MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

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 MGF Technical - TF rad?

After another journey with the cars' temp rising if I go over 70 for any length of time, I can't put off the new rad any longer. I remember someone saying a TF rad is a straight swap and better than the F rad.

Can anyone confirm that a TF rad is a straight swap? I would hate to buy one and find it won't go in. I seem to remember that the F rad is all metal and the TF rad is plastic and aluminium - do I remember that correctly?

Thanks
Kevins

Confirmed.

TF rad is a straight swap (same part, just made from different materials).

SF
Scarlet Fever

Abd you're right: the F rad is steel and the TF rad alloy. :o)
Rob Bell

Thanks for the replies, I'll get one ordered immediately - it will give me something to do over the Christmas break!!!!
Kevins

Kevin

Its a bigger job than you would think!

you will need to take the front slam panel off and get it all back together properly, and when it's all in place do a 100% proper coolant bleed!!

I used tippex to mark the screws on the slam panel and was careful about NOT haviong ther screws tightened before aligning the slam panel with the bonnet catch so that nothing got stuck SHUT!!!!

Then bleed the systems as per the manual
properly and repeatedly.

Be careful and diligent!

Neil

Kevin.
<car's temperature rising>.
At over 70 MPH with UK's current temperatures, any overheating suggests more than a rad problem.
Is this water or oil temperature ?? What temperatures ??
What oil are you using ?
SF says <same part, just made from different materials>. Is it more efficient ? Will it help with your problem ?
Geoff F.
p.s When you do it over the Christmas break, do not forget that your parts supplier(s) will also be on holiday so you will need all the parts beforehend.
G. Farthing

Geoff,
The water temp is the rising temp - oil stays at about 90 - 100 degrees. The water temp sits perfectly still at 1 bar below the longer half way bar if I drive at around 60mph. If I drive at 80ish for any length of time the water temp will rise quite rapidly and the rad fan comes on.
Over last weekend the water temp rose to just under the red in literaly a flash - I didn't even see the gauge rise and I constantly scan the guages.
The car has fresh oil as I changed the oil the week before, it uses Magnatec 10W40.

The reason I believe it to be the rad is that 60% of the vanes are missing from between the cooling tubes so as far as I can tell the rad cannot disipate the heat as designed - badly I might add but thats another nod in mind!!
Kevins

Yes kevin, unfortunateley Radiator corrosion is a fairly regular occurrence with age. Not all cars suffer, most dealers say something along the lines of 'never come across this before Sir'. The specialists have al met it and fixed it.

But I do accept Geoff's comments and caveats.
JohnP

Kevin

Meant to point you at Tony's site where there is an illustrated Radiator Replacement section.

http://www.apttony.co.uk/
JohnP

John,
I know the rad needs changing and as I have checked the coolant level every day - OK.
The heater is V hot so no air locks.
The rad fan comes on so that won't cause overheating.
Engine bay fan never comes on - nor does the enhine bay too hot warning light.
There are no leaks from anywhere.

The only conclusion I can come up with is change the rad!

I suppose it could be a faulty gauge or sender and I could easily fit a new sender and probably will when I change the rad but I can't think of anything else???
Kevins

Kevin, I was sure you were correct from the beginning but didn't want to upset anybody else.

If the car is off 'dead rad' age you might want to check out the underfloor coolant pipes (unless you already have) as these also corrode with age. OEM pipes available from most dealers or the usual suspects (Mike Satur, Brown & Gammons, MGF Centre etc). Also Mike Satur does a set of alloy pipes.

Also check out Mike's larger capacity rad - but I don't know how it compares with standad TF unit.

Looks like your XMAS break is going to be wetter than I want mine to be.

Good luck
JohnP

I had considered the MS rad but I understand (from Scarlet Fever) that it can be a pain to fit and I'm not sure the car warrents a larger rad.

I intend to fit some bonnet scoops and duct the air from the rad through them and block off the existing underfloor air path.

Two reasons: 1) I believe it will cool better than the route under the car (Lotus use this method) 2) it should help reduce the lift at the front of the car

Plus it will look great IMO
Kevins

With our warmer climate at the moment and after some fast speeds on a track day my water temp gauge did not rise above the half way mark infact stays one bar below.( As per Kevins ). Now the oiltemp that does move and after an hour of fast track driving without a break it will be at just over the half way mark. The car runs a standard cooling system and does not have an oil cooler.
Andrew Regens

The water temp gauge on the F is heavily damped and I’ve found that anything other than 1 bar under spells trouble.

Good luck!
Russ Mellor

>> I intend to fit some bonnet scoops and duct the air from the rad through them and block off the existing underfloor air path.
Two reasons: 1) I believe it will cool better than the route under the car (Lotus use this method) 2) it should help reduce the lift at the front of the car <<

I agree with you there Kevin - it should have both the benefits that you describe.

Incidently, I've spoke to Smith & Deakin, the GRP specialists. They tell me that they're quite prepared to make any panel from GRP, so long as a template is supplied. They can provide panels for motorsports (lightweight, no hinge brackets) or for road (heavier, with strengthening for hinges and catches). Might be an alternative route to consider rather than modifying the existing steel bracket.

Regarding the overheating problem, the rad is one area to check - the other the operation of the thermostat: it is opening when warm as it should?
Rob Bell

Rob
As far as I can tell, the stat is opening as it should. i.e. start car, after about 1/2 mile the temp needle starts to move, after about 3 miles the temp gauge is on normal and quite hot air comes out of heater, after about 5-6 miles the temp is still on normal and the air from the heater is v.hot.

Any other way to tell if the stat is OK?
Kevins

Unfortunately, the heater performance is not a great indication of the operation or otherwise of the thermostat.

Have a look at the coolant system diagram here: http://www.mgf.ultimatemg.com/group2/common_problems/hgf_pages/HGF_images/cooling_system_fig_small.JPG

In essence, the heater circuit is not guarded by the thermostat.

To get a good feel as to whether the thermostat is operating as it should, you need to delve under the front bonnet. Remove the shroud, and identify the radiator coolant pipes.

After the engine is fully warmed up, the radiator pipes (particularly the left hand one - from the perspective of the driver sitting in the car) should have warmed up and therefore warm to the touch. If they're still cold, then clearly there's a problem.
Unfortunately, this isn't a particularly sensitive test - but it is a good first step.
Rob Bell

I would have thought the fact the rad fan comes on means the rad is hot? doesn't the signal for the rad fan to come on come from the rad?
Kevins

No it doesn't Kevin. MEMS switches the fan, and the sensor for this is on the engine outlet stub pipe (it's the infamous MEMS temperature sensor!)

The only way to tell whether hot water is flowing through the rad is to get to the pipes or the rad itself and feel (or measure) the temperature.
Rob Bell

HMMmm, don't think much of that idea. i would have thought there should be some sort of input from the rad as it is so far from the engine. By the time the fan comes on to cool the rad the engine could be well on its way to overheating.
Kevins

Happily, the dynamics of the system means that this doesn't happen: the rad is usually highly efficient, and requires only a moderate airflow to result in adequate coolant cooling. The only circumstance that the rad fan is called upon is whilst the car is stationary in standing traffic.

But as you say, the system is not without its foibles - as we all well know ;o)
Rob Bell

This thread was discussed between 08/12/2004 and 10/12/2004

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now