Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Super 3 in the summer - overheat?

All,
I drove my Super 3 yesterday in about 82 degrees (F) weather. A bit of stop and go traffic but also some cruising. Of note - I did my own oil change and switched to Mobile One Synthetic 5w-20 oil last week. Yesterday, usually when stopped at a traffic light, the car kept dinging with this error Morgan Overheat. Sometimes it would switch to a red version of the same warning for a few seconds - I'd hear a fan pop on, and then back to the yellow warning. As soon as I revved the motor, or drove away I could clear it.

My concern is that it is about to be a whole lot warmer here in Houston!! Has anyone else experienced this type of issue in the summer months?

I am assuming the coolant level is OK?

Low oil pressure at idle? Might be worth checking that oil you used is recommended for that engine in those temperatures.

ford specifies 5W-30 (Castrol Magnetic WSS-M2C913-C) for the 1.5L Ecoboost, so might using 5W-20 be a bit thin when it warms up?

Think it needs to be at least a 15w40 for those ambient temperatures.

The Morgan Super 3 Manual specifies Engine Oil . . . . . . . . . . . SAE 5W-20 In fact the same oil I use (specified) in my 2023 Ford Maverick Hybrid Non Turbo 2.5), my wifes 2023 Ford Explorer Ecoboost 2.3 Turbo uses 5W30 synthetic

If you’re idling frequently in an ambient temperature of 82 degrees F and overheating, then I would put 5w30 in. You’re not going to harm your engine, you will if your running too hot frequently with the 5w20.

The recommended oil viscosity for my 2015 M3W X Wedge is 20w50. My local bike shop is owned by a master mechanic who worked on the S&S racing development team. He told me they found big V twins frequently running hotter than originally thought so he recommends 20w60 for big V twins. I’ve been using 20w60 for years rather than 20w50 without any issues.

Also wondering if your coolant pump is working properly.

My 2 cents.

Thanks for all the replies! Going to re-check coolant this afternoon (I park at a remote garage / club).... if that ends up being the cause I'll send everyone on here a beer. Jeez.

Assuming coolant is good - great points made about the oil. The manual does state 5w-20 and Warren99 lives in Dallas and he said he never overheats on that oil. So maybe coolant pump, thermostat...?

Lucky for me car is going back to dealer for the mandatory brake recall so they can sort it out.

Sorry - no beers - coolant is full.

Are there ways to check for airlocks on the S3's twin radiator layout?