Are turbo’s indeed worth the hassle?
 

I own and love a non-turbo, (we prefer the term “normally aspirated”) 1979 300D. I think I'm lucky not to have turbo. Seems like too many turbo related problems appear on this board. But maybe I like it just because it's mine.

Are turbo’s indeed worth the hassle?

What turbo-specific hassle is there, besides making sure you let the engine idle for a couple of minutes to cool the turbo down?

I've never driven a n/a 300D, but I love my turbo!! It'll outrun a '00 Honda Civic (not that I regularly race, but still), and I can maintain her myself. :)

Only turbo complaint I have is... I wish the sound was a bit louder.

i used to drive a 91 VW jetta with a N/A 5spd. diesel in it....not a bad little car,but slow as molasses.....i dont think i could ever drive another diesel that isnt turbocharged....the power difference is amazing,i believe the mileage is better in a turbo engine....there are numerous pluses to having a turbo engine....i cant really come up with a downside to having a turbo versus a nonturbo

go buy an intake with a cone filter on the end of it....thatll get 'er just as loud as you want it

or better yet,if you have the OM617 engine,i have a filter setup that i could sell to you for pretty cheap....i used it for a month or so,and just got tired of my turbo being so loud,sounded like a Freightliner comin at you

Do you have any pics of your filter setup?

The only complaint I have is the engine can't handle more than 13psi :( (If the turbo can create 30psi and we only use 13 of it, why not want more?)

The power difference is very much night and day. I've been spoiled to mine so much now, I don't think I could stand to drive a NA diesel anymore unless it naturaly has more power.

if you click this link,i have just one pic of it right after i put it on to check the fitment,its somewhere near the bottom of the page....also i taped the holes that were in it with aluminum A/C tape

http://members.sounddomain.com/drtysthbenz

I have 2 turbos and so far no problem, knock on wood. The only small problem is a small amount of oil seepage somewhere from the turbo of my 82 300D, but it's small enough that I don't have to add any oil between oil changes. It's true about the day and night difference in power between a turbo and non-turbo. As you can see from my sig I own the fastest and slowest MB diesel, plus the 82 300D which is about the average of the two in power. The fact is, I like the 240D as much as the other two and I would even like to add a non-turbo 300D to my collection just for the variety, but I wouldn't have the space or time to work on it. Help, I'm addicted. :D

The banjo fitting was pluged tight when I bought my 81 SD as I had hoped for more power than my 240 I was diapointed.But a little checking on this forum and well you turbo owners know the rest............
William Rogers

yeah,i just cleaned the banjo bolt on my 85 SD last week....that thing was clogged almost completely up with crap....a little WD-40,and it looks good as new....i swear i can feel a difference in the power now

The biggest problem I have with 'normally aspirated' engines is that, well, they're SO normal.

First, the MB turbos are amazingly hassle free. They run much cooler than gas engine turbos and seem to have been made very very well... We see very few complaints on this forum compared to the number of miles and number of vehicles equipted with them.
One of the few hassles concerning turbos is the lack of hand space when dealing with stuff under it.. like the starter...
But in general turbos are made to go with Diesels... some day I hope to redo my 240 engine with turbo pistons, oil squirters, etc, and add a turbo. The are available in India stock from MB that way.

Dunno about the KKKs but Garrett has been making them since dirt was new. Experience certainly pays off in this game.

Agreed. It would be nice to be able to get to that block drain plug too!
Now that would be the cat's pyjamas!!! All the accessibility of a 616 and a turbo! Do you know if the NA 616 has the galleries for those oil squirters?

IMHO turbo chariging offers the best bang for bucks and if a little tender love and care is given, they last as long as the normally aspirated ones. The 91BHP OM 616 turbo is one prime example of how a slow engine is transformed to a peppy engine without any reliablility issues as MB did its homework in full.

I agree with the positive turbo review.

I have five and am 2.5 years without a problem.

Don

I guess I don't understand the question. I have both a Turbo and N/A. Both have been troublefree. The turbo is nice because of the increased power and MPG. My turbo is in a 126 so the added size is nice on vacations. The N/A is better in my opinion around town where I plod around at speeds <55mph. The car is smaller, 123, so easier to manoeuvre. Without the vacuum modulated trans. it shift smoother as well. There is something about cruising in the 240D at 75mph and listening to the engine roar that makes me fall in love with the car all over again that I don't get at 90mph in the 300SD. Guess the 240D appeals to my primal side at that point.

Most importantly my girlfriend appreciates the 240D for its classic looks, smoother ride and ability to view the scenery before it whizzes pass.

Different horses for differnt courses.

Fred Johnson
1977 240D
1983 300SD
Chicago

Hi 85drtysthbenz.

Sorry not topic related.

Nice car and stereo.

What did you do with the old ported box?


Louis.

I guess it's a tie - NA is quick enough for some, turbo is troublefree enough for the rest.

You can ask the same question about MT vs AT and probably come up with a similar tie.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I have both turbo and n/a and appreciate both cars for their great qualitites.

However, the power increase is well worth the extra complexity, and in reality if the climate control was half as reliable as the turbo has been, i'd have the perfect car--

Amen to that, I would much rather have manual climate control than natural aspiration.

thanks for the compliment, louis....i ended up selling that box along with another sub that i had lying around on ebay recently....the box was too big for the trunk,and with it being vented,it rattled that absolute hell out of the trunk lid....i originally thought that could be due to the 1200 watts im pushing to the speaker, but i built myself a sealed enclosure,and it sounds a LOT better...it doesnt rattle much now,other than at really high volumes.....but if you were interested in getting one of those boxes, go check out www.bigdogaudio.com , i bought mine from them off of ebay,cost me 75 bucks shipped to my door

There is no downside to the turbo engines. They make more power, get even better MPG (seriously), and have no major issues with the turbo hardware. The myth about needed to let the engine idle for a minute or more before shutdown is exactly that - a myth. Show me where it says that in the owner's manual and I'll eat my hat. Just don't climb Pike's Peak at full throttle then kill the engine when you reach the top. Running synthetic oil will further eliminate any heat soak issues.

Don't get any crazy ideas about adding a turbocharger to a non-turbo engine, all the internals are different. It's always cheaper to just buy a used turbo engine complete and swap that in, or even better yet, sell the non-turbo car and buy one that had it from the factory. While the boost is limited to 10-12psi (OM617) or 12-14psi (OM60x), you can add an intercooler, turn up the pump (internally), and get probably 20% more power safely and possibly run a little more boost. I've been dreaming about adding a Mosselman kit to my '87... mmmm....

:)

I've been wondering the same thing myself. If I've been running the car hard, I figure that since I have to drive it at low speeds through my residential neighborhood to get to my house from the main road, that *should* be adequate time to let things cool off as opposed to an abrupt shutdown. Owners of hodrod turbo'ed gas cars have those turbo timers for a reason, but then again, a 300D isn't a Toyota Supra or a Skyline GT-R... :D

In the owner's manual for my '87, on page 14, it says,

"Turning off

If the coolant temperature is very high (e.g. after hard driving on mountain roads), do not shut off the engine immediately, allow it to run for 1-2 minutes at increased idle speed."

Speedy,

Exactly. The MB turbo is oversized to the application and never really gets hot enough to worry about such things under NORMAL use. If you race, hill-climb, tow heavy trailers, etc... THEN perhaps you may need to consider doing this - but probably only if you run dino oil! :D I'm a strong proponent of using synthetic oils in general, but for turbocharged engines, I consider it an absolute requirement.

:cool:

Yup - like I said - only in extreme circumstances. My temp gauge almost never goes over 100C under any conditions. I'd let it cool down for a while if it was hot after "hard driving". But you just DO NOT have to do this all the time, it just wastes fuel and carbons up the engine...! ;)

Turbo timers and blow-off valves are items needed (or desired) on hot-rodded gas engines. Don't waste your money trying to mess with that stuff on an MB turbo. You can turn up the boost to the high side of factory spec if you want (that's free), but this doesn't always provide a power gain. My '84 makes no more power at 15psi than it does at 10psi... it just makes more heat! ;)

I wonder if you can get a turbo timer and a blow-off valve for the Mercedes diesel... My friends tune RX-7s and that's what they're constantly praising- turbo timers and blow off valves.

But like everyone says, the Mercedes Turbo is way better than a N/A in terms of performance and robustness....

Letting a marine diesel idle for a few minutes before shutting down is sop. Marine diesel's are run harder then a MB could ever be, so they develope a lot of heat and the turbo's really get moveing. I would think it would be a good idea to idle a MB for a minute before shutting it off, it couldn't hurt.

Toblin

OK I just gota jump in here and say I am also a admirer of the naturally aspirated engine. I realize the boost you get from the turbo comes at little extra cost in maintenance or anything else for that matter as long as things are running well. However if you started with two new cars, (turbo & non turbo) and both engines were treated the same, I believe the non turbo would last longer and be ALOT cheaper to rebuild. ALSO I like shifting gears , which pretty much eliminates a turbo for me. On the other hand if I had a freeway commute every day I would be driving a 116 and put off the enjoyment of shifting gears till later:D

I wouldn't say that all Garrett turbos are that great, I believe my Talon has a Garret turbo in it from the factory but it is a bargain chrylser one. :-/ It has 102k miles on it, no coking in it, but somehow a few months back oil stopped going through it. :eek: It works fine again now, but I need a new one, a bigger one. ;)

The Mercedes Garrett turbos seem troublefree the only thing I'd think that adds hassle is the ALDA and the line to it, I can surely put up with cleaning it out every year or so for the extra power. Since I drive only turbo vehicles I get used to driving them very softly for the last mile or two, normally I don't let the MB idle at all before shutting it off. Only time I do is if I just got off the expressway or something like that. The talon however I have a gauge of what the exhaust gas temperatures are coming out of the motor and gauge it off of this. Once it hits 1000*F I shut it off.

No, there is no functionality for a blow off valve on a diesel since the air is free to flow where as in a gasser the throttle plate is there to restrict it. However you could get a turbo timer for a Mercedes diesel just like any other turbo car as all it does is delay the shutoff of the vehicle by watching when you shut it off and adding a certain time to that before it shuts the igntion off.

This would be interesting, considering that the Mercedes diesels we're speaking off have no electronic ignition controls whatsoever, and to add to that, the engine shutoff is vacuum actuated.

Perhaps I'm assuming something I shouldn't but aren't our igntion locks just normal electrical ignitions, I have no idea where that other side of the vacuum hose which goes to the IP goes or how it gets its business done.

It would be very simple. Insted of shuting off the ignition, just activate a solonoid with a vacuum valve.

To throw more gas (diesel?) on the fire... ;)

1- Letting it idle for a bit before shutdown won't hurt anything, as long as it's 2 minutes or less. MB has stated that if a diesel engine will be required to idle for longer than that, it's better to just shut it off. Again, it's just not necessary for normal driving, but if it makes you sleep better - go for it!

2- In my limited experience with turbos, the Garrett used on the OM603 tends to leak oil a lot - annoyingly so. They work great, just leak externally. They're also a little noisier. My KKK turbo is bone dry externally, dead quiet, and has an externally adjustable wastegate which I love. Both seem to last almost forever though.

3- A turbo engine will last just as long as the non-turbo. The internals are seriously beefed up so there is no compromise in longevity. I almost think the turbo engine might last longer. But yeah, it probably would cost more to rebuild. You don't hear about many people needing to rebuild them though - the chassis normally dies long before the engine *needs* a rebuild! :p

4- The non-turbos are just too damn slow! (yeah, yeah, I'm a power junkie - I admit it...)

I think that rule goes for almost all diesels, they shouldn't idle for a long time rather the speed should be picked up if they need to set.

When you are talking about 0-60 in 13seconds rather than 20seconds I don't see much of a comparison. I don't think 13seconds would fall into the category of power junkie perhaps your 87 300Ds could though with the right mods. ;)

Speaking for turbos IMHO the best ones come from KKK and Warner-ISHI. They have both been extensively used in race cars and KKK is OEM to Porsche and MB. The Warner-ISHI was used in the dominating F-1 Honda engine where it ran a boost pressure of 40psi and from 1.5 liter engine, 1200+ bhp was generated. It was of a variable vane ceramic blade design.

That sounds like fun!! My little 2.0L is only mid to high 200s (0-60 in high 4s or low 5s). :( I need a huge turbo to boost up 30psi and have some real fun, like real AWD burnouts. (~500hp) I have a good deal of the setup done, but the biggest pieces are missing, huge turbo and huge frount mount intercooler.

Just wondering, if you were to increase the boost pressure, wouldnt you need to improve the cooling system, lubrication and the pistons accordignly, apart from that the head gasket, studs, higher quality pistons as well as improved valves.

When MB turbocharged the OM616, almost all internal parts including the crank, oil pump, pistons, valves, radiator was redesigned and the head was re-designed for improved coolant circulation, now all this for a mildly turbocharged engine developing 91bhp from the original normally aspirated 65bhp.

The cooling system normally isn't a problem as a result of raising boost, but it does become a problem if you add a front mount intercooler as it is getting warmer air. At this point the radiator may have to be replaced with something thicker and more effiecent. The lubrication doesn't really need any improvement to speak of, the pistons aren't normally a problem (unless you are talking a huge increase) but sometimes the connecting arms need upgrading if they are the weaker style. The head studs always need to be upgraded with a huge power increase, my car can handle 400hp until the motor needs to be opened and beefed up.

One of my favorite examples of a modded, or as they say "bombed" vehicle is the dodge ram CTD. Take the diesel motor and swap different turbos on it, build up the motor a little, triple the boost and go from a stock output of ~300hp & 550ft/lb to 950hp & 2000+ft/lb! :eek:

> turbo timer and idling to cool the engine

I guess I'd be concerned if I lived at the bottom of an off ramp.

> blow-off valve

This device is only for air throttled engines. A BOV on an MB Diesel wouldn't blow if you sidestepped the pedal at WOT at 5000rpm (or 4800rpm in my case).

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Yes, they are worth having. I almost bought a 1983 300SD last summer, and I could tell a huge difference between it and my n/a 300CD. Instead I bought a 1993 Subaru Legacy Turbo, and I can tell a huge difference between it and the 300SD. For one, the subaru doesn't have the tourque, however, it is much quicker, and faster.

Now Eric, I'm SURE that your Subaru can benefit from a larger intercooler, free flowing intake / exhaust, blow off valve, etc! :)

I understand that the diesel turbo works on the exhaust gases, and
 

so has few of the problems a gas turbocharger has...Frank Barrett has nothing but good to say about them..."free" extra power.

BUT...ANY extra part is something that potentially can go wrong...it can't screw up if it's not there.

Hi 85drtysthbenz.


Thanks for the info.

Louis.

Well, it has no intercooler as of now, but I might add one, also I will probally add an exhaust, and blow off valve...

Adding a blow off valve (or shall I say "upgrading") on most vehicles is a waste of money. Some leak and can be crushed just like mine is. You just have to figure out at what pressure it leaks. On the newer eclipses 95-99 they leaked after 13psi, on mine it was ~17psi (mine is the older one) crushed it can withstand about 21psi. Anything over that and finally a Greddy or whatever BOV isn't such a waste of money anymore.... The gains off of an intercooler is just amazing, I can't imagine my car without that puny little (very effecient though) stock one, however it could use a bigger one. :)

BoostnBenz,

Your Talon must be a pretty darn quick car! How's it feel getting in the 300D after a spin in something that hits 60mph in less than half the time? :D

I know gsxr rides sportbikes, so again, another huge contrast in speed as opposed to the good ol' MB diesels. Doesn't the sheer difference in acceleration make you guys' diesels seem a bit on the slow side? :D

I had a 2002 Corvette Z06 for a year. It was a great car and sometimes I miss it a bit, but the truth is I like my old MB diesels more. I got used to the tremendous acceleration after a while and didn't appreciate it that much anymore. I'm totally satisfied with my 3 Benzes for a fraction of the Corvette's cost. :)