L67 Overheating Problem

[Luke VY L67]

Hi,
I just purchased a 04 VY L67 with overheating problems.
When I purchased it the rear hose had a split in it which comes from the thermostat housing.
Since then I have replaced the hose and the thermostat which I tested and was not working. I have now flushed the radiator and replaced the water pump and the radiator cap but I'm still having issues.
The car seems to overheat while the car is stationary.
The Thermo fan is working and running in the correct direction.
Both hoses are getting hot and seem like a similar temperature. The pressure builds in the system from idel yet the radiator cap stays at a much lower temperature. If I depressurise the system by opening the cap slightly then the temperature will drop temporarily.
I have looked at other replies and I'm guessing the LIM gasket could be the problem but wanted to see what other people thought before pulling the motor apart.
There are no normal signs of a blown head gasket as the coolant and oil seem fine and no mosture from the exhaust.
I haven't seen any coolant leaks at operating temperature.
I have bled the air out of the system multiple times to try to insure that there's no air locks.
I would appreciate your feedback as it's doing my head in.
Regards Luke

 

[lowandslow]

You've bled it at all 3 points?

 

[Immortality]

Sounds like an air lock, did you have the heater on full hot when bleeding. L67 can be a PITA to get all the air out sometimes.

I drill a small hole in the thermostat on the L67 so any trapped air can bypass the thermostat and makes bleeding the system easier/faster.

 

[Luke VY L67]

You've bled it at all 3 points?

Hi,
I didn't realise there are 3 bleeding points. I have bled the thermostat housing, and there is a bleeder on the top hose but it seems fine. Where is the third?

 

[Immortality]

There is also a bleed nipple located under the blower snout on the heater hose outlet area.

 

[Luke VY L67]

Hi,
I just purchased a 04 VY L67 with overheating problems.
When I purchased it the rear hose had a split in it which comes from the thermostat housing.
Since then I have replaced the hose and the thermostat which I tested and was not working. I have now flushed the radiator and replaced the water pump and the radiator cap but I'm still having issues.
The car seems to overheat while the car is stationary.
The Thermo fan is working and running in the correct direction.
Both hoses are getting hot and seem like a similar temperature. The pressure builds in the system from idel yet the radiator cap stays at a much lower temperature. If I depressurise the system by opening the cap slightly then the temperature will drop temporarily.
I have looked at other replies and I'm guessing the LIM gasket could be the problem but wanted to see what other people thought before pulling the motor apart.
There are no normal signs of a blown head gasket as the coolant and oil seem fine and no mosture from the exhaust.
I haven't seen any coolant leaks at operating temperature.
I have bled the air out of the system multiple times to try to insure that there's no air locks.
I would appreciate your feedback as it's doing my head in.
Regards Luke

 

[Luke VY L67]

Hi,
Ok so I have bled all 3 bleed point to a solid stream of coolant. On ide still overheating.
Any ideas?
Cheers luke

 

[Luke VY L67]

Sounds like an air lock, did you have the heater on full hot when bleeding. L67 can be a PITA to get all the air out sometimes.

I drill a small hole in the thermostat on the L67 so any trapped air can bypass the thermostat and makes bleeding the system easier/faster.

Hi yes I had the heater on full when bleeding.
I upgraded the thermostat to a high flow one instead.
Does drilling the hole in the thermostat affect the normal running of the car?
Cheers luke

 

[Immortality]

I only drill a small hole, I think the last one I did was 2 mm.

It still seems to me there is a flow issue, possibly a blockage. The lower hose should be cooler than the top hose. Is the lower hose collapsing at all? the fact that removing the radiator cap temporarily relieves the condition would also indicate a flow problem. Did you test the thermostat before fitting? I'm not a fan of high flow thermostats TBH, the whole point of the thermostat is to restrict flow to control the engine temperature which is totally counter-intuitive to what a "high flow" thermostat is supposed to do. I'd leave the high flow thermostats to those with hipo engines that need more flow because they create a lot more heat etc.

 

[Luke VY L67]

I only drill a small hole, I think the last one I did was 2 mm.

It still seems to me there is a flow issue, possibly a blockage. The lower hose should be cooler than the top hose. Is the lower hose collapsing at all? the fact that removing the radiator cap temporarily relieves the condition would also indicate a flow problem. Did you test the thermostat before fitting? I'm not a fan of high flow thermostats TBH, the whole point of the thermostat is to restrict flow to control the engine temperature which is totally counter-intuitive to what a "high flow" thermostat is supposed to do. I'd leave the high flow thermostats to those with hipo engines that need more flow because they create a lot more heat etc.

Oh ok well I can swap it for a normal one it's the only one that they had in stock at the time. I just found that when it is getting hot there is coolant leaking from the gasket on the thermostat housing even tho I just replaced the gasket so I will remove the thermostat housing again and drill a small hole in the new thermostat and make sure it is sealed correctly and test it again.
I'll keep you updated.
Thank you for all your help.
Regards Luke