creekman

Sorry for dragging this out and for so long...  I think we finally found the smoking gun, a vent line that has a valve in it...  The PET that I use shows a single 30" line with a valve

for $225.00. That in itself is over the top.  After getting the incorrect part twice from my Porsche Parts guy I went to Sunset Motors in Beaverton, OR.  The parts manager was very sharp, it turns out there's 2 vent lines on my C4 and my PET doesn't show the one I want, doesn't make any difference since Porsche no longer makes that available.

I see 2 options:

1.  Find a used one, but dealing with wrecking yards can be costly... I use to deal with Parts Haven in the Bay area, anyone know if they're still in business?  Or are there other reputable people I might try?

2.  Would take the new wrong part and cut out the valve and insert it with rubber hoses and hose clamps into the old line.  I would think it's a low pressure hose so why wouldn't that work?  The only downside you've got a $10 valve that cost $225.  But if it gets my car on the road so be it...

3.  Anyone have another idea...

I want the part on the right that is no longer available...

JFP in PA...  Many thanks for that info, I'll follow up...  On further discussion today with a knowledgeable car buddy of mine he asked if there's a chance that something could be plugged up in the vent system putting more pressure on the weakest connection in the tank, in this case it would be item 28, Tube...

As of today we know the leak is occurring at the rubber flange where the fill pipe is inserted...bber/neoprene flange, see pic...  Here's our bottom line, the tank is building pressure... My buddy Patrick has said that from the beginning, then it dawned on me that is the reason the gas cap has taken 2 hands to remove...  Plus no matter what the gas level is it continues to put out the fumes.

Then the question is, what should I do next, I've already replaced both solenoids, can they be tested out of the car?

Thanks for your help in advance...

I know what you say is true, but it doesn't make the job any easier.  While the car has grown in size some, the demands for space to accommodate safety features, smog and air pollution,  luxury options, engine requirements all need more space, I understand that...

OK, here's a gotsha:

This the part I think that was weeping.  Anyone have any ideas?  Do you think I could use a good adhesive that doesn't

breakdown from gas?  The rubber seal is complicated it runs from the the tank surface down around the pipe for some distance.  3-5 weeks is a big window, and it might get bigger.  Any thoughts would be appreciated...

JTA from PA, you deserve all the kudos that come your way since that's all you'll get...  Keep up the good work.

As to the parting tool, now you tell me...  Actually I thought the pickle fork tool was the standard of the industry, now I know better...

I'll check out the after-market rod end boots and report back with a P/N.  Replacement tie rod end ball joint boots

One last thing, I want you to know and I'm sure others will agree to thank you for your time and knowledge which you share daily and for so many years.  I think you and Loren have created a family of enthusiast.  I've had 5 Porsches over the years, all older,

but the 966 bridges the old and new.  Where some of the older Porsches styling have become dated, the 966 design has held up well.  And boys that is the test of good design...

P.S.  Porsche could have made removing the gas tank a little easier, the leaky pipe and rubber seal cost $30.00, but the labor would be around $3,000, but certainly doable for the DIY... 

2003 996 C4S

Howdy,

Yes, I'm still fuming over the fume leak which turns out to be a gas leak, but not sufficient to run on the ground.  To find it "John" JFP in PA says it's a nasty job, Nasty doesn't begin to find the words to describe the work involved and we still haven't turned the corner to put the front half of the car back together.  We have removed the big water pipes, partially dropped the "A" arms, steering rack, the front bumper cover, my Mini Cooper power steering pump and plumbing, and the list goes on.

Ok, I'm not changing the subject, but where can I find just the boots for the tie rod ends?  From Porsche you have to buy the ball joints which I don't need.  We had to use the pickle fork tool to separate the ball joints from the tie rods.   In doing so we ruin one of the boots.

I had the tank pressure tested, it was good.  It appears that the gas weep and fumes are from where the fill pipe is inserted into the tank.  I believe that shows in PET 2005, illustration 201-01, item 28, Pipe.  Not sure how to remove the existing neoprene seal, or install,  hopefully once we have the new part it will show the ins and outs of this...

Thanks,

Mitch.

OMG, you ain't whistling Dixie...  The trouble is it's probably loose hose clamp or a bad hose.  I doubt it's a crack in the tank.  I also noticed that when the tank is full it admits the most/worst gas fumes.   Are the gas tanks in the 4S subject to cracking?  I have my power steering pump mounted in the cavity after removing  the front diff.  I'd like to see if I could replace the 2 hoses under the black derby (C4S) first if I can find the other end.  I gently pulled on them and it seemed the fumes were worst after doing that.

I bet Porsche would get a couple grand for R&Ring the gas tank...  I think the San Antonio Porsche dealer gets $170.00 hr. now.

Many thanks for your help, at least I know now what I'm dealing with, and I don't like what I see.  The trouble is I might fix the gas tank problem, but now I've got a leaky radiator pipe or P.S. pump leaks.  In the end I'll do what I have to do.  

Mitch

P.S. I forgot one thing, when I installed the LS3 motor the additional horsepower would have shredded the tires so I opted to change the rear ring and pinion to a taller gear, but no such luck on the front diff which was removed.  So that was one less thing we had to take down...   If any one needs the front differential and driveshaft I'd nearly give it away.

Hi Jon, Glad you're still on the job... 

The trouble is the leak/weep is in the fill pipe connections or the other 2 hoses that come off the lid on top off the tank.  What's between the top and bottom of the  tank exterior is a mystery.  We pulled down the tank supports straps and nothing happen.  There appears to be another strap

that's forward and on top of the saddle bags.   To get to the bolting of the strap on left side you would have to remove some water pipes, that would be the last thing I would want to do, UGH...

P.S. I'm not even sure this what holding it in place, but something, that's for sure...                                

2003 996 C4S

I've had a gas fume stink for a year, but because I had another project on the lift that couldn't be moved so I soldier on since the car ran fine.  Well, I finally got the car on the lift, pulled down the belly pans and found that it was a gas leak, not fumes... It never leak enough to show on the floor.  However, I can't find the source of the leak.  it looks like pulling the tank is not easy, or next to impossible...  I read what Bently had to say, but I was hoping for real time help on the subject from someone on the forum...

I tried several search requests and a big '0"...  I'm sure there are posts on the subject, I'm just not asking the request right...

Thanks,

Mitch

Jon,

The color, everything was perfect, great looking car...  I think our cars are under appreciated...  The one thought I had was the short shifter by Porsche was better made than what I took out...

I've driven the car without the stuck in neutral problem several times.  The shift and trans are silky smooth and with my extra HP I never abuse the shift or clutch.  I appreciate the comments, all good.

Mitch

Right now I have another car on the lift, as soon as I can move it I'll put the Porsche on and really see if I can find out what's going on.  We have had a second guy (long time mechanic) under the car while we went through the gears and found no problem at the trans.  However, I still feel like there's a lot of play at the rod ends.

Just in passing, I still love my car, I think the styling has help up well considering it's an 18 year old car.  When you think about all the features the car has and the road going capabilities it makes for a mile stone car IMHO.  It still looks current as oppose to my '84' Turbo Look which became dated.  At least in my eyes...

Thanks, Loren, Jon and Flanders for the replies...

Mitch

Hmmm, I don't remember the alignment tool.  The transaxle was gone through when I changed the ring and pinion 7-8 years ago.  It shifts like a hot knife through butter.  But on those occasions when you're shifting from one gear to the next the shifter hits a brick wall.  I can sit in the garage (engine not running) and shift it without depressing the clutch and the shift is silky smooth.

There's a lot of movement on the rod ends at the transaxle...  Are the shift cable rod ends replaceable, do they wear?  I'm pretty positive I'm good inside the transaxle.

Thanks Loren for the reply... I'm glad you're still on the job...

I haven't found any repeating circumstances, but I might have been too busy trying to get it back in gear.  I thought it might be the rod ends at the transmission, but after looking them over we put that aside.  I have a Porsche short shifter for a number of years with no problem.  It's like there's a foreign object and the shift mechanism bottoms out on the obstruction.  I pulled the shifter cover and looked at the shifter and it appeared to be good.

It's a bad feeling when your in traffic and the car won't go... Anybody have an idea what I might look at?

Thanks

Joe, how lucky we are to have members like you that contribute so much to the enjoyment of our cars...  

Thanks,

2003 996 C4S

JFP, Jon and Loren...  many thanks for the support and direction.  I removed the battery and panel all looked good, I also removed the top hat cover next to the bulkhead on the trunk side, again no tell tale signs of cracks there either.

I guess next will be to look at the charcoal canister and gas fill check valve.  I think I'll change out the charcoal canister first. 6 years ago when I installed the LS3 V8 I had a problem connecting up the charcoal canister to the new conversion.  A friend of mine from the airport holds certificates on welding, A/C, Electrical, Diesel engines on unlimited tonnage for ships.  He's a civilian contractor hired by the navy to be in charge of maintenance on big ships...  Where he goes is always a secret.  This guy will always be the smartest person in the room... Anyway the Porsche might still be sitting in the garage if he hadn't figured out how the system worked.  Took him 30 minutes to draw out the system and 10 minutes to change some hoses.  But the charcoal canister had been full of gas, but the system has never given me a lick of trouble since, so long story short, that is why I might start with the canister...

Loren, say again how you assign points...  Thanks

7 hours ago, JFP in PA said:

 

Unless something codes, Durametric won't see it.

 

Before raping the car apart, open the front trunk, remove the battery cover, and have a sniff about; we haven often see problems with the top area of the fuel pump assembly involved with gas odor issues.

Thanks, I appreciate the direction, I'll give it a shot.  

I put the car on the lift and removed the belly pans...  I was hoping that would find the source of my stinky gas smell once the belly pans were removed.

Nope, no stains on the belly pans and no wet hoses.  So I guess the next step is to check/replace the fill pipe check valve and or the charcoal canister.  Can anyone tell me if the check valve is stuck open will the car run fine and could be the source of my gas fumes...

If there's a problem with the check valve will it show up on my Durametric program?

Thanks,

Do you have a TPS... Throttle position sensor or because your throttle body is cable driven you do not...    Can you manually pull the throttle back to an idle either at the pedal or throttle body...

I have a similar problem, but properly not related.  I replaced the TPS and throttle body, now it takes several ,minutes for the engine to return to idle...

Jon,  That's a good idea to step back before throwing a lot parts at the car.  I have my T-Bird restomod project on the lift right now.  To do it right I need to drop down the belly pans for a good once over.  

Speaking of belly pans...

Here's a tip if you're tired of replacing the belly pan brackets/retainer clamps.  I used aircraft loose nut plates and riveted them to the braces.

The fumes went away, now there back with a vengeance...  I changed the gas cap which was cheap and worth a try, what are the possible choices?

1.  Per 356, check for hairline cracks in the gas tank sending unit...

2. Per Judgejon, replace the check valve behind the right side fender liner.

3. Could the charcoal canister be full.  Where is the charcoal canister?

4. Can this problem be identified with my Durametric program...

Thanks, all replies will be appreciated...

Mitch

Jon,

The Bride of Frankenstein would blow the doors off your ''409'...  With a taller ring and pinion she clocks out

on paper at 206 MPH at redline in 6th gear, but not with me in it...

On an earlier post I mentioned that the idler pulley bolt backing out which is not good...  If you ever have to replace that bolt

I would recommend using loctite.

17 hours ago, DBJoe996 said:

A check engine light on simply means one of the parameters the ECU monitors was off, and it always records a code that tells you specifically what was wrong.  There are literally thousands of various codes that will throw the CEL.  Next time, read the code before you clear codes.  That code or codes will point you in the right direction.

 

Also, I would  get in touch with whomever did the LS3 conversion and ask them how they rigged the "fly-by-wire" throttle conversion.  There is going to be a lot of frankenstein parts involved with an LS3 conversion.  Just the fact the GM OBDII port didn't work but the Porsche OBDII port did is really questionable.  Did they somehow "marry" (connect) the Porsche ECU to a GM ECU?  How?

Joe,

I know I'm in dangerous territory pushing this conversion, but it's been a fun to drive car, gooobs of power and reliable.  My point Joe is the electrical was the most challenging part of the conversion snd was a major expense to get it done right. It does bring together different parts, but the word Frankenstein might be a little over the top...  Today the after market people have develop easier programs that tend to be plug and play where as 8 years ago you better have your Phd in order...

No, I believe both ECU's have their own job...  The Conversion utilized the GM gas pedal, so like you I was surprised when the Porsche OBD port cancelled the check light.  It has been years since I hooked up the Durametric program, but I did today with these results...

I just thought I need to see if I can date when these codes were thrown...  At the top of the attachment it says, "Current /Fault Codes.  I want to get to the bottom of

this pretty quick, I've never have been flat bedded home so far.  I did get stuck in Winslow, AZ for one night with the original engine.  The idler pulley bolt backed out, 

a local towing service came out with his flatbed, took me to the Chrysler dealer, charged me $85..   They had the Porsche dealer in a neighboring town overnight

the parts.  I was on the road again by 10:00 the next morning...  All in all it was a memorable experience and meant some nice people.

\

Coming home in the middle of the day, probably high 90's, good oil temp and water temp

was good when all of a sudden my gas pedal went away and the LS3 V8 cough and quit.

I tried to restart without success, Finally it started and got me home without further incident.

I plugged y OBD II reader in to the GM port and it wouldn't clear, then plugged it into the

Porsche port and it cleared.  I have 90,000 miles on the 2003 C4S model and 25,000 on the LS3 motor.

NMy question is this a routine mileage event or something else?  Certainly it was more of

a "have your car service" event since the gas pedal went away and the engine stopped.  I was surprised that I

cancel/erase it on the Porsche OBD port.

I was hoping for some rare insight which has its complications, but still puts a smile on my face...

Thanks,

Mitch

My longtime friend and master locksmith said Graphite and LPS 1 also work well...