Just bought a '98 E300 TD. Questions inside
 

Hello everybody. I'm back into the Mercedes fold, for now. I just piked up a '98 E300 with the OM606 turbo. I'm doing maintenance on it tomorrow and want to investigate a few things while I'm there. I'm doing all of the fuel lines, oil & coolant chain (trans fluid has already been done, I replaced the speed sensor plate not long ago - bought this from a colleague, so it's not a complete stranger to me), fuel filters, rear window regulators...

Does anybody have a diagram or p/n's for all of the PCV stuff on top of the engine? It's all oily, so I assume it leaks. if it's all cheap enough I'll just buy it all new.

I want to delete the EGR. Does the ECU use the MAF for anything besides EGR? Is there a tuner that can turn of the codes for EGR?

Diesel purge. 1 can or 2? Hooked up the way I've seen in some videos putting 2 hoses into the bottle, is that cleaning the injection pump too, or just the injectors? Is there anything I should be concerned with in the tank?

Tuning/software. Who are the recommended tuners around here? Not going for big HP, but a few more ponies and a few mpg gains would be nice (and getting rid of the pesky emissions equipment, of course).

EGR Delete here

I have done it, no codes, works perfectly

Thats a long read, thanks. I'll look into it, but if it can be done in the ECU with a flash I'd rather just do that.

Look at the diagram on the page EDBSO linked to. No need to read the whole thread. It's literally one diode and one resistor. Doesn't get much easier than that. Installed it a few months ago myself, and disconnected vacuum from the EGR valve so it will never open. No codes set. :)

While you're in there replacing the plastic fuel lines, swap the o-rings out for viton. I bought mine from fryer power, a nice complete kit: Viton for Mercedes Engines at FRYERPOWER HOME

For ECU tuning, you need someone who will replace the soldered on chips, with a pair of sockets. I know Jeff at Rocketchip has the equipment and expertise to perform this correctly. I've used him a number of times for VW TDI's, very satisfied, I'll be going back to him with my E300. He can dial the EGR duty cycle down to zero too, if you prefer this approach over the diode-and-resistor solution.

As for the PCV, it's only a few parts on our turbos. 65, 68, 71, 74 in the diagram. Thankfully unlike the internet of pipes and junctions like the normally aspirated 606 had.

Attachment 143027

I understand what the resistor/diode mod is, but as stated - if there's an ECU flash option, I'd prefer to do that instead.

Thanks for the link. I'll investigate these orings.


Oh, thats for the pic in the edit. Where do I find p/n's for those? I can't find them in my Worldpac Speeddial anywhere.

The fuel line that goes from the motor side of the shut off valve to the fuel filter is secured by a banjo bolt. There is a small lime colored o ring at the end of the banjo bolt. Buy one of those when you get your fuel line. Mine broke when I removed the banjo bolt, and I had to make a special trip to the dealer to buy a new one. When you change the fuel lines, put a new o ring on the connection between the shut off valve and the injection pump. That o ring causes lots of problems.

Check your shut off valve for cracks. You can do that by wiping it off and inspecting it and then trying, as best you can, to fill it with diesel fuel.

While you've got the intake manifold off, you should consider changing the glow plugs. The added cost is about $90 for the glow plugs and $50 for the reamer. There is a Pelican wiki paper on changing glow plugs and several instructive threads in this forum. Read the threads, because you can run into big trouble if you break a glow plug trying to remove it.

Also, the temperature gauge sender unit is under the intake manifold. If your temperature gauge is acting up, you may want to change it.

I should have mentioned that I have owned a '98 e 300 for more than ten years. It has been my only car during that period. I've enjoyed driving it and really like the car. I hope you have a similar experience.

A): A can of diesel purge is enough and plenty. It cleans the injectors and the pump.

B): Tuning the car doesn't gain any MPG. There's a member on here who chiptuned his '98 E300 who noticed more torque off the line, but didn't increase the MPG.

C): An EGR delete will resolve gunk in the intake. There's a thread on here about it.

D): Check all the fuel lines for leaks especially around the top of the pump around the delivery valves.

Do I need to pull the intake to get to all of the plastic fuel lines? If so, then ya I'll definitely just do the glowplugs while I'm there. I'm very familiar with how to do them. Had one break off in a friends and it took a long drill bit and a slide hammer moving the entire car to get it out.

Thinking of the intake manifold....the entire drivers side of the engine and intake piping is covered with oil & nastyness. I presume this is coming from the EGR or some other way out of the intake? I assume this is common, so maybe somebody can point me in the right direction there?

Yes intake must come off to replace the plastic fuel lines. And FWIW the fryerpower viton kit includes the two o-rings ESchwab mentioned. You will need to source your own copper crush washers though, two of them, for the banjo fitting.

I would also heed his advice re: the cylinder head temp sensor. It's inexpensive, but you have to remove the intake to access it, so might as well replace it preemptively while youre in there.

Yes this is common, there's a large o-ring that sits between the EGR valve and the piping. When the o-ring fails, it makes a mess as you describe. Replace the o-ring while you have the intake off. p/n 606-997-06-45

For me that would be a whole lot of stuff to do in one sitting. What I mean is if you have any problem after work is done, was is something I did and where to start looking. I know it's nice to do a bunch of stuff at once but could be harder to diagnose any problems after the work.

Here are instructions on removing the intake manifold and the glow plugs. I found them very helpful -- especially the intake manifold.

PeachPartsWiki: LightMan's Step by Step Glowplug change

Make sure your battery is fully charged before you take the fuel lines off. You have to crank the starter for a minute or more to get the fuel back into the lines. Do that in 20 second intervals, with 10 minutes or so between each interval, to prevent the starter from overheating.

Fill the canister fuel filter with diesel fuel just before you put it in place. That cuts down on cranking time. Also put diesel in the tube where you will insert the pre-filter. Don't forget the o ring for the pre-filter.

Remove the screen wash bottle and you can change all the o rings on the plastic fuel pipes and remove the stop solenoid quite easily.

you did things the hard way for no reason. everyone around here will tell you penetrating oil and a ratchet and hope for the best. the way that has a 100% guarantee is using an impact gun between 30-40 psi with a fully heated up engine and they will come out (all 6) within 45 minutes. i've done it 3 times and walked a member through the process who vouches for my technique.

I'm a mechanic by trade and own a small shop, but overly anal about my own cars. Tearing the engine down and reassembling is not a problem. I'm just looking to arm myself with as much info as possible before I get started :)

The glow plug was already broken when I was asked to assist. Don't make assumptions :)

A trick I use and highly recommend is to fill the fuel tank to the top, my drive slopes down so I start with the car level in the garage and after replacing the fuel filter and/or fuel lines I roll it down the driveway and start with the nose down and tank high. Yes have a fully charged battery.

The intake manifold comes off and goes on real easy and the gasket is cheap, you will not believe the gunk built up in there.

Heard more bad than good things about having the car remapped, usually causes some driving anomalies or quirks if you prefer.

Such as? Links? A tune is usually one of the first things I do to a new (to me) car. While factory tunes on newer vehicles have gotten quite good on modern cars with full widebands stock etc., the OE still has to make compromises that aren't always ideal for best running conditions. Doesn't help, I suppose, that my best friend is one of the best BMW tuners in the country, and a majority of the past god knows how many cars I've had have been BMW's.... :P That, and I'm just not a fan of 'fixes' that fool the ECU. Garbage in, garbage out is never a good way to go, so if there's a way to fix the issue in the software itself, thats always better.

Happy with my Rocketchip tune on my 98. Stage 2 gave me marked (though not dramatic) improvement. I was hoping for fuel economy improvement but didn't see any.

Part-throttle drivability any better, or WOT only?

Change all the o rings on pipes and then connect a pela pump or similar to the return line connection out off the main fuel filter ,put ignition on to open stop solenoid and then apply vacuum and all the lines will get bled.

Quicker, more responsive all the way around....turbo lag all but gone.

Thats what I like to hear, thanks! I'll shoot them an email.

usually drive-ability problems, stumbling, surging, rough and excessive rolling coal at part throttle.

Could be wrong but I recall that Shertex had a re-tune touch-up on his original tune. I could be wrong though.

I have read on other cars when deciphered the tune simply went full rich sooner and more often.

I would agree that a proper tune (perhaps available from your friend0 can work wonders BUT they are few and far between.

PS There are real limits as to how much the injectors can flow.

No, that's incorrect. The tune was perfect from Day 1.

Apologies, must have been someone else, I wasn't certain.

Would you spend the money again?

No offense, but I've dealt with quite few professional calibrators - yes, there are ****ty tuners out there, lots of them., But a quality tune is worth every penny, on most cars. You can stop the fear mongering now. Your post is nothing but that - not a single bit of first-hand knowledge, only fear.

So, to recap - thus far, we've confirmed the following:


There is a nice set of o-rings I should buy when doing the fuel system service.
1 can of diesel purge is plenty
There ARE ECU flash tuners available, but no confirmation thus far on if they delete emissions components from the software or not. And there is a resistor mod to fool the ECU if I wanted go to that route.
Pull the intake, clean it, and replace all of the glow plugs when I replace the plastic fuel lines & orings.

Am I missing anything?

There are definitely tuners out there will be delete EGR for you (for off-road testing purposes, of course).

Not so fast!! The experience of others on this forum contradicts you, there is more. Frankly Shertex has it right when he recommends bringing the car to the tuner.

Sometimes you have a bad flash, or it bricks during flashing, or any number of things can happen. Sad that they apparently don't have a procedure to bench test the DME's like we do before they go out the door, but really thats a moot point. Thats a flashing or checksumm error, not a 'bad tune' or something that will damage the vehicle. Not something to lose sleep over. Send it back again and they'll either reflash it correctly, or they'll see what they did wrong and if it's bricked I'm sure they'd find you another DME.


And yes - you're fear mongering. Because it's ever so apparently that you have absolutely NO IDEA what you're talking about.

You are aware people are making 500+ horsepower on these engines with "stock" injectors right? They may modify the pop pressure settings but as far as I know the nozzles are not modified.

Yes, absolutely. The expense was pretty minimal in light of the performance improvement.

What you may be thinking of is the hassle I had getting the dyno done...a thread which some has added to this thread.

Thanks shertex it is good to know. My 06 CDI goes like stink, have you considered doing your CDI?

Kendog you are an interesting person.

You start the thread as one of us common owners. Then you aggressively defend "tuners" and people slightly critical and then you disclose that you are shilling for them.

I know of what I speak, unlike your tunes which are obviously perfect, others have caused many problems, some immediately, some weeks or months later.

ebay has many resistors are used to double the Hp of Diesels and there are some also good tuners (my final comment re kendog)

I own an automotive repair shop. I specialize in BMW, but work on most makes & models. I have some Mercedes experience, but not a ton - hence my post looking for some insight from people with more experience than myself. Before I opened my shop, I used to work for TRM Tuning, who is one of the biggest BMW tuners in the country with MANY NASA, SCCA & club race wins under their belt, as well as extensive experience engineering for IMSA & PWC teams. I was a mechanic there, and work with them extensively now (I only run TRM software in any of my customers BMW's, for example). I know EXACTLY what I speak of, unlike yourself. I'm not 'shilling' for anybody - I'm speaking from years of experience with the performance aftermarket. Whens the last time you had a vehicle of yours tuned by an actual professional, and what was the experience?

Also, to add to that - my first engine swapped car is a '95 Volvo 960 wagon that I put an LS into. Yup, need custom tuning there too. Need to remove VATS, as well as some of the emissions devices from the software, and change other parameters. I used Brendan at LT1swap.com. The only mods to the engine were an LS6 cam and headers. Dyno'd the car after, and it's spot-on, AFR's are perfect, no CEL's, no limp modes or any other issues. Also used him for a custom tune on my truck when I upgraded to a newer PCM. I don't use 'resistors'. Thats ebay stuff, like for the people who use a resistor mod to lower the coolant temp the PCM sees. Garbage in = garbage out.

I've thought about it. But it would almost be doing it just because I can. The car is fabulous stock. I'm sure, however, that noticeable improvement can be extracted from it. Jeff at Rocketchip has done many CDI's over the years.

I thought about chip-tuning my E300's but have heard so many bad experiences of reliability with people tuning their cars in general. What can go wrong and what's the chance? Don't think I'd ever take a chance on knocking the reliability off my cars. They startup every time i need them to without a hiccup.

Because of were you live, you should head over to Rocketchip....Jeff is in Red Lion, PA. There's really no risk with someone of his caliber...of course there are a number of good tuners out there.

If you're perfectly happy with how the car is stock, then cool, I completely understand the hesitation. For some of us, we want something more. Sometime more than what the manufacturer decided they had to do to comply with EPA regs & CAFE fuel standards. There's never a sure-fire method for finding a good tuner - everybody has SOMEBODY thats been upset. But factory stock DME's or engines et al fail on the rare occasion as well. For me, it's a trivial issue. Do my research & due diligence, find somebody who's been in the business a long time with a prove track record, and start asking them questions. If they respond with logical answers that make sense, then ya - to me, it's worth that risk. If I feel they're blowing smoke or won't tell me anything at all - I'll pass along to the next.

In short - it all depends on what you want out of the car, and your assessment of risk. if you're modding the car at all - a good ECU tune is pretty low on the list as far as risk to the long term life of the car goes.

I would sure love to get a "Tune" done on my CDI. If for no other reason than to get rid of the "rolling Coal" issue. My first CDI went "like stink" as well, and that with no black smoke. I think programing the EGR out of the system would help greatly. Is there a capable tuner somewhere in So. Cal.? Having emissions testing every other year, any tune would need to be reversible.

If you're deleting EGR function but still leaving the parts in place (maybe pip-plugging the EGR tube) and turning off EGR functionality in the ECU shouldn't be a problem with emissions. EGR's sole purpose is to reduce NOx emissions during part throttle cruise situations. I'm not sure how Cali does their testing, I know they're nazis about it, but I doubt they run the car enough to actually show EGR usage out of the tailpipe?

It looks like it's literally an OBD check and visual inspection. If it's disabled properly in the DME software, that'll never show up to a scan of any kind. The rest is a visual inspection for smoke, according to this:

http://www.dieselhub.com/tech/ca-diesel-emissions.html