Z3 Won't Start - Er Help!

[Fenlander]

My z3 has decided to not start; the car wouldn't start it was spinning over but not firing properly so I jump started it off another car, but it struggled to start and as soon as it did and the revs increased it just cut out.
It might be coils or plugs, are the coils easy to remove when checking the spark plugs?
Any help would be greatly appreciated as the car is my main transport.

Fenlander

 

[GazHyde]

Hi Fenlander,

Which engine do you have? If it's a 6cyl then I posted this the other day which might be useful

http://zroadster.org/forum/threads/replacing-bmw-spark-plugs-ignition-coils.2708/

Gary

 

[Fenlander]

Hi Gazhyde,

You're a star! Just what I need to check this on my 2.2 6 cyl, a friend is to lend me a code reader too, do you know where it is that I'd plug that in on the car to get readings etc.?

 

[Macca]

Hi Gazhyde,

You're a star! Just what I need to check this on my 2.2 6 cyl, a friend is to lend me a code reader too, do you know where it is that I'd plug that in on the car to get readings etc.?

There should be an OBD socket underneath the steering wheel half way down towards the pedals.

 

[Fenlander]

There should be an OBD socket underneath the steering wheel half way down towards the pedals.

Great stuff, many thanks for your help indeed

 

[Aceman]

It could be a couple of other things, firstly it could be your MAF (Mass Airflow) sensor that has failed which would exhibit this kind symptoms but may not throw up a fault code. The best way to check this is to disconnect the MAF and then try starting the engine again, if it starts and remains running albeit running a little rough this will undoubtedly be your culprit. You will not do any harm running the engine with it disconnected as the ECU drops into a failsafe mode with reduced performance but it at least allows you to run the engine.

Other possible causes could be the camshaft sensors which are another common fault although rarely go to the extent of not being able to start the car just making it run very rough. Also the crankshaft sensor can be a cause as it is this sensor that the ecu takes its reading from for the spark plug firing again they rarely fail to the point of non starting just making the engine run erratic.

My money would be on the MAF if I am a betting man and it is an easy one to diagnose by just unplugging the MAF.

 

[Fenlander]

Me again,
We have checked with a code reader and no faults came up.
We managed to start the car and it runs unevenly, we noticed what looks like white smoke coming from the exhaust when driven and at tick-over.
How can you check if the coolant has leaked past the head gasket i.e. pressurised coolant system, as there is no sign of oil in the water or water in the oil?
Also can anyone tell me where the MAF Sensor it on a 2.2 please?
Many thanks (slightly more cheerful) Fenlander

 

[ge45ton]

You can check the coolant level to see if you've lost any water, failing that you can get the cooling system pressure tested, not sure how much that'll cost but it should show up a gasket failure. Hopefully it's a sensor problem...

 

[Aceman]

The maf is just next to the air filter box on the rightt hand side of the engine bay. On the large bore pipe that comes out of air filter box you will see an electrical connector on top of the pipe this is what you need to disconnect. Don't worry if it throws up an engine warning light this will disappear once reconnected and a few engine starts or simply clear it with your mates code reader.

With regards to the coolant you can get sniffer kits which basically show a chemical reaction if petrol/oil is detected in the coolant even very low levels. I would also get your cylinder compressions checked if you suspect head gasket problems.

 

[Fenlander]

Thanks to all of you; I reckon she'll have to go to a garage to get sorted out as I'd say this is getting beyond me!

But if anyone comes up with any more thoughts please let me know.

Once again thanks, Fenlander

 

[zedonist]

For fault reading you need to use the round port under the bonnet, the internal OBD does not report all modules.

If after diagnostics here you get no fault, then normal convention of fuel, air, spark applies, so I would check out be fuel pump, sark plugs, coil packs, air leaks etc, most cn be checked with a multimeter or visual.

But I would try the correct diagnostic first.

 

[Steebs53]

Broke down on sat on motorway. Power just dropped out. Breakdown guy disconnected the MAF and we continued on journey ok.........next step is what to do. Can the MAF be cleaned....video on Facebook. ????
Any one help with best course of action and how much I should expect to pay in UK?
Cheers.