Howdy folks, got some questions for you:

Was experiencing a hard start on my car and suspected that the plastic fuel lines were no longer sealing and allowing air into the fuel system. Replaced all of those and the car still starts hard as if it is starved for fuel or there is air in the system. Now for the questions:

1. I am still seeing a drip of fuel from behind the S/O valve...will replacing that o-ring solve the air/fuel leak-down issue causing my hard starts?

2. The line from the fuel heater to the pre-filter seems to be empty of fuel at shut down. Is this normal or also part of the leaking o-ring behind the S/O valve?

3. Also, any suggestions for an easy way to re-attach the intake manifold cross-over pipe to the EGR? That fitting is a pain!

This forum is great, but I was having trouble finding specifics like this. Thanks in advance for the help!

#1 - Yes, the bad oring at the SOV can allow air into the system.
#2 - Normal to drain back a couple of inches.
#3 - Yours is a little different than the turbo. I always had to crawl under and use long extensions on the rachet to get that bolt. The EGR flex pipe clamp I could get from the top.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Thanks Terry, I appreciate the info. My last question was reference the connection between the intake manifold crossover pipe and the EGR pipe connected to the flexible pipe to the air box. There is a metal ring with two large o-rings that is a really tight fit and makes it extremely difficult to get back together with trying to line up the manifold side at the same time.

Hoping that the o-ring in the back of the S/O valve solves my leak!!

Fritz

Hey fritz. That egr assembly and bracket for the crossover pipe are bolted to engine with like 6 10mm bolts. I take out all but one so those bolts so the egr can swing and pivot while you mate it to the pipe.

If you don't you will crack it at the intake side. Done it. Although its not the end of the world if it's just a little crack. I learned that on my friends car a couple years ago its still going fine.

__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

Thanks for the info. We had loosened that up and used some silicone grease to lube the o-rings during reassembly, but it was still a difficult fit. Guess that is just the design! Will update after I get the repairs done with the results. I am thinking that I will go ahead and replace the glow plugs too since I will have the intake off again anyway.

Thanks again, this forum is awesome!

It took me some practice to disassemble the crossover pipe with ease and efficiency. I loosen up the bolts on the supports where it fits into the big O ring and the bolt that helps hold it in place on the intake manifold. Then I wrestle it some and if necessary, tap it out with a rubber hammer. I use to use a metal hammer and have a beat up towel absorb the hits so it doesn't damage the crossover pipe.

As for fuel leak, the O ring in the shutoff valve could be a culprit. Also, check out the fuel pump and see if the nipples are on tight enough. Just keep checking all the obvious stuff for a loose fit. If you can get someone to help you as a spotter, start the car and give it gas and see if the spotter can see the leak.

The tricky part - sometimes you need to get the engine hot to expose the leak as when its cool, the "crack" will not be be enough to expose the leak.

I hope this helps.

Pabster

Thanks Pabster. When I did the fuel lines last week, I used the rubber mallet/prying/wrestling technique too. It just seems like that fitting is so tight! Guess that is a good thing, but, man, what a pain! In any event, I thought I was missing something easy.

I'll be checking everything twice this weekend when I replace that seal. I saw a visible drop of fuel from the S/O valve and the fuel pump itself looks dry, as does the fuel heater on the head. The I/P looks good too and I just replaced all of the plastic lines...so...I think it is that o-ring. I just got lazy when I found many of the fuel line connections were missing the o-rings all together. I also replaced the primary and secondary fuel filters and associated seals there. Seems crazy that one o-ring could cause so much trouble, but, it has to be the culprit!

Thanks again for all of your help. I truly appreciate it!

My car - 1997 E300D

My "mentor" always spoke about the infamous Fuel S/O Valve O ring being a culprit of many issues (letting in air, leaking fuel when "hot") and when in doubt, replacing it. I have two of those O rings hanging out in my supply box along with the washers and O rings for the fuel vavles. I had a very jumpy engine when I bought it last year and I went through much of what you did to find to the culprit. It turned out to be the fuel delivery valves needing some new washers and rubber o rings.

The good money is on your O ring replacement. You will become good at disassembling the crossover pipe and putting it back in like I did. I think I have taken it off 5 times during the past 12 months servicing parts and getting it up to speed. This car needed A LOT of basic maintenance, but it runs like a champ now!

Good Luck with it.

Pabster

Thanks for all of the help folks! S/O valve o-ring was indeed a problem. Replaced it and fired her up, only to find another tell-tale drip...off of the rubber supply line from the tank. Don't know how we missed that originally...the line had failed and was seeping fuel all along it! Trip to O'Reilly Auto Parts to replace the supply and return lines and all was well again and NO bubbles anywhere in the clear plastic lines. Also, no diesel smell in the cabin either.

Also replaced the glow plugs while I had it apart and the reassembly of the crossover pipe was much easier this time. It is amazing how easy it can be once you've done it before, right? Car is running great now.

Do need to investigate a couple of electrical issues, number one being the A/C fan assembly. Seems to twitch but not run. Is it serviceable? Or, just replace it?

Thanks again for everything. I love this forum!

Best,

Fritz

Always give servicing a shot first. This will help you rule out other issues.

Pabster