engine 'hunting' on idle

MCSL · 21-01-2014, 08:37 AM

anyone else have this? Took the CSL for an MOT yesterday - had a good 20mins drive before, so was up to temperature etc. The engine is hunting on idle - it's always done this since i've had it and Gareth did something to it last year (reset something?) but it's still doing it. It had an inspection 2 at BMW approx 1500-2000 miles ago (May 2012) so needs an oil service in a couple of months. Would like to get this sorted at next service. Any clues as to what could be causing it?

_Nathan_ · 21-01-2014, 10:01 AM

Turn the air con off and it'll go away, they all do it.

MCSL · 21-01-2014, 10:35 AM

A/C wasn't on

shane@mbtech · 21-01-2014, 01:44 PM

Throttle position sensor?

Monkey · 21-01-2014, 06:27 PM

There are a few pipes that connect into the bottom of the airbox, it's certainly worth checking if one of those has come loose.

It sounds like it may be an air leak, worth having a spray round the intake system with a can of brake cleaner, see if the engine runs differently. Obviously dont spray the cleaner anywhere near the actual intake, or that will make it run differently!

MCSL · 21-01-2014, 09:15 PM

thanks for the replies. Me being a bit of a hamfisted clumsy tw4t - I'm not safe to be around tools (banned in our house

), so i'll probably leave it till it's oil service. Good to have some insight into what it might be though.

terraphantm · 10-07-2014, 09:05 PM

Quote:

Originally Posted by MCSL

anyone else have this? Took the CSL for an MOT yesterday - had a good 20mins drive before, so was up to temperature etc. The engine is hunting on idle - it's always done this since i've had it and Gareth did something to it last year (reset something?) but it's still doing it. It had an inspection 2 at BMW approx 1500-2000 miles ago (May 2012) so needs an oil service in a couple of months. Would like to get this sorted at next service. Any clues as to what could be causing it?

I don't have a real CSL, but I've been running the CSL engine management for a little while. When I first installed it, I had a pretty bad idle hunt. I eventually replaced the idle control valve, and the hunt pretty much stopped. It'll sometimes do it on a cold start with the AC on, but it's much less pronounced and goes away within seconds.

0-60Motorsports · 10-07-2014, 09:19 PM

Mines still there with AC on only. I'll do an idle sync with the GT1 on Saturday.

MTRI · 12-07-2014, 01:22 AM

Quote:

Originally Posted by 0-60Motorsports

Mines still there with AC on only. I'll do an idle sync with the GT1 on Saturday.

Where in GT1 can do you do the Idle Sync.

21-01-2014, 08:37 AM	#1
MCSL S5 - Full Throttle Join Date: Mar 2013 Posts: 326 Casino cash: $4114	engine 'hunting' on idle anyone else have this? Took the CSL for an MOT yesterday - had a good 20mins drive before, so was up to temperature etc. The engine is hunting on idle - it's always done this since i've had it and Gareth did something to it last year (reset something?) but it's still doing it. It had an inspection 2 at BMW approx 1500-2000 miles ago (May 2012) so needs an oil service in a couple of months. Would like to get this sorted at next service. Any clues as to what could be causing it?

21-01-2014, 10:01 AM	#2
_Nathan_ Driving it like I nicked it Join Date: Sep 2008 Posts: 2,099 Casino cash: $13060	Turn the air con off and it'll go away, they all do it. __________________ Nathan

10-07-2014, 09:19 PM	#8
0-60Motorsports S5 - Full Throttle Join Date: Aug 2008 Location: Kingdom of Bahrain Posts: 481 Casino cash: $3271	Mines still there with AC on only. I'll do an idle sync with the GT1 on Saturday. __________________ EURO 04 M3 Current Mods: GC Coilovers, Eibach Sways, RE RCA?s, VCSL Bumper, OE CSL Boot, VCSL CF Rear Diffusor, DIETZ TV in Motion, SS Stepped Headers and catless, SS Res X Pipe, SS Race exhaust, OEM CSL Steering + interior, OEM CSL Intake, MSS54HP with HTE Tune, BBS CH's/LM?s FX-R Projectors + night breakers, STOPTECH ST60/40, RE Front strut brace, DINAN Rear Strut Brace,

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21-01-2014, 10:35 AM	#3
MCSL S5 - Full Throttle Join Date: Mar 2013 Posts: 326 Casino cash: $4114	A/C wasn't on

21-01-2014, 01:44 PM	#4
shane@mbtech CSL Register Uber-poster! Join Date: Feb 2009 Location: warrington Posts: 5,419 Casino cash: $19783	Throttle position sensor?

21-01-2014, 06:27 PM	#5
Monkey S5 - Full Throttle Join Date: May 2013 Location: Haywards Heath Posts: 266 Casino cash: $7387	There are a few pipes that connect into the bottom of the airbox, it's certainly worth checking if one of those has come loose. It sounds like it may be an air leak, worth having a spray round the intake system with a can of brake cleaner, see if the engine runs differently. Obviously dont spray the cleaner anywhere near the actual intake, or that will make it run differently!

21-01-2014, 09:15 PM	#6
MCSL S5 - Full Throttle Join Date: Mar 2013 Posts: 326 Casino cash: $4114	thanks for the replies. Me being a bit of a hamfisted clumsy tw4t - I'm not safe to be around tools (banned in our house ), so i'll probably leave it till it's oil service. Good to have some insight into what it might be though.