Hey Guys,
Looking for some help on this one. As you may remember, some time ago I posted about my coolant level issues. Just to recap: I followed the standard coolant fill and bleed procedures following the install of the 2zz. Coolant was at the "cold" mark on initial startup, then steadily rose to well above the "hot" mark. At one point it reached nearly to the fill cap of the reservoir. So I rebled and rebled, raised the rear, etc. Car continued to do the same thing, with the coolant level continuing to rise, but never return to the cold line even after sitting for weeks. I even went so far as to pump out the excess coolant to get it back to the cold line, where it would just rise back once at operating temp.
So today, after having the car sit for over a month, I decided to drive her around, just to get the fluids circulated. Total mileage was maybe 15 miles, with several stops and shutdowns along the way. Ambient temp is in the 60's. Then while sitting at a red light I noticed steam in my rear-view, coming from the engine lid. I glanced at my water temp and it was pegged at the upper end. I immediately cranked on the heat and coasted her into a parking lot and shut down. Popped the lid to see coolant sprayed from the filler cap. Oil temps were safe, and no signs of detonation. After sitting for a while I cranked her back up and drove home with the heat on, water temps remained at the mid-point on the gauge and it didn't overheat. I parked ass-end up my steep driveway and there she sits.
I didn't experience any coolant level / overheating issues with my previous NA 2zz. I just bled it as prescribed and it ran like stock. This engine / Rotrex has never been right in regards to the coolant level.
So what's different between my NA vs FI setups:
1. The hoses running to and from the coolant reservoir. On my NA setup I retained the stock airbox, so the coolant hoses were routed just like stock. With the Rotrex, obviously there is no airbox, but I used the OEM hoses, just routed behind my catch cans. They follow the same path (height-wise) for the most part, so I'm doubting they are the cause.
2. New Koyo high performance radiator. My old stock one was busted up from the previous owner. The Koyo hasn't show any signs of a leak, and I put together a pretty trick bleed ball valve to allow bleeding it. I doubt it is the cause.
3. Different engine. Possibly something internal to the engine creating air. Bad head gasket causing combustion gases to enter the water jacket. I would think this would lead to foamy or discolored coolant, which it isn't. It is green and looks normal. Haven't noticed any white smoke or sweat smelling exhaust, although it's hard to tell when driving. Nothing noticed when the car is idling. I ran both a compression test and leak down test, and both came up within spec. In fact the leak down showed a pretty tight piston/cylinder seal. So unless something is happening while driving (different rpms, detonation, etc.) I'd be suspect of a gasket issue.
3. New OEM thermostat installed prior to engine installation. This one somewhat concerns me, because I didn't make sure I installed it correctly with the port at the 12 o'clock position. I didn't know to do so when I installed it, so there is no telling how it is oriented. I'm not sure how easy (probably not) it is to pull the t-stat with the engine in, but that may be in my future.
That's all I can think of, hopefully someone has an idea. I'll cross post this on the forums just in case.
Thanks
Looking for some help on this one. As you may remember, some time ago I posted about my coolant level issues. Just to recap: I followed the standard coolant fill and bleed procedures following the install of the 2zz. Coolant was at the "cold" mark on initial startup, then steadily rose to well above the "hot" mark. At one point it reached nearly to the fill cap of the reservoir. So I rebled and rebled, raised the rear, etc. Car continued to do the same thing, with the coolant level continuing to rise, but never return to the cold line even after sitting for weeks. I even went so far as to pump out the excess coolant to get it back to the cold line, where it would just rise back once at operating temp.
So today, after having the car sit for over a month, I decided to drive her around, just to get the fluids circulated. Total mileage was maybe 15 miles, with several stops and shutdowns along the way. Ambient temp is in the 60's. Then while sitting at a red light I noticed steam in my rear-view, coming from the engine lid. I glanced at my water temp and it was pegged at the upper end. I immediately cranked on the heat and coasted her into a parking lot and shut down. Popped the lid to see coolant sprayed from the filler cap. Oil temps were safe, and no signs of detonation. After sitting for a while I cranked her back up and drove home with the heat on, water temps remained at the mid-point on the gauge and it didn't overheat. I parked ass-end up my steep driveway and there she sits.
I didn't experience any coolant level / overheating issues with my previous NA 2zz. I just bled it as prescribed and it ran like stock. This engine / Rotrex has never been right in regards to the coolant level.
So what's different between my NA vs FI setups:
1. The hoses running to and from the coolant reservoir. On my NA setup I retained the stock airbox, so the coolant hoses were routed just like stock. With the Rotrex, obviously there is no airbox, but I used the OEM hoses, just routed behind my catch cans. They follow the same path (height-wise) for the most part, so I'm doubting they are the cause.
2. New Koyo high performance radiator. My old stock one was busted up from the previous owner. The Koyo hasn't show any signs of a leak, and I put together a pretty trick bleed ball valve to allow bleeding it. I doubt it is the cause.
3. Different engine. Possibly something internal to the engine creating air. Bad head gasket causing combustion gases to enter the water jacket. I would think this would lead to foamy or discolored coolant, which it isn't. It is green and looks normal. Haven't noticed any white smoke or sweat smelling exhaust, although it's hard to tell when driving. Nothing noticed when the car is idling. I ran both a compression test and leak down test, and both came up within spec. In fact the leak down showed a pretty tight piston/cylinder seal. So unless something is happening while driving (different rpms, detonation, etc.) I'd be suspect of a gasket issue.
3. New OEM thermostat installed prior to engine installation. This one somewhat concerns me, because I didn't make sure I installed it correctly with the port at the 12 o'clock position. I didn't know to do so when I installed it, so there is no telling how it is oriented. I'm not sure how easy (probably not) it is to pull the t-stat with the engine in, but that may be in my future.
That's all I can think of, hopefully someone has an idea. I'll cross post this on the forums just in case.
Thanks