Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Fuel filler cap disengagement difficulty

That abrasion to remove sone material was a fix told to me when picking the car up from the dealer. Gently abrade off some of the small locating lugs. I have tried it and also put some silicone friction modifier on the black plastic part. Some improvement so a step forward. I’ll try that nut adjustment. Looks a good fix.

Just did my first mpg check using the fill to click method. 45mpg. E10 petrol. Low fuel light came on when the gauge was at 3/16 point. Just been round some bends. It went out shortly after and the gauge went back up to nearly 1/4. Came back on again after another 6 miles. Based on the advice from Williams that leaves about 70 miles fuel left. Car now on approx 900 miles. I’ll be checking that filler cap nut later.
Car is going in to Williams on Friday for the first 1k mile check. Rear brake check also requested due to a slight clunk on releasing the brake at slow speed plus a handbrake check. Oil change also on the list to clear out the first batch. Maybe not a necessity these days with modern engines but just me being picky!
No coolant issues after regular checks and inspections.
I’ll ask about the fuel gauge/light/tank capacity again on Friday. Looks like a rule of thumb 250 miles to refuel is about right.

Just spent an entertaining 15 minutes opening mine on my 2016 4/4. Consulted the blog for advice and have now got it open at last. Used some Thetford seal lubricant on the plastic bits and it now works smoothly.

When my car went in for a new pcb for the gauges at Williams they sorted my filler cap. A small sanding/filing of the sharp edges to the plastic inner part. Works perfectly now. The clearance makes both removal/refitting so easy.
Apparently the filler is also used on Caterhams.
A bit hit or miss as to whether any individual filler works ok or is a struggle. Maybe the supplier could modify them to prevent this variable.
Insufficient tolerance or variable component dimensions?

Brimmed the tank yesterday we did a100 miles before the needle went to full and after another 100 miles just under the halfway mark and decreasing rapidly. We did 43.7 mpg going up to Cardiff top down and 38.7 coming back with the top up all at between 68 and 72mph, the gauge is rubbish but the mpg as mentioned before very impressive. Don't quite understand the difference in mpg all the same as it should be the other way around surely......Em

I had a similar problem with mine. Some lubricant worked for me too.


Agreed. It's a pity Morgan couldn't use a tank sender unit and gauge that work in a normal manner.

I agree. I am puzzled as to whether MMC have done proper tests on tank/sender/gauge and given out clear advice on the results. We seem to have anecdotal comments from owners and dealers.
The new Plus Four just announced has the usual mods you see to visual elements. My guess is they make assembly of a car simpler and cheaper in some respects. OK the more expensive headlight/indicator combination probably increases unit cost ( borne by the buyer?) but offset by not needing indicators , assembly/fitting during build.
I assume that lessons learnt from the major radiator/brake issues would be built in anyway.

I've had 4 Mogs and not one had an accurate fuel gauge. They call it a feature, but on the CX cars costing 80-120k it should not be the case.

My old F Super has the most accurate fuel status of any of my Mogs, lift bonnet, unscrew proper brass cap, look inside tank...

My filler cap and assembly has just been replaced under warranty by Ledgerwood Morgan at its 1st year service (Plus Six) as I too was having great difficulty getting the fuel filler cap off when I needed to fill up. The new unit is an all metal design (i.e no white plastic inside) and works as you would expect it to. Still not lockable though