mrnastard

I recently purchased a well maintained 1998 E300 turbodiesel and have done about 500 miles in it so far (not that it feels like it ). Whilst driving in heavy rain on Friday with the cruise set to 60mph I noticed the car shifted into 4th whilst going up a really small incline! I put my foot to the floor - no power. Driving the car a few hours later the problem had gone away, plenty of power there as normal.

Yesterday the same thing happened. The car accelerates much much slower almost as if something is restricting the power output. There are no warnings on the dash or anything else obvious like unusual noise or smoke and the car is still smooth - just very slow! When it first happened my initial reaction was something had happened to the turbo but I dont think that explains why the problem went away. Is there anything I could check for before taking it to the stealer? Any help much apprechated.

Lancelot

It does sound turbo-related, but it seems to me like there might be some hose or connection loose or something. Have you inspected under the hood already?! Check out everything air-intake related and follow the routing to and around the turbo...

sosh

As a general rule, diesel's lose power and in some cases smoke excessivly when there is a blockage or restriction in the fuel system like a clogged filter or, possibly a failing fuel pump. We all can keep guessing however its in your best interest to have it correctly diagnosed before you get stuck somewhere.

mrnastard

Well I just went to take the car for a quick journey to see if the fault was there again and I'm now very worried Upon starting the car it ran smoothly for about 2 seconds then started hunting and then stalled. I restarted it with the bonnet open and again it ran roughly and stalled. What is worrying me (alot) is in the torchlight I could clearly see a haze of blue smoke coming from the engine and also noticed what looks like a fresh splash of engine oil on the catalytic converter and I think also on the bottom radiator pipe. Oh dear!

mrnastard

The problem was the air mass meter which has now been replaced (£65 genuine part) and the car is running fine again. The tech said that on the turbodiesel this is a common fault and does not always trigger an error message on the dash.

The rough idling/stalling was probably unrelated - I put a strong dose of Redex diesel fuel system cleaner in an almost empty tank and then drove to fill it up so there may have been a particularly high concentration of the stuff in the injectors as a few mins of revving up this morning corrected the rough running.

The car has 244k miles on the clock and will live to see another day

Lightman

Haha sorry I just caught this post Mrnastard or I would have told you that straight off...first thing check fuel filter or for signs of gelling, second thing MAF. The '99 E300 I had as well as my mom's '99 E300 both had mafs die around 30-35k. Same thing in both VW tdi's I've owned, '00 and '02- the bosch maf's they put on those cars are POS'. Not sure how long it's been for you, but especially with these recent temps, you don't need any restriction in the fuel system...fuel filters are less than ten bucks and don't forget to get the new pre-filter(and o-ring!).

mrnastard

Hello, Thanks everyone for adding to this thread; at one stage I thought my E300DT experience was going to be short-lived but in hindsight I really should have known that these cars are built to a higher standard compared to other Diesels I've owned from the other end of the spectrum shall we say.

I intend to keep this car for some time and inspite of the high mileage I'll be giving it to a local bodywork specialist to restore the paintwork and wheels back to showroom condition over the next few weeks. The only issues with the car are the A/C not working, no automatic fan control, and no apparent fan speed difference between 50% / 100% on the LCD. Otherwise, the car has been owned since new by a company (that I work for) which it has maintained for the last 8/9 years regardless of cost. I will however have the fuel system checked and all the filters replaced as per the advice on this thread.


The car I owned before this one had an Isuzu 1.7TD engine. I regularly ran between a 30-40% SVO/Diesel Mix and had no issues at all apart from the obvious exhaust smell and more money in the bank over several thousand miles . I've not added any SVO to the Merc yet but want to try a 10% mix soon. Are there any issues here? My way of thinking is the older Diesel Merc's essentially started this phonomena and my W210 isn't CDI so should work without glitch?

Lightman

I ran a lot of b20 in my E300 but would be wary of any svo...yes it will pass through the system provided the temps are warm enough, but I don' t think the IP will like it much. They have enough problems as it is with the copper crush washers leaking using regular diesel, let alone bio or svo mixes. Give it a shot tho, report back if you do 10% isn't much..

mysticblu999

try some propane injection!

EdzBenz

Do not run a mix of WVO in your car without the proper set up. The most important thing here is that your WVO is very hot before it gets to the IP.

Chrispyfur

Hey Guys,

The OM606.962 engine runs very well in 25% Kerosene, 25% Diesel and 50% SVO all year around. It gets below freezing here. It's already got a fuel preheater in the car. Might wear the pump a little when cold but its built to run over a million miles, possibly much more… The engine’s timing chain only requires changing every 500.000 miles! The Bosch IP will cope with this mix very well... for years... Use a fuel bactericide regularly…

Chris