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 - radiator flush

Had the car running perfectly , temp rock solid at 190 for two weeks. Went to start it and noticed tht the temp gauge when after five minutes to bottom out at 230. When driving the temp dropped 10 degrees abut back up to 230 when stopping. My accessory fan doesn't touch it. I think that there is soemthing obstructing coolant flow. NOt complete, for the temp does go down with driving. Have checked timing, etc and it is not the typical MGA running hot problem ( or so I believe ). I have even exhanged thermostat for blanking plate with no improvement. Any sugestions on flushing the block and the radiator. The radiator is new ( reproduction ) and the water pump was replace several hundred miles ago. No leak noted about the pump.

Michael
michael dvorkin

A bit of a coincidence here. You replaced the water pump several hundred miles ago and the temperature was OK until two weeks ago. Any chance that the belt is slipping?
Also, with the cap off the radiator can you see the water surge when you give the throttle a sudden opening?

Mick
Mick Anderson

Michael, First thought is the radiator air flow clear and unobstructed? ( ie: bugs, plastic bag bits, etc etc )An air hose from the back towards the grill usually cleans it out. Second thought is checking the hoses for obstructions ( internal collapse, etc )If nothing there, I would do a flush of the complete system. Oh yeah, if the timing checked out, a too lean mixture will cause the engine to heat up.
Let us know what you find.
/gil
gil

Michael,
Have you checked the flow in the radiator like Mick suggested.Two problems I have had in the past was the reproduction rad I bought for our A was no good . I took it into a radiator shop to have it flow tested and was told it was poor flowing. They boiled out my original rad and it has worked fine for the last 6 years.
The other problem was with the water pump on my B. I replaced the cast iron one with a new one that had a plastic impeller. It worked fine for a couple of years then failed. The impeller had broken lose from the shaft.I ended up having the original one rebuilt.
Good Luck,Tony
Tony Shoviak

Michael,
I just solved a similar situation with my Dodge Dakota. It would heat up in traffic, then cool slightly at speed...got worse over a weeks time. First thought it was the fan clutch...checked out good. Replaced the thermostat...no difference. Noticed some very small checks in the radiator cap gasket. Paid $7.00 for a new cap...problem solved!
I hope your remedy turns out to be as simple.
Mark
Mark Hoffman

I have one of the new Moss rads fitted, and if anything it is overcooling, as in cold weather I have to cover the rad to be able to get the car to operating temp. Even in hot weather, operating temp is only just achieved at 70C, and in very hot weather the car will get to 85C max, 90C in a traffic jam. I would therefore rule out the rad as the problem, particularly as it's been OK on the car till recently.

One of the other guys in our local club recently had a similar problem to that described by Michael, and on tear down, found that the thermostat housing was full of thick gunge that was blocking everything. We still don't know what caused this.

With a sudden change in performance like this, I would suspect something simple, if the coolant system is not similarly blocked up.

Check timing first (especially if you have points in the distributor - these may have worn and timing may be out because of this). Then check the fuel filters in the carbs etc to make sure you are not running too lean (blockages can cause a small difference at first before they cause an issue with poor performance).

If all of these simple things check out, I would also suspect that the new water pump has failed somehow.
dominic clancy

This thread was discussed between 03/08/2006 and 04/08/2006

MG MGA index

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