how many miles before you would need to change or rebuild injectors ?

thanks

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Audi TT

220D 260,000 miles never touched
300TD 175,000 miles 1 changed
300SDL 265,000 miles I think 3 changed before I got it.

So when they give you a problem, not before. Look for symptoms not just to feel better.

Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Some people run the same injectors for 3-4-500K and seem to have no trouble. Since an injector is a mechanical device with wear surfaces I find it hard to believe that MB injectors don't deteriorate in performance over time. I have changed the injectors in my truck at 120K and it made a huge difference. Engine sounded much more crisp, mileage went up 1.5mpg, and smoke all but disappeared. I replaced injectors of unknown vintage in my wifes Jetta and the smoking completely disappeared except when floored, it started much easier and power increased slightly too as it was no longer necessary to downshift on certain hills anymore. I haven't done the injectors in the MB as there is no indication anything is wrong with them. If your car starts and runs well, doesn't smoke and has good power likely yours are okay. An injection shop usually will charge a nominal fee to test injectors so you could always get them tested if you are concerned. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Mine are still original after 223.5K miles in my 300D but a few look like they are causing a little trouble.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

253K on mine, all seems well, or at least not un-well.


Original glow plugs too. Yes it starts just peachy..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

273,000 miles and still running well. One injector is starting to make noise sometimes, but it isn't really bad yet. Some smoke at idle, but that's probably due to chain stretch... haven't checked it yet.

Changed mine 233k, they were original as far as I know. One was nailing and the car didn't really idle or start to well. Now it idles smooth, no more noise, and better starting. I also did glowplugs at the same time, so they might have contributed to the better starting. However there was no indication that they were not working. (if you are familer with the 603's you know why I changed them)

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Hello kamil
A theoretical question of the first order.
You pose a difficult or impossible to answer question.
Here is my answer:
#1. If you are filthy rich, as often as you want. (Personal decision).
#2. If you are convinced in your mind, that it must be done. (Personal decision).
#3. If you have evidence that proves the need. (Judgment call).
#4. If your mechanic proves the need. (Professional advice).

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ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

FWIW, I've got 251K miles on the (AFAIK; there's a 20K mile gap in the maintenance records) original injectors in my car, and everything's happy.

I think that injector longevity is a function of the quality on the injectors themselves, the quality (lubrication properties) of the fuel used, and the efficiency of the filtration system. "Indefinite" may be asking a lot, but some injectors do tend to last longer than others. As the posts on this thread show, M-B injectors typically have a long life-span. The Stanadyne injectors used on '83-'94 Ford trucks (and I believe similar injectors were used on GM trucks in roughly the same timeframe; I'm sure rwthomas will correct me if I'm wrong), however, have a much shorter lifespan (probably in the 100K to 150K mile range), and unlike the M-B injectors, are not feasibly rebuildable (at least not by a DIY; there are shops that rebuild and re-sell the injectors).

Just my $.02...whunter probably said it best, though

Good luck!