Coolant leak with heater valve closed (1 Viewer)

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LSUfj

LSUfj

Joined
Nov 16, 2006
Threads
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Location
Fort Worth, TX
About a month ago I bypassed the rear heater because of a suspected leak. It didn't leak for about 2 or 3 weeks. We'll the leak is back. It's clearly coming from the heater valve area, but all the hoses are dry. Leak comes down the passenger side of the transmission and often drops as far back as the crossmember. I'm beginning to think it's a crack in the head or maybe head gasket. No oil in coolant or vice versa and no bubbling in overflow. Radiator is new OEM. There's no overheating, pressure test on cold engine didn't reveal anything. The really odd thing I'm starting to notice is that it only seems to leak when the heater valve is closed (climate control set all the way to blue). I'm planning to bring it to one of the local Cruiser shops on Monday, but wanted to see if there were any ideas beforehand.
 
What year?
 
maybe the heater control valve is cracked. or more likely it could be residual coolant left in the system from looping out the rear, i looped mine out and after it was loped out it still leaked out a little bit from where the lines were rusted out.
 
Heater valve is also less than 1year old. Initially I thought it was residual from the rear lines. It's way too much though. I've probably put over a gallon back in there. It leaks about 1/4 gallon each time I drive it. Probably too much for a crack or HG leak right?

I assume PHH wouldn't leak mostly on passenger side? And is it correct that PHH is the inlet side of heater valve.
 
LSUfj said:
Heater valve is also less than 1year old. Initially I thought it was residual from the rear lines. It's way too much though. I've probably put over a gallon back in there. It leaks about 1/4 gallon each time I drive it. Probably too much for a crack or HG leak right?

I assume PHH wouldn't leak mostly on passenger side? And is it correct that PHH is the inlet side of heater valve.
Click to expand...
If you're loosing a quart at a time, it should be pretty easy to find the leak. It would be pouring out.
 
I would be checking all hose clamps. The change in the temp outside could be expanding the coolant and if your clamps aren't tight it could be leaking out.
 
Check the oil cooler housing under the exhaust manifold. Mine was leaking here and would drip down and back onto the transmission. If it is coming from this area I have a video on this forum of mine and how i fixed it.
 
I can see coolant on the top of the transmission, right behind the head and below the heater hose/valve area. Hoses all appear to be dry. I'm worried it's a crack in the head, but it also seems like too much fluid to be a crack. I'm dropping it off tomorrow and will report back.
 
LSUfj said:
About a month ago I bypassed the rear heater because of a suspected leak. It didn't leak for about 2 or 3 weeks. We'll the leak is back. It's clearly coming from the heater valve area, but all the hoses are dry. Leak comes down the passenger side of the transmission and often drops as far back as the crossmember. I'm beginning to think it's a crack in the head or maybe head gasket. No oil in coolant or vice versa and no bubbling in overflow. Radiator is new OEM. There's no overheating, pressure test on cold engine didn't reveal anything. The really odd thing I'm starting to notice is that it only seems to leak when the heater valve is closed (climate control set all the way to blue). I'm planning to bring it to one of the local Cruiser shops on Monday, but wanted to see if there were any ideas beforehand.
Click to expand...
That actually makes sense, considering there's more pressure upstream of the valve when it's closed. If you have a pinhole leak (maybe in the housing, along the parting line?), that's most likely when it'll open.

I agree it's probably not a headgasket. I'd look long and hard at the xmsn cooler.
 
LSUfj said:
Well, its the head gasket. Mechanic says its spraying out during pressure test, right in the middle of the back of the head. ugh.
Click to expand...
Damn.
 
IMG_3640.JPG
Started pulling the front end apart yesterday. I'm hoping to have the engine out today. Checked compression to get an idea of work ahead. All cylinders were around 180, so I'm guess the HG hasnt started leaking internally.

I still need to find a machine shop. I found one that seemed reasonable and had good reviews, but don't know their familiarity with the 1FZ. Any recommendations are appreciated.

Full gasket kit, water pump and fuel filter coming from Beno. Thanks again for the advice and expertise, Onur.

I may also send off the injectors. Is the consensus to use witchhunter? Other options that have worked well?
 
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Had a heck of a time with the nuts/studs on the exhaust manifold to pipe connection. Had to cut two of them off. Other than that, it's went pretty smooth. I left the A/c compressor in, hope the condenser doesn't get in the way.

I have to disconnect the trans from the engine this morning and the engine will be ready to come out.
 
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