[SOLVED] a bit strange misterious perfomance daytime vs nightime

[poisas]

Hi, now i'm trying to figure out, what is causing my car to perfom so easy and perfectly in the evening time, engine starts to run so smooth, so much extra power is coming no matter if engine is cold or hot, but...
In daytime, in the morning and daytime, engine is working so hard, if its wrong ignition, engine wont rev so easy like it does in the evening.

So for me is the question, what engine senses that makes it run better ?
I would say as everybody, evening, density of oxigen is more in the air, but there are days also when car perfoms good., i don't think that intake temp drops so much in the evening.. and totaly i dont see that here is somethink temperature related. I noticed that when the car perfoms better, there is no 3rd condition, its bad perfomance, or good perfomance,
i was driving 17oclock about 240km, till 19.30 and sun was go down in that time, and i felt when i was driving in town, that the car start to perfom better. Also when driving in bad condition, engine heats up very slowly, much faster is when driving ad "good perfomance" need to drive about 5km in town, to get over 60C, compairing, that i was driving over 20km to catch that temp in bad condition
Also when i hit the floor at good perfomance, i have more diesel smoke 2 3rd gears..
so this is like car has 2 modes, and i need to find that switch..

Start to look if its atmosferic pressure related, (can be map sensor )
also i start to wory about viscous fan, cause its so tight cold engine, 40C engine, and start to be very tight abit over 80C engine.. can cool weather loosen it more that ussualy ?
is there any thing like diesel fuel temperature sensor ?

[grober]

Does sound as if your "problem" is temperature related. I would suggest that you work thro all the possibilities one by one. First make sure your engine cooling system is working efficiently- renew the thermostat- check the action of the viscous fan-it will rotate when cool but should be stopped easily -people use a carrot to stop the blade rotating to see the clutch is free- when it engages the "fan sound" will increase a lot. Check your coolant is the correct 50/50 water antifreeze mix. You might want to remove the radiator and back flush it with lots of water. Next would be all temperature sensors on the engine air inlet temperature and coolant temperature ( this is not the temperature gauge sensor but the one which feeds the engine ECU) The other possibility is the MAF sensor. The other possibility is a problem with the turbo which might be related to the temperature of the intake air. Don't know if your turbo is the variable vane type or not but sounds as if that sometimes you are getting boost and sometimes not?

[poisas]

Originally Posted by grober

Does sound as if your "problem" is temperature related. I would suggest that you work thro all the possibilities one by one. First make sure your engine cooling system is working efficiently- renew the thermostat- check the action of the viscous fan-it will rotate when cool but should be stopped easily -people use a carrot to stop the blade rotating to see the clutch is free- when it engages the "fan sound" will increase a lot. Check your coolant is the correct 50/50 water antifreeze mix. You might want to remove the radiator and back flush it with lots of water. Next would be all temperature sensors on the engine air inlet temperature and coolant temperature ( this is not the temperature gauge sensor but the one which feeds the engine ECU) The other possibility is the MAF sensor. The other possibility is a problem with the turbo which might be related to the temperature of the intake air. Don't know if your turbo is the variable vane type or not but sounds as if that sometimes you are getting boost and sometimes not?

Turbo is not VNT, no maf sensor also. I was checked intake temp sensor with multimeter, shows like its working normaly, i was a bit looking for coolant temp sensor, but not found it, show like i would need to take down the intake manifold... how can i reach ECT sensor ?
about the termostat, i have bought one with 85C opening time, at 70C engine temp, i was checking the coolant hose after termostat, they stay cold, until 80C, for me is strange if i go highway at 130km/h @~3000rpm engine temp dont go higher than 60, but if i slow down to 85-90 it comes up in few km to 80-82C, if i rise speed again, it drowps down. this is happening with covered front grills, less wind is coming inside..
Viscous fan, i cannot stop with my finger cold/warm/hot engine,
as i can do with cold engine with my fathers audi 2.5tdi
but if somebody hold fan, and i start cold engine, they can hold the fan easy. i dont think viscous fan can be sometimes not working i showed this fan to few service all of them told this is normal, usaly viscous fan are getting to loose when hot engine.

for me show like this is about fueling engine,
what kind of sensors is adding extra fuel on this 2.5D turbo 110kW no MAF
i think one is IAT, does fuel temp sensor has any effect >? coolant temp ?

[grober]

As far as the viscous fan clutch is concerned it should "freewheel" when cold but the viscous fan should "lock up" when hot to provide extra cooling. The clutch works via a bi-metal strip at the front of the unit which is directly in the path of the airstream thro the radiator. As it bends when heated it moves a pin which allows fluid into clutch mechanism to lock it up. As far as the radiator is concerned remember that there may be an air to air intercooler which cools the air from the turbo going into the inlet. You are not blanking off the airflow thro this are you? I'm surprised you don't have a MAF? On some cars they are mounted in/on the aircleaner box and are not obvious to see. Perhaps you can post your exact engine number which may help. I am not very familiar with this model but there are others on the forum who can help.

[poisas]

Originally Posted by grober

As far as the viscous fan clutch is concerned it should "freewheel" when cold but the viscous fan should "lock up" when hot to provide extra cooling. The clutch works via a bi-metal strip at the front of the unit which is directly in the path of the airstream thro the radiator. As it bends when heated it moves a pin which allows fluid into clutch mechanism to lock it up. As far as the radiator is concerned remember that there may be an air to air intercooler which cools the air from the turbo going into the inlet. You are not blanking off the airflow thro this are you? I'm surprised you don't have a MAF? On some cars they are mounted in/on the aircleaner box and are not obvious to see. Perhaps you can post your exact engine number which may help. I am not very familiar with this model but there are others on the forum who can help.

i did cover the grils similar like dieselman did in his rat blind experiment, but more rough way. i will never want to cover air intake, or intercooler... any way i have removed it, cause now i dont se much difference in how fast engine heats up, with or without cover. Much more effect is to set climatronic wind speed on "2" then engine is geting warm faster then in auto setting. I can beleave that thermostat is not perfect, also I am aware abit about my coolant, cause we have this device to measure freazing temperature, this is from medical stuff, but only up to -25C, and this coolant was off scale. But this winter we had over -25 ;D. fact is this car is cooling down when it has higher rpm, i can stop with 80C and hold a bit 1700rpm, and egine cools down emidiatly. i had changed the thermostat, when i bought the car, then temp no way will go over 60C, then it was bad thermostat. No i have feeling that engine is not getting hot enough, since it dont get enough fuel, or its sometimes running too lean. I can set resistor over IAT sensor to make it think that its cooler and see if this will make car heat up faster, ithink i will add about 20% more resistance, and see if this makes difference.

model and engine 210.015 605.962
buy the way, today car responds good.

[lynall]

Have a look here http://www.detali.ru/cat/oem_mb0.asp?TP=1 W210 e250td intake and exhaust side cant see any sensors but may be egr at fault if you have that fitted?



Lynall

[poisas]

Originally Posted by lynall

Have a look here http://www.detali.ru/cat/oem_mb0.asp?TP=1 W210 e250td intake and exhaust side cant see any sensors but may be egr at fault if you have that fitted?

Lynall

egr is blocked or turned off, diagnostic founds no error codes. when egr is bad or stuck, you can easyli feel it, after ~3500rpm engine loose poower,
i had major improvement when i washed out my tank, and screen, and later on i cut of CAT with they told was partial blocked, and put a resonator, car start to take ~1.5ltr less per 100km, one day driving on highway 440km it took 28ltrs = 6.36/100km driving 100-120km/h

i mean that his is not permenent power difference, but in the evenings 100% that car will perfom very good. also compairing yesterday i was driving, and today, yesterday turbo spinn sound was much stronger, and turbo boost was starting alitle at 1500rpm and more at 1800..
at day time it comes like about 2000. i must fit boost gauge, but now i'm so out of money, any one got second hand one for a little pressent for my birthday coming after month ?

[lynall]

If its a purely mechanical injector pump not counting the egr sensor switch do a google for discovery tdi pump tweaks or similiar, done all my old ones 1/4 turn on the max fuel screw makes for a very nice drive.



Lynall

[poisas]

this fuel pump is hybrid, its practicaly mechanical, but has how they call "electronick back" so there is no such screw, or i don't found that exists...

Originally Posted by lynall

If its a purely mechanical injector pump not counting the egr sensor switch do a google for discovery tdi pump tweaks or similiar, done all my old ones 1/4 turn on the max fuel screw makes for a very nice drive.



Lynall

[Dieselman]

The whole fuel system is electric operation. The sensors are the air temp, water temp, fuel temp, MAP sensor and pedal position sensor.

Out of that lot only the air and MAP sensor are likely to vary day to day.

[lynall]

Oh well if its elc you will need a chip or similiar.

If its got a map sensor it may be worth changing it as this went wrong twice on my last landrover iirc about £40, sensor on disco measured boost pressure and inlet temperature.

I reckon your motor is okay and it just gutless of boost and probably not a lot better on boost ie its toatlly std with a few miles under its belt.

I remember driving a mates c250 n/a diesel years ago and whislt it revved quite well it didnt make a lot of forward progress



Lynall

[poisas]

This mistery was solved, now i have nice and smooth perfomance all day long this was solved advancing timing about 5degree, i can feel about 10% more power now. engine runs smooth like nevere

[grober]

Originally Posted by poisas

This mistery was solved, now i have nice and smooth perfomance all day long this was solved advancing timing about 5degree, i can feel about 10% more power now. engine runs smooth like nevere

glad you solved your problem. I suggest you use the new SOLVED option to wind up the thread. http://www.mbclub.co.uk/forums/feedb...17-solved.html