running way too hot.

[Will_Ringrose]

Alright, it seems like the last few weeks have been a nightmare for me.

Electrical fire- Fixed wiring

Alternator died - GM swap

Now the thing is running way too hot. Just at idle it will get nearly in the red. When just a few days ago it would just barley get above 3/4 at idle. And when driving it would be just a hair over 1/2.

The timing is good, The pump is working. What do I check next?

 

[Andrew Mace]

Get whatever kind of thermometer (infrared, candy or other kitchen thermometer) and see what the actual coolant temperature is. With all the wiring and related problems you've had, it wouldn't surprise me if something is amiss with the gauge sender or the voltage stablizer for the temp and fuel gauges, or related wiring?

Or, you could actually have a cooling system problem. But confirm the relative accuracy of the gauge first!

 

[TR3TR6]

I would check to make sure the thermostat is not stuck in the closed position.

 

[Brosky]

Don't get mad, but the belt is tight from changing the alternator, right? Thought so, but had to ask.

First check coolant level. Make sure no leaks or air pockets.

Next, check thermostat. Take it out, cool it down and then drop it into a pot of boiling water and see if it opens all the way.

Good time to flush the system and add 50/50 mix for winter.

 

[tinman58]

Double or triple check your timing!! If I did, it would have saved me from removing apron, radiator, head,water pump, etc. Catch my drift?

 

[Will_Ringrose]

looks like I have a long day in-front of me tomorrow. I will just replace the thermostat, I have a nice little digital thermometer that I use to use for Tea. I will get the car up to temp and check it.

I assume the Voltage stabilizer is working well because my gas gauge seems to be doing just fine.

Should I take the time and flush it all out to make sure there is not a blockage?

On the GT6 motor i have every number been thrown out at me for timing. I currently have it set at 8 after.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Should I take the time and flush it all out to make sure there is not a blockage?

On the GT6 motor i have every number been thrown out at me for timing. I currently have it set at 8 after. [/QUOTE]

Yes, drain, flush and replace and it's done once and for all.

And PLEASE tell me you mean 8 degrees BEFORE TOP DEAD CENTER,

NOT AFTER TDC.........if you are after, there is your overheating, starting and running like a pig problem.

 

[TR_Jim]

If there is no vacuum retard, (mine didn't have one)I ran 8 degress BTDC.

 

[Brosky]

Actually, I'd make it 10 BTDC, with the retard or advance unit disconnected, the engine warmed up and at 850-900 rpms and the vacuum line from the carb to the dizzy plugged.

 

[Andrew Mace]

On the GT6 motor i have every number been thrown out at me for timing. I currently have it set at 8 after.

Is that static timing with engine off, or is that "dynamic" timing at the "proper" idle speed as per underbonnet sticker?

I ask, because the factory workshop manual states that, for "emissions controlled vehicles" 4 degrees ATDC at idle, which is approximately 6 degrees BTDC "static" timing.

 

[poolboy]

Vacuum Gauge for setting the timing unless the engine is fairly new..
https://automotivemileposts.com/garage/v2n8.html

 

[TR3driver]

I ask, because the factory workshop manual states that, for "emissions controlled vehicles" 4 degrees ATDC at idle, which is approximately 6 degrees BTDC "static" timing.

That's strange. The 73 emission system training notes say that for a GT6 MkIII, 4 ATDC at idle should be 12 BTDC "static".

The difference of course is the action of the vacuum retard module. If your module is non-functional or disconnected, then you should use the 12 BTDC number. And especially if you are having overheating problems, I would suggest disconnecting or disabling the vacuum retard.

Another thing to check while you've got the timing light hooked up is that the centrifugal advance is working. Just rev the engine up somewhat slowly, while watching the timing mark. It should advance smoothly up to about 4000 rpm. Total advance @ 4000 should be 32 degrees (all according to the training notes). But I wouldn't worry about checking the exact value, just that it moves smoothly and falls back when the engine rpm is let back down.

 

[Andrew Mace]

I ask, because the factory workshop manual states that, for "emissions controlled vehicles" 4 degrees ATDC at idle, which is approximately 6 degrees BTDC "static" timing.

That's strange. The 73 emission system training notes say that for a GT6 MkIII, 4 ATDC at idle should be 12 BTDC "static".

Ah, semantics...and the ever-present common language that separates the UK from the US!

Yes, there is also a figure given in the workshop manual for "ignition timing -- conventional -- static"! That is 13 degrees BTDC for the ["Mk1"] GT6, 10 degrees BTDC for the GT6+ and 12 degrees BTDC for GT6 Mk3 (USA MARKET).

 

[TR3driver]

Ah, well, Will says he has a 73 GT6 and lives in the US (presumably making it a US market car), so we should probably quote the numbers applicable to his car.

And even 6 degrees slow on the timing can cause the engine to run hotter.

 

[Andrew Mace]

Ah, well, Will says he has a 73 GT6 and lives in the US (presumably making it a US market car), so we should probably quote the numbers applicable to his car.

Which is exactly what I did!

And even 6 degrees slow on the timing can cause the engine to run hotter.

Agreed!

 

[poolboy]

I'm guessing that the reason for not worrying about the exact value when observing the advance with a timing light is because you think that the damper marks may no longer be accurate ?

 

[Andrew Mace]

That's possible. There's also the reality that some of the cars just plain didn't run well at the "factory" settings, for any number of reasons! :laugh:

 

[poolboy]

From reading "TIMING FINAL ADJUSTMENT" in this publication apparently Lucas techs agree.
https://mgaguru.com/mgtech/books/lts_otcc/Session3_CoilIgnition.pdf

 

[angelfj1]

Will: Looks like you've received some great advice here! Let me add something that I do each fall when I flush and refill my coolant. I disconnect the heater from the cooling system first. Then I proceed in flushing the engine and heater separately. That way crude from the engine doesn't get forced into the small tubes in the heater core and vice versa.

Good luck!

 

[Brosky]

Great point Frank!!