Hi. I worked on my car for he first time in almost 2 years (not ncluding my suspension swap a few mos ago). It felt weird being under the hood again. Also the first time wrench was put to supra in my new house.
Backstory all begins when this motor was built about 5 years ago for a guy named Bucsfanatic59. He handled everything and I did the assembly and install. Idk who did the machine work and if the head and deck were smooth enough. Iirc, it must have been acceptable cuz I didn't tell him to redo it. But, the guy told me the machinist said "who ported this head? It looks like it was done with a chainsaw." idk if that. Was good or bad. Also, the head is milled to the limit... I have a 2.0 cometic and new cryo stock pistons and it comes out to 178-183 psi of compression! When I put it together, I torqued the studs to 105 in 3 stages on the first go around: 35-75-105. Then I untorqued in reverse and retorqued in 2 stages: 65-105. Then I repeated the process a 3rd time. The motor had Zero issues untill last summer
Coolant slowly began disappearing, from filling recovery bottle once a month to once a week. When I parked it this spring, it was every few days. It Only blew one hose, on the back of the head: it was eroded internally at the bend. It has Never pushed coolant into he overflow. It has Never overheated. It has never blown white smoke while running and driving. Never pushed coolant into the oil. It has never had the "steam cleaned" plugs from combusting coolant. The piston crowns are typical carbon-coated: no steam clean effect either.
This is what tipped me off to a def coolant leak; Extremely difficult cold-starts. This is the only time when anyone can confirm coolant in the comb chamber. I essentially have to de-flood the motor by cranking for almost a total of 90 seconds with WOT. Then it'll stumble and fire on 4 cylinders and misfire for 30 seconds or die unless I keep jockeying the throttle. Then it'll clear all out then run smooth all day untill I park it and it has time to cool down. It's def burning coolant but Only on cold start. I think that he comb pressure keeps the coolant in the jackets untll I kill the motor. Then as it sits with 1.3bar coolanr pressure, the cylinder fills with coolant and sits untill I come back and try to start it again.
I've confirmed that only #3 cyl was filled with coolant and the rest were dry. I pulled the plugs and purged it. Installed spare plugs and started it (easier with less coolant in he cyl) and got to op temp and shut it off. Ipulled he plugs again and put 3 at tdc to visually confirm If I get a pool... Nothing yet :nono:
it's not very likely that my mhg is leaking, right?
Is it probable I cracked the head by torquing to 105?
Or is it possible that the original owner of the head ported the runner paper-thin and it just recent cracked thru the water jacket?
The latter would explain why I have no coolant in #3 yet after cooling down with pressuriZed rad. Maybe it's pooled up behind the intake valves. Idk what I wanna do if I have to go into the motor due to the hg retorque not working....
Backstory all begins when this motor was built about 5 years ago for a guy named Bucsfanatic59. He handled everything and I did the assembly and install. Idk who did the machine work and if the head and deck were smooth enough. Iirc, it must have been acceptable cuz I didn't tell him to redo it. But, the guy told me the machinist said "who ported this head? It looks like it was done with a chainsaw." idk if that. Was good or bad. Also, the head is milled to the limit... I have a 2.0 cometic and new cryo stock pistons and it comes out to 178-183 psi of compression! When I put it together, I torqued the studs to 105 in 3 stages on the first go around: 35-75-105. Then I untorqued in reverse and retorqued in 2 stages: 65-105. Then I repeated the process a 3rd time. The motor had Zero issues untill last summer
Coolant slowly began disappearing, from filling recovery bottle once a month to once a week. When I parked it this spring, it was every few days. It Only blew one hose, on the back of the head: it was eroded internally at the bend. It has Never pushed coolant into he overflow. It has Never overheated. It has never blown white smoke while running and driving. Never pushed coolant into the oil. It has never had the "steam cleaned" plugs from combusting coolant. The piston crowns are typical carbon-coated: no steam clean effect either.
This is what tipped me off to a def coolant leak; Extremely difficult cold-starts. This is the only time when anyone can confirm coolant in the comb chamber. I essentially have to de-flood the motor by cranking for almost a total of 90 seconds with WOT. Then it'll stumble and fire on 4 cylinders and misfire for 30 seconds or die unless I keep jockeying the throttle. Then it'll clear all out then run smooth all day untill I park it and it has time to cool down. It's def burning coolant but Only on cold start. I think that he comb pressure keeps the coolant in the jackets untll I kill the motor. Then as it sits with 1.3bar coolanr pressure, the cylinder fills with coolant and sits untill I come back and try to start it again.
I've confirmed that only #3 cyl was filled with coolant and the rest were dry. I pulled the plugs and purged it. Installed spare plugs and started it (easier with less coolant in he cyl) and got to op temp and shut it off. Ipulled he plugs again and put 3 at tdc to visually confirm If I get a pool... Nothing yet :nono:
it's not very likely that my mhg is leaking, right?
Is it probable I cracked the head by torquing to 105?
Or is it possible that the original owner of the head ported the runner paper-thin and it just recent cracked thru the water jacket?
The latter would explain why I have no coolant in #3 yet after cooling down with pressuriZed rad. Maybe it's pooled up behind the intake valves. Idk what I wanna do if I have to go into the motor due to the hg retorque not working....
back to an anemic 7m i guess