condensation from exhaust at start-up
I was wondering if anyone else has experienced this problem before?
My truck on startup spits out a lot of smoke in the back. It starts off a little darkish in the first twenty or thirty seconds but once a smooth idle is on, it's all white smoke (presumably condensation) that lasts until the car is fully warmed up (about 5 mins or so / when the temperature guage needle is in the middle). Is this normal?
Also, does everyone have problems during cold starts, i.e. need to crank it for a while and give it a bit of gas on the accelerator?
I also have to hold on to the pedal until it smoothes out to a steady idle- otherwise, it putts along at 400 rpms for about a minute...
Thanks in advance guys! :wink:
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Thanks,
Suspect leaky injectors...how is it on a hot start after having been stood for approx 1 hour?
Or worse, keep a very close eye on water and oil levels as well as their condition - could be the early signs of imminent head gasket failure... :shock:
The water level in the radiator going down could mean quite a few things...
Probably a good idea with the engine hot and idling to observe things around the hoses, radiator and cap/overflow hose. If you can't see any leaks, even when revving it up a few times, do these:
With the engine cold, remove radiator cap, start engine and look for air bubbles in the water - keep looking until warm. Bubbles at this stage means head gasket letting compression through into the water system.
Check the exhaust in the mirrors(or someone driving behind) under hard deceleration for excess white smoke/steam, indicating water being sucked into the cylinders and then being evaporated there before being sent out via the exhaust... Try something like 2nd or 3rd gear near max revolutions and then letting go of the throttle and not touching the brakes, ie letting the engine do the braking - even better downhill.
Also do a compression check of each cylinder, hot and cold engine, writing down the readings cylinder by cylinder as you go along. A good screw-in compression tester can be bought for around £20 and is dead easy to use. Once you've got the results, post them here and myself and everyone else can give you an opinion.
If all the above checks out OK, I'd say your cylinder head gasket is absolutely fine!!!
Be very careful about taking your car to a mechanic/garage at this point as this is the ideal time for them to get you into emptying your wallet... :evil: In fact avoid doing so at this stage at all costs!
Once the above is done, we can go onto other possibilities...
Most importantly :!: , remember to record everything - take notes, make sketches, take pictures...but record everything: ambient temperature, weather, engine temperature, colour of the oil and water, type of oil, any noises, and anything else you are thinking of at the time...
Take your time, work step by step and ENJOY!
The water level in the radiator going down could mean quite a few things...
Probably a good idea with the engine hot and idling to observe things around the hoses, radiator and cap/overflow hose. If you can't see any leaks, even when revving it up a few times, do these:
With the engine cold, remove radiator cap, start engine and look for air bubbles in the water - keep looking until warm. Bubbles at this stage means head gasket letting compression through into the water system.
Check the exhaust in the mirrors(or someone driving behind) under hard deceleration for excess white smoke/steam, indicating water being sucked into the cylinders and then being evaporated there before being sent out via the exhaust... Try something like 2nd or 3rd gear near max revolutions and then letting go of the throttle and not touching the brakes, ie letting the engine do the braking - even better downhill.
Also do a compression check of each cylinder, hot and cold engine, writing down the readings cylinder by cylinder as you go along. A good screw-in compression tester can be bought for around £20 and is dead easy to use. Once you've got the results, post them here and myself and everyone else can give you an opinion.
If all the above checks out OK, I'd say your cylinder head gasket is absolutely fine!!!
Be very careful about taking your car to a mechanic/garage at this point as this is the ideal time for them to get you into emptying your wallet... :evil: In fact avoid doing so at this stage at all costs!
Once the above is done, we can go onto other possibilities...
Most importantly :!: , remember to record everything - take notes, make sketches, take pictures...but record everything: ambient temperature, weather, engine temperature, colour of the oil and water, type of oil, any noises, and anything else you are thinking of at the time...
Take your time, work step by step and ENJOY!
thanks for the tips...
i agree with you that bringing the truck to the mechanic = $$$$. I wish I knew someone here that I could trust. I'll have a go with those tests sometime soon. WIll let you know what I find.
Cheers!
if it is a head gasket then this is a 600 pound job which will include valve guide seals as the 280 are re-nowned for this. The 280 is a strong and relaible lump and will give you miles of life. Unfortunatley when they do blow smoke garages are quick to say the engine has had it. its just not true.
If you need the work doing I would take it to Spilsby road garage in Lincolnshire. What they dont know about the 280 just aint worth knowing. There are also various cold start elements on this engine which never get replaced and everyone assumes its the injectors when they dont run from cold. If you dont have anyone in your area thats not familiar with 280 your better spending the extra fuel and taking it to nigel at splisby.
If you want to use a compression tester I have one you could buy/ borrow. Its virtually new as I only used it once.
I used it for a 280E engine too. Mine was buring oil on over run. Easy to check just take it to max revs in 2nd, and back off suddenly. The oil will get sucked by from the sump past the rings and burn and be discharged as blue smoke out the exhaust. Mine was shot as the rings were worn. I rebuilt the engine boring it and 1st oversize pistons. Of course that may not be your problem. Check oil consumption and record L/100miles etc.
Check all the cylinder head nuts are torqued up as well. Is there any sludge in the cooling system? Any discolouration to the lube oil with moisture? May be only a simple radiator leak and as Ian says a problem with the cold start device. Look at the simple problems first before worrying about everything else. :wink:
A leak down compression test could tell a lot: its basically an device that pumps compressed air in to the cylinder (with both valves closed – done an all cylinders) you then listen at various places for tell tale hissing – exhaust pipe hiss is exhaust valve leak – air filter hiss is inlet valve leak – oil filler hiss is rings leaking and bubbling from the radiator filler is head gasket leaking – well that’s the theory – you can make one out of a regular screw in compression tester and a few extra bits and bobs if you search online for leak down compression tester – but you need a source of compressed air.
Good Luck
this all sounds far too familiar.
Reluctance to start up, very low starting rpm when cold, excessive fuel consumption.
On a cold start you can actually see the puddle of fluid on the ground from the exhaust (presumably something condensing against the ground).
Did you work it out? or is it still a mystery?
Hi does the engine start from cold off a cylinder or two (lumpy)? a good indication that the plugs are wet from a cylinder head gasket failure.if not I would look at the cold start devices. all the vacuum hoses. air mixture set up.any loss of vacuum or extra air will change the mixture to lean stop the seventh injector working properly and generate condensation.hence the slow idle. poor power.and steam and water from the exhaust when cold ..petrol engines generate more moisture than diesels anyway.
Cor,
Am I glad I got a dear old diesel, they seem to be simple by comparison ?
Now no doubt she will start playing up :oops:
Marcus
well I have had a compression test and emissions test done at the local bosch service centre, all good, and yet the cold start problem is still there.. and worse than ever. so its not the cylinder head or mixture.
It appears that the vaccum system from exhaust-block-injection system was missing entirely and had been capped off. so I replaced the tubing. still no luck.
on start up the engine could be described as "lumpy" yes! it runs so bad it makes the whole car shake.. but all this goes away once the engine is warm.
any advice greatly appreciated.
you should not be too concerned about the exhaust steam.... the m110 engine produces more the colder the ambient temperature is....go on to the internet "jetronic fuel injection"read and study all you can see including the trouble shooting pages. the cold start system is a fifth injector managed by and sensor on the side of the block underneath andf to the rear of the inlet manifold...the system is vacuum controlled... any pipes off or split on the vacuum side will affect the fuel management at cold. check all thoroughly from the sensor on the exhaust manifold to the pipes on the air intake.remove the fifth injector which is on top of the engine block next the distributor when you switch on the ignition at cold the injector should work.....just follow the Jetronc instructions
sounds like the cold start sensor,
well I have now realised that the EGR valve appears to be completely bug***ed.
on advice I attached a length of vacuum hose to it and sucked.. no resistance and definitely no "click" of the valve opening or closing. I tried the same on the vacuum valve on the distributer, this seems to work but required a lot of negative pressure to hold it open.
Does the EGR valve stay open or closed at cold start? could this be the source of my duff cold start?
btw a new temp sensor (the two pronged electical version) is 150 quid from mb. anything I can do to avoid paying for that would be welcome. and the new EGR valve will be 200 if I need one. DOH.
same engine in the w 126 series saloonl ots in the merc breakers over here must be more over there...for bits...you need to thoroughly check each function of the JETRONIC K SERIES fuel system before you start changing bits at random ....crawl underneath and disconnect the fuel outlet pipe on the temp sensor on the side of the block ...switch on ignition...no fuel ...no cold start fuel to the injector...you can remove the sensor and open it up to check electrical function..no function no fuel.function ok put back...... BEFORE doing this remove the seventh injector on the top of the block six inches back on the right hand side as you stand in front of thr vehicle.has an electric plug and a pipe fitted to it....if you have fuel at the injector no need to remove cold start sensor... it has to be mixture or poor suction /compression on one or more cylinders or vacuum leaks causing lean mixture. it is imperative that you have a secure NO LEAKS vacuum system all round the engine......
The erg valve is designed to reduce NOx emissions - it does this by releasing inert gas (exhaust gas) to cool the combustion temperatures. The 280ge used to have 115Kw or 156HP until the fitment of an ERG when it was reduced to 110Kw /150HP. I am not certain if the cam timing was changed and that was responsible for the power loss but if there is little or no difference I would have thought that the EGR could be disabled by blanking the pipe to the inlet manifold – whether the emissions would be acceptable for MOT is another matter. But it they are acceptable and there is 6hp on offer it’s not a bad idea. To check if it’s causing problems disconnect it and block both ends.
Your problem does sound like too rich mixture but if you want to sort it your self it won’t be easy as the mixture is controlled by a combination of extra air and extra fuel from an auxiliary air valve, cold start valve and variable fuel pressure. Your simplest check is to disconnect the cold start valve buy taking off the power to it – though even then it could be leaking and making a rich mixture all the time.
The auxiliary air vale is a pig to get at as it’s under the inlet manifold though they are pretty reliable.
It’s always a good idea to remove the air intake on top of the fuel distributor and carefully clean the air flap and make sure it doesn’t stick.
Check that the air filter is clean.
If you get nowhere take it to a Bosch expert – like most things on these beasts you have to me methodical and eliminate things one at a time going to the wrong mechanic can cost a fortune in replacing things needlessly. Your valve clearances, ignition timing, spark plugs, leads no vacuum leaks and the like should all be up to scratch before attempting to fix the fuel injection. The idle mixture (on the top of the fuel distributor – left – lean – right rich) is adjusted in conjunction with the big white screw.
Don’t rely on the cars tacho as they can be well off – I spent ages wondering why my truck kept stalling only to find that an indicated 750-800 rpm was really 450-500.
If you really want to get into the repair of you truck yourself get a manual from the club it invaluable.
Good Luck
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sorry, just updated my profile. didn't see that information box earlier...
i'm a bit worried now. :shock: I have to fill up my radiator quite often. I was told by my mechanic that there was a radiator leak although i've always wondered if it was my engine. oil consumption seems fine but I have to top up the radiator with 2L of coolant once every three weeks.
is this a sign of head gasket failure? I have noticed that my car isn't very powerful and feels very sluggish when not warm. I was told that was a Compression problem? I have no idea what that means...
how much would a fix cost?