when RPM drops, back of the car vibrates left and right

[ttttttttttaa]

sorry to bother, but i am about to get the car tomorrow, so need some answers

Car model: 2001 Carrera 4

Tran: 6 Speed Stick

Milage: 63,000 mile

My first question is:

when I start the car (parked, with hand break), I rev up to 2k-3k rpm and up, when the rpm is going up, the car is stable and engine sound really nice.

But after I release the gas, when the rpm is dropping, I felt the back of the car vibrating left and right.

I know, porsche has H6, so 3 rows. the left and right cylinder should cancel out the vibration and make the car stable.

so i guess in my case, the cylinder didn't cancel each other (not running at the same time, maybe?)

is this normal?

Second question is:

My friend told me, Carrera 4 is the one most likely to have the RMS problem, it that true?

If i park the car for 1 hour, am i able to see the oil drop? (I am going to try it at dealer's place, before i buy it)

It is my first porsche, please forgive me for asking these stupid questions.

once again, thanks

Edited February 17, 2008 by ttttttttttaa

[vette67]

sorry to bother, but i am about to get the car tomorrow, so need some answers

Car model: 2001 Carrera 4

Tran: 6 Speed Stick

Milage: 63,000 mile

My first question is:

when I start the car (parked, with hand break), I rev up to 2k-3k rpm and up, when the rpm is going up, the car is stable and engine sound really nice.

But after I release the gas, when the rpm is dropping, I felt the back of the car vibrating left and right.

I know, porsche has H6, so 3 rows. the left and right cylinder should cancel out the vibration and make the car stable.

so i guess in my case, the cylinder didn't cancel each other (not running at the same time, maybe?)

is this normal?

Second question is:

My friend told me, Carrera 4 is the one most likely to have the RMS problem, it that true?

If i park the car for 1 hour, am i able to see the oil drop? (I am going to try it at dealer's place, before i buy it)

It is my first porsche, please forgive me for asking these stupid questions.

once again, thanks

Mine is a 2000 cab 4 so I believe you have a different engine and a few other things. Could you be feeling a clutch problem? As far as RMS there are several posts on this site and/or on rennlist.org with photos and detailed descriptions on what an RMS leak looks like. My understanding is that they were not any more common on AWD models than they were on RWD and most often seen on MY's earlier than yours.

Edited February 18, 2008 by vette67

[ttttttttttaa]

Mine is a 2000 cab 4 so I believe you have a different engine and a few other things. Could you be feeling a clutch problem? As far as RMS there are several posts on this site and/or on rennlist.org with photos and detailed descriptions on what an RMS leak looks like. My understanding is that they were not any more common on AWD models than they were on RWD and most often seen on MY's earlier than yours.

I don't think it is the clutch problem, since I was in nutual. when i was driving all the viberation are gone, the car, engine and clutch run smoothly.

I do know when people rev engine, the engine will viberate, since most of cars' engines are I-6 or V6, the cars cars vibrate up and down.

I just never had H6 before, and don't know if it is normal.

I though 1999-2001 they all have the same engine.

but same or not, since you has H6 as well, did you feel the car viberating left,right,left...?

thanks

[Loren]

So does the engine really stumble when you back off the gas? or could it be something like a loose rear swaybar?

An RMS (or IMS) problem may be a few drops from the center of mounting point between the engine and transmission or a gusher.

There are a lot of cars out there that have no RMS/IMS problems but there are a good number that do. So I would not worry unless you starting seeing an oil puddle under the car - and confirm the location where it is coming from. There are other places oil leaks can occur.

[flyingpenguin]

See if you can get your hands on a Durametric cable and check the idle rpm's. Often times the throttle body gets fouled up with crank case return fumes and idling becomes rough. A simple removal of the air box provides access to the throttle body and cleaning with a bit of carb cleaner and rags around the butterfly valve will usually do the job.

Rgds, JP

[ttttttttttaa]

So does the engine really stumble when you back off the gas? or could it be something like a loose rear swaybar?

An RMS (or IMS) problem may be a few drops from the center of mounting point between the engine and transmission or a gusher.

There are a lot of cars out there that have no RMS/IMS problems but there are a good number that do. So I would not worry unless you starting seeing an oil puddle under the car - and confirm the location where it is coming from. There are other places oil leaks can occur.

thanks, i think i will worry RMS/IMS later.

but for the engine, when i back off the gas, it is like vibrating .5 cm left and right. to me it felt like,

for each row,

the left cylinder goes in (or compressed), it makes the car to the right, and when it goes out (gas+air+fire), it will make the car go left,

the right cylinder goes in, it makes the car to the left, and when it goes out, it will make the car go right,

so the vibrations should cancel out. (may not be all rows, but for each row, both left and right cylinder should go in and out at same time)

in my case, it just made me felt, when i gave the gas, the vibrations were cancelled (very smooth).

but when I back off the gas, felt like the left cylinder is out, while right cylinder is in. and because each row were moving differently, the car vibrated.

sorry being paranoia, it just because i asked other owner of Carrera, he told me it may be either one of the cylinder of that car is cracked or the engine mount needs to be change. the cylinder is cracked part is scaring me :(

Edited February 18, 2008 by ttttttttttaa

[ttttttttttaa]

See if you can get your hands on a Durametric cable and check the idle rpm's. Often times the throttle body gets fouled up with crank case return fumes and idling becomes rough. A simple removal of the air box provides access to the throttle body and cleaning with a bit of carb cleaner and rags around the butterfly valve will usually do the job.

Rgds, JP

Hey, Jp, thanks for reply,

So do you have the same experience, vibration left and right? or you heard from others who had the same issue?

because, if it is just cleaning issue, i will just get the car.

as i know, boxer engine lie horizontally opposed. This type of engine should runs perfectly smooth and free of vibrations - regardless of number of cylinders.

As you can see in the picture, a pair of pistons are not only always in the same position but also move with the same speed - only into different directions so that all vibrations are cancelled.

I guess in my case, when I release the gas, for some reasons, they didn't move with the same speed,

Because my friend who owned carrera, said it may be either one of the cylinder of that car is cracked or the engine mount needs to be change. the cylinder is cracked part is scaring me. :(

what is Durametric camble? sorry being a newbie,

when the car is in idle, the car is not vibrating left and right,

it only happened when i suddenly release the gas when the rpm is about 2k-3k or up.

I am hoping cleaning the the throttle body will do the work (from Farfax and AutoCheck, the car is being sit since 9/15/2006 til now)

thanks,

I only have 18 hours to make the decision.

Edited February 18, 2008 by ttttttttttaa

[doubleb]

If you want to be sure (and you should be!) have a PPI (Pre Purchase Inspection) done by a respectable specialized Porsche shop. I cannot emphasize enough how important that is. FYI, if you buy the car and the engine (cracks?) blow up in notime you're looking at 10-15K costs to repair!

What should be one of the best experiences (to own a Porsche) will become a nightmare. Take it from someone who learned the hard way.. ;-) (just very persistant.. haha).

Don't mess around with Durametric software (with this tool you can dig intro the computer and such), but have the DME and all electrical stuff onboard read out by whomever is performing the PPI. There is a lot that can be wrong with the car without you even noticing it and could potentionally be very expensive to repair!

Just make sure you do your PPI, then you'll be fine..

[dcporsche99]

If you want to be sure (and you should be!) have a PPI (Pre Purchase Inspection) done by a respectable specialized Porsche shop. I cannot emphasize enough how important that is. FYI, if you buy the car and the engine (cracks?) blow up in notime you're looking at 10-15K costs to repair!

What should be one of the best experiences (to own a Porsche) will become a nightmare. Take it from someone who learned the hard way.. ;-) (just very persistant.. haha).

Don't mess around with Durametric software (with this tool you can dig intro the computer and such), but have the DME and all electrical stuff onboard read out by whomever is performing the PPI. There is a lot that can be wrong with the car without you even noticing it and could potentionally be very expensive to repair!

Just make sure you do your PPI, then you'll be fine..

+1 on the PPI. There's A LOT of cars out there for sale....so, take the time to check it out thoroughly! Good luck! :)

[vette67]

Definitely get a PPI (pre-purchase inspection) before you buy. The few hundred $ it costs you is well worth it. If this is your first porsche, dont get so excited that you skip this step. Youll be sorry if you do!

Edited February 18, 2008 by vette67

[ttttttttttaa]

If you want to be sure (and you should be!) have a PPI (Pre Purchase Inspection) done by a respectable specialized Porsche shop. I cannot emphasize enough how important that is. FYI, if you buy the car and the engine (cracks?) blow up in notime you're looking at 10-15K costs to repair!

What should be one of the best experiences (to own a Porsche) will become a nightmare. Take it from someone who learned the hard way.. ;-) (just very persistant.. haha).

Don't mess around with Durametric software (with this tool you can dig intro the computer and such), but have the DME and all electrical stuff onboard read out by whomever is performing the PPI. There is a lot that can be wrong with the car without you even noticing it and could potentionally be very expensive to repair!

Just make sure you do your PPI, then you'll be fine..

ya, i will definitely do the PPI, should i bring it to porsche dealer's service department? I asked this dealer who selling the car, he said he can only allow me to go 5 mile distance. But the cloest porsche dealer is 10 miles.and if there is a crack in the engine, how will they know? I thought the only way to know is to take out the engine. :(any hint on how the car act when there is cracks in the engine? and before the engine blow up?

thanks

Yu

Hi vette67

I know, and i will buy the warranty too, since i am not buying from Porsche dealer who can give certified warranty.

is there some good third party warranty i can buy? (will cover RMS/IMS/engine/etc...)

thanks

Edited February 19, 2008 by ttttttttttaa

[vette67]

If you want to be sure (and you should be!) have a PPI (Pre Purchase Inspection) done by a respectable specialized Porsche shop. I cannot emphasize enough how important that is. FYI, if you buy the car and the engine (cracks?) blow up in notime you're looking at 10-15K costs to repair!

What should be one of the best experiences (to own a Porsche) will become a nightmare. Take it from someone who learned the hard way.. ;-) (just very persistant.. haha).

Don't mess around with Durametric software (with this tool you can dig intro the computer and such), but have the DME and all electrical stuff onboard read out by whomever is performing the PPI. There is a lot that can be wrong with the car without you even noticing it and could potentionally be very expensive to repair!

Just make sure you do your PPI, then you'll be fine..

ya, i will definitely do the PPI, should i bring it to porsche dealer's service department? I asked this dealer who selling the car, he said he can only allow me to go 5 mile distance. But the cloest porsche dealer is 10 miles.and if there is a crack in the engine, how will they know? I thought the only way to know is to take out the engine. :(any hint on how the car act when there is cracks in the engine? and before the engine blow up?

thanks

Yu

Hi vette67

I know, and i will buy the warranty too, since i am not buying from Porsche dealer who can give certified warranty.

is there some good third party warranty i can buy? (will cover RMS/IMS/engine/etc...)

thanks

If that dealer wont let you take it to the Porsche dealer for a PPI at your expense, tell him to stuff the car and you walk. The dealer will plug in the car and run full diagnostics in addition to doing a physical inspection. If there is anything as dramatic as a cracked block Im sure they will find it. Probably they will find a lot of little stuff instead (but each little thing will end up costing you $1000 to fix, ha). You also want to do a Carfax on the car using its VIN before you buy.

RE: warranties I never bought one but most Porsche dealers will sell you one. You might post this question as a seperate topic and get some feedback from other users.

Relax and go through the steps. There are plenty of cars out there.

Edited February 19, 2008 by vette67

[doubleb]

Definitely don't buy that car if the shop who is selling doesn't want you to have it checked out by a dealer (10 miles.. come on). Why don't you let them drive it to the porsche dealer and you just follow in your own car... Any hesitations regarding this should make you stop buying this car immediately, something must be wrong!

Just like vette mentioned, just don't fall in love with the first car you see until you are absolutely sure it is in mint condition.

Good luck man, this is really the most fun part.. just finding your car.. B)

[viper501]

Definitely don't buy that car if the shop who is selling doesn't want you to have it checked out by a dealer (10 miles.. come on). Why don't you let them drive it to the porsche dealer and you just follow in your own car... Any hesitations regarding this should make you stop buying this car immediately, something must be wrong!

Just like vette mentioned, just don't fall in love with the first car you see until you are absolutely sure it is in mint condition.

Good luck man, this is really the most fun part.. just finding your car.. B)

+1. Run, don't walk, away from that dealer.