Engine 'chugging' and puffing blue white smoke - T
Hi..
New member here.. My 300GD (1985) which has either 150k or 250k on it has started to run rough.. It still starts but chuggs - runs very rough and will only idle either very roughly or with the idle throttle dialed out.
It has just had a full service with new filters etc and the problem has got worse. The fuel filter shows very light yellow fuel (correct) with some black particles in it (and an air bubble the size of a pea).
The garage have put injector cleaner in and put some in the tank.. Since then I have stuck a wyns injector cleaner through the system as well. Was initially fine - and has done 600+ miles since the service
Now the problem used to be at cold start and occasionally when dropping to idle after a long run at full throttle. Initially it was noticable by a rough idle with some smoke.
It now produces a lot of white/blue tinge smoke. and feels like not all the cylinders are firing - very low on power and really needs full throttle to get it going until the temp is mid dial. there is a definite smell of un-burnt fuel associated with the smoke.
Once warm it runs ok.. but will now usually idle rough - shakes the car pretty much all over the place and the smoke returns. If you leave it at idle it will eventually sort itself out and begin to idle ok, especially when warm. This can take a while 30 secs to a minute or so..
I am pretty sure the car has spent time stood - perhaps years and has not been looked after.. I now use it full time and intend to keep it as my main car - love it.
Only other thing that might not be related is the vacuum engine stop needed to be sorted as it had stopped working.. It might be a co-incidence, but this problem i.e. taking longer to cut out before eventually refusing to cut out - did track with the rough running problem.
Final thing - you get black soot like particles on your hand if you hold it under the exhaust.
Garage (who are very good BTW) think the injectors might be on the way out - treatment either buys you some grace or kills them off!
Any views - I have put a lot of info as I know the tech buys on here tend to need more info... but I bet I have missed something important so if I have just ask..
Mechanically minded.. but not much experience since tinkering with motorbikes 20 years ago.. but I did get the idle throttle on (and finally brought the engine cut off to a terminal point!!)
Any help greatfully received by me and the garage..
Ta
Simon
Hello Simon,
You have mentioned that the engine has been serviced, can we take it to mean the valve clearences have been checked and adjusted? If not, I would suggest this to be done. Then, have the compresion of the cylinders be checked and recorded.
The injectors will need to be tested of course, initially here I, suggest when the engine has improved its idle speed or that you can trim the idle speed with the aid of a second operator, increase the idle speed a little, so the engine runs better, so not, to cut out and maintaining an even idle speed; individully, crack open the injector nut, tighten the nut and move on to the next injector and repeat this exercise with all injectors. Do not compensate for idle speed drop, it is important to maintain the aclerator at the same position where you got a good idle speed. Once the engine regains its better idle speed, crack open the next injector, note and compare the drop in idle speed. If, all the injectors drop the idle speed equally, then ther is no problem with the injectors or esle they are all equally bad.
The alternate way to check injectors is at a Diesel specalist. Give them the injectors to test out for you. They, should check the Diesel injection timing for you, as well. It may wel be the injector pump needs servicing and recalibration, or else the problem lay with engine wear, in which case further test are need to confirm this aspect.
Cheers,
Just an update.. a couple of the members have followed on private message...
Finally after much messing (and two months off the road) and trying to sort just the head out... we got a remanufactured engine and took the opportunity to drop in a re-cored rad and new clutch...
Runs like a train (well as much as a 300 GD ever will).. but pretty much re-vitalised... and very pleased with the end result.. if not the end cost..
All just in time for the snow to melt!!
Ta
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Hi.
Many thanks for the advice both public and private MSG. I really apprecite your help. The G has been to Crewe engines (I used them for an old 420 SL) and to cut a long story short the engine is in terminal decline.
So time for a re-manufactured enginee thinks.
Ta
Simon