Dont congratulate me yet- noobie needs help! - PeachParts Mercedes-Benz Forum

WINGAS · #1 03-18-2007, 08:13 AM

Folks, I'm using the site and searching for my answers, but I thought I'd ask teh STRATEGIC question:

Just brought home a 220k mile 95 E300. Great shape, except it has a terrible cold start racket going on. One heAvily metallic ping which doesnt go away with rpm, and only diminishes when warm. Reappears on heavy acceleration. I seem to haveleftthe service records at the dealer's 400 mile away!

No matter, I prefer to assume NOTHING and go bottom up on a diesel tune up, which it desparately needs ( and hopefully not a cylhead reman!).

This is a 606.910 enigne. Got decent mpg (35) tooling along at 80-85, so I'm hopful its nothing deeply mechanical ( valves,head leak etc.)

Please describe to me the proper cadence of service to get this engine in a proper state of tune. Only thing so far is to putfresh oil/filter in. I've ordered a deisel purge kit, but me thinks I should be pulling injectors and having them tested. ??? Havent bought the IP timing light yet either.

HELP! I'd like to minimize my learning curve so I can put this thing on the road soon! Could someoine give me the right sequence of "events" so I can get cracking on it. Looks like the intake comes off before anything, so I'll pull that off today ( and detail it with some stainless steel paint which looks jsut like nat alum!)

Without knowing anything about these motors, but being a "gearhead" I would guess I have a failing injectorin the mix.

Thank you in advance for any advice and helping with my "baptism by fire" on maitaining a MBz diesel

dieseldan44 · #2 03-18-2007, 09:46 AM

As a fellow newbie I can say all the help you need is here on this forum, it's amazing...

I don't know the 95 at all, and Im sure folks are going to chime in with reccomendations to check injectors for nailing etc. On my car, sometimes the air cleaner housing bangs against the valve cover right after startup, making the same sort of sound. Sorry if youve already done this, but just make sure its not something like that before diving into the injectors.

Congrats, and good luck,
dd

WINGAS · #3 03-18-2007, 09:51 AM

DD, its my style I'm afraid. when faced with soemthing new, or a challenge, I just " JUMP IN " all-the-way, total immersion! DOnt be surprised if I have the head removed in a week!

I jest, being a firm ' if it aint broke, dont fix it ' beleiver. I prefer not to go that far. I think I'll pull the winshield washer bottle and intake manifold though.

Dan, its not that kind of noise, more of a ball peen hammer on a forged steel crank sound. "Nailing" whatever that means, is a prefect " onomonopia". Not purdy. Must be squared away. Beautiful sunny day here in Buffalo, and I'd like to take the family out in a spin in the new MBz, but that sound is an anathma to the joy of a "new" MBZ!

Yes, a great site it seems! It'll save my hide from expensive pro repairs, I HOPE!

WINGAS · #4 03-19-2007, 06:42 AM

Are the earler engines easier to work on. I read guys saying, " crack the injectors a bit while its running to bleed air from the lines ".

Huh? I assume they all have that "1959 Chysler 300 cross ram Intake manifold" which obscures access to the IP and the brace of injectors.

rrgrassi · #5 03-19-2007, 10:42 AM

Nailing is like a miss on a gasser engine.

Cracking the injector lines while the engine is running helps to narrow down which injector is the suspect, if in fact it is an injector issue. Cracking the lines also reduces idle quality due to a starvation of fuel.

As you crack the lines take note of what happens at each line. If idle quality does not change when a line ir cracked, then that injector becomes the prime suspect. Then, you swap the injector with the cylinder next to it, and repeat the test. If the problem follows the injector, then you have your answer. If it does not, then it's more testing time.

WINGAS · #6 03-19-2007, 10:50 AM

Yup, its a decided miss with a concurrent "ball peen hammer on my valve cover" ring. Much more noticeable when cold.

Does that sound like "nailing"?

Dang, hope so, dont want a head R&R in my near future.

Might as well pull them all. Purging wont cure this will it? Found two Bosch service centers here in Buffalo. They 'll rebuild them.

Rebuilding them is best not dont at home by a newbie? I mean , I have degreed camshafts and am quite good at gas carb rebuilding Qjets and Holley's > naw, never mind. I'll have them done by a pro so I know they're good going back in. R&R'ing is the big PITA. Hate to do things twice ( or thrice - btdt

).

Thank you RR for your reply. BTW, I bought some Praise Dyno Brake shoes for my old big Chevelle. MAN! Thinks it has discs coming down from a 118+mph 1/4 mile run! Royce City makes one helluva good product there.

barry123400 · #7 03-19-2007, 10:56 AM

When you have the suspect injector out have a look in the prechamber for a loose small part. It is part of the prechamber and it can break loose. Just costs nothing to check for it anyways although it is most likely not your problem.

WINGAS · #8 03-19-2007, 11:09 AM

Barry, thank you. I have not yet figured out what this "prechamber" is , although I've seen a picture of it. I hope they "reveal" themselves once I get to disassembling. I'll start tonight. I would love to find the the ONE injector thats failing as it is is clear ( to my ears, being a bassist and all

: ) I "gots" one bad "jug" of the six.

TMAllison · #9 03-19-2007, 12:49 PM

Sounds like a bad injector.

DP may help, certainly wont hurt.

At +200K, re-balancing the group and one or two new nozzles if necessary is not inappropriate.

WINGAS · #10 03-19-2007, 01:30 PM

Sir, please define " re-balancing the group".

TMAllison · #11 03-19-2007, 01:52 PM

Pop testing and adjusting openning pressure if/as needed, observing spray patterns and replacing nozzles if/as needed.

No Sir required, am a poor working stiff like yourself.

WINGAS · #12 03-19-2007, 02:13 PM

Hahaha! That's my line :" I was an NCO in uniform, WE WORKED FOR A LIVIN' Dont call me Sir! "

Well it sounds like I could either DIY with the Bosio nozzles with Russell's excellent instructions, or simply have the local Bosch diesel injector shop go ahead and rebuild them and bench them for me.

Because those tests you describe cant be done in my garage or workbench, methinks I'll spend the long dollar for a pro rebuild. Not cheap at $70 a pop, being that the MBZ dealer quoted me $75 a pop new.

New still means untested to me though. At least $70 gets you the bench test.

TMAllison · #13 03-19-2007, 02:32 PM

New (rebuilt) inj's run around $60-70 ea. Rebuilt pressures are set within 5% range I believe (if incorrect someone will correct me).

Pop testing should be more on order of $10 ea?

Nozzles ~$20-30 ea if needed.

WINGAS · #14 03-19-2007, 03:13 PM

Terry, what can I say, there are only two shops in town that'll do it. $70 seemed rich BUT you figure $30 a nozzle and then time.

Sounds like I should replace them at $5 more for new MBz ones.

Folks here said that QC isnt 100% with the Bosch replacement injectors. ?? But for $5 more...?

rrgrassi · #15 03-19-2007, 03:22 PM

That depends on where the new injectors are made. IIRC the ones from India are better as fishing line weights.