Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - V8 Runs hot

can anybody give me some advice on keeping a V8 cool. the problem appears to be the number plate in front of the air intake? i have attempted to get a stick on plate for the rubber bumper but have been informed these are not illegal anymore?
S Greasley

I bought stick-on numbers and backing from my local go-faster shop and put them on the front bumper. No problem so far from the police and no problem on my last MOT.
I expect that if you have an overheating problem that you will have to alter a batch of things to fix it. I can't imagine that moving the number plate on its own will fix it.

Haha welcome to having a V8.... ;) In all seriousness, look at creating an air duct that goes between the bottom of the radiator to the back of the front valence. That will help dramatically.

Additionally, make sure your timing is in good shape, check the radiator to make sure the core is in good shape (old core could be clogged) and even check out the thermostat. Maybe it's stuck closed?

Like Marc said, you probably have a little bit of everything all adding up to a big problem. Fixing all the systems will really revolutionize the quality if your driving experience.


The original V8 workshop notes suggested moving the number plate - in addition to the advice above - change your primary coolant frequently - a high detergent semi-synthetic will do the job without breaking the bank. Finally, move your fans so that the blades are within 1cm of the rad core. They should keep the temperature well short of the red on a hot summer's day.

Safety fast.


Hi.....Lots on this website over the years on that one.

Overheating when standing still is usual, when moving it's not. I've fitted the largest pusher fan I can in place of the two silly yellow ones, puller fans are evidently better but there is no room in front of the engine.

Louvres in the bonnet help a lot....I can see a heat haze rising when stopped. I've also used Water Wetter which dropped the running temp a little,but I've switched this week to the Forlife special offer from MGOC, this evidently boils at 180c !!!!

Michael barnfather

My V8 came with a ratty stick-on number 'plate' on the scoop-type valance. I replaced it with the pukka item and didn't notice any worsening.

If it isn't losing water it isn't overheating. I've had mine stuck in traffic in the high 90s with the needle in the red and all that happened was the idle got a bit rough, so I just used a bit of fast-idle to compensate. Unfortunately this makes the engine generate even more heat, but I'd rather have the oil pressure. Since then I have fitted an uprated (outwardly identical) rad, but the biggest difference came from going through the fan electrics, I was losing 3v at one fan and 2v at the other. I cleaned up all the standard connections, but the biggest improvement came from giving each fan a local ground to the body rather than then having to ground through that puny wire that is shared with the headlights and everything else in the engine compartment, and connecting the unused output spade on the alternator direct to the fan relay contact with a length of heavy gauge. Having the heater on and blowing on the screen helps quite a bit, the Navigator moans a bit, but it still doesn't seem as hot as in the Celica on a sunny day.

I was unwilling to go to the expense of actually buying them but I mocked up a Pacet 6" puller and reckoned I could get at least one if not two on the back of the rad.

Louvers will help a lot, but unfortunately feed any engine compartment fumes straight into the cabin unless the air vent is sealed off. RV8 exhaust vents are also said to help quite a bit, the problem being not so much getting the heat out of the water as the hot air out of the engine compartment. Compare bonnet up with bonnet down and you will see what I mean.
Paul Hunt

I had problems with my V8 overheating when sitting in traffic. The one thing that solved it was fitting a 13" heavy duty Kenlowe pusher fan.

Chris Holmes

I've just changed from water plus Water wetter to the new Longlife coolant from MGOC.

According to the blurb it's boiling point is 160c, so presumably you could drive on hot forever without a problem. I used a thermometer to test the radiator on the hottest day last year, and it registered 97c steady wityh no airflow and the fan running.

Michael barnfather

This thread was discussed between 08/07/2003 and 14/07/2003

MG MGB GT V8 Factory Originals Technical index

This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.