Lots of vibration in pedals and cabin - Please guess and suggest.

So my 02 C4 isn't acting right again. I'm getting a ton of vibration in my pedals, steering wheel and console. This is with the car in neutral sitting still or with the car in motion in or out of gear. I really feel the vibration in the clutch pedal right when I have it pushed about 1 inch. The further I press it to the floor the lessor the vibration gets (in the pedal). The intensity of vibration also increases with RPM's in the clutch pedal, throttle and in the car. At 3-3.5k RPM's the car starts to sound different. It's like I can possibly hear the vibration at the same pitch as the exhaust. I can't tell exactly what the sound is but I do know it's different. My first thought was the motor mounts. I replaced them but it didn't fix the issue. Would a bad transmission mount cause this? For the record I believe the transmission has not been removed from the car for any repairs. At this point it's sitting in my garage because i'm scared to drive it even to the shop. I'm open to any suggestions and will try to find a good deal on a durametric tool if that could help. A bit more information in case you think it's related. The problem seemed to have started around the day I was cursing down the highway behind a few cars and we all hit a dead deer in the middle of the road. It went right between my front wheels and right out of the back. I did felt it hit the bottom of the car. Not 10 feet later I took a fresh dead raccoon under my passenger side front and rear wheel. Neither left apparent signs of damage on the car. I can't say positively that this was the day it stared because I was too angry at myself for following to closely or not passing everyone sooner. I'm doubting this caused it but thought it was worth mentioning. Edit I'd also like to add that the car shifts perfectly especially after the new motor mounts. I also have no other issues with the clutch other than an occasional chirp noise at take off in first gear. It's done that since I got it 20 months ago. There also doesn't seem to be any decrease in engine performance. I did see a couple tiny glittery specs in my oil filter during the last oil change for the first time. I'm going to change the oil tonight to see if I find anything unusual.

Did you check out the underside of the car after you hit the deer? It could be driveshaft related. There could be something wrapped around it or caught between the shaft and the tunnel (causing it to be out of balance). It could also be the transmission mount is torn/collapsed (accounting for the vibration when you're sitting still)...

If it is vibrating in neutral and the car is not moving, that would eliminate a lot of drive train issues. Maybe it is the dual mass flywheel damper and clutch assembly. Running over a dead deer in the road sounds pretty bad. Glad you came out all right.

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I didn't notice anything caught under the car at all. I can't inspect the transmission mount with the transmission in the car correct?

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I had thoughts of it being the flywheel too. Do you think any internal parts of the engine could cause the vibrations? Crank maybe? Now I'm also wondering if it could be something from the exhaust system that could be sending the vibrations. Seems unlikely because it's quite powerful in the clutch pedal but I will inspect it tonight after the oil change. I will also try to pick a better word than vibration and try to figure out what i'm hearing. I do know that when I get out of it after a drive my hands and feet are tingling. I've been doing a lot of reading and everyone seems to have different symptoms. I'm really hoping whatever is happening is unusual and a simple fix but then again don't we all. Driving over the deer wasn't too bad. All the cars in front of me got the worst of it. I think...

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I believe you can add something like Function First's inserts without dropping the motor? http://www.pelicanparts.com/catalog/...pg3.htm#item12 "Installation can be completed with basic hand tools in about one hour. Pressing out the stock transmission mount bushing is not necessary."

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Thank you. At this point I will try about anything to avoid tearing in to the tranny. I will probably order it tonight.

If you can get the car up in the air and support the transmission, you can remove the two brackets that mount the transmission to the engine, at which point you could look at the transmission mount. I'm not sure what that would tell you, other than perhaps if the rubber is badly degraded. You may be able to put a screwdriver in the metal center section and twist it to make any cracks more visible. My transmission mount was pretty shot, but on a quick visual inspection it wasn't obvious. Once I tried to twist the center section, it became apparent how damaged it really was. The function first insert won't fix a failed mount. It'll just stiffen up a good stock mount. Since we're playing the guessing game, I guess that is is a failed dual mass flywheel.

First job I would remove the undertrays and inspect, it sounds like something is transferring the normal engine vibrations through the body, could be something wedged where you can’t see, worth a look before the spending begins, maybe on top of the gearbox there’s a dead raccoon , poor bugger!

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You are the second vote for the flywheel. You are thinking it wouldn't be worth installing the FF transmission mount just to see? I'm ok with a few small wasteful purchases to avoid going all in if I have too. For those who think it's the flywheel what damages would that cause if I drove it more? Would a flywheel just fail over night or over a couple days time?

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lol.. well said! I think I might go look now since I didn't get to change the oil because it was sold out.

I�m with everyone on pulling the belly pans to inspect. That�s cheap. Inspecting the transmission mount is cheap. Just a couple of bolts while supporting the transmission. That said, I will guess flywheel too. If it failed and is stuck weirdly it would cause vibration. Not crazy hard to replace but costs about $700. Plus it�s the kind of job that will have you spending on the clutch, RMS and IMS (unless you are sure when/how it was last done.) I am doing a job like this now so a little too familiar with it right now. Good luck.

I did have the chance to start it and focus on the vibrations more. I used my hands on the pedals instead. Mainly the clutch. When I started to push it towards the floor (the first 1-2 inches) while raising the RPM's the clutch felt a lot like it were pulsating. If it were the dual mass flywheel what would actually be wrong with it. Warped or bent? Would the pulsating be the rotation of something bent? Just after start up I walked around it and touched the panels and they seem to be vibrating more than usual too.

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Kind of what I'm feeling. I just needed to replace a strut mount which ended up being 2 strut mounts, an axle, lower control arms, bushings, H&R sport springs and motor mounts. All those darn while you're in there things that fixed so many issues except for this big one. Such high maintenance but she sure is pretty. I will be checking everything suggested before making any big decisions and continuing not to give up on what i signed up for.

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Just thinking out loud but if a spring failed it would vibrate strangely. Maybe some impact shock from the deer? But I�m really just making a WAG.

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Nice thought. The vibration was happening before I installed everything. I felt almost 100% sure it was the motor mounts causing it so I replaced those and other suspension components that were acting up. That darn deer took a ride through the old springs. Besides, the vibration is both while moving and sitting still regardless of clutch position. You can feel it at idle and it drastically increases with RPM's. I haven't taken it over 4k RPM's to see how it feels. I'm a bit nervous to do so.

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I should had said if one of the springs or components in the dual mass flywheel failed it would vibrate.

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I am not a fan of throwing parts at problems, but I don�t see any harm in installing the function first piece. I suspect it will increase the vibration, since it makes the mount stiffer. The dual mass flywheel has two big hunks of steel, one attached to the end of the crank, and another that contacts the clutch disk via friction (clamping the disk between the pressure plate and the flywheel). There is a dampener between them to absorb driveline shock. If the dampener goes, it could cause vibration in the driveline. No way to know for sure without removing the transmission, taking off the pressure plate and the clutch disk, and doing the twist test from the shop manual.

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Of course you can. Just put a jack under the transmission so it doesn't fall when you remove the mounting plate/bracket...

Hmmmm, after reading through all the posts it seems like you're trying to diagnose the problem by committee without actually doing any work/getting your hands dirty - Not a good idea. It really doesn't matter what anyone here speculates on - go out and get under the car (make sure it's properly chocked and supported) and figure out what's going on...Obviously if it's nothing that you can see on the outside, it must be something on the inside - start with the simple stuff (what you can see) and go from there...

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No way. My hands are dirty alright. The community got me through this journey last week on another thread. ( https://rennlist.com/forums/996-foru...ncluded-3.html ) You included and I appreciate that. First time I've ever touched anything suspension related. My car is now back on jack stands with the front panel off. Going to remove the rear panel tonight and inspect everything I can see. If I see nothing and end up with the majority say it's the flywheel without needing any more information, that makes me a little more comfortable with the decision to spend 4-5k to fix it, and the while you are in there items. I was really hoping that someone would be like mine did just that and I did this simple thing to fix it. I don't think I'm going to be that lucky though.

Awesome, looks like you are right in there and aren't afraid to get your hands dirty. I'd say that pulling the transmission and swapping out the clutch/flywheel assembly is 3x more work than the suspension (off the top of my head). If you go the DIY route, you'll want a good tool set (lots of extensions to get at that top mounting bolt), make sure you have a M10 triple square, a torque wrench, buy or make an engine support bar, and grab a transmission jack (can be purchased inexpensively at Harbor Freight). The rest is just R&R. You may want to get your car higher off the ground too (so you can slide the transmission out easily). Sachs makes a clutch kit and Luk the flywheel - shop around and you can find better prices. Replace all the mounting bolts (flywheel to crank, pressure plate to flywheel) and consider whether you want to do any "while you're in there" items - IMS bearing, RMS, transmission input seal, clutch actuation arm, pivot etc. I didn't add it up, but I think I spent under $1200 in parts when I did a clutch recently, the flywheel being the most expensive part.

Did the motor bottom out on the deer?

Verified that none of the exhaust got smashed into contact with something it's not supposed to be touching? Those muffler mounts are STOUT, but I've never smacked on mine with a deer. And a raccoon.

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I'm not sure really. I didn't se any signs that it did. It didn't do any front bumper damage so I'm thinking it couldn't have hurt much under there.

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Fair enough then! Unfortunately, that's what needs to be done. Once you've eliminated all the stuff on the outside, it's probably time to drop the engine/transmission and check out your clutch and flywheel - certainly not the end of the world, but better done sooner rather than later. The upside is that while it's not inexpensive, relative to some engine work it's not bad at all, and it's comparatively easyto do - Good luck

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It's hard for me to inspect all of this from jack stands so I took it down and put the wheels back on. I'm taking it down the road tomorrow to my friends shop to use his lift at noon when they close. I'm starting to have a little more hope that it's exhaust related. When inspecting things yesterday more I noticed that the exhaust sounds like it has a lot more bass to it than usual and I can feel the vibration in my wheels and tires. But maybe this was caused by the new motor mounts. I raised the RPM's to around 5k and held it. Once the exhaust was in a higher pitch range the vibrating/pulsating turned into a tingly feeling. Gosh I hope I find something tomorrow!

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Thanks for the info! Honestly though the thought of it being 3 times more work than the suspension is going to make me look over this thing with a fine tooth comb and then pay the shop to do it if I find nothing wrong.

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3x more work? Eh, I don't know... I did my suspension (struts, springs, sways and drop links, and front wheel bearings) - it wasn't much less than dropping the engine/tranny. Granted I've got a C4 which is a little more involved due to the front axles. Dropping the engine/tranny is not difficult, but there are a whole bunch of ancillary things that need to be removed (under-body trays, axles, clutch slave cylinder line, transmission cables, suspension braces [cross brace and angle braces], rear sway bar, headers, mufflers/cats, rear bumper cover and other bumper parts, rear wheel liners [not totally necessary but it makes access and visuals much easier] all chassis to engine wiring connections, chassis to engine fuel line, coolant lines, power steering lines etc...- once again, not difficult but pretty involved - make sure you've got plenty of tape/labels and zip-lock bags/containers for nuts/bolts, connectors etc. The main thing I would recommend is that you get the car up much higher than it is in the photo. For me, the magic number was 25.5" and I was just able to roll the engine/tranny out from under the car. By doing my own work I saved about $5k - The way I like to look at it is that I payed myself $5k - perspective is everything!!!

Maybe not 3x, but just trying to convey that it is more complex. I found swapping in coilovers (preassembled), swaybars and drop links very straightforward and fast work, using no special tools and having no contortionist moves. The transmission drop had a lot more to it, first removing a lot more bits before you get to the actual drop, getting to the slave cylinder, getting at those top mounting bolts, balancing the transmission on the jack, and aligning the input shaft upon reassembly. I also had to procure a specialized transmission jack and an engine support bar, so for me it seemed like a lot more work and a lot more time. As they say, YMMV.

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The only things that make me cringe about doing it myself really are the darn rusted/corroded bolts or the bolts that strip out. They really get the 4 letter words a rollin and I end up with DIY remorse. I might as well buy 10 cans of PB blaster and keep soaking every bad looking bolt I can see to make current and future work easier for me or someone else. I love your perspective with paying yourself! lol I will let my wife be the deciding factor if I do it or not when I show her the shop quote if it comes down to it. I could buy a small lift with the savings

Have you checked your CATS? I've never had one go bad but maybe someone with first hand experience could chime in.

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Haven't checked them. Was actually just reading something about that earlier. Someone said to test it just hit it a bit with a rubber mallet while the car is off to see if you can hear something moving in it.

A chunking catalytic converter can add significantly to the noise, but the in-cabin NVH OP complains of sounds much more drastic than what I can attribute to a failing converter. A bad cat is a "wow, that's annoying; even more with the window down" kind of sound, not a "lots of vibration in pedals and cabin" kind of sound. I'm inclined to think that tenderizing several hundred pounds of wildlife with a single thump is profoundly involved with OP's issues, but I'm a sucker for the classics.

I would have to say it has something to do with your flywheel and it's an imbalance issue, something moved when you hit the deer.

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If you do go this way check out Parts Geek Pricing for DMF and Clutch. https://www.partsgeek.com/catalog/20.../flywheel.html Cheapest I could find (unfortunately do not ship to Canada). And Ahsai did point me in this direction.

^and remember to use the SAVE15 coupon to get $15 off

Myself and 2 other mechanics looked over the bottom of the car thoroughly on Saturday and found nothing that could be the cause of the vibration. Also no animal remains on the bottom of the car. They actually brought up too that my exhaust sounded louder/different with more low end than last time I was there. It seems both unlikely the flywheel or the new motor mounts would alter the exhaust sound at all. I'm taking her in to a Porsche Indy on Wednesday morning for them to check out. Fingers crossed they figure it out at a reasonable cost.

Took it to the pro's. They said out of balance flywheel and worn clutch. What a bummer. They also said my clutch pedal was about an inch higher than it should be which I found odd. Anyways looks like it's time to spend some money.

How many miles on the flywheel?

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77k

Their diagnostics seems to match your issues perfectly, nothing fishy here.

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My car has the exact same symptoms and has 70k miles. Will be going in for this exact service in April. I heard it can really change the feel of the car, so I am pretty excited.

How dies a flywheel get “out of balance”? Is that shop speak for a failed dual mass flywheel?

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my thoughts too.

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yes You Tube I think this guy drinks a lot of coffee. Look around 1:37 to see why you get vibration. You Tube

^^ That was a good explanation of what is happening. Mine has the clutch vibration feedback but none of those noises yet. Must be in the beginning stages of failure. Would it be possible the crankshaft could be a little bent which would cause the flywheel to seem "off balance" I do see some wobble with the harmonic balancer but it doesn't look any different than it did 6 months ago.

Well I just got my car back from the shop. They installed new clutch kit, IMS, RMS as well as trans and diff mounts. They confirmed there was nothing wrong with the flywheel and suggested not replacing it. While it was in there they also replaced the driveshaft flex joint, both stabilizer bars and both front sway bar links. The car feels much better along the lines of performance than before. Unfortunately the vibration issue is still there and it's so bothersome. Just to recap the issue. When it's running and the car is in neutral and you put your foot on the clutch pedal and push it barely you can feel a vibration/pulsating sensation in the pedal. You can also feel it in the accelerator and steering wheel. The vibration/pulsating intensifies when the RPM's are raised (especially 3k and up) to the point you can easily feel it if you were to touch almost any spot on the car including the wheels so it makes it difficult to find where it's coming from. It's the same vibration/pulsating in or out of gear. I do think that there is a tiny improvement though after they replaced the trans and diff mounts. I installed the Function First v2 motor mounts back in October because my tail pipes were 1.5 inches from the bumper and I was experiencing this vibration issue. Maybe the vibration was there because they were bad and now it's still there because i installed them wrong? I'm thinking not. Are there any other things I could do to troubleshoot this? After this last shop visit I really can't afford to have them misdiagnose it again.

You took it to a shop, they replaced a crap ton of stuff, and didn't fix the issue. How is that okay? Aren't they the professionals? If they can't figure it out in the shop, I'm not sure there is much more people can do from afar over the internet. I have the Function First motor mounts and a Rennline street performance transmission mount in my 2000 and it doesn't have any unusual noise, vibration or harshness. I doubt that is the issue. I'm not sure how you could install motor mounts wrong, but I suppose anything is possible if you try hard enough. The source sure sounds like an issue with something that is rotational on the motor and transmission assembly. I'd rule out all of the driveshaft and rotating assemblies outboard (since you aren't driving and still get vibration) including wheels brakes, wheel bearings, etc.. Other than the DMF, I don't have ideas for you. For the couple of hundred bucks the DMFs cost, I would have had them replace it anyway while they were in there... You need someone more experienced than I can offer. Sorry. Good luck!

DMF. I had bad vibration too. The flywheel appeard to be good, no excessive play or anything. But something was broken inside. I replaced it and it is all good now.

Considering the flywheel is the only thing they DIDN'T replace... it really seems to be the culprit with the symptoms you describe.

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You're right. I called them yesterday and they told me to bring it in. Hopefully they cooperate and figure this out on their dime. I've paid them enough.

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Was it figured out there was something broken inside before the car was put back together? I would've told them to just replace it but he called me and said it was good and he recommended not paying the $1000 to replace it.

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True. I keep wondering if it could even be in the engine or the harmonic balancer or something. I don't know these engines as much as i'd like to. I need to get it back to the shop in the next couple days and hopefully if they conclude again it's the flywheel they take full responsibility for their screw up willingly.

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Good luck with this^^^ If they're interested in "doing the right thing", they'll (offer to) replace the flywheel for the cost of the parts only - they may even let you buy the flywheel and give it to them to install (in other words, give you the part at your actual cost -not their inflated "cost" or cost + markup). The potential downside to this scenario is that they do a "rush job" and actually damage something else without telling you. Bad situation all around... I hope it works out well for you.

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A flywheel with new bolts is less than $600 (I think I paid in mid $400's but am questioning my memory). Luk, original equipment manufacturer. Labor wise, they were almost there when they replaced the pressure plate. Good luck.

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I replaced it myself. It was the only logical conclussion I could come up with. I only paid 400 for a new one.

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Zombie bump. What else, if anything, did you replace in addition to the DMF? I suspect mine is nearing the end of its life but the clutch is only 3 years old (15,000 miles). I'd like to not have to replace the clutch again if I don't have to. I'll be doing the work myself so being "in there for the cost of labor" isn't an issue as it pertains to other parts.