Postby Powerman on Mon Jan 26, 2009 2:29 pm
Hi,
I have noticed that when starting at around 0 degrees celsius, it's like the engine would misfire at idle, and with more throttle you sometimes can notice it very clearly. This isn't something it does constantly or with a certain pattern, and it's like it gets better when the engine gets warmer.
I did some paintwork on the car and it stood in a warm garage, when I started it there(around 15degrees cels.) I couldn't notice any misfire, the engine run very smoothly.Tested it a couple of times.
It's like the temperature has something to do with this, does anyone have any idea what it could be?
I have recently changed the upper engine wireharness and the rotors and caps are changed last summer, or at least should be by the recent owner.
I could also add that I've driven the car twice this winter, only been starting it once in a while.
Thanks!
280E '81
500E '92
Powerman
===================================
Postby omegabenz on Mon Jan 26, 2009 3:32 pm
Maybe your oil is too thick for the climate that you live in?
My car does that when it's really cold. Like today it was -5 C this morning and it ran a little rough and rich for a few mins. I just changed the oil and it's a 5w40 synthetic oil.
===================================
Postby Powerman on Mon Jan 26, 2009 4:18 pm
Maybe..but I doubt that, because I never started it below 0 C, and there is 10w-40 in it.
Could it be, because every time i start it up, it runs rich because cold and never gets any load on the engine nor normal temp, the plugs gets wet and does this? It's very frustrating that I can't drive it yet and see how it works in regular and normal use.
This 'running rich' sounds logical to me, what could cause it?oxygene sensor?
280E '81
500E '92
===================================
Postby 195910 on Mon Jan 26, 2009 5:26 pm
Powerman wrote:Maybe..but I doubt that, because I never started it below 0 C, and there is 10w-40 in it.
Could it be, because every time i start it up, it runs rich because cold and never gets any load on the engine nor normal temp, the plugs gets wet and does this? It's very frustrating that I can't drive it yet and see how it works in regular and normal use.
This 'running rich' sounds logical to me, what could cause it?oxygene sensor?
I would suggest looking at the engine oil too. I remember when I start the car in winter at less than 5C (yes. it happens, but only 2-3 days a year) it shows the same symptoms.I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Regards
195910
===================================
Postby Powerman on Mon Jan 26, 2009 6:29 pm
195910 wrote:I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Did you notice any changes in the fuel economy when changing to 5w50? Isn't it too high tech for a 17 year old car..?
280E '81
500E '92
===================================
Postby 195910 on Mon Jan 26, 2009 7:47 pm
Powerman wrote:
195910 wrote:I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Did you notice any changes in the fuel economy when changing to 5w50? Isn't it too high tech for a 17 year old car..?
The most noticeable difference is when switching from 15w50 semi-synt to Mobil1 0w40. the fuel consumption improvement is clear and engine noise is alot quieter. I then switched to M1 5W50 , because our weather exceeds 50C in the summer. its the SLR motor oil, I had to wait more than a month for a box because they only get it for the MB dealer to service the SLR.
The 0W40 is better than the 5W50 in fuel economy. But 5W50 is higher spec.
I will be switching (for the last time) to M1 15W50 because of an issue that me and Omegabenz have. and because its easier to get hold of.
Regarding the "old car". it all depends on how well maintained your engine is. you can hear horror stories from people, about how their engines started leaking a few days after changing the oil.. And you can also hear stories from people ,about how
they used M1 for years and every year they change the oil exactly 8 liters come out.
Regards
195910
===================================
Postby Powerman on Mon Jan 26, 2009 8:10 pm
I could give the 0w40 a try, hope it solves my problem but not start leaking. I must say I never heard of theese cases when oil can cause misfire, but it's sure worth a try, besides I had planed to change it in any case.
Many Thanks so far!I'll be hearing from me.
280E '81
500E '92
===================================
Postby omegabenz on Mon Jan 26, 2009 9:25 pm
Just to be clear - my car just idles rough when it's that cold it doesn't really misfire.
===================================
Postby 195910 on Tue Jan 27, 2009 12:08 am
omegabenz wrote:Just to be clear - my car just idles rough when it's that cold it doesn't really misfire.
Yes, this is what I meant too.
I don't think he has a misfire. or any oil leaking into the cylinders. But then its best to check before going a specific route.
195910
Hi,
I have noticed that when starting at around 0 degrees celsius, it's like the engine would misfire at idle, and with more throttle you sometimes can notice it very clearly. This isn't something it does constantly or with a certain pattern, and it's like it gets better when the engine gets warmer.
I did some paintwork on the car and it stood in a warm garage, when I started it there(around 15degrees cels.) I couldn't notice any misfire, the engine run very smoothly.Tested it a couple of times.
It's like the temperature has something to do with this, does anyone have any idea what it could be?
I have recently changed the upper engine wireharness and the rotors and caps are changed last summer, or at least should be by the recent owner.
I could also add that I've driven the car twice this winter, only been starting it once in a while.
Thanks!
280E '81
500E '92
Powerman
===================================
Postby omegabenz on Mon Jan 26, 2009 3:32 pm
Maybe your oil is too thick for the climate that you live in?
My car does that when it's really cold. Like today it was -5 C this morning and it ran a little rough and rich for a few mins. I just changed the oil and it's a 5w40 synthetic oil.
===================================
Postby Powerman on Mon Jan 26, 2009 4:18 pm
Maybe..but I doubt that, because I never started it below 0 C, and there is 10w-40 in it.
Could it be, because every time i start it up, it runs rich because cold and never gets any load on the engine nor normal temp, the plugs gets wet and does this? It's very frustrating that I can't drive it yet and see how it works in regular and normal use.
This 'running rich' sounds logical to me, what could cause it?oxygene sensor?
280E '81
500E '92
===================================
Postby 195910 on Mon Jan 26, 2009 5:26 pm
Powerman wrote:Maybe..but I doubt that, because I never started it below 0 C, and there is 10w-40 in it.
Could it be, because every time i start it up, it runs rich because cold and never gets any load on the engine nor normal temp, the plugs gets wet and does this? It's very frustrating that I can't drive it yet and see how it works in regular and normal use.
This 'running rich' sounds logical to me, what could cause it?oxygene sensor?
I would suggest looking at the engine oil too. I remember when I start the car in winter at less than 5C (yes. it happens, but only 2-3 days a year) it shows the same symptoms.I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Regards
195910
===================================
Postby Powerman on Mon Jan 26, 2009 6:29 pm
195910 wrote:I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Did you notice any changes in the fuel economy when changing to 5w50? Isn't it too high tech for a 17 year old car..?
280E '81
500E '92
===================================
Postby 195910 on Mon Jan 26, 2009 7:47 pm
Powerman wrote:
195910 wrote:I used to run a 20W50 mineral, 15W50 semi-syn oils.
But when I changed to M1 0w40 and later M1 5w50. it starts normal.
Did you notice any changes in the fuel economy when changing to 5w50? Isn't it too high tech for a 17 year old car..?
The most noticeable difference is when switching from 15w50 semi-synt to Mobil1 0w40. the fuel consumption improvement is clear and engine noise is alot quieter. I then switched to M1 5W50 , because our weather exceeds 50C in the summer. its the SLR motor oil, I had to wait more than a month for a box because they only get it for the MB dealer to service the SLR.
The 0W40 is better than the 5W50 in fuel economy. But 5W50 is higher spec.
I will be switching (for the last time) to M1 15W50 because of an issue that me and Omegabenz have. and because its easier to get hold of.
Regarding the "old car". it all depends on how well maintained your engine is. you can hear horror stories from people, about how their engines started leaking a few days after changing the oil.. And you can also hear stories from people ,about how
they used M1 for years and every year they change the oil exactly 8 liters come out.
Regards
195910
===================================
Postby Powerman on Mon Jan 26, 2009 8:10 pm
I could give the 0w40 a try, hope it solves my problem but not start leaking. I must say I never heard of theese cases when oil can cause misfire, but it's sure worth a try, besides I had planed to change it in any case.
Many Thanks so far!I'll be hearing from me.
280E '81
500E '92
===================================
Postby omegabenz on Mon Jan 26, 2009 9:25 pm
Just to be clear - my car just idles rough when it's that cold it doesn't really misfire.
===================================
Postby 195910 on Tue Jan 27, 2009 12:08 am
omegabenz wrote:Just to be clear - my car just idles rough when it's that cold it doesn't really misfire.
Yes, this is what I meant too.
I don't think he has a misfire. or any oil leaking into the cylinders. But then its best to check before going a specific route.
195910
