Blown HG?

[atkinson40]

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

 

 

[IZRL]

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. 

 

[atkinson40]

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

[IZRL]

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

[datzenmike]

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.

 

[atkinson40]

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. 

[atkinson40]

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.  

[Crashtd420]

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.... 

 

[datzenmike]

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.

[atkinson40]

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

[atkinson40]

Maybe I have a miss?   I'll top off the radiator and half fill the recovery bottle.

 

 

 

 

Edited April 24 by atkinson40

[Stoffregen Motorsports]

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

[banzai510(hainz)]

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?