Over heating

[smitstix]

I was out in my 93 last night and it started over heating.

The temp gage was working fine if anything a little low when steam started coming from under the hood and it was over flowing at the header tank. The water had been quite low and i toppped it up, Is this an air lock as i seem to remember this being a problem with these cars.

[pro-five-oh]

I was out in my 93 last night and it started over heating.

The temp gage was working fine if anything a little low when steam started coming from under the hood and it was over flowing at the header tank. The water had been quite low and i toppped it up, Is this an air lock as i seem to remember this being a problem with these cars.

Air locks only happen after you re-fill an empty system. I think your thermostat or something like that is your FIRST problem. :)

[Go Fast Get Tickets]

Sound's like a bad thermostat. See here to replace: http://www.markviii.org/LOD2/Thermostat.htm

Cooling System--Filling

NOTE:
A 50/50 mixture of Premium Cooling System Fluid E2FZ-19549-AA (ESE-M97B44-A and ESE-M97B43-A) of equivalent and water is required to prevent damage to the cooling system.

1. Check all hose clamps for proper tightness. Ensure radiator draincock is closed.

2. Place heater temperature selector in maximum heat position.

3. Remove pressure cap from cooling system reservoir and fill plug from engine crossover tube.

CAUTION:
Do not fill cooling system through reservoir only. Coolant will not enter engine. Only reservoir and radiator will be filled and engine overheating will occur.

4. Add coolant into fill neck on engine crossover tube until coolant reaches top of fill neck on cooling system reservoir.

5. Reinstall cooling system pressure cap to reservoir.

6. Continue to fill cooling system at engine crossover fill neck until full.

7. Start engine, run at idle. Add coolant at engine crossover tube until full.

8. Reinstall engine crossover tube full plug.

CAUTION:
If engine temperature gauge does not move, coolant level is low in engine and must be filled. Stop engine, allow to cool and fill cooling system as outlined.

WARNING:
TO AVOID THE POSSIBILITY OF PERSONAL INJURY OR DAMAGE TO THE VEHICLE, DO NOT OPERATE ENGINE WITH HOOD OPEN UNTIL FAN HAS BEEN FIRST EXAMINED FOR POSSIBLE CRACKS AND SEPARATION.

9. Run engine until thermostat opens (coolant flowing through radiator lower hose becomes hot).

10. Stop engine and add coolant to engine crossover tube fill neck until cooling system is full. Reinstall fill plug.

11. Repeat fill procedure if necessary.

This is where I would start. Also check all hoses, clamps, and signs of leaks.

Be careful not to get coolant on serpentine belt. Can cause pre-mature failure. I always put some anti seize on the crossover cap threads as well. Those things get tight.

Hope this helps.

[smitstix]

Ensure radiator draincock is closed

What is this?

[Go Fast Get Tickets]

Bottom of rad on passenger side. Used to drain radiator, coolant reservoir, upper engine.

[smitstix]

So even thought i'd topped up a quiter low level you think its the thermostat? I hope so and will order one today.

So am I right in thinking the thermstat housing is at the bottom of the pipe that runs directly down from where the bleed valve is on the cross over pipe?

Cheers chaps.

[luxuryrules]

So even thought i'd topped up a quiter low level you think its the thermostat? I hope so and will order one today.

So am I right in thinking the thermstat housing is at the bottom of the pipe that runs directly down from where the bleed valve is on the cross over pipe?

Cheers chaps.

Correct. On the driver's side of the crossover pipe is a radiator hose that leads straight down, directly beneath the power steering fluid reservoir is the Tstat housing.
On the bottom of the radiator on the driver side is a short piece of hose that shoots straight towards the rear of the car and then makes a 90 degree turn straight up, that is the bottom of the Tstat housing.

Take real good note of the condition of those two hoses, consider replacing them while you've got three quarters of the job already done.

Good luck!

[smitstix]

I've just tested the old and new thermostat and they both open so i guess thats not the problem!

Is this starting to sound like the headgasget?

:(:(:(

[Go Fast Get Tickets]

I've just tested the old and new thermostat and they both open so i guess thats not the problem!

Is this starting to sound like the headgasget?

:(:(:(

I'm not a 4.6 modular expert, but I would think if it was a head gasket there would be antifreeze in the oil. It's got to go somewhere. Have you checked the oil?

If oil is clean, I would put the new thermostat in, fill cooling system as described above, then test drive the car. Stay close to home in case it overheats again.

[smitstix]

Oil and water are fine.

Been a long time getting this mk8 limo ready so i'm a bit on edge now about stuff going wrong :(

[smitstix]

"4. Add coolant into fill neck on engine crossover tube until coolant reaches top of fill neck on cooling system reservoir."

Just a question as in my mind is this not now making the water level to high? I've been driving it around a bit and its not getting hot but some waters coming out from the header tank.

Don't want to drive it to far and in traffic as its 30ft long and not good if it brakes down :(

[smitstix]

Looking like BAD i've been to the garage to do a check to see if the head gasgets gone and couldn't even use the tool on the header tank as it sucked the fluid out and then pressurised the system :(

Looks like i might be changing the engine as i have another and then strip the other to see whats going on!

Any thoughts?

[turborich]

If you do not have oil in the coolant, coolant in the oil or coolant coming out of the exhaust then I doubt if you have a head gasket issue.

If you are sure there is no air left in the system then start looking elsewhere. Is your fan turning on? Is the temperature gauge reading correctly? What is the temperature at the cross over tube where you add the coolant? The factory gauge can be screwy at times.

You can buy a laser teperature gun for around $30-$40 dollars here in the US. Not sure what they cost over there? It's a good tool to have though.

Just to make certain, you are not filling the cooling system up from the plastic tank near the battery, are you? I'm sure you know this but just to be safe, you fill the cooling system from the cross over tube on top of the front of the engine.

Good luck.

[smitstix]

No oil any where.

Been topping up from the cross over for a few days to make sure theres no air in the system.

Temp gage around 1/3 to 1/2

[smitstix]

Note its not over heating, Although i'm not driving it far.

[smitstix]

More questions

I filled up the water on my doner car and its water came out the fill hole in the cross over pipe bubbly and with a real flow (water pump leaks on this car) on the car i that pressurizes the water just rises out of the hole so quite different, Do you think the water pump could be not circulating on the pressurizing car?

[luxuryrules]

More questions

I filled up the water on my doner car and its water came out the fill hole in the cross over pipe bubbly and with a real flow (water pump leaks on this car) on the car i that pressurizes the water just rises out of the hole so quite different, Do you think the water pump could be not circulating on the pressurizing car?

Just to make sure I follow:
You have two Marks, one that is the subject of this thread, and another that is your donor car.
Your donor car has a functional but leaking water pump.
The donor car has actual flow to it at the crossover pipe.
The driver has no flow to it.

I'd start wondering about the water pump too.

[smitstix]

Just to make sure I follow:
You have two Marks, one that is the subject of this thread, and another that is your donor car.
Your donor car has a functional but leaking water pump.
The donor car has actual flow to it at the crossover pipe.
The driver has no flow to it.

I'd start wondering about the water pump too.


Although i think the doner car might be like that due to possable no thermostat! but not 100% as i bought it and drove it home 300 miles and parked it.

I have to buy the water pump if i change engines so it might be worth fitting it on the runner.

[smitstix]

Worth noting with this being a stretch theres heat pipes to the rear section as well but iive spent ages getting the air out.

Don't want to change an engine and have the same problem!