
the humming could be the dash loose or something. try pushing down on things in side the car cuz it must be in there somewhere something has came loose.
is the car bogging when its shaking? or is the motor running good

GlHlOST
11-15-2005, 11:55 PM
Do you have a system?

CandianCelicaGT
11-16-2005, 12:11 AM
My car just recently started ot make a noise when its at high RPMs and I dump the clutch to change gears, kinda makes a WWWWWWWWOOOOOOOOoooooooooooooo sound from the passenger side of the engine. I figure its a bearing. But im gonna leave it until I feel ill effects. DOnt have time ot be at it.

alltracman78
11-16-2005, 12:11 AM
Sounds like the exhaust is hitting something, if you only hear it inside. Maybe the heat shield. Or rear suspension.
Probably from the extreme vibrations of the engine.

Have you done a tune up on the engine yet?
Also, why are you replacing the manifold if one of the studs is broke?

locker
11-16-2005, 12:49 AM
Im just curious how you were only able to find 3 mounts??? which one didn't you find? The one at the back???

alltracman78
11-16-2005, 01:05 AM
That or the dr side one...

Morwan
11-16-2005, 06:17 AM
I'm not replacing the manifold just because one of the studs is broken.. It's just labor-intensive to remove a broken stud (and therefore quite expensive). I certainly don't have the tools or the experience to do it, and I figure if I'm paying for a shop to take apart my manifold, I might as well get them to install a better one while they're at it.

EDIT: Here's a really stupid question: What's is a header? Is it the same thing as an exhaust manifold?

OldUsedCelica
11-16-2005, 11:37 AM
as far as mounts, i only found the passenger side, transmission, and rear. no power lost, it just vibrate to a hum, heat shield is on tight. When you press down on the engine, the tone changes, and it also does the same thing CandianCelicaGT celi does when it is cold. Once it warmed up it dont exactly go away but it is muted to almost normal.

Oh and I should say that the rear bushing on the suspension including the torsal bar(?) (the bar that connects to the rear wheel hub slanting up toward the middle of the car) and the drive axle(?) been replace. I thought maybe it is the bearing that was going too but it does this when it is sitting still so... *shrug*

If anyone can suggest something for me to check that does not include me taking the whole car apart... I'll run out and give it a look see.

p.s. The not sure about the exhast manifold, but the exhast header is the external exhast pipes that are connected directly to your engine (you got a four banger it will be four pipes running down to merge into one). Intake headers are the external intake pipes that are directly connected to your engine (you got a four banger it will be one pipe seperating into four). :hyper:

alltracman78
11-16-2005, 01:02 PM
Yeah, "header" is a exhaust manifold.
"HeaderS" is 2. Which you don't have. :) That would be on a V engine.

There are actually 3 transmission mounts.
One in front, one in the rear [both bolt to the front to back crossmember], and one on the end of the transmission.

If it's related to the engine, it won't be bad bushings in the rear.
Have you done that tune up?

OldUsedCelica
11-16-2005, 06:56 PM
Work second shift and it is snowing right now where I live. This weekend is a volunteer weekend for work so planing on doing the complete tune up to all my cars ('93 Paseo, '91 4Runner, and the Celi).

People who work second shift don't have a life. Also, only one car at a time in the garage.

On an interesting note though... When my wife and I meet on the road we always do an impromptu race (she in the Paseo and me in the Celi) I usually get owned hehehe.

Getting beat by a 5F-FE Paseo is really starting to get lame...

Gonna wait until this weekend, tuneup, rechecked the engine mounts, then post if anything changed or not.

Thanks guys...

oh and another things... some of the terms you guys use in these forum confuse me... for example, in another thread, a member was talking about that mod Celi in europe, about cutting the CF or whatever... wtf is a/an CF?

Slider
11-16-2005, 08:32 PM
oh and another things... some of the terms you guys use in these forum confuse me... for example, in another thread, a member was talking about that mod Celi in europe, about cutting the CF or whatever... wtf is a/an CF?

CF=Carbon Fiber reffering to the black trim on the front of the celica. At the tip of the hood and headlights. It's not actually made of carbon fiber but it sort of looks like it.

OldUsedCelica
11-17-2005, 04:47 PM
oh. :slap:

OldUsedCelica
11-22-2005, 05:54 PM
hehehe... stupid me. When I did the tune up this weekend, I also did a once over on the car checking everything out. I did miss an engine mount. The one in the front hehehe. Anyhow, the plastic (rubber?) part inside the metal housing in the front mount is cracked. Can that really cause all that rattling and humming?

What would you guys recommend for new mounts? Should I replace them all?

Sean
11-22-2005, 09:15 PM
Is this an electrical humm? You missed someones excellent question above, do you have aftermarket stereo system in your car? Are you sure its not being picked up, and coming through one of your speakers?

PINOIZE
11-23-2005, 08:38 AM
hehehe... stupid me. When I did the tune up this weekend, I also did a once over on the car checking everything out. I did miss an engine mount. The one in the front hehehe. Anyhow, the plastic (rubber?) part inside the metal housing in the front mount is cracked. Can that really cause all that rattling and humming?

What would you guys recommend for new mounts? Should I replace them all?

If you're cheap like me, then fill them with polyurethane.

http://celicatech.com/forums/showthread.php?t=1341&highlight=polyurethane

I filled the front and rear mounts with PL construction adhesive and the shaking was cut in half. They were totalled effed up. The rest I suspect is coming from the broken flex pipe.

Galcobar
11-23-2005, 09:08 AM
One note on the header/manifold issue: 5SFE Celicas came with log-style manifolds, which basically means hunks of metal with holes bored in it. I don't recall anybody ever referring to them as headers. That term is usually reserved for tubular manifolds, which essentially every aftermarket manifold is, and why it's become common to refer to aftermarket exhaust manifolds simply as headers. Third, typically non-North American term: extractors.

OldUsedCelica
11-23-2005, 02:54 PM
Ok... to answer the electric hum... no its not electrical in nature. The humming sounds almost exactly like what a broken muffler that is directly under where the front compartment is. When the car is started cold, it is VERY loud. Then as the car warm up, it starts to fade until it is almost gone. Then as you rev up it get louder until you hit a certain rpm (say about 55-60mph in fifth gear), then it starts to fade away until the road noise is louder then the humming.

Its not a broken muffler... I color smoked the pipes (orange hehehe) and did not see any color leak anywhere under pressure... the only thing that I can think of is the crack front engine mount. Will post a link to my website and will try to upload the sound after thanksgiving if I get the chance.

-Thanks guys.

elektrateq
12-04-2005, 11:38 AM
Often all engine and tranmission mounts are refered to as just engines mounts. There are 4 .... left, right, front, and rear. Left is the easiest prolly, just next to the belts. Front is directly in front of the engine and down next to the transmission. Rear is hard to see but is in the same spot as the front, just beind the the engine instead. The right, u have to look under the intake box, and is some what hard to find since u may not know where to look. You must remove the intake box to replace the right. The front and rear are connected to the front and rear crossmembers, and are typically removed by taking off the cross memebers first. You must support the engine with a jack with a peice of wood in between to prevent damage to the oil pan, or tranny (depending on how u support the engine/tranny) when replacing any of the mounts. Do one at a time and make sure the jack is supporting the weight properly by jacking up the engine just a bit before removing the mounts. Use common sense when supporting the engine/tranny.

OldUsedCelica
12-05-2005, 02:39 PM
Bought new engine mounts, installed them, and lo and behold... the sounds still there... I give up. Guess I am going to have to live with the sound.

If anyone else has any other idea... please post. And the link for the sound... well... I'm still trying to get it up and going.

schmooot
12-05-2005, 10:47 PM
just turn the radio up, its an old car it doesn't seem to be doing any damage.

And I would check your belt tension too

angryyoungnpoor
12-06-2005, 03:43 AM
Mine hums like a mofo for a good 5 to 10 minutes when it's cold. All I have is an intake. I think it's just normal. I don't mind it. Kinda makes it sound like a have a loud car. <-ricer.

Morwan
12-06-2005, 04:08 AM
I have the same problem, too. =P

When my friends first saw my car, it had been sitting in the cold for about a day... So when I started it up, they thought the roar was coming from my exhaust, not from my vibrating engine bay. Almost makes me want to buy an aluminum wing and some TRD stickers.

OldUsedCelica
12-06-2005, 08:17 AM
eh... Guess gonna go work on that Maverick now. I like my car quite, not sounding like it needs a muffler replaced. Dont get me wrong... I love the car, just not the sounds and vibrations it makes. (To those sick minded people, I did suggest my wife and we trade cars. Told her she would get more out of it then me hehehehe... *SLAP* OOooowwwww!!!)

I guess I'm gonna have to take the whole darn thing apart when I get the chance.

-Thanks again guys.