check valve anyone? 98 e300TD - PeachParts Mercedes-Benz Forum

John Doe · #1 10-24-2006, 02:12 PM

So my 98 300TD wouldn't start 2 weeks ago. Towed in, mech says it is sucking in air through the fuel lines. Thinks he finds the 2 in question ( I had just spent big bucks on trans and another fuel issue so he was trying to do me a favor). he replaces the 2 lines for $200 and the car is fine for a week. Then same deal. Towed in, he kicks hiimself and says damn, I should have replaced the other 4. He does it for the costs of the parts--$117. I got it back yesterday. This morning, it wouldn't start. I called him and told him that the last two times it wouldn't start, it was parked on a fairly steep uphill incline. He immediately says, "its the check valve." Towed again.

I really like this guy and he knows his stuff--this is the first time he hasn't nailed something on the first try, so lets not get into hes a dumbass conversation. As this is the 3d time though--anyone else have any ideas I can share with him?

TIA

TMAllison · #2 10-24-2006, 02:26 PM

Assume there is no leak present to follow to the source?

In no particular order:

First replace the o-ring at the fuel pre-filter. It has a separate part number and is often overlooked.

Second is feel up under the shutoff valve on the side of the IP and see if there is wetness there. It has an o-ring between it and the IP.

Third replace any remaining fuel lines not already replaced.

Car should start with air leaks, albiet with varying degree of difficulty pending the amount of air entering fuel system.

Prime using starter motor. Crank 30 secs at at time, resting 30 secs inbetween for three cranks and then let starter cool for 5 minutes before repeating.

John Doe · #3 10-24-2006, 02:33 PM

Thanks for the info.

I have replaced the pre-filter oring and it recently got new pressure valve seal, fuel element o rings, fuel line seals and shut off valve o rings.

Anything to this check valve? Never heard of one not on a boat.

PS: I also have put white butcher paper under the cara to check for leaks.

TMAllison · #4 10-24-2006, 02:51 PM

The other likely source would be IP delivery valves (x6) on the top of the IP but should be able to see fuel if they are leaking.

There is a fuel thermostat/pre-heater mounted to the left of the prefilter in the cyl head. A couple folks have had problems with it although is rare.

Dont know of any check valve. Terminology problem with your mech i think.

The valve on the side of the IP is the fuel shutoff solenoid.

Parked nose up on a hill allows air to enter more freely. Try parking nose down and see if wetness develops somewhere.

John Doe · #5 10-24-2006, 03:00 PM

OK--thank you very much.

John Doe · #6 10-27-2006, 03:13 PM

Well, Mr. Allison, and other interested parties, it was the oring at the pre-filter. My man didn't check it, because his shop had changed the filter the last time and he always replaces this. One of his new guys had apparently done the work and not changed it and it was flattened probably when he put the new prefilter in seated on top of the old oring. He ate crow on it and although he replaced all the fuel lines--he only charged me parts ($200 total) and he ate the three tows. I know he replaced the lines unnecesarily, but I don't mind paying $200 for new fuel lines, because they look so freaking frail on this car.

BUT--FYI, he showed me the check-valve that he put in--it was a little ball bearing in a banjo fitting. The invoice stated fuel line check valve.

thanks again for the suggestions--they were obviously correct!!

nhdoc · #7 10-27-2006, 04:58 PM

Quote:

Originally Posted by John Doe

Well, Mr. Allison, and other interested parties, it was the oring at the pre-filter. My man didn't check it, because his shop had changed the filter the last time and he always replaces this. One of his new guys had apparently done the work and not changed it and it was flattened probably when he put the new prefilter in seated on top of the old oring. He ate crow on it and although he replaced all the fuel lines--he only charged me parts ($200 total) and he ate the three tows. I know he replaced the lines unnecesarily, but I don't mind paying $200 for new fuel lines, because they look so freaking frail on this car.

BUT--FYI, he showed me the check-valve that he put in--it was a little ball bearing in a banjo fitting. The invoice stated fuel line check valve.

thanks again for the suggestions--they were obviously correct!!

99% of the time this problem is traced back to that damn O-Ring!

I don't think there's any check valve in this car's fuel system. The EPC calls that banjo bolt an overflow valve, but that could be lost in translation. If it is a check valve it doesn't ever seem to work.

Zeitgeist · #8 10-27-2006, 04:58 PM

I believe all OM60X engines have this same check valve. It works in concert with the feed pump to keep the reservoir around the pump plungers/barrels with a uniform and constant pressure source of fuel.

John Doe · #9 10-27-2006, 05:50 PM

Quote:

Originally Posted by Zeitgeist

I believe all OM60X engines have this same check valve. It works in concert with the feed pump to keep the reservoir around the pump plungers/barrels with a uniform and constant pressure source of fuel.

Dood, its called an 'overflow valve'!!!!

I think ya'll are right--I think check valve is my mech's description--but the thing is a check valve in reality from what little I know.

PS: Z, I said I would never do it with this car, but I just obtained a free source for WVO that is 90% processed/ ready to burn, and I am going to give it a shot. I am going to get a couple hundred gallons and send a sample fromthe batch off for testing then see what i need to purchase to finish the job

Zeitgeist · #10 10-27-2006, 06:21 PM

We'll make a bonafide treehugger out of you, yet.

Bio300TDTdriver · #11 10-27-2006, 10:07 PM

but Z can you tell me more about the probane injection? I have the same wagon as you also with a 22 head.

Thanks

Chris

John Doe · #12 10-27-2006, 10:17 PM

I don't know why people get so ticky about high jacking--I would rather talk about the propane and intercooler anyway.

Nice work on the Banks package btw--I had a Chebby diesel with a banks kit long ago.

Zeitgeist · #13 10-27-2006, 11:17 PM

Well, since I have the cetaceous one's approval...it's a Powershot 2000 kit, originally installed on an '05 Chebby Duramax. Easy install, and really gets the ol' 603 pulling hard. Best 0-60 run so far is 7.30 secs, but can possibly get closer to the 6 sec range with adjustments. That's almost into CDI performance territory.

Bio300TDTdriver · #14 01-01-2007, 07:39 PM

I forgot I asked about it. I've been reading up on your IC and what the Finns are doing. I'd be happy with another 25 hp for those uphill merges on I-5.

Chris

I'm working on the violet wire afterglow right now.

Bio300TDTdriver · #15 01-01-2007, 07:46 PM

Quote:

Originally Posted by John Doe

I don't know why people get so ticky about high jacking--I would rather talk about the propane and intercooler anyway. ME TOO

Nice work on the Banks package btw--I had a Chebby diesel with a banks kit long ago.

The PO did the Banks, a new Bd transmission and a few things that ended up costing him about $10,000. After spending way too much on the 300TDT I looked for a CTD that someone else had already fixed up.

Chris