I have experienced strong gas odors for years with a full tank + emission system issues and just came across this study plus this forum (very helpful). I bought a used CA car (a so called PZEV - partial zero emission vehicle) in TX and now live in NC. It's a 2007 E350 with 100k miles on it. When I called MBUSA Customer Service - and later the local dealer - I was told that my VIN does not show up on the Extended Warranty list so I'm out of luck. The Warranty Booklet says that for PZEV vehicles the Emission Performance/Control system is covered for 15 years/150,000 miles already so I'm guessing the folks I talked with don't know I am a PZEV. My question is whether anyone with a PZEV has dealt with MB and/or dealers and can provide me some coaching on how to get them to address my issues since my VIN is not showing up. I'll take the obvious step of waltzing down to the dealership with my paperwork but I'd be interested to know how others handled this issue. Thanks.
Analysis of Fuel Tank Leaks, Model Years 2003-2008
rds53benz
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The Nylon Fuel Line came in late this afternoon. I was able to route it, had to be careful because there are two fuel level sending units in this tank, one on each side. The Nylon hose comes in a coil like a rope, it wants to stay in the coil. Getting it to route proper means you need to persuade the nylon to stay in the proper shape. I ran some TV COAX cable into the nylon 3/8" hose, I had read that others used old spark plug wires for this purpose but I did not have one handy so I used the Coax cable., the Coax TV cable was just about the perfect size to fill the hose opening. With the Coax installed I warmed the Nylon hose till it was almost hot to the touch and was able to bend the Nylon hose into the shape I needed. Of course you also need to hold it in shape as it cools to be successful. At the Fuel Filter end of the tank the nylon needed a 90* elbow and that came out well also. I worked the straight part of the line about 1' at a time with the heat and used a fan to cool it quicker. the 90* bend was only about 4" of the tubing and I did this bend all by itself to hold the proper shape while it cooled. Without the Coax cable inside the hose would just collapse as you heated it and tried to bend it. With the Coax in there it was pretty easy to form. The fittings do not want to go into the Nylon and there are a few techniques to use to install a fitting into the nylon. Youtube had several videos showing a variety of ways to do this. I have a tubing flaring tool already so I used it to hold the new Nylon hose tight while I tapped the fitting into the tube. Worked perfect with only a strong mix of soap and water for lubrication and gentle quick hammer taps to install one end but the other was slightly larger and I had to use a little heat along with the soap and water to tap the fuel pump end into place, the fuel pump fitting is a sharp 90 and there was not much I could tap on without worry of breaking the fitting. Quick taps moves the fittings into the hose, you can watch the fitting slip in as you tap. Both went in and fit very nice. fittings are barbed to help hold the pressure from the fuel, to remove the old hose off the fittings a gentle slice with a razor blade is all you need and the hose will pull right off. Be gentle with your cut because the fitting needs to seal against fuel leaks and if you cut the fitting it could create a leak path. I went ahead and added cinch clamps to both ends of my hose but I think they were not necessary, the factory did not use cinch clamps. The new fuel line looks good, fit very well and should be as long lasting as the factory part. Got the Pump module and the new fuel pump access cover completely assembled tonight and ready for install again. Hopefully I have time tomorrow to get this car running again. The Tank and rear differential have to be raised up at the same time on this install because the tank fill tube and vent tube both route through the rear differential assembly. While raising the units you also have to reinstall both coil springs. Once this is done the emergency brake can be hooked up, then the driveline installation, all the heat shields and finally the exhaust. A bit of work still to do.
With a little practice the nylon is not bad to work with. I am glad to know this product now. My wifes BMW X5 has a nylon hose on the intake that failed, I spliced it with a rubber fuel hose to fix it and it works but now I see making a new nylon hose is not much of an issue.
With a little practice the nylon is not bad to work with. I am glad to know this product now. My wifes BMW X5 has a nylon hose on the intake that failed, I spliced it with a rubber fuel hose to fix it and it works but now I see making a new nylon hose is not much of an issue.
Got the tank installed, put 5 gallons gas in it, pump is working, no leaks visible. Problem, fuel pressure does not hold. Key on 60 PSI, key off instant zero PSI. You can watch the gauge fall. Has me thinking maybe the 3 lines to the filter are not routed correctly. I don't think the fuel rail pressure relief valve would fail in this manner. They usually hold low pressure or allow a slow drain when they fail. I think there is a check valve somewhere in this tank but I do not know where. Maybe it was in the Factory fuel pressure line that I replaced? I will have to look at the manual. I did order and receive it, got it loaded but have yet to take time to open it. I guess it is time.
I have it fully assembled now and it appears the tank repair is a success. No leaks, no smell of fumes at all. Car is parked inside in my garage so if there was gas leaking I would smell it. I left the back seat out and the two gas tank access holes are still open to the top of the tank. No smell at all. Have not had time to test drive except on my driveway. Will be away for a week but will get back to this when I return. Odd, the fuel system does not hold pressure at all once the key is shut off. Holds steady at 60 PSI any time engine is running. Engine starts instantly every time which will not happen in most cars when there is no residual pressure in the fuel lines. I am wondering if this is normal to the PZEV system because the car acts normal and starts normal even though my pressure gauge clearly shows pressure is fully lost as soon as the key is off and there is no fuel return line, the return and pressure relief are both contained inside the tank. I will put more gas in and test drive it when I return but the tank repair appears to be a full success. The amount of work to remove the gas tank is a lot. Putting the rear differential back in and raising it at the same time as the gas tank takes some special attention but I got it done alone, one tranny jack under the differential, 2 floor jacks working raising the gas tank. A lot of jiggling and it went in. The trick to remove and install the emergency brake cable is to remove the brake rotors from the axle. This allows the brake to move more than normal and gives you the room needed in the cable to disconnect and re connect it. I fought it an hour or more before pulling off the rotors. At this point the brake calipers were all ready off as part of the diff removal so it is not a lot more work but necessary. I installed new brake pads and rotors while in there. Cost a little more but labor is the same and now it is all new.
1999 S500; W140.051; 2003 E320; W211.065; 1973 220; W115.010
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Congratulations on your hard-earned success.
If the relevant MB engineers were following this, I think they would give you some applause for your ingenuity; persistence and drive to find a solution and make it a happen.
I can only hope that if they were given the choice, they would have chosen NOT to utilize the PZEV tank design at all.
You should post an update after some driving evaluation period to confirm all is well with your repair.
If the relevant MB engineers were following this, I think they would give you some applause for your ingenuity; persistence and drive to find a solution and make it a happen.
I can only hope that if they were given the choice, they would have chosen NOT to utilize the PZEV tank design at all.
You should post an update after some driving evaluation period to confirm all is well with your repair.
Still no time to work on the E350, should be able to get back to it Monday. I hope to report success. I did some quick accelerations and hard brakes on my driveway trying to splash the new cover And make it leak. That is all so far. I will report back the actual road tests.
On the other hand, you’ll get away from a burning car more quickly if there isn’t a fire extinguisher tempting you to hang around.
We really need someone to hack EPC so we can do things like query all the parts unique to a US PZEV 211.
Sixto
05 E320 wagon 180K miles
We really need someone to hack EPC so we can do things like query all the parts unique to a US PZEV 211.
Sixto
05 E320 wagon 180K miles
First test drive done, car starts and runs flawless so far. No visible leaks of gasoline, zero odor of gasoline. I did add 12 gallons to the tank tonight while test driving. Gauge now reads 3/4 full. I did not fill it all the way just because I am still checking it out. I have a few bugs not related at all to the gas tank/fuel pump repair to fix now that I am looking at everything. Starts instantly, has full acceleration power. Funny on this test drive I left the insulation for the back seat rolled up, I rolled it back out of the way and used the seat belt to hold it out of the way while I worked on everything. I test drove it like this, both floor covers were open. It was raining hard today, an amazing amount of road noise entered the cabin. I pulled over, un snapped the seat belts in the back and rolled the insulation back over the access holes, did not install the two covers at this time. The car was quiet again with just this roll out. With 3/4 tank of gas the gas is certainly splashing all over the new cover and so far no leak, no smell. I will drive it a while, maybe 150 miles to gain confidence in this repair before bolting the two cover plates back on and re installing the rear seat. If it is going to show any problems I want to find them right away. So far everything is clean and dry. With the insulation rolled back down you can't hear the fuel pump running, OK, I, can't hear the pump running at all but my ears are not brand new anymore. I am thinking this repair is a success. If anything fails I will report back but the car runs again and starts each time as it should.
A second job like this could be done much faster, less trial and error and more time just executing but this is not an easy job by any means. Doing this job wrong could certainly cause a fire and maybe burn down the structure you are using to work on this car. (your home) I am not advising anyone to do this, just stating that I did it and it is working like new so far. The work done was not done with any professional tooling so the shape is not factory perfect but functional. Hope it gives someone hope when their PZEV in tank fuel pump goes out. I do like that the new cover is removable. I already had to use this new cover once to repair that cut fuel line. If the tank had been welded shut after the pump install I would have been out of luck. I read the Viton tank seal should last 20 years. That sounds like plenty to me. I am thinking about pulling the hold down screws one at a time and sealing the threads with Hylomar Blue just to make sure the fuel does not find a way to wick up the threads and cause a small leak or smell issue. Guys on the MG forums seal the fuel gauge which is removed from the bottom of the tank on those cars with Hylomar blue and say it works perfectly. The cover seal at the bottom of the tank is pretty important. My seal is at the very top of the tank so easier to seal. The tank cover is no longer perfectly round, you might remember I had to shrink it down from 8" to 7 7/8 approximately. I cut it down with a grinder and a template for a guide. It is not perfect but is functional.
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Pics show the finished tank with new removable cover. Close Up of the hold down screws, the back up plate that goes inside the tank, the two fittings I removed from the factory pressure hose and re installed with the new Dorman 3/8" nylon fuel hose. Did not take a pic of the finished hose before installing, at least I can't find a pic of that. The fitting with the P written on connects to the Fuel Filter, the 90* fitting connects to the Fuel Pump directly at the top of the fuel pump module. The Complete PZEV tank with the new cover is shown prior to installation in the car. Yes I used string on the fittings when I removed them. I was afraid they might go down in the tank where I could not get the hose back up. The string was just for peace of mind. I will have to snap a picture of the tank installed from inside the car before re installing the access cover and seat.
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A second job like this could be done much faster, less trial and error and more time just executing but this is not an easy job by any means. Doing this job wrong could certainly cause a fire and maybe burn down the structure you are using to work on this car. (your home) I am not advising anyone to do this, just stating that I did it and it is working like new so far. The work done was not done with any professional tooling so the shape is not factory perfect but functional. Hope it gives someone hope when their PZEV in tank fuel pump goes out. I do like that the new cover is removable. I already had to use this new cover once to repair that cut fuel line. If the tank had been welded shut after the pump install I would have been out of luck. I read the Viton tank seal should last 20 years. That sounds like plenty to me. I am thinking about pulling the hold down screws one at a time and sealing the threads with Hylomar Blue just to make sure the fuel does not find a way to wick up the threads and cause a small leak or smell issue. Guys on the MG forums seal the fuel gauge which is removed from the bottom of the tank on those cars with Hylomar blue and say it works perfectly. The cover seal at the bottom of the tank is pretty important. My seal is at the very top of the tank so easier to seal. The tank cover is no longer perfectly round, you might remember I had to shrink it down from 8" to 7 7/8 approximately. I cut it down with a grinder and a template for a guide. It is not perfect but is functional.
Pics show the finished tank with new removable cover. Close Up of the hold down screws, the back up plate that goes inside the tank, the two fittings I removed from the factory pressure hose and re installed with the new Dorman 3/8" nylon fuel hose. Did not take a pic of the finished hose before installing, at least I can't find a pic of that. The fitting with the P written on connects to the Fuel Filter, the 90* fitting connects to the Fuel Pump directly at the top of the fuel pump module. The Complete PZEV tank with the new cover is shown prior to installation in the car. Yes I used string on the fittings when I removed them. I was afraid they might go down in the tank where I could not get the hose back up. The string was just for peace of mind. I will have to snap a picture of the tank installed from inside the car before re installing the access cover and seat.
Great job! It's awesome that you had the perseverance and skill to do all this! I would totally have been looking at the non-PZEV tank swap if this were my car.
One of the evap fittings on the tank in my then-girlfriend's A6 broke and sloshed fuel off the top of the tank when full. Access was not possible without removing the tank, even through the access ports under the back seat... It was similar in that the rear suspension had to come out in order to drop the tank... so I feel your pain in every word! 🤣
Also note the flare connection on the tank. I @$$ume that's a European 45 degree flare rather than an AN 37 degree flare
One of the evap fittings on the tank in my then-girlfriend's A6 broke and sloshed fuel off the top of the tank when full. Access was not possible without removing the tank, even through the access ports under the back seat... It was similar in that the rear suspension had to come out in order to drop the tank... so I feel your pain in every word! 🤣
That's a really cool way to get a backing ring through a hole that's smaller than the backing ring!
Also note the flare connection on the tank. I @$$ume that's a European 45 degree flare rather than an AN 37 degree flare
The Mercedes PZEV tank eliminates the common Return line from the fuel rail. This PZEV tank has a pressure relief valve inside the tank and a return line to the fuel pump inside the tank, it goes from the fuel filter to the fuel pump so any fuel is pressure fed from the bottom of the tank to the engine and no pressure is held in the system once the key is shut off. Very odd but it works perfectly,. I was taught that the bevels fall in two groups, JIC. 37* or SAE std. 45*? My training is now 40 years ago so maybe I am slipping.
Addition, I went ahead and filled the tank as far as I could. Still no leak and no gasoline odor at all.. I am going to button up the back seat finally and call the pump good the pump is working perfectly so far but now I fear the dreaded timing balance shaft issue might be showing its head. Dang.
EDIT: I was able to compare the factory PZEV threaded line connection to the JIC and SAE fittings, you are correct Dark Side, they are unique, some european strange connection with extended threaded tips, the stuff we buy hear does not interchange.
Addition, I went ahead and filled the tank as far as I could. Still no leak and no gasoline odor at all.. I am going to button up the back seat finally and call the pump good the pump is working perfectly so far but now I fear the dreaded timing balance shaft issue might be showing its head. Dang.
EDIT: I was able to compare the factory PZEV threaded line connection to the JIC and SAE fittings, you are correct Dark Side, they are unique, some european strange connection with extended threaded tips, the stuff we buy hear does not interchange.
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4 Posts
Hey West, thanks to your post I just removed the fuel pump from my 2006 e350 PZEV tank. I ended up drilling holes around a 5 inch diameter and using tin snips and plyers to "pull" the disk from the tank, worked perfect as I left the tank right in the car. I placed a high power magnet next to the drill bit to catch the filings and I also used an old fuel pump from an e320 to pump the tank dry before, and drilled very slowly. So now I have the pump out, and I am trying to figure out how it comes apart. Would you be able to give me any guidance? Looks like it should just pull out the bottom but I figure it is not replaceable should I break it so better to reach out to you beforehand.
Wow, you do realize that the electric drill has sparks that can ignite gasoline? Procedure sounds very dangerous to me and installing a new cover takes a lot more holes and drilling. Please be careful I knew of a respected mechanic in Sacramento that was burned nearly to death when a fire sparked while he was changing out a fuel pump. I think it was determined his shop compressor sitting about 15 feet away turned on and ignited the fumes from his tank. He survived but was in a hospital for 6 mos or so and will never live the same life again.
The gasoline fumes are what ignite, a spoonful of gas in the tank is enough to make the fumes. I filled my tank with soapy water before cutting and drilling it and I was still a little nervous.
I am familiar with Fuel Pumps having worked on many over the years but I do not recall how I removed the pump from the module, I do not remember it being difficult or anything that concerned me? I do remember the filter at the bottom was very unique in shape and I ended up re using my old pump filter after cleaning it which does not do much to clean it, a new filter would have been first choice but I had no options. My new pump fit in very similar to the factory pump and I recall it was slip connections holding it in, it just has to stay in place. I wish I had recollection, just did this in December/January and I don't recall it being anything odd.
Glad you went with the 5" opening that will make yours a better repair than mine. I think the vendor I used had a 6" cover just like my 8" cover but I don't know if that leaves enough material on your tank for the sealing lip. It will take 1/2" minimum and maybe more to locate all the sealing screw holes in your tank. I remember wondering if a Mercedes pump from a non PZEV pump the same year car would have been an exact swap pump for the failed Mercedes PZEV pump inside the module.
Mark
The gasoline fumes are what ignite, a spoonful of gas in the tank is enough to make the fumes. I filled my tank with soapy water before cutting and drilling it and I was still a little nervous.
I am familiar with Fuel Pumps having worked on many over the years but I do not recall how I removed the pump from the module, I do not remember it being difficult or anything that concerned me? I do remember the filter at the bottom was very unique in shape and I ended up re using my old pump filter after cleaning it which does not do much to clean it, a new filter would have been first choice but I had no options. My new pump fit in very similar to the factory pump and I recall it was slip connections holding it in, it just has to stay in place. I wish I had recollection, just did this in December/January and I don't recall it being anything odd.
Glad you went with the 5" opening that will make yours a better repair than mine. I think the vendor I used had a 6" cover just like my 8" cover but I don't know if that leaves enough material on your tank for the sealing lip. It will take 1/2" minimum and maybe more to locate all the sealing screw holes in your tank. I remember wondering if a Mercedes pump from a non PZEV pump the same year car would have been an exact swap pump for the failed Mercedes PZEV pump inside the module.
Mark
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4 Posts
Thanks mark, I ordered a pump for a 2006 non PZEV e350, should be here next week. I used a brushless 18 Volt drill and kept car well ventilated. Once I know it works I will buy the same cover you used, wish they had a 7” version.
The downside to the 8" cover is you can't pull it out of the 7" opening under the seat. Maybe the 6" cover could be used? That would be best if you have enough metal in the tank to bolt it down.
Can you post pictures of the OEM pump you pulled out? I might remember what I did if I see the pump again. I hope your install goes better than mine. Mine turned out fine but I had a few time wasting learning adventures before it ran.
Can you post pictures of the OEM pump you pulled out? I might remember what I did if I see the pump again. I hope your install goes better than mine. Mine turned out fine but I had a few time wasting learning adventures before it ran.
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