1987 300d turbo - PeachParts Mercedes-Benz Forum

strictlymb · #1 08-08-2002, 12:01 AM

Hi i have just recently bought a 1987 300D
with a 603.960 engine.My question to everybody is there anyting that i could do to bump up the hp or is ther any chip i could buy for the EDS ecu.A intercooler is the first thing on the list.Anything i could do with the pump timing? .Or howabout the diesel black boxes that there selling for the newer diesel vehicles.The reason why i mentioned the black box is that the pump on the car has some electronics to it like fuel rack position sensor,and has a mass air flow sensor.
PLEASE HELP I NEED SOME MORE POWER.THANKS

speedy300Dturbo · #2 08-08-2002, 12:05 AM

Crank up the turbo boost, and open up your ALDA a bit. The latter requires removing the intake manifold. I haven't done this yet because I see no need to. The car (in proper running condition) has excellent performance for a diesel.

I'm looking into doing an intercooler myself. I'll keep everyone updated.

sixto · #3 08-09-2002, 04:25 PM

Newer Diesels have electronically controlled boost. I don't think your car has that. There's no black box to modify.

Before tweaking anything, I suggest you make sure your car is operating as it should. Things like a clogged boost signal to the ALDA on the injection pump or a stuck overboost cutoff valve will cause significant power loss.

Your car is one of the fastest Diesels of that era. Your car should be able to run with just about anything on the freeway and will chirp the tires off the line under the right conditions. If it's not doing that, find someone who can help you get it back in tune.

A question in hindsight, why did you buy the car if it doesn't have the power you want from it?

Sixto
91 300SE
87 300SDL

goldenbear · #4 08-09-2002, 04:59 PM

Just my opinion, but I don't understand the interest of those who would like to alter the best engineered cars in the world. With routine maintenance and proper treatment, the cars run great and will last forever. I would be afraid to tinker with anything for fear of diminishing those two truths. That said, I agree with Sixto, check into the common items that typically affect boost. This model is a great performer. Good luck.

psfred · #5 08-09-2002, 07:15 PM

Stricktlymb:

What on earth have you been driving that makes you think a car that does 0-60 in ten second and goes 130 mph is too slow?

First, change the fuel filters and verify that you get good fuel movement in the clear pre-filter -- if not, check the tank screen for blockage. No fuel = no power, and it will still start and run!

If you don't get the typical turbo surge at 2000 rpm (believe me, this car rockets!) even at moderate throttle, you have something wrong, and messing about with the boost won't help, since you don't seem to have any. Besides, you already have 13.9 psi at factory settings -- any more will seriously impair engine longevity, or MB would have give the engine more to start with.

Here's the scoop -- you DO NOT have EDS -- the rack position sensor and actuator mostly control fuel "mixture" (read smoke) and idle, you cannot get more power by "chipping" it -- I would be shocked if such a chip existed, given the very few of these on the road. Ain't adjustable, don't try.

My information on the ALDA is that they rarely if ever go out, and they are a ***** to adjust anyway -- it has to be removed to get to the adjustment!

I will make the following guesses: You don't have turbo boost, probably none at all OR -- you still have a trap oxidizer on there and it is plugged. Do you have a "turbo" whistle -- high pitched squeal -- no smoke, no power, and VERY good milage, along with a large, ovaloid thing beside the engine on the passenger side? If so, you still have a trap oxidizer and it is PLUGGED -- the sound is the exhaust escaping from the seal in the pipe in front of the oxidizer. Hie thee hence to the closest DEALER and get it replaced, for free, with new turbo, most likely, at once. DO NOT TOUCH IT!!! If messed about with or removed, you void the warrenty and will be out the $2500 it will take to repair the turbo and buy the catalyst FROM YOUR POCKET. Dealer replacements are FREE.

If the trap has been replaced (insulated pipe instead of trap), check the following:

White plastic line from the center of the intake, next to the little switch, to the switchover on the firewall. Line must be connected and clear -- take it off and try to blow through it -- if you hear air coming out of the switchover, replace the switchover and you will have full power. Ditto for the line from the switchover to the ALDA -- and don't forget, the line also goes to the tranny transducer on the driver's fender -- if you have leaky lines there (or the transducer is bad), you vent off all the boost signal and won't get extra fuel.

If that is all OK, you will need to find a pressure gauge and install it in the boost line and check for boost -- you should get 13.9 psi at full throttle. If not, you need to check the turbo (wastegate and free rotation). If the wastegate actuator is stuck, you won't get any boost, and if the turbo wheel is slow or dragging, ditto.

YOu can check the turbo for free rotation by taking the air duct off the front and spinning it by hand, ENGINE OFF -- never take the duct off with the engine on, if you touch the compressor it will eat your finger (or hand!). If the compressor wheel has any axial play (goes in and out) you need a new cartridge. If it has "sticky" spots in rotation, you need new bearings, or a new cart. too.

This covers the main stuff. If you can tell me more about performance, especially in comparison to what you expect, the amount and color of any smoke, oil consumption, etc, I can help more.

These things are road rockets for diesel cars, I've never heard much complaint about lack of power, except maybe in comparison to a 6.9 or some such. It has almost as much poop as my 280 SE 4.5!

Peter

#6 08-09-2002, 07:29 PM

I have a 1983 300SD, is there any way I can check the boost pressure? I have checked the boost line, and it is clear.
I also cjecked the operation of the wastegate accuator, and with about ten lbs. of force it smoothly pushed in & out.
It seems that with the windows down, and the AC blower on low I can hear a slight turbo sound. Nothing to write home about.
I would like to check the boost pressure though.

psfred · #7 08-09-2002, 07:44 PM

Rob:

Most likely your ALDA is worn and needs adjustment -- see posts. You will need a gauge that reads 0-20 psi and a way to connect it into the boost line.

Also, check for leaks, bad switchover valve, or plugged line to the ALDA before you adjust it!

Peter

gsxr · #8 08-09-2002, 08:18 PM

Well, it sounds like the regulars (sixto, psfred, etc... hi guys) have already answered with all the right things to check. Please post back with your 0-60 time, so we know how slow your car is, and have an idea of just how "wrong" things are. If it's 10-12 seconds, then sorry, you should have bought a gasser (preferably 400E/E420) because that's about the best you'll do.

About mods, to date nobody has SUCCESSFULLY installed an intercooler on an 80's MB diesel and reported hard facts (dyno numbers or 0-60 times). Well, actually one or two did, and the results were either no change or a power LOSS. Critics may claim those guys screwed up. I think it's a whole lot of work, time, and $$$ with near zero payoff. You decide. But I wouldn't bother with it. The only minor mod I know of is to advance the pump timing to the far side of spec, to 14 degrees ATDC or maybe 13.5 (but no more than ~13.0). However this requires some special tools, an accurate TDC indicator, and mechanical knowledge (not simple like installing a chip). You'd probably get more gain replacing the timing chain and having the IP calibrated for performance at a Bosch shop.

Oh, psfred and sixto are right - you do have an EDS (Electronic Diesel System), but it exists mostly to control the idle speed (with the ELR) and the emissions junk (EGR & air recirc valve, which you should disconnect anyway). It does NOTHING for power and only has a sensor on the IP, which doesn't affect power. No free HP there. You can increase boost a few PSI, up to maybe 15-16 psi max, however experimenting with my cars this gave no measurable improvement over the factory 12.5psi setting. You can try if you like, though. Also make sure your "cruise surge fix" is properly installed, if it's on your car, search for my thread on this forum a few months ago.

PS: With this engine, you should be more concerned about whether or not you have a cracked head! Both of mine cracked, and I know way too many others who have had the same thing. The new head is redesigned and won't crack again, but it's not cheap (or easy) to fix. Again, there's some threads started by me, search if you're interested in learning the symptoms!

Good luck, and please post back with more info....

Regards,

strictlymb · #9 08-10-2002, 12:37 AM

Thanks to everyone who reponded to me with my hp concern.All of your help is greatly appreciated.Don't get me wrong the car has power i was just looking for some hidden power.My car is currently of the road due to some maintenance.Transmission is being rebuilt.After removing the oil pan to replace the gasket i saw pieces of plastic i'm thinking its pieces of guide rail so this weekend i'm removing the front cover and replacing all of the guide rails with all of the pins,also the timing chain with tentioner.And while i'm there i am going to inspect the bearing for the vacuum pump.I know there is definety 1 thing i am going to do and that is to install a intercooler.
1 more quick question to all.How much faster is the 1999 E300 turbodiesel (210) then the 124 300 D turbo ? Because my friend that i work with at Mercedes Benz with the 210 said to me any time your ready.After im done with my maintenance i think im ready.Who do you guys have your money on and why?. The race will be around 0-80 mph

gsxr · #10 08-10-2002, 12:48 AM

Sorry, but he'll kick your butt with a 1999:

Your car: 148hp (with trap removed), 0-60 in 10.5 seconds at BEST, if it runs PERFECT

His car: 175hp, 0-60 in 8.5 seconds stock

Both weigh about the same. If he has a 2 second advantage at 60 it will be a 3-5 second advantage at 80. And there's almost nothing you can do to increase the power of yours to beat him. Increasing the power of your engine, through whatever means, is more likely to melt pistons than lower 0-60 times. Bring cash...

BTW, are you sure you know what you're getting into, pulling that front cover off? It's a HUGE job...! Good luck. :p

sixto · #11 08-10-2002, 01:10 AM

Don't you have to pull the head to pull the front cover?

Intercooling has been discussed in a number of threads. The general thinking is that turbodiesels get more air than they need right out of the box. The key to generating more power is to provide more fuel which intercooling alone doesn't do. I don't know how many times this has been said and I've never seen a valid counter argument.

Very different thinking from turbocharged gasoline engines which manufacturers set to run excessively rich so you don't blow up your engine driving up Pike's Peak. All sorts of power can be made by brining the A/F ratio under boost closer to stoich by introducing a cooler charge of air.

Sixto
91 300SE
87 300SDL

RiceCakes619 · #12 04-05-2006, 05:14 PM

I thought I'd bump this to prove I do at least some researching =P

Since I'm mechanicly inept. I plan to take my car to a local shop, since I'm not doing 0-60 in 10 seconds (well I'll count how long it takes once i get out of work) what do I tell the shop?

I want to say "hey give the engine a full inspection" but with my luck they'll overlook everything I'm assuming they will look at. I saw a list of common things that go wrong, should I just read that off to him?

http://sandiego.craigslist.org/pts/146840929.html I kinda want to buy this turbo and throw it on. >The other guy with the black mercedes never called me back =( ... < I had no idea I should be getting 13psi. That sounds like a hell of a lot of boost comming from a tube in my engine. (I'm used to seeing snails as turbos)

Anyhow, I bought the car cause I wanted a project car different from all my import friends. I would love to enter a show someday. I'm dropping the WVO kit dreams for now, I'm thinking about propane or turbo for now.

Thanks for all the info! and putting up with a noob >_> haha

psfred · #13 04-05-2006, 06:52 PM

Stock is 149 hp and 195 ft/lbs torque, not bad for 3.0L and a diesel to boot (this is somewhat more hp than a Chevy Vortec per cc displacement).

I would check the integrity of the boost signal from the manifold to the altitude compensator on the injection pump. The rubber hoses are likely bad by now, and failure to hold pressure will cause low fuel delivery -- as the boost comes up, more fuel is added by the altitude compesator (ALDA for short). It may also need a different shim underneath.

Also, replace both fuel filters, the small in-line clear one and the main "spin on" (actually bolt on). A clogged fuel filter will severely restrict hp output by fuel starvation. If you dont' get some black smoke with it floored at high rpm, this is a distinct possiblity.

Check to see if you still have a trap oxidizer instead of trap catalyst -- the oxidizer is a football shaped thing above the turbo on the passenger side -- if it has been replaced, there will be an insulated exhaust pipe from the rear of the manifold up to the turbo instead. If you still have the trap oxidizer, likely it's shot or plugged, and will be replaced (for free) under warrenty by MB. DO NOT replace it yourself, if the turbo is also bad you get a new one, and a new exhaust most of the time -- something like $4000 worth for nothing.

Stock boost is 13.9 to 14.1 psi.

Do not use propane fumigation, you are very likely to blow the head off from pre-ignition, this is NOT a low compression engine like a cummins or detroit, and the propane will ignite long before TDC on a hot engine if you get a burnable amount in there. Prechamber engines don't do well with propane.

The Finns love these cars, and there is an outfit there that will retrofit your injection pump to produce something like 300 hp (with an intercooler). Way hot for a diesel!

Do not monkey with the timing, you will only lose power or burn the prechambers! Again, this ain't a detuned Cummins, it's a high rpm mechanically advanced MB. There is no electronic control of fuel delivery, so you cannot "chip" it, and I also advise against upping the fuel delivery unless you also increase the airflow -- all you will do is make more black smoke, and power will drop off rather than increase as it goes over-rich.

Check for dragging brakes, especially the rears (pull the pads, clean all the rust out of the slots, and put a little anti-seize on the sides of the backing plate and the cross-spring were it contact the pads). This can cost you lots of acceleration. Fronts don't usually drag without you knowing it, but rears just eat fuel and acceleration.

You should also check the suspension rubber front and rear -- very likely the suspension links at the rear are sagging and need replacement (not a big deal) and the sway bar bushings front and rear are gone as well. If the strut mounts are cracked at all up front, replace those as well, and you probably need rear subframe mounts (I'm part way through this on the 300D). Amazing improvements in handling -- the car is totally immune to crosswinds, I don't even notice them except for wind noise and other vehicles wandering around!

Peter

RiceCakes619 · #14 04-05-2006, 07:36 PM

Thanks!

I'm going to make a new thread with your help =D

gsxr · #15 04-05-2006, 08:41 PM

Most of what Peter said is spot-on. Forget propane injection. With intercooling, you can get 20-25% power gain with the stock injection pump. Beyond that, you'll need to send it to Myna Diesel in Finland for a performance rebuild, including governor mods with external full-load adjustment, with your choice of baseline power settings from 200-450hp (assuming you have the intake, exhaust, and intercooler set up to handle that power.) Me, I'll be happy with a 20-25% gain with the stock pump - for now.

Also, stock boost is 0.85-0.95 bar, which is approx 12.3-14.0psi, and all four of the 1987 300D's in my family tested at 12.5psi boost stock. I have tried increasing boost to 18psi and got zero, repeat zero, power gain. TO make more power you need more fuel (increase full load screw) but to make the engine survive with the extra fuel, you need to keep EGT's down via intercooling. Be careful, you don't want to blow up the motor, these cost $2-$4k used at salvage yards...!