HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

Comments: 0

Latest topics
» ecotec swap
Yesterday at 11:03 pm by sharkey

» transmission fluid survey
Yesterday at 10:47 am by Rich L.

» Did anyone do a before and after weight?
Mon Jun 26, 2017 7:43 pm by yamamtx

» Late Spindles on Early Struts
Mon Jun 26, 2017 11:09 am by superman22x

» 1987 944 Turbo --> LS
Mon Jun 26, 2017 9:33 am by chrenan

» lS1 CONVERSION COOLING QUESTIONS
Sun Jun 25, 2017 10:23 pm by turbobob924

» Magnuson supercharged car?
Sun Jun 25, 2017 9:29 pm by yamamtx

» Always throwing code P0502
Sun Jun 25, 2017 3:39 pm by matty89

» Actual experience breaking an n/a transmission?
Fri Jun 23, 2017 3:59 pm by Jasonscottw

» RX7 Caliper Swap
Fri Jun 23, 2017 7:36 am by osx86ftw

June 2017
MonTueWedThuFriSatSun
   1234
567891011
12131415161718
19202122232425
2627282930  

Calendar Calendar

Log in

I forgot my password

weird vibration

View previous topic View next topic Go down

weird vibration

Post  matty89 on Tue Apr 04, 2017 11:43 am

hi guys i finished my swap up and now im getting a weird vibrant of the whole car between 2700-3100 rpms in any gear .... my keys shake my dash my seats .... its really a annoying . I dont want to wait for it to break the part of whatever. my car has a mail in tune and does have many parts mixmatch like a 2003 6L engine , a 2005 4.8 pcm( DBC) Ls1 intake, corvette injectors , truck throttle body , 5wire truck maf , custom headers 2.5inch to a Y pipe - catted back to 3inch from the Y and a straight thru magnaflow muffler

what i did :
checked for loose in the front end
verified tire balancement and put new tires ,

The vibrantion is only in these RPM`s before or after there is no vibration ... im asking my self if its the tune that i would have to get fine tuned on the dyno???

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  sharkey on Tue Apr 04, 2017 12:25 pm

if the engine seems to have smooth power delivery (basicly its not missing or bucking) its not likely the tune. does it do it all the time, or will it not do it at very light loads? myself i would check for something in the powertrain hitting the body, such as exhaust hitting something, oil pan touching the subframe, a bad engine mount, etc.

sharkey

Posts : 367
Join date : 2014-11-21

Back to top Go down

Re: weird vibration

Post  matt889 on Tue Apr 04, 2017 5:17 pm

I have no misfires or bucks... In data I have no misfires history . Fuel trims are close to zero. I have one check engine code it's high idle but I figure it's because I don't have the vss hooked up on the transmission yet.. my exhaust does hit the left axel when I do acceleration .. but cruising I can't see it touching .. it does it in all gears from 3rd to 5th in lower gears I can't notice it. When freereved it.doesnt shake (standing)

matt889

Posts : 136
Join date : 2015-04-03
Age : 28
Location : canada Quebec

Back to top Go down

Re: weird vibration

Post  Rich L. on Tue Apr 04, 2017 11:52 pm

This is odd and others have had similar problems. I'd guess something in the driveline isn't lined up right. What I'd suggest is to loosen slightly all of the fasteners in the engine mounts, rock the engine a bit and then tightening them all back up. Then do the same for the front and rear bellhousings.

Did you do a solid transmission mount? Maybe going back to a rubber mount would help. I filled my stock mount with urethane, the semi-solid trick.

How does the clutch feel? If you slip it a bit does it vibrate? Perhaps the clutch kit isn't properly balanced. This would suck to investigate if you don't know.

Good luck.
avatar
Rich L.

Posts : 801
Join date : 2011-05-30
Location : Seattle

Back to top Go down

Re: weird vibration

Post  matt889 on Wed Apr 05, 2017 6:14 am

For the engine mounts they are stock black one with a eurethan bushing from TPC.  
The rear trans mount is a late model I filled with eurethan windshield filler. I did install the transmission than the coupler didn't want to slide in the TT well so I slacked the transmission and angled it to get it on.could i unbolt the transmission coupler and make the car drive to that rpm and see if there is a vibration or for sure due to the coupler not ok the TT shaft will go crazy in there??

As for the.clutch I'm using the stock Porsche slave and the c5 throw out so the engagement is very low but I wouldn't say it's slipping.the clutch kit I bought for TPC it's clutch flywheel pressure plate and all new bolts from ARP . I didn't balance it I thought it was when.i bought it

I did bolt up the front bellhousing before installing the engine in the whole and.i.did move the engine a couple of time after it was installed. For the engine move it around I unbolt the angle bolt and the subframe.bolt or just the angle one ?

matt889

Posts : 136
Join date : 2015-04-03
Age : 28
Location : canada Quebec

Back to top Go down

Re: weird vibration

Post  Rich L. on Wed Apr 05, 2017 9:52 am

I don't know if it's a good idea to run the engine and spin the driveshaft without the trans on there. Maybe okay, but I don't know. Sounds like you already did get everything seated happily. I got the same clutch kit from TPC, mine seems to be balanced well. Sorry, not sure what else to suggest.

Rich
avatar
Rich L.

Posts : 801
Join date : 2011-05-30
Location : Seattle

Back to top Go down

Re: weird vibration

Post  Arthropraxis on Wed Apr 05, 2017 9:28 pm

I have a vibration around 3K RPM. The difference is the vibration is the same with clutch engaged or disengaged. So I know my vibration is somewhere in the engine but damned if I can find it.

I changed my clutch three times on two different clutches and got them balanced. It did get better with the LS7 clutch probably because of the flywheel weight absorbing some of the vibration.

Replaced the front pulley/harmonic balancer, tightened the header bolts, replaced the intake manifold gaskets and sealed up all the vacuum ports. All that made the engine run smoother at idle but did not change the vibration.

The only thing left is possibly a bent valve pushrod. I am not going through the trouble of pulling them.

I found through research on Corvette sites that this balance issue happens with Corvettes as they have the same drivetrain layout. They fix it with hot balancing. The mechanic uses a device that senses the vibration with the drivetrain intact while running. He then can add weights to the flywheel.

I gave up. From what I can find it is a NHV and will not damage the engine. I like that confirmation bias.  My car has been a daily driver for the last five years with no issues.


Last edited by Arthropraxis on Thu Apr 06, 2017 12:02 pm; edited 1 time in total
avatar
Arthropraxis

Posts : 1067
Join date : 2009-09-02

Back to top Go down

Re: weird vibration

Post  matty89 on Wed Apr 05, 2017 9:39 pm

with my vibration its more the whole car shakes * keys in ignition , water bottle , in ur seat , shifter , dash .... from what i can see nothing is loose. ... really annoying but hey i learned to drive slower that that or faster mine is only engaged as i cant sense this vibration when the car is stoped freereving if i push the clutch there is no more vibration when im say in the 3k peak

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  Arthropraxis on Thu Apr 06, 2017 6:52 am

If you can't feel the vibration with the clutch in and stopped, then it is behind the engine or the rolling assembly. Could be drive shaft or bearing related.
avatar
Arthropraxis

Posts : 1067
Join date : 2009-09-02

Back to top Go down

Re: weird vibration

Post  fantic on Thu Apr 06, 2017 8:04 am

I drove my car last night to try to replicate what you have. If I leave my hand on the shifter going through the gears I get a buzz in the shifter around 3k. Thinking maybe the coupler in front of the trans. For a vibration like you have it must be big. I had a truck that did that between 60 and 65 mph. Had to hold onto the cup in the cup holder. Found out I had a broken cord in a back tire.

fantic

Posts : 43
Join date : 2017-01-22

Back to top Go down

Re: weird vibration

Post  spence on Thu Apr 06, 2017 4:17 pm

Try loosening all the bolts on the torque tube adapter. Start the car then re-tighten the bolts. This might help center the torque tube shaft if its not quite centred.

What condition was your torque tube shaft and bearings before you installed the new motor?
avatar
spence

Posts : 526
Join date : 2009-07-21
Age : 35
Location : St.Catharines, Ontario, Canada

Back to top Go down

Re: weird vibration

Post  matty89 on Thu Apr 06, 2017 5:06 pm

spence wrote:Try loosening all the bolts on the torque tube adapter. Start the car then re-tighten the bolts. This might help center the torque tube shaft if its not quite centred.

What condition was your torque tube shaft and bearings before you installed the new motor?
the vibration is only driving for sure . the TT is probly OEM i didnt change anything on it . it didnt have severe wear on the tip and no major noise so i didnt change the bearings yet. when you say the Adaptor bolts u mean the 4 bolts that hold the TT assembly to the front bellhousing ?

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  zeusrotty on Fri Apr 07, 2017 9:15 pm

I've had the same issue. Might be harmonic balancer or possibly the flywheel?

zeusrotty

Posts : 429
Join date : 2010-07-30

Back to top Go down

Re: weird vibration

Post  matty89 on Sat Apr 08, 2017 7:02 am

zeusrotty wrote:I've had the same issue. Might be harmonic balancer or possibly the flywheel?
if it was the harmonic balancer wouldnt it do it all the time even parked ? and the flywheel how could i test it ? the balancer is new of this year with a new bolt weird is that its only between those rpms that it shakes my whole car

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  matty89 on Sat Apr 08, 2017 5:37 pm

**UPDATE** i drove the car today and i was looking for some loose nuts and i noticed it also does this parked ...i guess before i didnt notice it since i dont drive the car much but its the same vibration just a little less aggressive than when driving ... hope this lead to something easier to diagnostic.... thanks for all ur inputs i hope i didnt just burst ur bubble on the only driving part of my story :S matt-

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  sharkey on Sat Apr 08, 2017 5:55 pm

that makes a huge difference in the diagnostics. next question, does it to do it with clutch in and out, or only with the clutch out in neutral?

sharkey

Posts : 367
Join date : 2014-11-21

Back to top Go down

Re: weird vibration

Post  fantic on Sun Apr 09, 2017 8:34 am

That helps a lot with diagnosis. You said the harmonic balancer was changed this year? A friend of mine replaced his with an aftermarket one. Can't remember brand. It kept coming loose. Since there is not a key on the crank it could slip. Also I put a " lightweight racing flywheel " on my Camaro when I was 16 and it buzzed like crazy. I put the stock one back on. I feel your pain. Been chasing a misfire for 2 weeks now. Good luck.

fantic

Posts : 43
Join date : 2017-01-22

Back to top Go down

Re: weird vibration

Post  matty89 on Sun Apr 09, 2017 9:58 am

sharkey wrote:that makes a huge difference in the diagnostics. next question, does it to do it with clutch in and out, or only with the clutch out in neutral?
so parked in neutral it does it , when driving it does it at the same rpms so 2700 ish to 3100 rpms . for the balancer its a doorman from rockauto with a new bolt !i dont have a flywheel lock so its torqued with my 1/2 impact gun . the only tests i did is in neutral stoped ( i called parked idle ) and driving on the freeway in those rpms . it shakes more when its in decelleration of those rpms also i noticed ... only drove the car 3-4 times since hibernation stoped here in canada

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  sharkey on Sun Apr 09, 2017 12:38 pm

i would try testing it again at a stop with the clutch pressed and transmission in gear. if the vibration still happens you can rule out torque tube and transaxle and look specifically engine/clutch/flywheel.

in my experience you cant get away with an impact gun for an ls balancer bolt. you either dont get it tight enough and it can loosen off, or it over stretches the bolt and the bolt can break. i would replace the bolt, id recommend an arp bolt because you wont have to replace it next time it has to come off, and you dont have to worry about getting the torque angle correct as its not torque to yeild. and to torque it put the transmission in 5th with the parking brake on, or have someone step on the brakes.

sharkey

Posts : 367
Join date : 2014-11-21

Back to top Go down

Re: weird vibration

Post  matty89 on Sun Apr 16, 2017 10:42 am

sharkey wrote:i would try testing it again at a stop with the clutch pressed and transmission in gear. if the vibration still happens you can rule out torque tube and transaxle and look specifically engine/clutch/flywheel.

in my experience you cant get away with an impact gun for an ls balancer bolt. you either dont get it tight enough and it can loosen off, or it over stretches the bolt and the bolt can break. i would replace the bolt, id recommend an arp bolt because you wont have to replace it next time it has to come off, and you dont have to worry about getting the torque angle correct as its not torque to yeild. and to torque it put the transmission in 5th with the parking brake on, or have someone step on the brakes.
if i understand correctly you want me to PUSH THE clutch pedal to the floor and put it in first still fully pressing the clutch pedal to the floor and rev it to the RPM it vibrated in ? can i just press the clutch pedal to the floor and rev it for this test ? im trying to understand why put in 1st ? if the clutch is fully pressed down i retorqued the balancer thinking it was that it whent a little i put it at 250 lbs i cant do the 140* i took the strap off to see and i find it vibrates more with no strap... weird i have yet to retry the car since i retorqued the balancer !

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  sharkey on Sun Apr 16, 2017 1:36 pm

thats exactly what you need to do. the reason for putting it in gear (any gear will work) is in neutral even with the clutch pushed in a slight drag on the clutch disc can make the input shaft turn, putting the trans in gear ensures the driveshaft cant turn.

since you have made a change, try it in neutral with the clutch out again, make sure you can replicate the vibration. once you have done that, try it with the clutch in/trans in gear. this will let you know if your dealing with an engine vibration or torque tube/trans.

the balancer bolt, that could be an issue in the long run. the torque to yield bolt just sucks, its hard to get proper torque on it in the car. ive had one where i torqued it to 250 like people said, it proceeded to spit the thing out after 5 dyno pulls. the problem with doing it to a static torque is its not designed that way. any time i pull a balancer off an ls it gets an arp bolt, they are around $30 canadian and its never a problem. and you can torque them to a static torque number, no more torque to yield and stretching bolts.

sharkey

Posts : 367
Join date : 2014-11-21

Back to top Go down

Re: weird vibration

Post  matty89 on Tue Apr 18, 2017 7:24 pm

does it when its in gear and clutch pressed down !!! guess we are looking at a balancer or a flywheel combo not balanced

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

Re: weird vibration

Post  sharkey on Tue Apr 18, 2017 10:13 pm

you are for sure looking at something engine related. you could go one step further and remove the belt, this would rule out the slight possibility of the an accessory causing it, although i highly doubt it. its likely clutch/flywheel or balancer.

tell us more about your engine. is it a take out thats never been apart? or is it something thats been built?

sharkey

Posts : 367
Join date : 2014-11-21

Back to top Go down

Re: weird vibration

Post  matty89 on Wed Apr 19, 2017 11:46 am

sharkey wrote:you are for sure looking at something engine related. you could go one step further and remove the belt, this would rule out the slight possibility of the an accessory causing it, although i highly doubt it. its likely clutch/flywheel or balancer.

tell us more about your engine. is it a take out thats never been apart? or is it something thats been built?
2003 LQ4 6L engine out of a junk yard express van i took it apart and rebuilt it , my alternator just let go on me so now im on that .... i might try loosening the engine mount bolts the angle part and start the car up to see if its just not well seated ? the clutch kit was from tpc.... flywheel was branded jegs and pressure place i dont remember ...

matty89

Posts : 43
Join date : 2012-04-15

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum