I need some serious advise. Please
#1
05-17-2017, 10:18 PM
I need some serious advise. Please
Here's what's going on with my 05 Cooper S.
I started it the other day and got a red battery light and then it went away, so I started out the road and immediately it went into Limp Mode.
Then I turned around and got it parked, shut down and waited a few minutes and started it again and when I turned on the A/C it went back into limp mode and gave me a P1688 code.
I cleared the code and went to work in another car.
The next day I decided to take look at it and when I started it, all was good until I turned on the A/C. It went into into limp mode again.
Now I am hearing an engine rattle, possibly the timing chain tensioner.
The thing about all of this that is confusing for me is that it seems to run right without the A/C on. But if I turn on A/C it will go Limp and Code P1688.
The engine rattle is there with the A/C on and off and it seems lessen when I rev the engine some.
Also I did check the Alternator and it's good.
Can someone please give me some ideas as to what I need to look for?
I'm thinking that it's one of the following items:
Timing Chain Tensioner
Serpentine Belt Tensioner
Crank Shaft Pulley
Thanks
I started it the other day and got a red battery light and then it went away, so I started out the road and immediately it went into Limp Mode.
Then I turned around and got it parked, shut down and waited a few minutes and started it again and when I turned on the A/C it went back into limp mode and gave me a P1688 code.
I cleared the code and went to work in another car.
The next day I decided to take look at it and when I started it, all was good until I turned on the A/C. It went into into limp mode again.
Now I am hearing an engine rattle, possibly the timing chain tensioner.
The thing about all of this that is confusing for me is that it seems to run right without the A/C on. But if I turn on A/C it will go Limp and Code P1688.
The engine rattle is there with the A/C on and off and it seems lessen when I rev the engine some.
Also I did check the Alternator and it's good.
Can someone please give me some ideas as to what I need to look for?
I'm thinking that it's one of the following items:
Timing Chain Tensioner
Serpentine Belt Tensioner
Crank Shaft Pulley
Thanks
#2
05-18-2017, 05:50 AM
While your Timing Chain Tensioner and Serpentine Belt Tensioner may well be on their way out, your symptoms point more squarely to the Crank Shaft Pulley. Are you experiencing a 'burning rubber' smell after running the engine with the A/C on?
#3
05-18-2017, 05:54 AM
DME Fault P1688 - Electronic Throttle Monitoring - Air Mass Fault
First, Check your battery, make sure it is good. a bad battery can cause strange electronic issue from the ECMs (Electronic Control Modules).
Yes, always check the Timing Chain Tensioner, Serpentine Belt Tensioner, and Crank Shaft Pulley. As explained by AoxoMoxoA. But also take a look at the AC Compressor Clutch and also make sure the cooling fan is coming on when the AC is turned on. (this is good to always check, make sure the fan comes on, possible that circuit is draining the electrical system and causing a Low Voltage condition, this can be coupled to a battery on it's last legs and/or an alternator that is not charging properly. Electrical issues as stated before MINIs really don't like low voltage.
If all that checks out OK, take a look at you Air Mass Sensors, connectors, wires, and also check your Air Filter and look for things like possible chewed on wires.
And if you are hearing the dreaded Death Rattle of the timing chain it could be you have a broken Timing Chain Guide as seen here items #3 and 4 : http://www.realoem.com/bmw/enUS/show...diagId=11_3095
this is a plastic part and can break and if yours have never been changed it is a big possibility. But I don't think this has anything to do with the P1688 code.
Unless the code is thrown due to mechanical timing issue resulting in bad Air Flow Readings, why only when the AC is on? I would guess because the added resistance the Compressor Clutch engaging causes additional Timing Chain Lash making the air flow out of spec.
But also check and make sure ALL your vacuum lines are connected... like the one that is under the Supper Charger that connects to the intake manifold. This one is difficult to see and get to.
Best of Luck.
Motor On!
First, Check your battery, make sure it is good. a bad battery can cause strange electronic issue from the ECMs (Electronic Control Modules).
Yes, always check the Timing Chain Tensioner, Serpentine Belt Tensioner, and Crank Shaft Pulley. As explained by AoxoMoxoA. But also take a look at the AC Compressor Clutch and also make sure the cooling fan is coming on when the AC is turned on. (this is good to always check, make sure the fan comes on, possible that circuit is draining the electrical system and causing a Low Voltage condition, this can be coupled to a battery on it's last legs and/or an alternator that is not charging properly. Electrical issues as stated before MINIs really don't like low voltage.
If all that checks out OK, take a look at you Air Mass Sensors, connectors, wires, and also check your Air Filter and look for things like possible chewed on wires.
And if you are hearing the dreaded Death Rattle of the timing chain it could be you have a broken Timing Chain Guide as seen here items #3 and 4 : http://www.realoem.com/bmw/enUS/show...diagId=11_3095
this is a plastic part and can break and if yours have never been changed it is a big possibility. But I don't think this has anything to do with the P1688 code.
Unless the code is thrown due to mechanical timing issue resulting in bad Air Flow Readings, why only when the AC is on? I would guess because the added resistance the Compressor Clutch engaging causes additional Timing Chain Lash making the air flow out of spec.
But also check and make sure ALL your vacuum lines are connected... like the one that is under the Supper Charger that connects to the intake manifold. This one is difficult to see and get to.
Best of Luck.
Motor On!
#4
05-18-2017, 09:59 AM
#5
05-18-2017, 10:18 AM
your problem is most defiantly your crank pulley. When the ac clutch engages. it is slipping the crank pulley and the supercharger is now not pushing as much air as the ECU is expecting. Bam, limp mode throw code.
The alternator light may be related to something else. I have a similar problem on my old MCS parts car. I have this light at idle and no power steering at start up. If I rev it the light goes out, there is some charge. ECU thinks it is charging but it isn't fully. ECU lets PS pump turn on. But the alternator can't keep up with power demands. Voltage wise it looks like it works. But it doesn't have the amps. I have a new to me alternator on the shelf from ebay for $60 that I am putting new brushes in and ill get that parts car going. I need it to run for 2 weeks while my JCW goes in for paint.
The alternator light may be related to something else. I have a similar problem on my old MCS parts car. I have this light at idle and no power steering at start up. If I rev it the light goes out, there is some charge. ECU thinks it is charging but it isn't fully. ECU lets PS pump turn on. But the alternator can't keep up with power demands. Voltage wise it looks like it works. But it doesn't have the amps. I have a new to me alternator on the shelf from ebay for $60 that I am putting new brushes in and ill get that parts car going. I need it to run for 2 weeks while my JCW goes in for paint.
