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Injector and glow plugs?

What mileage did you have on the old bus Gino and had you tried neat injector cleaner through the old injectors first.?
Have you had the old injectors tested to see whether they are still good.?
 
Whilst we're on the subject of injectors and glow plugs, I'd appreciate some clues regarding how to check / remove the glow plugs on a '99 E300 TD.
biggrin.gif


I'm assuming that the glow plug light comming back on after starting is trying to tell me something....

Electrically am I looking for continuity to ground from the relay for each plug, and is it inlet manifold off if I have to remove them?

Thanks guys!
 
>>Electrically am I looking for continuity to ground from the relay for each plug, and is it inlet manifold off if I have to remove them?

Yes, the glow plugs should each have a low resistance to earth.

Yes, it's an inlet manifold off job to replace them, but, there's lots of other good bits to sort out with the manifold off.
 
Hi DM, I have 117k on the old girl now, the reason i changed them was due to a dark damp exhasut on local runs alsoo the same on motor way use. As i said before i live in Italy and this is where the old girl is. Its very hot here so i exspected on a motor way journey to clear but i had also noted the drop in fuel econimy as well. At a glance bearing in mind i have not done any heavy trips, but with aircon on today I only notice the gauge not dropping like it normally does, but a proper check i will do next week. I wont get the old ones testedas they are exchange anyway. the only think i have noticed is they seem louder, why ! my guess is they are set up to the correct hi presure now, maybe they will quite down after some miles. The cost was £170 ish for 6 Boccsh exchange. If anyone wants me to get more please ask, as my friend helps me out where i go.As for the real check, io will report back to you with figures within the next couple of weeks. As i need to do a drive sensible test and a hard motorway test. Gino
 
I bought 6 bosch exchage £170 all in. I rang Bosch as i wanted to knnow what was the main differance between new and exchange. They said that new is all new. exchange is all new running gear like you would get with the new units just the main parts ie body bits are used. So I was happy to have these, with the same gaurentee as the new ones.
Gino
 
As long as the pintles and nozzle holders are new, not reground then they will be fine.
Your mileage seems surprisingly low for injectors.
 
DM What Mileage would you say they would need attention. The car lives on mostly long hard journeys. always around 90mph. i just noticed a drop in fuel econ and a damp black tail end. hence why I changed them. I was told that the ends are all new, they said ' we could not gaurantee them if they did not repace the main bits Nozzole and end bits, as i did question this my self.
Gino
 
I would have thought maybe 300Km given mainly longer journeys. It sounds like yours were blocking up a bit, but not necessarily worn.

I prefer to run injector cleaner every fill to stop this happening and to reduce wear and recently ran neat injector cleaner through via the filter inlet and return.
 
I paid about the same for exchange Bosch injectors from a local Bosch service centre. It was also noisier when first installed - diesel knocking - it has gradually quietened down over the next 10k miles. The mpg figure seems to be creeping up and up (ie getting better) - which is great for a 200k mile car! I am pretty sure it is the injectors that have made the difference - mine have paid for themselves now.
Well worth doing at over 150k miles - not so sure about 117k though.
Mine is a late W124 btw same engine without the turbo.
 
bill_mill_65 said:
Whilst we're on the subject of injectors and glow plugs, I'd appreciate some clues regarding how to check / remove the glow plugs on a '99 E300 TD.
biggrin.gif


I'm assuming that the glow plug light comming back on after starting is trying to tell me something....

Electrically am I looking for continuity to ground from the relay for each plug, and is it inlet manifold off if I have to remove them?

Thanks guys!
Click to expand...

Bill do a search on this site and on mercedesshop.com for glow plug replacement. If you are competent then DIY the job - but set aside a whole day or better a weekend - it is not a 15 minute job. The manifold does have to come off - not that hard and will give you the excuse to clean it (2 hour job itself) and change all the fuel lines before they start leaking. The hardest bit is getting the old glow plugs out - they seize in the head - lack of patience or some inexpereince and they will snap in the head - and then you are into head removal and a £1000 bill potentially. Best bet is to remove the manifold, get access then start the engine to warm it up - then remove the glow plugs with plenty of pentrating oil.

And yes the glow plug light coming on is telling you that at least one plug is dead.
 
To add to Smiley's post;

Beru publish a failure torque of 45Nm for their glow plugs. I have heard people say that they can actually take over 80Nm before failure.

For mine, I think they came out between 50 and 60 Nm - I have a click type torque wrench rather than one that reads the value from a dial, but, I don't think I would be happy going much beyond 60Nm when removing them.

When re-installing glow plugs, the vital thing is to make sure the taper seal is in good condition - it is carbon getting past this taper which causes them to stick and snap. So, do not undertighten the new ones in the hope that it will make it easier next time. Undertightening just increases the chance of taper seal leakage.
 
Smiley, and Number Cruncher, thanks both for you replies. I shall start to make plans to operate!
 
The job should take a couple of hours all in.
Car on ramps remove centre undertray and one allen bolt mounted vertically up into the EGR valve.
From the top remove EGR recirculation pipe clamp, MAP sensor from inner wing, EGR vac line from modulator and push through, MAP electrical connection.
14 torx bolts holding manifold onto head and lift away at head end first.

Pull connector from glowplugs and with a 12mm deep socket, with a good grip undo the plugs.
If any are stuck keep the engine running to keep them hot whilst undoing. Loosen a bit and re tighten a bit works.
Don't undo the thread all the way with the engine running as that will blow the plug out at the last bit of thread, damaging the thread.

Clean out the glowplug seats with a brush and put anti seize compound on the seat and thread on replacement.

Bill_Mill. Where abouts are you in the Midlands?
 
Dieselman said:
The job should take a couple of hours all in.
Car on ramps remove centre undertray and one allen bolt mounted vertically up into the EGR valve.
From the top remove EGR recirculation pipe clamp, MAP sensor from inner wing, EGR vac line from modulator and push through, MAP electrical connection.
14 torx bolts holding manifold onto head and lift away at head end first.

Pull connector from glowplugs and with a 12mm deep socket, with a good grip undo the plugs.
If any are stuck keep the engine running to keep them hot whilst undoing. Loosen a bit and re tighten a bit works.
Don't undo the thread all the way with the engine running as that will blow the plug out at the last bit of thread, damaging the thread.

Clean out the glowplug seats with a brush and put anti seize compound on the seat and thread on replacement.

Bill_Mill. Where abouts are you in the Midlands?
Click to expand...

Anti seize compound is very good advice.
 
A bit further than I hoped, but let me know if you are struggling.
 
OK thanks for that, I'll check the electrical side first before the spanners come out !
 
Just pull the connector off the relay and probe into the contacts. Handily the connector is numbered.

Only use Bosh or Beru plugs, the rest won't last.
 
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