Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 ENGINE LIGHT EASY FIX

Hello all. I have found a quick fix for the intermittent engine light issue. Mine came on just after buying my M3W. Worried me until I remembered my Ducati days and listened to the engine. No oil light. Have oil pressure. Engine sweet ? Yes. So don't worry. Later came to this site at a service station. Read every thing. Not satisfied so had a good hard think. Was sure that the ECU was getting confused and not adapting. Why ? probably an odd electrical input. Loose HT cap ? No. Checked aluminum nipples on plug tops. Both slightly loose. No pliers. Borrowed some. Started engine. NO LIGHT hooray. 30KM later light on again. Stop. Left plug nipple moving again. Tightened up and all good. When ever the light came on again I always found some slack . The problem is that the steel thread and Ally nipple expand and contract at different rates. This is perfect for unscrewing things. When home a brutal tightening has eradicated the issue. The tiny sparks jumping when the nipples can move, even a tiny bit puts a back emf into the ECU and it cannot adapt to the changes and puts the light on. You can have a situation where on a cold day or short run all is well. A long run may loosen the nipples and then a cool off overnight can tighten them. Try this FIRST before paying a dealer. They probably won't find this fault because the nipples tighten overnight. Hope this helps before expensive checking and ECU changes.

Most, if not all M3Ws suffer from this, although on mine it just manifested itself by causing rough engine running and I didn't get a warning light. A dab of Locktite on the plug caps solves the problem for good. Or, at least until you replace the plugs.

Be aware certain Locktite products are conductive , some are not.
I stayed with the brutal tightening approach when i had this issue , just in case.