hugokan 0 Report post Posted March 28, 2013 Hi guys, I have a 1990 e34 518i manual. After a long trip from Auckland to Wellington, it developed a random jerk whilst driving. Have checked the spark plugs and they look fine. It's weird as the jerk only starts when the engine is at operating temp. (the needle right in the middle) and not before that. I think it only occurs upon acceleration over 2.5k revs and stops if I go past 3k. Just wanted to see where I should start diagnosing the problem. Thanks Quote Share this post Link to post Share on other sites
Allanw 1051 Report post Posted March 28, 2013 Sounds a bit like a misfire, which could be plugs, leads, dizzy cap etc, or if could have a vacuum leak. It could be a lot of things. When did it last have a proper service (including the parts above?) Quote Share this post Link to post Share on other sites
hugokan 0 Report post Posted March 28, 2013 Had its head rebuilt last beginning of last year and if I recall correctly, plugs and leads were changed. Will check the dizzy cap tomorrow (was too difficult/lazy to do it earlier). Might just change all three and see what happens. Quote Share this post Link to post Share on other sites
Eagle 1525 Report post Posted March 28, 2013 Best guess it may be the coolant temp sensor(blue plug) playing up if ignition components are good and you have no vac leaks. Quote Share this post Link to post Share on other sites
