Cooling system -> Stop Leak. Does it work?

[Climber]

Yesterday started my truck, goes about 5 miles - temperature rises. Checked hose from thermostat to radiator - hot. Means thermostat is working. level with anifreez is low. My nextr step: got rental from AutoZone this tool to pump pressure into cooling system. Pressure is foling fast (on hot engine).
Checked oil... oh my got. It's white.
So I got ether block or head leak. before spending thousands I'll try to use "STOP LEAK".
my questions:
1) is any one used this kind of product?
2) if so, what exactly? So many of this. "Radiator stop leak", "liquid aluminum", "liquid copper" etc.
3) did it worked?
4) any ideas about cooling system filter?
Please need your advise.
Thanks for any input.

[Gary_C]

First what engine are you talking about here. If it's a diesel it's toast. Even if it's a gasser, it is not good. I've never used that stop leak stuff before, but doubt it will work on head gasket leaks. And if it's a diesel, it could be a pin hole in the cylinder wall or sleeve and that takes a complete teardown to fix.

I would sure never trust that engine again. Get it fixed right. You probably have already scored some bearings with that anti freeze in the oil.

[Black_Bear]

I used the radiator stop leak in a 96 Jeep Cherokee I had and it worked fine. Don't know if the stop leak did it, but about 6 months later I had to replace the water pump; the radiator never leaked again and it could have been a coincidence that the pump failed, but I'm not much of a believer in coincidences. I ended up replacing the radiator and water pump and flushed the system, but the parts were cheap and I did the work myself.

I had leak problems with a T-100 head gasket so I put the industrial stop leak to it. 3 days later I was at a red light when steam started coming up through the hood. I was about 3 miles from home and was able to get home, but the engine was cooked. I'd consider the industrial stop leak to be more of a temporary fix, like fix-a-flat, to get you home or to the shop. I know in my case the engine got so hot it warped the head and I had to go out and buy a new truck. I think I may have subconsciously allowed the head to get hot, I really wanted a new truck!!

Ed 

[WH_Conley]

Put that pressure tester on the cooling system, pump it up til it just reads on the guage. Start the engine. If the needle jumps and pressure builds rapidly, (needle will jump everytime the affected cylinder fires) you have a compression leak, usually at the head gasket. No amount of stop leak will cure that problem. Many times, not always this goes hand in hand with water in oil. Stop leak is dangerous, if leaking water to the atmosphere, black pepper is about as good a fix to get you home.

[pineywoods]

Don't waste your time with stop leak. It's OK for a temp fix for pin holes in the radiator.You obviously have something more serious, best case blown head gasket, could be cracked or warped head, worst case is a cracked block. There is some stuff called block seal, goes by various brand names. Sometimes it works, but follow the directions. Stuff is a thick liquid you pour into the cooling system. The engine needs to be hot when the block seal is added. In my early years I used a lot of it mostly in the old ford flathead v8's. The blocks were bad to crack. Block seal would work about half the time. Might be worth the gamble.

[SPIKER]

I THINK that this has been broached here or over at TBN, myth busters did a show on the radiator stop leak stuff and found the best fix was a EGG cracked into the HOT radiator... go figure.

I have tried the stuff never with much success if any.  usually to try and save a heater core when it was winter and the heater core was leaking into the car heater box...   (always breaks in winter why is that? :( >:( anyhow like others if it is some thing you need to go long distance then dont trust it in my opinion.   while simply shutting the heater off worked for me there were a few times when I tried it for head gaskets on old beaters that were destined for the junk yard and were used primarily as farm beaters and or demo derby stuff that had low life expectancy.   Engine radiators and such it had worked for pin leaks but normally if you had one pin hole a 2nd or 3rd would be popping up very soon after the first one is fixed.

With water in the oil not much hope of sealing those leaks with it as heads/gaskets move a lot with each heating & cooling cycle breaking loose any SEAL that may have been made...
bearing failure and engine failure is probably if driven with water and oil mix for a very long time.   like others said depending on the car/engine there are typical problems some gaskets and others heads cracking.   post a bit more and probably you can get a good idea as to which it is...
Mark

[stonebroke]

I like Bars Leak. It works on radiators very well, on head gaskets and block leaks it is a gamble but what do you have to lose, the price of the stop leak.

Stonebroke

[ErikC]

  I have used Bars and alumaseal on badly damaged radiators, that the fan hit with a broken motor mount. Aluminum means I couldn't solder it. I crimped over all the damaged parts and used a couple bottles, it leaked less and less then sealed. Lasted a long time that way. I never used it for a head gasket or anything of that type though.

[Ron Scott]

My experience with most of them has been only a temporary fix.

[isawlogs]

They are only temporary fixes at best .  :-\ 

[jesse]

if it has a oil cooler on engine it may be letting antifreeze  in oil

[timberfaller390]

I used a bottle of bars leak in my girlfriends truck the other day and so far it is holding fine. I have watched it stop a pencil sized leak in radiator before and that fix has held for 5 years. I don't know about heads or blocks but as others have said the engine is probably going to have to be torn apart so you just as well give it a try. It's only 4 bucks

[CLL]

we have used liquid glass several times and it has not leaked

[H60 Hawk Pilot]

The advice (above) is Spot  On !

Bars Leak is Good and the Stop Leak John Deere sells is Very Good.

All the Stop Leaks are the same, just little blocker flakes that circulate in the cooling system. Stop leak works best on the radiator where small pin holes show up ... usually caused by internall corrioson or other causes. Also, some head gaskets will seal up with stop leak. Depends on what is going on, just a head surface (small spot) that allows coolant to sneak out and will dam up with the small flakes of stop leak mix.

However, if you have other engine problems that are beyond the small head surface/ head gasket type... then it's over ! !  How do you know, try it and see what happen's, it will cost you about $ 7 or $ 8 bucks or so.  Don't even think about trusting this engine on a long trip (stay close to the house)  carry extra coolant with you.

I'd be scheduling it in for Real Deal Repair in the near future.  Also, don't over heat this engine, it will  cost you big bucks  in the future. The electric temp. gauge will not read properly when the coolant is not touching the temp. bulb sensor. This is when the coolant level is down to nothing and serious internal damage is going on inside. Forgot to mention, you may or may not smell the hot engine and see steam venting...  most likely.

Avery 

[Climber]

Thanks to all for your input.
Here are some facts.
The engine is International diesel DT360/466. I don't know exactly. No body does. Even dealer. It was swaped by previos owner.
It does have iol cooller.
It does have coolant fluid filter.
The preessure in cooling system on running engine is NOT rising.
I belive it has wet sleaves.
I did NOT cooked it for long time. May be under 1 minute.
The oil was not white when I parked. It become after few short tests while standing. So no bearing issues.
The problem is the time. This truck has a plowing contract with state. And I am about to fail this.

[stonebroke]

I would be looking for another engine or truck in that case. Stop leak is not something to depend on for a plow truck. Even if it worked.

Stonebroke

[logwalker]

If you want to try this I will just say that I have had good luck with it. Your system has to have a way to pressurize it. The overflow tube works with a air nozzle.

Napa sell K&W block sealer that has as an active ingredient, sodium silicates. The way I used it was to follow directions and drain the radiator completely and flush well. No hint of antifreeze can remain. Then mix a warm bucket of water and sealer and pour into the rad till full. Run the  motor until hot and a little longer.

Now this is my twist on the directions and I think it is what has made it so successful for me.  Shut the motor down and then using the overflow tube, put 15 lbs. of compressed air in the radiator. Basically whatever the rad cap will hold. As the engine cools it will lose pressure so you must top it back up. Let it set for 24 hours so the silicates can harden in the leaks. Before I flush I try to run the truck for a few hours to see if it is sealed. If no then I let it set for another 24 hours with pressure.

I have done this to 2 small diesels and then continued to use for several years with no further problems. Of course I have no idea whether it will work for you but it has for me and maybe it will for you.

[Magicman]

I used K&W on a 1960 Chevy 6 cyl.  I followed the instructions and it did the job.  I'll never know what was cracked or leaking, but that engine was still going when I sold it 5 years later.

[Den Socling]

logwalker's method sounds pretty good. I think I'll try it on one of our fork trucks. It has a flathead Ford with a cracked block. It never shows much water in the oil - just enough to be troubling.