Oil Change - Car not happy when hot

[admranger]

RB: is 0w-40 not the recommended oil for this engine? If you believe it is the oil and you put in oil that isn't what BMW recommended, then a quick test of your hypothesis is a simple oil change. Thinking about it a bit, is the oil you put in rated for diesel engines (different additive package)? My only guess at this time is that your high pressure oil pump (which feeds the fuel injectors, or are yours all electric) is probably having an issue as it heats up. Only other guess is fuel filter (low fuel pressure), but that's a stab in the dark.

I've had three diesels, though none of them BMWs (a 6.6 liter V-8 Isuzu badged as a Chevy Duramax, a 7.3 liter V-8 Navistar badged as a Ford, and an 8.3 liter straight 6 Cummins, surprising badged as a Cummins!). I ran Chevron Delo 15w-40 dinosaur juice in them (met factory specs).

I'm sure it is frustrating for you, I know it would be for me. Good luck!

[powers1]

Originally Posted by rb0135

Powers1, hello again.

I have DIS Software with the Yellow Head Diagnostic unit. There are no code/faults showing through this system.

The problem has only happened when the oil was changed. Yes, I am familiar with coincidences...


Rob

Hi Rob,
Be assured that the oil has nothing to do with your problem!The 0W 40 is not "too heavy" for the turbo!A lot of turbos work on 5W 40 and even 10W40,so this would not be a problem as this more than adequate to lubricate the spinning rod in the turbo.
But ,I know you will not be satisfied if you dont change that oil,so change it on all accounts but drain it to a clean recipient ,because if you find the car is still the same after the oil change,you can always re-use that oil for something else.
I would take the car to the dealer ,DONT tell them that you did anything in the car and just mention the loss of power issue when hot and you explained here,and ask for a full diag test to be done on the car .They may have a software update that will cure the issue.
Keep us posted.

[rb0135]

Originally Posted by admranger

RB: is 0w-40 not the recommended oil for this engine? If you believe it is the oil and you put in oil that isn't what BMW recommended, then a quick test of your hypothesis is a simple oil change. Thinking about it a bit, is the oil you put in rated for diesel engines (different additive package)? My only guess at this time is that your high pressure oil pump (which feeds the fuel injectors, or are yours all electric) is probably having an issue as it heats up. Only other guess is fuel filter (low fuel pressure), but that's a stab in the dark.

I've had three diesels, though none of them BMWs (a 6.6 liter V-8 Isuzu badged as a Chevy Duramax, a 7.3 liter V-8 Navistar badged as a Ford, and an 8.3 liter straight 6 Cummins, surprising badged as a Cummins!). I ran Chevron Delo 15w-40 dinosaur juice in them (met factory specs).

I'm sure it is frustrating for you, I know it would be for me. Good luck!

Thanks for the reply (and Powers1). The castrol Edge Sport 0W40 has the correct ratings for BMW Petrol and Diesel engines that mine fits into, and "can" be used. The "can" came from BMW Service.

Ok, for AU$100, I am changing the oil tonight. I rang BMW Service and they were actually helpful. They dont like 0W40 for the climate we experience in Sydney, and they prefer to use 5W30, but then they said as long it fits the LL01 spec..

Ok, I hear everyone saying its not the oil, but its cheap enough to change first, and if I dont, then I wont be able to rule that out (in my own mind)and then I'll go from there.

Powers1, yes, the Service Centre is next, but i would rather a proper diesel mechanic. However, they seem to be very few and far between in Sydney..

I'll report back (wont be until mid next week, as I wont be giving it a long run until then to test)..

Thanks All,
Rob

[powers1]

Originally Posted by rb0135

Thanks for the reply (and Powers1). The castrol Edge Sport 0W40 has the correct ratings for BMW Petrol and Diesel engines that mine fits into, and "can" be used. The "can" came from BMW Service.

Ok, for AU$100, I am changing the oil tonight. I rang BMW Service and they were actually helpful. They dont like 0W40 for the climate we experience in Sydney, and they prefer to use 5W30, but then they said as long it fits the LL01 spec..

Ok, I hear everyone saying its not the oil, but its cheap enough to change first, and if I dont, then I wont be able to rule that out (in my own mind)and then I'll go from there.

Powers1, yes, the Service Centre is next, but i would rather a proper diesel mechanic. However, they seem to be very few and far between in Sydney..

I'll report back (wont be until mid next week, as I wont be giving it a long run until then to test)..

Thanks All,
Rob

Hi Rob,
Because you said you the revs drop without you moving on the pedal,you may have an electrical issue such as a loose ground connection or a faulty pedal ....hence why I suggested you go to the dealer only for a proper diag check and at the same time they may even know from having the car there and from past experience what the issue is.Its very difficult for me to suggest what your problem maybe without actually seeing the car.If its an electrical issue and you take the car to a diesel specialist ,he will only be looking for a mechanical fuelling problem..
Anyway,keeps us posted and nice weekend.

[rb0135]

Originally Posted by powers1

Hi Rob,
Because you said you the revs drop without you moving on the pedal,you may have an electrical issue such as a loose ground connection or a faulty pedal ....hence why I suggested you go to the dealer only for a proper diag check and at the same time they may even know from having the car there and from past experience what the issue is.Its very difficult for me to suggest what your problem maybe without actually seeing the car.If its an electrical issue and you take the car to a diesel specialist ,he will only be looking for a mechanical fuelling problem..
Anyway,keeps us posted and nice weekend.

Thanks again,

Yes, i see your point about the dealer, but I want them to do a proper job, not just turn around and say "ohh, thats a turbo problem" without even doing anything.

I've run my own full diagnostics with the DIS and yellow head unit and it came back with nothing.

But, i am getting to the point of not wanting to spend anymore time on it and get someone else to do it....

Certainly will keep you posted.. Have a good weekend yourself..

[rb0135]

Update:

Well, I changed the oil back to 5w30 and for a day or two i thought it was Ok.

But alas, yes, you were all right, it wasnt the oil (unless the 0w40 did some damage).

Anyway, I have checked for codes again (as I have all the BMW gear) and there are NO codes recorded. Wish there was, it would atleast give a starting point

I was talking to a mechanic, who isnt a diesel mechanic, but a mechanic that spends the time to fix things and fixes BMW's (not X5s). He said it wouldnt be the oil.

BUT, he had two words for me FUEL FILTER. Ok, are you sure i said and he kept saying FUEL FILTER, as if to say "are you listening".

I thought that would be easy to change, until I saw the DIY. Is there any thing simple to do on the X5 (ok, i did the oil change this time in 10 minutes, not counting the hour I let the oil drip out from it)

Now, before I start changing parts willy nilly, I really need help from you guys. As i have mentioned, there are NO codes, NO leaking pipes, Turbo is verified as fine, and there are NO loose electrical connections, etc.

The local BMW dealership have NO fully qualified diesel mechanics (plenty of trainees) and there are NO diesel specialists around my area.

Now what seems to be happening, is what I thought was auto clutch/gear slipping when it changes gears (auto gearbox), but I was told by the mechanic above, it looks more like the engine revs dropping off (and sometimes hunting during/after gear change) that is causing the gear change to be somewhat slow and isnt as quick as when the engine/gearbox/oil is warm (not up to operating temperature).

If you gun it, there seems to have some flat spot (no not a turbo lag, or gear change issue) but the engine revs seems to drop slightly, but then it comes back with a rush.

I wish I could explain it better. I will look at changing the Fuel Filter (it is probably due for it) but I have to find a lot off time to be able to do it (unless someone knows a fast way other than the DIY. I dont have much money at the moment (waiting for people to pay me) so I really need some help/pointers as to what to look at myself.

Thanks All,
Rob

[powers1]

Hi Rob,
Dont understand why that mechanic would say FUEL FILTER,when you say the car has a problem when warmed up!
Its because you say your problem is only when hot ,that indicates thats its an electrical/sensor problem or Egr related.
You can carry out two tests to see if changes anything.
1.Disconnect EGR valve vacuum pipe and plug it with screw and road test.
(The EGR always opens fully when car is cold and if its malfunctioning or blocked it
may be opening when engine is warmed up,when it should be partially closed or
completely closed on WOT)
2.Disconnect MAF plug and road test.

[rb0135]

Originally Posted by powers1

Hi Rob,
Dont understand why that mechanic would say FUEL FILTER,when you say the car has a problem when warmed up!
Its because you say your problem is only when hot ,that indicates thats its an electrical/sensor problem or Egr related.
You can carry out two tests to see if changes anything.
1.Disconnect EGR valve vacuum pipe and plug it with screw and road test.
(The EGR always opens fully when car is cold and if its malfunctioning or blocked it
may be opening when engine is warmed up,when it should be partially closed or
completely closed on WOT)
2.Disconnect MAF plug and road test.

Powers1, thank you again for your reply.

That's what I couldnt understand about the Fuel Filter, and questioned that about the hot part. He mentioned something about the fuel being heated when cold and at operating temperature, the fuel heater is turned off, but I thought that it the heater for the fuel only came on in "freezing" temperatures.

Thanks for the two suggestions. This is what I am really after.

Could i drive and get it to the point of it warm, and then disconnect the vacuum pipe (#1 first) and then when i test the MAF, do the same?

Just that I have to drive for atleast 20 minutes to warm it up before the problem occurs, or is safe just to drive the whole test with it disconnected (I think I read somewhere that if it doesnt sense the sensor connected to it, it uses a default value to supply the computer anyway????)

I shall "test" on the weekend and report back.

Rob

[powers1]

Originally Posted by rb0135

Powers1, thank you again for your reply.

That's what I couldnt understand about the Fuel Filter, and questioned that about the hot part. He mentioned something about the fuel being heated when cold and at operating temperature, the fuel heater is turned off, but I thought that it the heater for the fuel only came on in "freezing" temperatures.

Thanks for the two suggestions. This is what I am really after.

Could i drive and get it to the point of it warm, and then disconnect the vacuum pipe (#1 first) and then when i test the MAF, do the same?

Just that I have to drive for atleast 20 minutes to warm it up before the problem occurs, or is safe just to drive the whole test with it disconnected (I think I read somewhere that if it doesnt sense the sensor connected to it, it uses a default value to supply the computer anyway????)

I shall "test" on the weekend and report back.

Rob

Hi Rob,
Yes ,,you can test the car straight from cold..Make sure you do each test individually,otherwise you wont know what is what.
Yes ,you are correct,in some cars if you disconnect the MAF it the ECU will give it default values and in some cases it wont even let the car start.
Either way its perfectly safe ,no problem.Only thing ,of course is thet will bring youe EML on but not a problem to you because you can reset this with Diag equipment.
Let me know if you are not sure which egr vacuum pipe you need to disconnect and block off

[rb0135]

Originally Posted by powers1

Hi Rob,
Yes ,,you can test the car straight from cold..Make sure you do each test individually,otherwise you wont know what is what.
Yes ,you are correct,in some cars if you disconnect the MAF it the ECU will give it default values and in some cases it wont even let the car start.
Either way its perfectly safe ,no problem.Only thing ,of course is thet will bring youe EML on but not a problem to you because you can reset this with Diag equipment.
Let me know if you are not sure which egr vacuum pipe you need to disconnect and block off

Great, Thanks.. I was wondering about what Lights might come on, but yes, i can atleast reset them..