C250TD W202 not starting - ish?

[ali.shaikh22]

Hello

My Mercedes C250TD was running sweet....on tuesday evening it ran a bit low on fuel - the light was on.

On Wednesday it wouldnt start in the morning, it would try to turn over but nothing

I got hold of a can of easy start. I sprayed for about a second in the air box and car burst into life, with a puff of smoke from the exhaust.

Car ran fine all day, picked up speed, no jerking etc. tried to start the car on Thursday morning. Again wouldnt start. tried the easy start and again it was running.

May I ask if anybody has an opinion on what is wrong? could it be air in the fuel system? could it be glow plugs?

Any help. Much appreciated

 

[spoton]

hard to tell

difficult to say definitively as these engines as a rule wont start if none of the glow plugs are working

however with easistart and air in the fuel system Id still expect it to crank a bit til it pulls air free fuel thru

best look at the clear fuel pipes before you start to see whether theres air in them and once started see if you can see bubbles travelling along them


most likely its the O rings on the fuel pipe unions that need replacing but on these diesel engines there are several other components that can also let air into the system, its a process of elimination unfortunately, theyre a brilliant engine when running right but badly let down by an ill designed fuel delivery system which can result in much swearing and hair pulling

 

[ali.shaikh22]

No start - easy start

Hello

Thank you for the response, just been so busy lately not had a chance to take a look at he car, I've been using te easy start but once the car is a bit warmed up it tends to start up fine.

I do see the air bubbles in the fuel lines. I have replaced all the unions not long ago. I imagine when the fuel ran low it cause the issur?

Any idea on how to bleed the fuel lines?

Thank you

 

[ali.shaikh22]

Hello, I replaced the pre-fuel filter lastnight, and as expected it struggled to start, with a fair few go's with easy start, it did start and run perfect.
Tried again this morning and again no start, tries to turn over but just doesnt catch.

When the car is warm I am able to start it with no issues. Do you think this suggests it is the glow plugs that are not working as they should?

Any advice much appreciated

 

[HarioH]

No, all glow plugs would have to die at the same time to cause an overnight difference, unless its been getting progressively worse?

1. Replace all O-rings as this is the likely cause, happened surprisingly suddenly with me also, there are kits available on eBay.
2. Fit a one-way valve in the fuel pipe between lift pump and filter (in the engine bay) takes 5 minutes and stops any fuel - hill related issues.
2. Multimeter across a/all glowplugs - open circuit or infinite resistance means broken.
IMHO.

 

[ali.shaikh22]

No start still

Hello thanks for your response

I am still starting the car with easy start, just not had the time to look into it. I can't imagine it's doing the engine any favours

I have bought some beru glow plugs so I may try to replace this weekend

I shall test the glow plugs with a tester first.

Could this issue be a combination of glow plugs and the fuel system?

I have previously (within 6 months) replaced the o'rings in fuel lines.

I replaced the I rings under the inlet manifold 6 months ago as well.

As far as I know the glow plugs are located under the inlet manifold so will I have to replace the o'rings again?

Any other bits you know of that I shall/should replace whilst doing the glow plugs?

Thanks

 

[chubbs111]

sorry to be the bearer of bad news but your car will eventually get addicted to easy start.i used to be a mechanic working on a fleet of 100+buses and at least 80% would not start without easy start.in my opinion it should be thrown away.

 

[Kenner]

sorry to be the bearer of bad news but your car will eventually get addicted to easy start.i used to be a mechanic working on a fleet of 100+buses and at least 80% would not start without easy start.in my opinion it should be thrown away.

hi I tend to agree that once you start using easy start you find you have to carry on but you should not need to use it in the first place if all is good these are good compression, heater plugs all working,injection timing correct and speed of compression which is cranking speed , battery & starter etc hope this has helped

 

[ali.shaikh22]

No start

Hello

Thank you for all your advice. I appreciate that easy start shouldn't be used and trust me at 6 in the morning, lifting the bonnet is the last thing I want to do.

I'm hoping after changing the spark plugs it should make a difference.

I've just driven 200 miles in it and it starts up once has driven a little but leave it for say 12 hours and it just won't start.

The drive in this car is smooth and effortless, no jerks or loss of power, however tonight when I put my foot down, there wasn't a surge power as there is usually, could faulty glow plugs put the car in limp mode? It was picking up speed, but just felt like it lost some of it's push

Thanks

 

[ali.shaikh22]

Hello

Urgently need help

I have started to take out the Glow plugs and they are super tight. Ive been patient and have been turning them with lots of plus gas.

One of the plugs feels like it is out, as in doesnt feel like there are any more threads left to turn however it still feels stuck in the chamber.

Does anybody have any ideas on how to take it out?

With the plugs soaked in Plus gas, would turning the key to ignition help? i.e would the compression help to shoot out the plug?

I have attached a picture of where the plug is currently.

Thanks

 

[ali.shaikh22]

Glow plug pic

Please find attached picture of glow plug, how do i take it out now?

 

[Harley Man]

Looks like you have space between the thread and the head if so spray some plus gas in the gap and leave overnight then very carefully work the glow plug back and forth with a socket till it comes out, for future reference its best to remove them from a really hot engine, as its very easy to snap the tips off which then means a special tool to drill them out

Dave

 

[toolman1954]

Hi, You seem to be getting yourself into a bit of a bit of pickle. I feel your frustration at the lack of starting, but I think you need to step back and look at what you are doing. Your immediate problem is the Glow Plug half way out. Glow plugs really should only be removed when the engine is hot and trying to "" shoot it out "" could cause some damage to the bonnet and to you I would be tempted to put a smear of copaslip on the half out Glow Plug and temporarily screw it back in. I see no mention from what you have written so far that the glow plug relay is faulty or the glow plug light on the dash is remaining on. So for the moment forget about the glow plugs and deal with the main issue. Back to basics and as already mentioned, Diesel engines just need compression and fuel. Obviously you have compression otherwise it would not run so its back to fuel and these engines suffer from having a poorly designed fuel system with their plastic pipes. Somewhere and somehow you are getting air entering the system and until you eradicate the air, it will never start properly. You say you have replaced all the O rings?? But what condition are the plastic fuel pipes in. In my opinion you are better replacing all the plastic pipes complete with their proper O rings. Also as previously mentioned a non return valve in the system helps. Next, what condition are the delivery valve seals in?? is there any dampness around these?? Just a spec of dust can let in air and cause the non starting. Eventually I had to send my 300td to a Diesel specialist to get the delivery valve seals done properly as I had not done the job right.
When you have gotton rid of the air in the system, then it will start and then you can sort out glow plugs. As much as I hated admitting defeat,and it cost me £120, it might be just as easy to get a specialist get the lot sorted for you. Regards

 

[SilverSaloon]

if its past the threads do this:

start the car and let i idle. (get it as warm as poss)

give it a bit of revving. See if the plug starts to come out

leave the engine running. if not get a pair of plyers or the socket and wearing thick gloves, turn it a bit, it should start to ease out

watch out as when it does go it will fire out like a bullet complete with flame, but it will be out!

be careful you dont want to snap the plug in the head which is common with these engines.

you could of tested the plugs at the relay using a multimeter.

it could also be the relay at fault if all plugs appear to be dead.... are you getting 12v to the relay?

 

[guydewdney]

Having done the plugs on several of these, that looks quite clean and new. Lots and lots of (rotating type)wiggling, wd40, more wiggling and pulling carefully but firmly with pliers. Its going to be sooted up.

 

[DSB SL AMG]

+1...seems crazy to be throwing money at an old car when you do not have root-cause of your problem...get it booked into a recommended MB indy asap and save yourself some money...

Hi, You seem to be getting yourself into a bit of a bit of pickle. I feel your frustration at the lack of starting, but I think you need to step back and look at what you are doing. Your immediate problem is the Glow Plug half way out. Glow plugs really should only be removed when the engine is hot and trying to "" shoot it out "" could cause some damage to the bonnet and to you I would be tempted to put a smear of copaslip on the half out Glow Plug and temporarily screw it back in. I see no mention from what you have written so far that the glow plug relay is faulty or the glow plug light on the dash is remaining on. So for the moment forget about the glow plugs and deal with the main issue. Back to basics and as already mentioned, Diesel engines just need compression and fuel. Obviously you have compression otherwise it would not run so its back to fuel and these engines suffer from having a poorly designed fuel system with their plastic pipes. Somewhere and somehow you are getting air entering the system and until you eradicate the air, it will never start properly. You say you have replaced all the O rings?? But what condition are the plastic fuel pipes in. In my opinion you are better replacing all the plastic pipes complete with their proper O rings. Also as previously mentioned a non return valve in the system helps. Next, what condition are the delivery valve seals in?? is there any dampness around these?? Just a spec of dust can let in air and cause the non starting. Eventually I had to send my 300td to a Diesel specialist to get the delivery valve seals done properly as I had not done the job right.
When you have gotton rid of the air in the system, then it will start and then you can sort out glow plugs. As much as I hated admitting defeat,and it cost me £120, it might be just as easy to get a specialist get the lot sorted for you. Regards

 

[HarioH]

**Air in transparrent fuel lines causing difficult cold start - Very very very very likely.

**O-rings' replaced by yourself incorrectly - Very likely.

**O-ring BETWEEN fuel shutoff valve and IP not replaced and the root cause of the problem - very very likely.

Please find attached above list of issues causing your problem..

 

[mongrelpom]

Do you have return lines on your injectors, only one of mine was leaking, the one closest to me which goes back into the fuel filter, someone had misrouted it so it got squashed under the plastic cover & I think the pressure build up broke it's seal down beside the injector, the fuel actually pooled around the injector, it caused me a lot of cranking to start sometimes, if replacing then after replacing the line you may break down a few minutes later , I did, I then switched the ignition on , waited 10 seconds, then repeated ten times (incase there is a lifter pump) then used easy start. It self-bleeded from then on and was fine. My boat has no glow plugs but always starts even in freezing weather, just takes a bit of cranking, yours seems to be aerated fuel.
That air is sneaking in somewhere. They got rid of the primer pumps, shame really, I see some cars have a little pump on top of the filter where mine just has a nut. Hope you get the injectors out, some are so hard to get to on the 5 cylinder engine.

 

[philhoward]

If it's any consolation, I've just replaced my plugs which were really, really tight - 3 cleared the threads but wouldn't pull out as you described. Partly my own fault - engine was warm-ish but was actually cold by the time I was 2 plugs into the job last night.

Using some Duck Oil (WD40 isn't really that good, although better than nothing) they did unscrew with constant unwinding and pulling at the same time. Probably 10 minutes per plug in the end.