Lumpy idle - help please
Lumpy idle - help please
Car 2.8 auto - been driving like a dream until this afternoon.. now ticks over lumpy like it's running on 4 cylinders instead of 6.. drives perfect, smooth and fast.. but when ticking over its lumpy as hell.. ideas and suggestions welcome
1999 facelit Z3 Roadster 2.8 Auto in Cosmos Black aka 'Gloria'
- Southernboy
- Joined: Thu 07 Oct, 2010 12:39
- Posts: 6437
- Location: Johannesburg
Re: Lumpy idle - help please
1. check all the rubber "hoses" from the MAF to the throttle - remove them and check for cracks where air can leak in.
2. Spark plugs.
3. injectors - use a short length of 8mm plastic hose / pipe and place next to each injector with the other end in your ear, and listen for rythmic "ticking" sound as they are opened / closed during idle. If you find an "oddity" - use an injector cleaner additive in the fuel as a first resort before going to a mechanic. If it doesn't sort it you may need to have the injectors professionally cleaned / serviced.
4.Check the CVV (Crankcase ventilation valve) that it's still operational - located below the intake manifold.
5. Possibly sticking valve lifters - Get a decent engine flush additive - follow the instructions on the product and do an oil change afterwards.
6. check the air filter element is still serviceable and air can pass through unrestricted.
7. could be one or more of the individual spark plug coils - use the same 8mm plastic pipe and listen for even firing at each plug - any misfire can be checked by changing the coil to another plug for confirmation of a faulty coil.
2. Spark plugs.
3. injectors - use a short length of 8mm plastic hose / pipe and place next to each injector with the other end in your ear, and listen for rythmic "ticking" sound as they are opened / closed during idle. If you find an "oddity" - use an injector cleaner additive in the fuel as a first resort before going to a mechanic. If it doesn't sort it you may need to have the injectors professionally cleaned / serviced.
4.Check the CVV (Crankcase ventilation valve) that it's still operational - located below the intake manifold.
5. Possibly sticking valve lifters - Get a decent engine flush additive - follow the instructions on the product and do an oil change afterwards.
6. check the air filter element is still serviceable and air can pass through unrestricted.
7. could be one or more of the individual spark plug coils - use the same 8mm plastic pipe and listen for even firing at each plug - any misfire can be checked by changing the coil to another plug for confirmation of a faulty coil.
Re: Lumpy idle - help please
Thanks Barry.. In that order?
1999 facelit Z3 Roadster 2.8 Auto in Cosmos Black aka 'Gloria'
- Southernboy
- Joined: Thu 07 Oct, 2010 12:39
- Posts: 6437
- Location: Johannesburg
Re: Lumpy idle - help please
Not in any order, but useful to do the ones that don't cost anything first...
Re: Lumpy idle - help please
Looks like l've found the culprit.. this little elbow on the air intake system.. could actually put my finger into the split..
1999 facelit Z3 Roadster 2.8 Auto in Cosmos Black aka 'Gloria'
- Southernboy
- Joined: Thu 07 Oct, 2010 12:39
- Posts: 6437
- Location: Johannesburg
Re: Lumpy idle - help please
There you go - tape it up and start the motor to check if it sorts the issue - then order a new part...
Re: Lumpy idle - help please
Cheers Barry ☺
1999 facelit Z3 Roadster 2.8 Auto in Cosmos Black aka 'Gloria'
Re: Lumpy idle - help please
Looks like you found the culprit, noticed the list of things to check didn't include the idle control valve ICV, that may have been worth a check and clean if the hole wasn't the cause.
http://www.realoem.com/bmw/enUS/showpar ... 3411744713
Colb
http://www.realoem.com/bmw/enUS/showpar ... 3411744713
Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
- Southernboy
- Joined: Thu 07 Oct, 2010 12:39
- Posts: 6437
- Location: Johannesburg
Re: Lumpy idle - help please
Good call on the ICV - Not as common a fault though.