Back on the road !!! Coolant/temp issues

[mgaut]

All

it's been a few months since the body lift and chassis refurb started, but finally the Taimar has had it's first proper run out (to Goodwood) today.

Please can I ask for some assistance on the temperature, which is reading 90 when blatting along at speed but getting close to 95/100 when in traffic.

It's not losing coolant, which is good, and the thermostat has been replaced for a a low temperature one.

There is no bleed valve on top of the radiator, the 'tower' has a sealed cap on it, and the expansion tank has some sort of valve on it. Other than that I've not touched the cooling system, other than the rad and heater matrix have been repaired and pressure tested.

I filled the system via the 'tower' then topped it up from the top hose on the heater matrix.

So, hoping that it's just a simple air lock, how does one go about sorting that out ? Of course, I have no idea if the gague is reading true.

Other than that, a cracking little car and no other niggles to report; well chuffed ! Worth all those cold freezing days in the garage.

thanks in advance

Mike

edited to add; both fans are running on the rad, and the heater was running hot.

Edited by mgaut on Sunday 7th March 14:55

[Adrian@]

Voltage stabiliser....The temp and fuel gauge run via an earth out dissipation, find it behind the dash (2 male lucar and 2 female lucar, most likely near the volt gauge) and check the earth, (replace with an electronic version) go back to the new fan switch and read the temp off that and check that this cuts in and out in relation to the temp gauge.
Adrian@
Semiconductor Voltage Stabilizer- MG Midget MGB MGC.......Ebay current number...280472126934

Edited by Adrian@ on Monday 8th March 17:08

[nwarner]

If after doing what Adrian suggested and the temp. gauge is still reading high it could also have the wrong temp sender fitted. You need a sender from one of the specialists such as Adrian not a Ford one.

[mgaut]

many thanks; I now have a new voltage stabiliser and an infra red thermometer, so hopefully I can work out if the gauge is wrong.

Will also check the state of the plugs and get the timing checked, incase it's running rough.

many thanks

Mike

[mgaut]

bugger.

A quick timing and carb set up (and a run on the rollers, just for good measure) didn't highlight any major issues, nor solve the problem. 145bhp and a flat 163 torques was nice though !

Gauges are working fine, based on the readings from the infra red toy, so going to try removing the new thermostat, new water pump (peace of mind), and getting the coolant tested (re head gaskets).

all good fun

Mike

[heightswitch]

Is it the original radiator?

Have you also checked the heater matrix for sludge?

When you are eliminating air in system set fan to full blow and full hot.

Jack the car up as high as you can get it on stands to lift the front end in the air.

Fill the car engine running from cold with the coolant cap off let it warm up a tad so you can see circulation and the system venting vapour.

Another obvious question, have you checked your cap?

the sealed cap in the tower? do you mean a brass plug? this to my knowledge is the highest point in the system and where you should be filling / venting the system from.

N

Edited by heightswitch on Saturday 13th March 20:55

[mgaut]

Neil

the radiator and heater matrix were both flushed and pressure tested while I was doing the chassis refurb.

Happy to try raising the front end and topping up as you described.

meantime, this is keeping me happy:

http://www.youtube.com/watch?v=sjCH8vmXbGU

(and yes, the engine was warm when we did this, not thrashed from cold)

Edited by mgaut on Saturday 13th March 21:05

[mgaut]

heightswitch said:

the sealed cap in the tower? do you mean a brass plug?

my '77 Taimar has a small rad, a nice shiny 'tower' with a large silver cap on it (gasket, hence non-vented) whereas the expansion tank on the o/s has a cap with a pressure jobbie built into it.

Taking your advice I have run it for a couple of minutes and topped up the 'tower'.

Bit late to get it warm and see if it has made any difference, so will give it a run out in the morning.

Edited by mgaut on Saturday 13th March 22:07

[Adrian@]

Mike ..so that it completes the picture..after our phone call...the steel pipe under the thermostat can rust up and needs checking for flow, tin impellers on cheap water pumps thrash water rather than pump, (replace with cast impeller version) as silt builds up around No4 bore (due to age and poor pumping), Taimars and S's do not have a high point vent so removing the rear carb pipe (whilst still just warming up) is only way of venting the top of the engine. M's need a restrictor within the 2 T pieces (engine side of the heater valve) to force flow through the heater matrix BUT still allowing the auto choke to operate when the heater valve is closed. The second pipe that is on the coolant reservoir tends to be butt soldered on and it is common that these fail (solder a new/longer piece on AND extend the solder so that it has some support onto the top surface of the reservoir), change the otter switch (press in version) to a screw in version (SILVER solder a threaded boss in place on the radiator end tank) and back flush from the drain plug under the No4 bore. 13lb cap on expansion tank blank cap on reservoir, 82 thermostat.
Adrian@

Edited by Adrian@ on Sunday 14th March 08:31

[mgaut]

as always, many thanks Adrian; will progress through that list.

MIke

[mgaut]

Bingo !!

Having gone through Adrian's list, and fitted a new water pump, I've finally tracked down the voltage regulator and it's chucking out 12v rather than 10.

Bingo !!

Quick swap of that at the weekend and (hopefully) it will be reading correctly.

Adrian; your ongoing assistance is MUCH appreciated.

Mike