Replace O-Rings on Prefilter on E300D, now NO start! - PeachParts Mercedes-Benz Forum

cewyattjr · #1 01-07-2012, 06:17 PM

So, what I thought would only be about a 15 or 20 minute project turned into an all-afternoon fiasco. I simply replaced the rubber o-rings with Viton around my pre-filter (top fitting and base of assembly). Started her up and then it died. After some effort, I thought I'd better back out my change and put the rubber o-rings back and snugged it up. It does SEEM snug around the prefilter.

All afternoon I spent bleeding/purging/cranking having had to jump it with my wife's car. After a couple of hours of work, she stumbled to a full start and then died again.

I think what's working against me is that I've got maybe a 4 degree incline with nose-up in the driveway, and I'm on less than half-a-tank. I know, I should have known better.

Tomorrow's plan is to coast it out of the driveway and have it tail-up/nose down on an incline. That may require some gentle nudging with another vehicle

Does that seem like the way to go?

Thanks for any thoughts/opinions, much appreciated.

-Chuck

sixto · #2 01-07-2012, 06:32 PM

How did you bleed the system? The manual will tell you to crank the engine with the pedal floored for a minute at a time pausing for 5-10 minutes in between to cool the starter until the engine catches and idles smoothly. I don't know how much work it entails in your car but I loosen each injector line at the injector and crank in 10-15 second bursts tightening the lines that show fuel.

Sixto
87 300D

cewyattjr · #3 01-07-2012, 06:36 PM

Quote:

Originally Posted by sixto

How did you bleed the system?
Sixto
87 300D

Mine is a little different -- with the intake manifold over the injectors there's no easy access here. I have a fuel line 'T' that I can raise to the highest point in the engine and then attach a Mity-Vac and then purge out the bubbly fuel. I then immediately clamp that line before I try a crank again. Pausing probably 3 or 4 minutes between attempts.

I'm thinking that it is literally an uphill battle though because I'm parked nose-up inclined.

biopete · #4 01-07-2012, 07:08 PM

Quote:

Originally Posted by cewyattjr

Mine is a little different -- with the intake manifold over the injectors there's no easy access here. I have a fuel line 'T' that I can raise to the highest point in the engine and then attach a Mity-Vac and then purge out the bubbly fuel. I then immediately clamp that line before I try a crank again. Pausing probably 3 or 4 minutes between attempts.

I'm thinking that it is literally an uphill battle though because I'm parked nose-up inclined.

Intake manifold over Injectors? Are you sure? On the 606 i'm working on now there is just a cover over the injectors and you can easily take it off and crack the lines at the injectors.

Mine would lose prime every time parked up hill. It would not prime for anything. I could never get fuel at the 1 2 3 injectors even after 30 minutes of trying. The back three would get fuel eventually. I'm still trouble shooting where the air leak is. There is some fuel on top of lift pump. I bought all new fuel lines since they were old and am starting with that. I'm thinking it might be the fuel shutoff valve on top of big filter maybe . But i don't understand how that would cause it to lose prime.

Another thought is the check valve in the return line. But some cars don't have that. If the other stuff doesn't fix it i'm going to replace that check valve with a ball valve and close it off when i park (or maybe a good pair of hose block off pliers or two would do it.

Good luck.

connerm · #5 01-07-2012, 08:12 PM

did something get knocked loose when you were changing o-rings? What's the status of the primary filter? Fill new primary filter with fresh fuel or diesel purge then reinstall it - easier on the starter when the filter is full of fuel. Did you crack or break one of the fuel pipe connectors?

(bad day when you have to involve your wife's car. been there, done that. Sucks)

You'll figure it out. Just take a break and go back later.

Remember to jump car batteries safely. Positive to positive, good ground on battery, bad ground on block of bad car (bad/block). That's how I remember it.

NJ300sdl · #6 01-07-2012, 08:14 PM

I had the same problem when working on a friend's car. Old o-ring would not seal. Replaced it with a metric o-ring from a Harbor Freight set which was not a exact match, but worked. Dealer supplied o-ring installed later.

connerm · #7 01-07-2012, 08:18 PM

Quote:

Originally Posted by NJ300sdl

Replaced it with a metric ring from a Harbor Freight set which was not a exact match, but worked. Dealer supplied ring installed later.

Good catch NJ300sdl.

Viton o-ring may be culprit. Are you using veg-oil or regular diesel? Those pre-filters get changed so often, there's no reason to go with viton.

cewyattjr · #8 01-07-2012, 09:14 PM

Quote:

Originally Posted by connerm

Good catch NJ300sdl.

Viton o-ring may be culprit. Are you using veg-oil or regular diesel? Those pre-filters get changed so often, there's no reason to go with viton.

I did switch back to the others thinking that the viton one seemed so bloody hard. They rubber ones seemed to be working fine, thought I'd start changing to viton and these were low-hanging fruit so to speak. But you make a great point!

Also connerm that's a good suggestion on the fuel filter. I'll fill it!

Thanks to all, and for the sympathy as well.

Chuck

cewyattjr · #9 01-08-2012, 12:32 PM

http://bit.ly/zn37fX

So I jacked up the back, which is kind of a dubious prospect as you can see in the link above. Also filled up the primary fuel filter, per suggestion. Took a few purges and cranks but within about 20 minutes I go it going. You'll notice on the video she's pretty noisy though.

On the down side, somehow with all the stress of glow-plug lighting and cranking, I'm not throwing a code: P0380, which is related to glow plugs, I believe. Also the glow plug light stays on. I do have a set of new glow plugs at the ready, but not going to do that project THIS weekend! In the back of my mind, I'm kind of wondering if this code will resolve on its own?

-Chuck

dauber · #10 01-08-2012, 08:50 PM

I bet you light goes out as well within the week. Congrats on getting her running.

cewyattjr · #11 01-08-2012, 09:04 PM

I'd like if that happened.

But now, when she starts now the engine is rough for about half-a-minute, so I think I must have tired out one of the GP's.

dauber · #12 01-08-2012, 09:08 PM

or you have a air/fuel leak now.

cewyattjr · #13 01-13-2012, 10:33 PM

Clearly the cranking pushed a glow plug to failure that was probably marginal anyway. As it turns out all but two are completely seized. Frozen tight despite heating, pb blaster, etc. It's at my indie mechanics and he has the head taken off, working on it, may end up having them drilled out. Ugly. I think the mechanic wants to blame WVO, though I kind of doubt it given others experiences regardless of fuel type.

Anyway, I got the car about a year ago, now with 170k miles. Not sure if they have EVER been changed. I now understand why some just change them annually regardless.

I'm now in a crappy Chevy Aveo rental. Ick.

-Chuck

dauber · #14 01-13-2012, 11:29 PM

WVO did not do this. Mine was frozen and only ran pump diesel at 180k. If I had all new ones I may change them every two years as long as they broke free. I had one stuck and snap off after soaking in PB blaster for 3 days. Its the worst part about this car, otherwise I love it.

I dread the day when another glow plug light shows up. I have 189k and I think they are original as well (5 left). I am in the mind set of if it's not broke don't mess with it right now.

Sorry for your luck

cewyattjr · #15 01-20-2012, 03:30 PM

The head has been to the machine shop and back and STILL they can't get two of the GP's out yet. My indie also wants to do a valve job he has these pieces pulled out and they have a lot of thick black sticky stuff at the top of the taper.

It's been over a week, and I'm really jonesing to get it back.