MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

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 MGA - Unusual Radiator Problem...

Inside the neck and coating the bottom side of the radiator cap on my '59 MGA is a rusty brown paste material about the consistency of warm butter. This material seems to be water soluble and seems to have no adverse effects on the cooling or running of the car. Anyone have any idea what it is and where it came from? There isn't a lot of it. About enough to fill a couple of toothpaste caps.

Cheers - Dennis
Dennis & Pat Rainey

Are you running DexCool antifreeze?

Seems to be a common problem with some late model GM vehicles.

Chuck
Chuck Schaefer

Hi Chuck,
I really don't know what antifreeze is in there. I haven't changed it from whatever the PO had put in. I've had the car a little over a year so probably changing the antifreeze would not be a bad idea. I'll give that a try.

Thanks - Dennis
Dennis & Pat Rainey

Dennis,
Not to cause undue alarm,but,if you clean this brown paste out, and it returns, you might want to consider checking for a head gasket leak or other type of block problem. Changing the coolant is a good first step.

Regards,
GTF
G T Foster

Do not forget to flush the system BEFORE adding new anti-freeze. Drain the rad and engine block as much as possible collecting as much of the old liquid as possible (to avoid polluting). Remove the petcock from the side of the engine block,then stick a hose into the rad and let it run till the water comes clear. Remove the lower rad hose and do the same thing.
Then add fresh AF.
Gordon Harrison

Dennis. Spoke with a mechanic friend today and described your problem. He showed me a radiator his people are working on with exactly the problem you describe. His diagnosis was chemicals breaking down in the anti-freeze (recommended replacing every two years) and rusting caused by the breakdown of the anti-rust chemicals in the anti-freeze. His recommendation was to run some radiator flush in the system, then back flush it to try and get as much of the crud out as possible. Follow with fresh anti-freeze.

Les
Les Bengtson

Thanks everyone, for your suggestions and recommendations. I did drain the radiator and replaced the anti-freeze but the problem persists. Albiet, not as much. I must admit here that I didn't do a thorough job of draining the block before I replaced the water/anti-freeze mixture. That will be the next thing I do when time permits. Thanks once again, you guys are the best...

Cheers - Dennis
Dennis & Pat Rainey

Regarding Dex Cool. If you have it in your MGA, replace it. It is not designed for cast iron engines, and will continually corrode the engine. If you are unsure of the life of your anti-freeze, use a ph test strip (like swimming pool strips). If you show acidic anti-freeze, replace it.
If you have normal anti-freeze, (although I can't find it anymore)the sludge you describe could be a head gasket leak. Check your cooling system with a pressure tester.
mike parker

This thread was discussed between 08/06/2006 and 15/06/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.