MG Sports Cars

Enjoying the GT this summer but ...... been off the road with a couple of annoying issues lately:
a) last month.......burned up alternator after only 1700 miles from new...........rebuilt it but why did it burn out?
b) this week..........coolant dripping from under the car with no evidence of a leak in the engine bay or rad........

I suspect the heater core is leaking and the coolant is dripping out the drain hole in the heater well. There is evidence of coolant in the footwell heater outlets but none is dripping into the interior.

Did I cause a leak by using a 20psi rad cap? Perhaps the core just got old and started to leak?

I'm not looking forward to removing it :(

Is there some kind of an "upgraded core" that I should use or do I simply replace it with an old spare one I have in my parts bin?......after making sure it is in good condition, of course.

Martyn,

To answer your question. The alternator burned up because nothing was leaking. Now that the heater core has failed the alternator will be just fine.
20 psi is considerably more than the heater core was designed for. But it should hold up well if it's in good condition.
If you're using an old core. Take it to a rad shop and have it cleaned and pressure checked. Make sure that they are aware of your system pressure.
If you use a new one, make sure that is a copper construction and not the plastic tanked variety.
Or just have the rad shop recore your old one with a heavy duty core.

Cheers
Fred

"The alternator burned up because nothing was leaking. Now that the heater core has failed the alternator will be just fine."

.....yes, of course :)

Thanks Fred!

was it a lucus alternator? i have never had a lucus alternator go vary long end up replacing it twice a year. we ened up putting the alternator out of another car, i dont recall witch one at the moment, and rewiring it and that has lasted years that way

Heater core is out

Martyn, don't know if it is important but the inlet/outlet pipes of the heater core shown don't look like they fit the holes on the front panel of the heater box. The core shown looks like an 1800cc core and the panel looks like a UK Rover V8 panel i.e. inlet and outlet about 4" different in height.

My radiator cap is 15lbs, so 21 lbs might have found a pinprick hole....which would have been found out by a lesser cap a bit later.

Enjoy.....Regards Ian

Good news bad news.
Heater core testing good showing no evidence of any leaking. So it looks like the hose was leaking?.......even though there was no coolant in the engine bay. Well....actually there was some coolant laying around the bottom of the heater box but the vast majority was inside the heater box. The hoses were tight too. I'm rather confused.....I suppose the coolant could leak from the top hose and run back or be forced into the heater box and drip down the core.

Martin,

I saw a youTube from John Twist where he states that it is very rare to find a B heater core that leaks. He says that it's usually the hoses that leak, FYI.

Scott

It was the hose....all is good now :)
I guess I am happy that (once again) I learned a lot from this adventure!

Martyn, are you going to make it to Twists' show this weekend? Hope to see everyone there! Mike

I'm driving up on Saturday...will see you Spuriites sometime between 1030 and noon at the showfield....camping out at Carricks that night....home on Sunday.

Won't be at Twists........I'm sure you will all have a great time around so many awesome cars and MG people :)
Carol and I are booked in the Talley Ho for the October Meet in Townsend......hope to see everyone there.

Great!