Friday, April 01, 2011 - 02:19 am, by: Frank Csapo(264ttr)
Hi all,
I've been battling an issue with my radiator where it's swollen up and cracked due to a sudden overpressure, as my radiator specialist explained. I run a custom copper/brass radiator and the top plate has bent upwards like a banana, and the cooling fins have separated from the tubes. It's also caused the straps that hold the top and bottom plates down to pop off. Initially thinking this was due to an air-lock, I had the radiator repaired and the coolant re-bled but a week later it's happened again. I am worried I might have a head gasket problem and the cylinders are pressurising the cooling system.
However, the car never gets hot or displays any signs of overheating. Both my water and oil temperatures are reading normal, and my thermofans which are on a 85/90deg switch are operating normally and not running for extended periods of time.
I had some issues a couple years ago where my heater cores kept bursting, so I had it replaced with a custom tubular heater and have had no problems since.
Some history on the car: - New thermostat and water pump 3 years ago. - Running red Toyota coolant - Cooling system has been fully flushed 6 months ago. - No milky oil - No steam from exhaust - No power loss - No loss of coolant - Rad cap rated for Soarers - Heater is intact - Radiator is mounted on soft rubber mounts to ease shock and allows a few mm of play. - Radiator is completely rubber mounted and does not touch the body to prevent electrolysis - verified by tests done by auto electrician.
I am planning to get a cylinder compression test done next week, and a coolant gas test as well, but would anyone have any ideas as to what could be causing this overpressure?
Friday, April 01, 2011 - 09:07 am, by: Adrian McGuire(Adro)
im with christian, sounds like a faulty rad cap. can you press the spring in on the cap? its designed to release under a certain amount of pressure so if its building up so much thats it bending metal it sounds like its not releasing correctly.
Frank Csapo Tinkerer NSW Volvo 244GLE with 1JZ-GTE
Wednesday, April 06, 2011 - 07:32 am, by: Christian Molenda(Christof)
Frank, is the cap the right type for your radiator? you said its an aftermarket one. When the cap releases, is the water getting to the overflow bottle? If its pressurising that much, then the overflow tank should be overflowing. Simple as that!
only other cuase would be your impellor fins on your waterpump have discintegrated from wrong coolant mix causing excess pressure also.
Saturday, April 09, 2011 - 01:36 am, by: Frank Csapo(264ttr)
Hey guys, Just had the radiator repaired and took the cap (plus some other spare caps I had, some with a pressure release lever) and asked to have them all tested to see if they work. The two caps with the release levers were not releasing at all, my current cap was releasing moderately, and the new 0.9bar cap that is now fitted is releasing pressure properly. It does seem like it's been a cap issue. Christian, I don't think it'd be a water pump issues as it's only 3 years old and I've been using Toyota red coolant all its life.
But I'll have to wait and see over the next few days on how things behave.
Frank Csapo Tinkerer NSW Volvo 244GLE with 1JZ-GTE
Monday, April 18, 2011 - 12:37 am, by: Frank Csapo(264ttr)
Well as far as I can tell, no more overpressure, the radiator has been running about a week now and so far no more swelling or bloating that I can see.
However, there's now a leak from somewhere, looks to be at the bottom of the radiator but I haven't been able to confirm just yet. This is driving me nuts!
Thursday, April 21, 2011 - 12:09 pm, by: Danny Dinh(Xtc)
You'll find most of the heater hoses would have been expanded/stretched over their limits due to overpressure. I would change them too in case they fail when the temperature gets a bit hot.