atkinson40 Posted April 23 Report Share Posted April 23 I've been fighting water loss and can not figure out where. First I tried to adding an overflow jug to see if it was escaping out the overflow tube and not being recaptured. I see the level go up and down sometimes on the overflow jug. I'm loosing maybe a half a quart every time I fire it up and do a test around the neighborhood and on the freeway for one exit then home. Maybe 5 miles max. This time after the test, I checked the overflow jug and air was coming out the overflow tube into the jug. The truck does not overheat unless the coolant gets too low. The needle runs a little less than half. Before I did the test this time checked the coolant level and it was down about a quart. When I unscrewed the cap there was a hiss. The engine had been sitting for a couple of days. Maybe the hiss was vacuum and not pressure? If there is a hiss on the radiator cap after sitting for a couple of days, can it be HG? Thanks Quote Link to comment
IZRL Posted April 23 Report Share Posted April 23 You might have been losing the water out of the overflow tube. How many times have you topped off the radiator after you installed the over flow tank? What does your oil look like? With that much water loss. If it were going into your engine. You'd already have a proper milkshake in there. Quote Link to comment
atkinson40 Posted April 24 Author Report Share Posted April 24 (edited) 28 minutes ago, IZRL said: You might have been losing the water out of the overflow tube. How many times have you topped off the radiator after you installed the over flow tank? What does your oil look like? With that much water loss. If it were going into your engine. You'd already have a proper milkshake in there. I've maybe topped off twice with about 1/2 quart each time. I just went out and opened the cap after letting it cool down after my 5 mile test run and bubbles came out the overflow house into the overflow tank. The level was not down this time. Oil does not look milky. A little dark because it needs changed. I only run this beast maybe 500 miles a year at most. Runs good. No overheating as long as I keep the water topped off. Edited April 24 by atkinson40 Quote Link to comment
IZRL Posted April 24 Report Share Posted April 24 (edited) Yeah it might have just been leaking out the overflow tube. When you added the overflow tank it was probably still low. So once you go through a couple heat cycles you'll have to top it off again. But after that you should be fine. I'd keep an eye on the level for a bit longer to make sure. Make sure the overflow tank always has enough fluid in it to do it's thing. Edited April 24 by IZRL Quote Link to comment
datzenmike Posted April 24 Report Share Posted April 24 Bubbles are engine compression getting into the cooling system. It will push out through the rad cap causing bubbles and to some extent pushing coolant out ahead of it. Compression alone is over 130 PSI and hundreds of PSI when firing. The rad cap opens at 13 PSI so no contest. For coolant to get into the oil it would have to get into the cylinder (against the compression mentioned earlier) and heated into steam. As steam, it can get past the rings and into the sump. You would also have a steamy exhaust which wasn't mentioned. If it's that bad you could set each cylinder to TDC on the compression stroke and try a fitting that threads into the spark plug hole and apply compressed air. Fill the radiator and wait for air bubbles to show. When replacing the HG do NOT remove the cam sprocket before learning how to prevent the timing chain tensioner from falling out. Now you may already know how to do this but never hurts to say it again. If it falls out when the chain goes loose the entire front of the engine must come off to put it back in. Quote Link to comment
atkinson40 Posted April 24 Author Report Share Posted April 24 7 hours ago, datzenmike said: Bubbles are engine compression getting into the cooling system. It will push out through the rad cap causing bubbles and to some extent pushing coolant out ahead of it. Compression alone is over 130 PSI and hundreds of PSI when firing. The rad cap opens at 13 PSI so no contest. For coolant to get into the oil it would have to get into the cylinder (against the compression mentioned earlier) and heated into steam. As steam, it can get past the rings and into the sump. You would also have a steamy exhaust which wasn't mentioned. If it's that bad you could set each cylinder to TDC on the compression stroke and try a fitting that threads into the spark plug hole and apply compressed air. Fill the radiator and wait for air bubbles to show. When replacing the HG do NOT remove the cam sprocket before learning how to prevent the timing chain tensioner from falling out. Now you may already know how to do this but never hurts to say it again. If it falls out when the chain goes loose the entire front of the engine must come off to put it back in. I have not been filling the radiator up to the top. It's maybe half an inch down. Could this air at the top cause the bubbles? I'll top it off today. I have not noticed steamy exhaust. I'll check today. Quote Link to comment
atkinson40 Posted April 24 Author Report Share Posted April 24 I'm wondering about the radiator cap also. I'm nor sure how to tell if it's right. I probably bought it at O'reily's or Autozone. Yesterday when I got the engine warmed up, I did not notice any change in the coolant reservoir. Quote Link to comment
Crashtd420 Posted April 24 Report Share Posted April 24 15 minutes ago, atkinson40 said: I'm wondering about the radiator cap also. I'm nor sure how to tell if it's right. I probably bought it at O'reily's or Autozone. Yesterday when I got the engine warmed up, I did not notice any change in the coolant reservoir. Those are cheap enough.... Might be worth replacing.... I had one that would randomly let coolant out.... you could actually hear the spring pop open..... a new one solved my problem..... Looks like a factory radiator so auto parts store should have.... Just make sure when installing there is a little tension pushing back up when you push down.... Something I ran into with my radiator being an aftermarket aluminum was that a factory cap fit but wasn't long enough to seal the bottom opening.... Quote Link to comment
datzenmike Posted April 24 Report Share Posted April 24 This is a coolant recovery cap, see the two rubber seals? It allows coolant out if it exceeds the 13 PSI limit and stores it in the coolant recovery bottle. As long as the hose is submerged in the recovery bottle, when the air in the radiator cools and shrinks it will draw the expelled coolant right back into the radiator keeping it topped off. The radiator should be filled to the top when you check if working properly. All coolant expands when heated and after shut off the temperature inside the block can rise slightly above boiling and the pressure goes up before returning to normal. This is why an air space of an inch or so is used on regular radiators to allow for expansion. I used to top up a cup or so every week in the summer, but after installing the coolant recovery it's once a year. The recovery bottle should be about 1/2 full and the hose submerged. If coolant is being expelled as in a blown HG, the recovery bottle will over fill. You would notice this. Quote Link to comment
atkinson40 Posted April 24 Author Report Share Posted April 24 (edited) Do not see steam in exhaust. https://drive.google.com/file/d/1Y7-SIQh-DC6SosFEU_LPosPOTzNU-S2J/view?usp=drive_link https://drive.google.com/file/d/1ztZzeNp8c015dkn0l5W_xZWXgtx69M_T/view?usp=drive_link Edited April 24 by atkinson40 Quote Link to comment
atkinson40 Posted April 24 Author Report Share Posted April 24 (edited) Maybe I have a miss? I'll top off the radiator and half fill the recovery bottle. Edited April 24 by atkinson40 1 Quote Link to comment
Stoffregen Motorsports Posted April 24 Report Share Posted April 24 (edited) Stop removing the cap and watch the coolant level in the bottle. Every time you loosen the radiator cap, you're allowing air into the system. Top off the recovery bottle a few days in a row if need be and see if the level begins to remain constant. Note - you need to have a siphoning radiator cap. Note - you should not fill the recovery tank to the top. It needs room for expansion. Note - the recovery tank should be adequately sized. If it's too small, it will puke fluid out of the recovery tank during its cycle. Edited April 24 by Stoffregen Motorsports Quote Link to comment
banzai510(hainz) Posted April 27 Report Share Posted April 27 I use a flip type Rad cap. and see if it pops and water on the ground motor timed ? If sucks water try pulling a spark plug if very clean then its sucking water in. have you swapped in a new stat? Quote Link to comment
EDM620 Posted May 5 Report Share Posted May 5 On 4/23/2024 at 8:56 PM, datzenmike said: engine compression getting into the cooling system. Also would be evident in the rad hoses pressuring up solid. Rad drain plug not weeping? Quote Link to comment
datzenmike Posted May 5 Report Share Posted May 5 Yeah that would quickly reach the relief pressure of the radiator cap. The hoses would be rock hard. Coolant recovery bottle would bubble. Quote Link to comment
atkinson40 Posted May 7 Author Report Share Posted May 7 (edited) I put a new flip top radiator cap on. I filled the radiator to full and made a new recovery bottle. I drove it on an approximately 40 mile trip and then let it sit for 3 days. I see no change in fluid in the recovery bottle, ever. After sitting 3 days, I pulled up the radiator cap relief lever and it was under pressure. Air came out the recovery bottle hose into the bottle. In addition I needed to add 1/2 gallon of radiator liquid to top off the radiator. The little amount of wetness on the radiator shroud in the picture is from my unsteady hand topping off the radiator. There is no steam coming out the tailpipe. I do not see any leaks anywhere. Edited May 7 by atkinson40 Quote Link to comment
datzenmike Posted May 7 Report Share Posted May 7 Are you positive you bought a coolant recovery radiator cap???? Quote Link to comment
atkinson40 Posted May 7 Author Report Share Posted May 7 10 minutes ago, datzenmike said: Are you positive you bought a coolant recovery radiator cap???? It's got 2 seals and 13PSI on the top. I started it up after my last post and have new symptoms. I left the flip top released and have a steady stream of air bubbles in the recovery tank when it runs. In addition, I now see steam (I think coming out the exhaust) and drips of water. Quote Link to comment
Stoffregen Motorsports Posted May 7 Report Share Posted May 7 Sounds like the cap may not be right or isn't working properly. Buy a cap for a vehicle that you know has a recovery tank. The level in the rad will drop. They are almost never completely full. How much will it drop? Depends on the vehicle. Quote Link to comment
Stoffregen Motorsports Posted May 7 Report Share Posted May 7 If you had a blown head gasket, it may pressurize the cooling system and blow coolant into the reservoir. If yours is not filling up, then the chances of a blown head gasket are low. Have you replaced the water pump? Are you still running the coolant bypass hose at the thermostat housing? And coolant pipe to the intake? Bubbles will happen with the cap off. If you want to be 100% sure that the system is bled, park the vehicle pointing up a hill and let it idle for an hour with the cap off. This will allow the t-stat to cycle (open/close) and work the air bubbles out. Then put the cap on before you turn off the engine. Quote Link to comment
datzenmike Posted May 7 Report Share Posted May 7 2 hours ago, atkinson40 said: It's got 2 seals and 13PSI on the top. I started it up after my last post and have new symptoms. I left the flip top released and have a steady stream of air bubbles in the recovery tank when it runs. In addition, I now see steam (I think coming out the exhaust) and drips of water. Constant bubbles is compression getting into the cooling system. Steam, a little, and condensation can be normal in the exhaust, specially when engine is cold. Excessive clouds are not. Quote Link to comment
Stoffregen Motorsports Posted May 7 Report Share Posted May 7 Yes, constant bubbles can be a blown head gasket. Combined with all the other info, it still doesn't feel like a blown head gasket. Quote Link to comment
CharlieWhiskey Posted May 7 Report Share Posted May 7 Additionally, you can use a carbon monoxide (CO) detector to find out if exhaust gas is coming from the radiator's top. Quote Link to comment
atkinson40 Posted May 7 Author Report Share Posted May 7 1 hour ago, datzenmike said: Constant bubbles is compression getting into the cooling system. Steam, a little, and condensation can be normal in the exhaust, specially when engine is cold. Excessive clouds are not. Could a leaky HG be caused from not retorquing the head bolts since the last time I replaced the HG? Quote Link to comment
banzai510(hainz) Posted May 7 Report Share Posted May 7 this is Me and my 521. I have a flip cap as you have pictured and amountain dew recovery. but thats is for more or less when I release it goes in the bottle than the ground. If me I would first see if you have a heater line to the manifold for a water passage./ maybe the bolts are loose. if loose water can leak there. or get sucked in the intake thru the gasket if bolts are loose. if sucked in then the spark plugs would look clean. This could be it. If you want a recover type ssytem you need a recovery they Rad cap. either way your loosing water I think. Half gallon is lot Quote Link to comment
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