Clunk When Engine Starts, Broken Mount?

[Ski Bum]

Ever since I've had my GSX the engine clunks when I start it as if the torque is causing a broken motor mount to shift. So I replaced the front, drivers side (which was broken) and passenger side mounts with Proflex polyeurethane inserts. The only mount that is stock is the smaller mount directly under the intake manifold (really tough to get at). I cannot really tell if the mount is broken but if it were would that cause the engine to clunk like that when starting? Is there another mount somewhere that's related to that sort of engine movement?

 

[Ski Bum]

Sorry to bump my own thread but its been a day and no reply yet.

 

[majik2k5]

If it is that mount, then you would notice that clunking anytime you put a load on the motor more than likely. Like getting on it hard, or driving up a big hill. Things of that nature. Do you experience any of these?

 

[Ski Bum]

If it is that mount, then you would notice that clunking anytime you put a load on the motor more than likely. Like getting on it hard, or driving up a big hill. Things of that nature. Do you experience any of these?

Not at all then motor seems firmly planted while driving. The only clunking I experience while driving is when releasing the clutch while entering the next gear on the tranny (114k miles on her)

 

[wolf20043]

Not at all then motor seems firmly planted while driving. The only clunking I experience while driving is when releasing the clutch while entering the next gear on the tranny (114k miles on her)

Just a suggestion from a friend of mine with the exact same symptoms. His '93 was doing it a lot and finally stopped going into gear all together. Turns out, the flywheel bolts were slowly coming out and finally gave in. If it is possibly the rear mount, you should be able to get to it, although it is a PITA. I usually just pull the one bolt from the timing side motor mount and lift just slightly on the motor from the oil pan and use a really long extension to get to the three bolts that hold the mount to the frame and jack it up a bit more to slide it out. Amazing what a 3 ft long extension can do for you in tight places.
Mike

 

[Ski Bum]

Just a suggestion from a friend of mine with the exact same symptoms. His '93 was doing it a lot and finally stopped going into gear all together. Turns out, the flywheel bolts were slowly coming out and finally gave in. If it is possibly the rear mount, you should be able to get to it, although it is a PITA. I usually just pull the one bolt from the timing side motor mount and lift just slightly on the motor from the oil pan and use a really long extension to get to the three bolts that hold the mount to the frame and jack it up a bit more to slide it out. Amazing what a 3 ft long extension can do for you in tight places.
Mike

I really hope that my flywheel is not the culprit with that particular clunk.

As far as the rear mount, I may be pulling the head here sometime so that seems like the time to replace that mount.

Thanks.

 

[blazebolt]

Not at all then motor seems firmly planted while driving. The only clunking I experience while driving is when releasing the clutch while entering the next gear on the tranny (114k miles on her)

I had similar symptoms and it was my rear motor mount. When it was in gear it was fine, it's when I shifted, stepped on the gas pedal hard after braking, or stepped on the clutch while putting lots of torque to the wheels (sometimes) that I would hear a clunk. I just replaced it last week and no more clunk.

It's not so much a PITA if you have the right tools. What got me stuck was nut on the long horizontal bolt connecting the mount to the engine. It's really tight down there and my regular 14mm socket could not fit over the long bolt. After practically giving up doing it the hard way with a flare nut wrench, I discovered I had a 9/16 deep socket that fit perfect. I put my 14mm on the bolt on the other side and braced it against the firewall, the deep socket on the nut, and got that nut off in no time. The 3 bolts holding the mount in was cake as I had tons of extensions that allowed me to access the bolts from above the engine. Then it was just a matter of wiggling the mount out. Now I could ###### get all the bolts off in 5, 8 minutes tops.

 

[wolf20043]

Exactly, you never know when you will need all 14 ft of extensions put together, but when you find out you are happy you bought them.
Mike

 

[majik2k5]

Sounds like the rear motor mount. It doesn't appear to clunk at all whenever you apply any load to it; However, it appears to do the clunking when you release the load off the motor. Atleast, this is the idea I get from what you're saying.

 

[Ski Bum]

Sounds like the rear motor mount. It doesn't appear to clunk at all whenever you apply any load to it; However, it appears to do the clunking when you release the load off the motor. Atleast, this is the idea I get from what you're saying.

That may be something totally unrelated. The clunking while driving is when I release the cltuch going into gear. It feels as if the drivetrain is just loose if I slowly realease the clutch (slip it a bit) there is no clunk.

The only time the engine clunks for sure is when I start the car. The initial torque when it fires causes somehting to clunk. Now I'm not sure if the two instances are relted but I guess I will find out.

I had a thought last night as I was working on my other GSX (1990) that doesnt have cruise control. The throttle cable box is mounted near the air box in that setup. With that box out of the way I could reach down easily and touch the rear mount. I might see if unbolting the throttle cable box on my 91 would make it any easier.

 

[GVR4592]

Could be a U-Joint or the carrier bearing, if it isn't a mount. If you have a broken mount it's pretty easy to tell.

 

[Ski Bum]

I thought I'd ad a bit more information regarding the feel and occurance of the clunk.

When starting the car there are actually 2 clunks. The first is immidiately when I turn the car and the starter motor engages. Then as the the engine turns before combustion it is smooth. It is taking about 4-5 turns/revolutions before it fires up at when it does the second clunk occurs identical to the first clunk.

Other then at that time the engine feels planted. Does that still sound like the rear motor mount?

 

[highpsi93tsi]

How about you look at the rear mount while someone else starts the car up? These are odd issues, mine makes a snapping noise when I hit the gas, I have a metal on metal hitting noise when driving (sometimes) and a severe shimmy in the d/s front end somewhere. Iam laying all the bets on balljoints..YOURS? I actually had all my flywheel bolts come out, if the clutch is laying on the floor or it makes a wicked noise when driving thats the culprit. I'd just look under the hood while a buddy hammers on the gas pedal, or pull the throttle cable yourself while under there.

 

[cfisher]

I've been having something strange happen as well but it is only when I start the car and only if it is cold outside. The colder it is outside the longer it takes for the clunk noise to appear. It seems for the past 6 months or so, I'll start he car and about a second later I hear a clunk or something and then it is gone. I have no noise when driving but it is just when I first start the car. Sometimes when it is really cold out it takes a couple seconds and then I hear it. I'm hoping this has nothing to do with my crank.

Also the noise is coming from right where my clutch pedal is.

 

[blazebolt]

Where are the clunks coming from? When my rear motormount was bad I could actually feel it right next to/under my feet. The rear motormount is located right next to the firewall. If that's where the sound is coming from or where you feel it, then go ahead and replace it