c-mac Posted September 17, 2016 Share Posted September 17, 2016 I've been running the overheads on several mp8's lately, 2008 to 2012 models. I've noticed on the older trucks the lash spec is on the label on the valve cover, 3.5mm. It's not shown on the 12's. Someone told me the lash was updated to 2.5mm. IF this is true is it just for later models or for 08's as well. Quote Link to comment https://www.bigmacktrucks.com/topic/46877-mp8-exhaust-brake-valve-lash/ Share on other sites More sharing options...
turckster Posted September 20, 2016 Share Posted September 20, 2016 The new exhaust adjustment for MP8 engines is adjust the exhaust valve with 1.0 mm or .040", leave the feeler gauge in while checking the engine brake rocker with a 2.5mm shim/feeler gauge. The old adjustment had you remove the 1.0 mm then check the engine brake rocker with the 3.5mm shim/feeler gauge. When I say new I mean it's been that way for quite some time. I guess the engineers feel the newer method is more accurate. Quote Link to comment https://www.bigmacktrucks.com/topic/46877-mp8-exhaust-brake-valve-lash/#findComment-346291 Share on other sites More sharing options...
Nidiesel Posted May 9, 2019 Share Posted May 9, 2019 Just replaced #1 injector and cup on 2013 MP 8. Truck starts and runs just fine until turbo spools up and get a very noticeable knocking sound in Number one cylinder. Cut injector out noise goes away. Also when engine is running at higher rpm's the knock lessens and pretty much is gone. Any idea's ? Quote Link to comment https://www.bigmacktrucks.com/topic/46877-mp8-exhaust-brake-valve-lash/#findComment-422272 Share on other sites More sharing options...
turckster Posted May 10, 2019 Share Posted May 10, 2019 When replacing injector(s) you should program their calibration codes and perform a learned data reset. That way the engine ecu relearns idle characteristics and so forth to adjust for a smooth idle. Or, let the engine idle for a while with all accessories turned off so it can re-adjust/learn accordingly. Quote Link to comment https://www.bigmacktrucks.com/topic/46877-mp8-exhaust-brake-valve-lash/#findComment-422384 Share on other sites More sharing options...
Luis2413 Posted March 13, 2020 Share Posted March 13, 2020 I’m trying to adjust the valves on a mp8 I bought the valve lashes 3.5 MM and 2.5 MM and the 1mm I’m trying to figure out the pattern to adjust the valves and injectors and what valve lash goes where help me out Quote Link to comment https://www.bigmacktrucks.com/topic/46877-mp8-exhaust-brake-valve-lash/#findComment-445305 Share on other sites More sharing options...
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