Hi Guys,
This is proving to be a bit of a disaster which is a shame - I quite like my Jackaroo.
About 8000KMs ago I replaced the head on my 4JX1. New head, gaskets, injector sleaves, seals etc. Soon after an injector/rail seal blew so that was replaced but I had to reuse the copper seals.
3000KMs ago I replaced those copper seals, injector seals, ORPS and RPCV as I was trying to get it to start a little easier and wanted to get the 'reused copper seals' issue sorted.
About 1000KMs ago on a very hot day the Jackaroo started spraying coolant out of the bottle and the radiator would be an inch or 2 low in coolant - enough to make the temperature rise to the 3/4 mark on long drives or on the beach. I checked the thermostat - it opened at the right temp put the seal around it was stuffed so I replaced it. I also replaced the radiator cap with one of those fancy ones with a pressure release lever.
The coolant issue has been getting worse and ever so often it starts with a CEL which I haven't been able to get any useful MIL codes for (engine restart seems to clear it).
One test I did was a few hours after a drive I removed the overflow pipe from the overflow bottle and put the end into a clear water bottle. I then released the pressure with the fancy radiator cap - it was all gas!
Another test I did today - got it up to operating temp with the radiator cap off and a thermometer probe in the coolant. Coolant temp got to 50C while the engine was running, and raced up to 65 when the engine was off. I also noticed every 15 seconds or so I'd get one largish gas bubble.
I haven't had a CO test done yet.
I've never let the temp go over the 3/4 mark.
Any thoughts?
I'm thinking it could be:
cracked head (argh)
head gasket
Stuffed water pump causing it to boil somewhere (I hope it's this simple but I doubt it).
Injector sleeve seals or copper injector seals somehow...