consuming rad fluid at an astonishing rate (1 Viewer)

[rghouse]

the 92 consumes about 1.5 to 2 liters of radiator fluid a month. The cooling system has been completely overhauled --all the way to the point of removal and machining of the warped head. It holds pressure when tested. new pump/fan clutch/hoses/t stat/on and on. Runs great, pushing 200k, daily driver, all stock

Adding water is not difficult but common, that is a lot

Help/comments much appreciated

 

[leonard_nemoy]

leaky heater core, wet floor?

 

[76FJ40]

Does your oil look frothy? Is there froth inside the oil filler cap? Leak in a heater core?

 

[inkpot]

I would put the pressure tester back on the radiator and pump it up to about 18 psi to check for leaves. You may need to run the engine up to full temperature for a while to see if any of the hoses get soft and/or have pinhole leaks .

 

[Technician1985]

It’s probably the rear heater

 

[rghouse]

no wet floors. oil is not frothy, but last time I tried taking off the filler cap it required channel locks. I noticed a little bit of sludge on the inside of the cap, but honestly it didnt look out of sorts to me.

 

[rghouse]

ok will do inkpot

re: rear heater
whats the protocol for remedying/checking that? anyone else experienced this? would prefer to keep it, not easy to heat the cab on cold days

 

[scottryana]

When was the last time you replaced the PHH? I used silicon and constant tension clamps when I did mine, but I didn't get them tight enough and had seepage probably not that much but maybe 1/2 a liter a month.

 

[mudgudgeon]

what condition is the radiator cap in? I've had a mystery loss of coolant on one of my cruisers that was down to a fault with the little flap valve inside the radiator cap

 

[Technician1985]

ok will do inkpot

re: rear heater
whats the protocol for remedying/checking that? anyone else experienced this? would prefer to keep it, not easy to heat the cab on cold days

Loop the line feeding it back into the return line and keep checking the coolant level over time

 

[HARDGEAR]

what condition is the radiator cap in? I've had a mystery loss of coolant on one of my cruisers that was down to a fault with the little flap valve inside the radiator cap

Yea maybe replace rad cap as the steam will evaporate before you can spot it. Its a potential blow by spot.
@NLXTACY has oem rad caps.

 

[Irish Reiver]

When was the last time you replaced the PHH? I used silicon and constant tension clamps when I did mine, but I didn't get them tight enough and had seepage probably not that much but maybe 1/2 a liter a month.

This and its neighbor . I think it is called the No1 bypass hose. It runs from the throttle body under the intake manifold. If it is weeping you will be hard pressed to spot it.

 

[LINUS]

If you park outside - drop cardboard under the whole motor-width back to the rear heater area.

If you have a house & garage you park in, do the same with either cardboard or some form of paper.
Garages are nicer so wind doesn’t shift/blow your cardboard/paper around, so even if you can temporarily swindle ‘the Boss’ out of her spot for this, it’ll help.

You need to track the loss point, and if it is escaping to atmosphere then these 2 ways help pinpoint it.

From there we can “do the Sherlock thing” if it seems to be migrating into other fluids before escaping.

Have you looked for any form of emulsion in your oil, etc?

 

[Qball]

Did you replace the radiator cap?

 

[TerraNerva]

X2 on rear heater lines. I had pinholes weeping and were hard to find. Bypassed rear heater and no more leaky or loss. I do think they were evaporating or steaming off before wet spots were evident, but would occasionally get a drop or two behind passenger front tire.

 

[inkpot]

no wet floors. oil is not frothy, but last time I tried taking off the filler cap it required channel locks. I noticed a little bit of sludge on the inside of the cap, but honestly it didnt look out of sorts to me.

If it is that hard to remove either you have the wrong cap or the water neck on your radiator is damaged!

 

[HARDGEAR]

If it is that hard to remove either you have the wrong cap or the water neck on your radiator is damaged!

Bingo, I read that, just assumed things were very crusty. Shouldn’t be though.

 

[Funner]

OP says it’s a 92, so I don’t think it has the heater bypass hose and the PHH that was advised to check on. I’ve never had the 3fe, but I thought those two items were unique the the 1fzfe?