1,6,7,8 - Series and Mini CooperGeneral Chat related to models that do not fit into particular categories above. Please try to put your discussion in more appropriate sections. This section does cover the 1 Series, MINI Cooper and 8-Series vehicles: BMW 830i, BMW 840Ci, BMW 850i, BMW 850Ci, BMW 850CSi, M8, Alpina B12, BMW CS Concept and others.
This car has started to exhibit a skip (a friend described it as a 'stumble') intermittently at idle, either in drive or not. Under throttle it runs excellent; gas mileage is still good. One of two local dealerships was unable to replicate the problem (a toothache stops when you go to the dentist). Mileage is 124k, new plugs 15k ago, all filters changed including gas filter, old school maintenance, no check engine light, ran techtron through it, ran it very low on fuel to eliminate bad gas. I am not driving it for fear of damage to something or other. Your thoughts are greatly appreciated, nice weather is here and I want to drive it!
Is the car using any oil?
Have you checked for vacuum leaks on the intake manifold & ducting between the MAF and throttle body, also check around throttle body gaskets.
Start the engine and let the idle settle, then pull the engine oil dipstick, listen for a drop and then recovery in the idel, as well as a slurping noise from the dipstick tube, if you get that symptom its most likely the rear intake manifold cover, aka OSV.
Has the transmission ever had a fluid and filter change?
The easiest way I found to check for vacuum leaks is to get some carbie cleaner spray and a nozzle to focus the spary to a jet, and start spraying along any joins in the manifold or intake ducting. Do this with the engine running and if the idle changes when you spray an area, you might have found the issue.
It sounds like the dealer has already done that replacement for you. I'll try to check mine in the next few days to see what the noise from the dipstick tube is like.
Have you changed the spark plugs recently? Was anything done prior to the problem starting?
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