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Discussion Starter · #1 ·
Hi
I purchased several months ago a 2000 model of E39 M5 with 80 miles on the meter and ever since I have loved every minute of it.
However these last couple days the car has been quite rough when i start it up in the morning with uneven acceleration for couple hundred meters. After that everything feels quite normal however when i rev it quite hard (above 5k rpm) i feel in some instances that the engine loses power (laggs). On two off these instances (high rev) the car has gone into limp mode which disappears when i switch it back on.
Not in any of these instances a error message has appeared on the dashboard.

I've have already ordered a inspection with the local dealer however it is still 2 weeks away. Am I save driving the car until then or should i parked it :sad3: ?


Best regards
Johannes
 

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Johannesp said:
Hi
I purchased several months ago a 2000 model of E39 M5 with 80 miles on the meter and ever since I have loved every minute of it.
However these last couple days the car has been quite rough when i start it up in the morning with uneven acceleration for couple hundred meters. After that everything feels quite normal however when i rev it quite hard (above 5k rpm) i feel in some instances that the engine loses power (laggs). On two off these instances (high rev) the car has gone into limp mode which disappears when i switch it back on.
Not in any of these instances a error message has appeared on the dashboard.

I've have already ordered a inspection with the local dealer however it is still 2 weeks away. Am I save driving the car until then or should i parked it :sad3: ?


Best regards
Johannes
In order of probability, I would suggest candidates are MAFs, cam position sensor and Vanos unit(s). You can test for MAFs through the OBC if you search the thread that talked about bad MAF's at 57,000 miles. I don't think you are doing any harm even if SES light comes on.
Regards,
Jerry
 

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I agree check the MAFS, also consider the petro that you put in the car. I have had similar symptons after a batch of 'bad' gas.
 

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Discussion Starter · #4 ·
martybm5 said:
I agree check the MAFS, also consider the petro that you put in the car. I have had similar symptons after a batch of 'bad' gas.
I've been using Shell (V-power) 99+ octane petrol.

I do agree with you that i think that the mafs are the prime suspects. I pushed the car pretty hard tonight, it went several times into limp mode after engageing high revs 5,5 krpm +. But at other times the acceleration was smooth and vivid up to redline.
Anyway i will treat the car like a kitten until this problem has been sorted out, i'll keep you posted on the outcome.

Best regards and thanks for the feedback
Johannes
 

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Discussion Starter · #6 ·
DavidS said:
Johannes,

I like Iceland a lot!

Gsfent, and Marty are right, this is probably a MAF problem.

Have a look at:
http://www.m5board.com/vbulletin/showthread.php?t=54788

about how to test the MAFs.

David
Went out and did the MAFS test
1.st gear : 40 L/h @ 7000 rpm
2.st gear : 65 L/h @ 7000 rpm hmmm

Few other things i noticed:
When i floored the car from low rpm in both 2. and 3. gear it loses power above 5500 rpm after that the tone of the engine changes and it gets a bit rough when running (loses power but pulls though across the whole rpm spectrum). Everything is normal again though when i restart it.
When i started it flooring from higher rpm (ca. 4000) it ran smoothly to 7000 rpm.

Doesnt this all point to the MAFS ?

Best regards
Johannes
 

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Johannesp said:
Went out and did the MAFS test
1.st gear : 40 L/h @ 7000 rpm
2.st gear : 65 L/h @ 7000 rpm hmmm

Few other things i noticed:
When i floored the car from low rpm in both 2. and 3. gear it loses power above 5500 rpm after that the tone of the engine changes and it gets a bit rough when running (loses power but pulls though across the whole rpm spectrum). Everything is normal again though when i restart it.
When i started it flooring from higher rpm (ca. 4000) it ran smoothly to 7000 rpm.

Doesnt this all point to the MAFS ?

Best regards
Johannes
Those numbers are way too low. You are looking for something around 135 at WOT as you approach redline. Make sure you on on test 2 on NR #4; test 1 is L/100km.
If those are the correct numebrs, clean/replace the MAFs and then see if there is still something else that is wrong (CPS?).
Regards,
Jerry
 

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Those numbers are extremely low. Either you have been looking at the l/100 km numbers, as Gsfent suggested, or something is very wrong with the fuel supply. I am amazed that the car even runs.

(The low numbers could of course be due to a faulty fuel-flow sensor. It is only used for indicating the fuel-consumption. It is not involved in the fuel injection system.)

As Jerry (Gsfent) says, cleaning the MAFs is a good idea.
If it gives an improvement, you will know the MAFs are at least a part of the problem.

With really dirty MAFs you typically get numbers like 80-90 l/h. Your numbers are very much lower.

After that I´d suggest to do the following:

1. Check for fault-codes. It does not say everthing, though.
On some parts of BMWs things can be functioning very poorly without getting a fault-code.

2. Have the dealer check the fuel pressure. There should be 5.0 bar fuel pressure at idle with the vacuum hose connected, and 5.5 bar with the vacuum hose disconected. Make sure they test both pressures.

3. If the fuel pressure is fine, and the car still runs bad after cleaning the MAFs, replace the MAFs. (You can easily do this yourself for US$350 in parts, rather than paying twice that to the dealer.)

4. Have the dealer check the alignment of the crankshaft sensor. The crankshaft sensor should be located 0.55 +- 0.20 mm from the vanes on the fly-wheel. That is a rather tight tolerance, and it has to be met to make the engine run well under all conditions.

It is rather easy to check the alignment (BMW TIS RA 12 14 520):

1. remove the crankshaft sensor from bellhouse.
2. measure depth from seating plane to teeth on the flywheel.
3. measure distance from seating plane of sensor to front of sensor.
4. measure shims if any.
4. add or remove shims between sensor and bellhouse to get a distance of
0.55 +- 0.2 mm between front of sensor and flywheel teeth.

David
 

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Here's a link on how to clean the MAFS. Do a search and you'll find a lot more posts. Its certainly much easier to clean them and save the $$. It takes about 30 minutes if you've got the right tools.

http://www.louv.tv/cars/m5/MAF/
 

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you have a 2000 m5 with 80 miles on it? or do you mean 80,000? Also stop running 99 octane it's ok to do once and awhile but 93 would be better most of the time.
 

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Jayson said:
you have a 2000 m5 with 80 miles on it? or do you mean 80,000? Also stop running 99 octane it's ok to do once and awhile but 93 would be better most of the time.
He´s running the right fuel in the car. He´s in europe. European Octane numbers are different from US Octane numbers. 99 Octane in Europe is just a little higher than US Premium.

The S62 engine is designed for 98 or higher European Octane number fuel.

David
 

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I had the same problem (rough when cold, herky jerky acceleration through the rpms) and I replaced my MAFs and it runs MUCH better and cold start problems are gone. They only cost me $320 bucks. YMMV
 

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DavidS said:
He´s running the right fuel in the car. He´s in europe. European Octane numbers are different from US Octane numbers. 99 Octane in Europe is just a little higher than US Premium.

The S62 engine is designed for 98 or higher European Octane number fuel.

David

hmm, interesting when I was in Germany, i could have sworn when I filled up it said 87,89,91
 

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Discussion Starter · #14 ·
To bring some closure to this thread.
Had MAFS replaced today, no more misfiring at high rpm or stutter and car seems to be more powerful then ever.

It seems though that the car runs better on 98 octane petrol than the V-power (99+ octane), had fewer misfires and stutter with the 98 octane (with the old MAFS). But I could be mistaken.

Anyhow thx for the advice :thumbsup:

Best regards
Johannes
 

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Johannes,

Nice to hear your car is well!

Would you like to do the MAF test again, so we get a fuel-flow figure with the new MAFs, please?

David
 

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Your problem most likely lies with the MAF sensors. Try cleaning them, there's a post on the board somewhere about how to clean them.

Also, you might want to consider switching brands of gasoline. Here at least in the States, Shell's V Power stuff isn't very good. It caused both my cars to run more "sluggish" you could say. I use 76 exclusively. But I don't think you guys have Unocal 76 stations in Europe. Try Esso or BP, that I know you guys have.
 

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///M5_Madman said:
Your problem most likely lies with the MAF sensors. Try cleaning them, there's a post on the board somewhere about how to clean them.

Also, you might want to consider switching brands of gasoline. Here at least in the States, Shell's V Power stuff isn't very good. It caused both my cars to run more "sluggish" you could say. I use 76 exclusively. But I don't think you guys have Unocal 76 stations in Europe. Try Esso or BP, that I know you guys have.

Read two posts up, he got it fixed.
 

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Discussion Starter · #18 ·
DavidS said:
Johannes,

Nice to hear your car is well!

Would you like to do the MAF test again, so we get a fuel-flow figure with the new MAFs, please?

David
Did the mafs test, same as before :
Now:
2nd gear @ 7000 rpm : 150 L/H
3nd gear @ 7000 rpm : 152 L/H

And rough cold starts are gone as well. The acceleration was fast before but it has become quite scary :cheers:

Johannes
 

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Johannes,

Those are very nice numbers indeed! What was the weather like? Temperature/humidity/barometric pressure/altitude, please?

David
 

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Discussion Starter · #20 ·
DavidS said:
Johannes,

Those are very nice numbers indeed! What was the weather like? Temperature/humidity/barometric pressure/altitude, please?

David
Didnt check them yesterday so i just did the test again :hihi:

2nd gear @ 7000 rpm : 152 L/H
3nd gear @ 7000 rpm : 147 L/H

Temperature :11°C
Humidity: 76%
Barometric pressure : 1007.5 hPa.
Altitude: 50 m above sealevel

Hope this is sufficient cherrsagai
Johannes
 
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