As like many of us I have an overheating issue, but here is the kick...I think I know what is causing the problem, I just want your opinions.

As many of you know I had to rebuild this motor after it overheated on me and blew the head gasket while I was going down the interstate. After rebuilding the motor it was running fine except for a couple times where the fan motor wasn't working. Although the fan not working is intermittent the overheating isn't and is still there even while the fan is on. My coolant levels are fine, but I have noticed a ton of copper colored junk that wasn't there in the radiator when I put the motor back together. I have had 3 thermostats go bad on me, all of which are the "fail-safe" ones that fail in the open position. So I think that the junk in the radiator that is restricting flow is from those blown thermostats. There little flow between the tubes in the radiator and almost no flow and pressure on the return line for the heater core. So I'm really thinking that the very small holes in the head gasket are clogged with this crap and not letting the heads cool as necessary.




I've been running the engine for a while and let it warm up, but before I did that I removed the thermostat as you can see. The engine is still trying to overheat even with the thermostat removed and with the fan running. The air coming from the fan isn't that hot though, which is probably because of the lack of coolant running through it. The temp gauge in the car shows the needle on the third tick mark, almost in the red, and that is just with the engine idling. The air dam is still installed even though it wouldn't explain the overheating at idle. The water pump is almost new and before the engine rebuild still worked great. If you want to gauge the water pump by visual flow through the radiator then it was working great right until after the thermostats started failing.

If I am correct about that junk being from the thermostat and causing the flow restrictions....how in the hell do I get that crap out without replacing the radiator and tearing the motor down again? I'm pretty broke until next month so I can't afford anything expensive.

 

so replace the valve and get the radiator flushed?? maybe...

 

I wish it was that easy, but it has blown the third valve and it gets quicker every time. I think the first time was because of the fans not working at some point. And the stuff is almost hard as a rock, a knife takes a while to get the stuff off the radiator cap.

Anybody know what the crap is made of on the inside of the thermostats? Maybe I can find something that will break that junk apart so I can drain the system and refill it.

 

Was your block hot-tanked after the machine work? Sounds like rust from inside the block. The inside of a thermostat contains a wax pellet. The thermal wax melts at the given opening temperature which means that is not whats plugging up your system. The wax would remelt at the temps you are seeing. I think you need to flush out your block and radiator and see if that helps.

 

It is the wax crap not rust...rust doesn't scrape off stuff and leave it shiny. I'll just have to look it up after I get done here and see if there is anything I can use.

 

Just finished putting in a double fan setup from another car that I had junked out. Right now I've got both fans wired to stay on with the ignition like I had the last one. We'll see soon if this will at least let me drive the car without fear of overheating on the short term. I'll still do something about the radiator, but hopefully this will at least get the car useable.

 

Well you could try runnig CLR through the system, but I don't know what it will do to the gaskets.....if anything?????

 

It's not rust or calcium that is built up. It is the wax pellets from inside the thermostats. I did get some of it scraped off the inside of the radiator cap but that was it, what I really need is a way to dissolve the wax so I can flush the system.

 

The wax should melt at HIGH temps like what you are seeing. I would try doing a rad flash when the engine is hot, maybe 2-3 times even!......It maybe the only way to drain out those wax pellets.

Other then that, I can't think of anything that brakes down wax!.....Sorry bud.

 

That radiator is shot!!! There is no flushing it, you will need to take it to a radiator shop and have them rod it. That is where they take it all apart and run a rod through each tube and then hot tank it. First I would run an acid based flush through the whole system for 30 minutes or so to clean the block and heater core, then take the radiator to a shop, they might just tell you it is shot and you would be better of buying a new one. My radiator looked about the same as that and I had over heating problems, new radiator and a good flush fixed all those problems.

 

Did your rad have as much wax in it as mine?

Did you have any problems afterwards with clogged head gaskets?

What acid based wash did you use?

 

I might try flushing what I can with high temp, but I really don't know what I'll be able to pull out just doing it that way. I might try some acid wash if it says it'll break it down enough, otherwise I'll I think this radiator is shot too.

 

The car is still running a lot hotter than it should and this is with the thermostat still out. I have some full strength Muratic acid so I may try to drop of the pieces that I got from the rad cap into a small bit of it to see if it will do anything against the wax. If it does then I'll test it against a bit of aluminum, copper, and rubber to make sure that it doesn't react negatively with them. If it does then I'll have to use progressively diluted strengths to find out where it stop reacting, or at least at a much slower rate.

I'm guessing that I'll just have to send the heater core and the radiator to a local shop to have cleaned and repaired, but I'd like to at least get the rest of the block ok to go.

 

I just used Muratic acid to flush my system, it is real hard to find acid based flush now days because of the tree huggers. I never had no wax in my system, it was just corroded real bad and the flow looked just like yours, ended up having to buy a new radiator. Flush your system with the old radiator in it so if you get a new radiator you are not running acid through it. No friggin idea why you have wax in the system, in my 40 years I have never ever seen that. Sure it's not left over gelled up dexcool or something? Thats kinda what it looks like to me!

 

Thats It! Thats exactly what it reminds me of......Dexcool. I've seen rads look like that before, I just could not remember what, when and where.

 

I have never used that stuff, just plain water and anti-freeze, plus about three failed thermostats. Wax is the stuff inside the thermostats, melts at a certain temp and expands to push the piston. If overheated it would do the same thing as everything else expand too much and rupture.

 

I've, in over 20 Rad Shop years, never seen that before.
First off, if you think it's wax, go with the stock Delco stat now.
Next, did you maybe mix coolants? Dexcool, and any long-life coolant for that matter, does not get along with the old-style green stuff. They react to each other chemically, but I've never seen what it actually looks like when they do.
Thirdly, yes, maybe someone could 'rod-out' your core, but it cannot be 'hot-tanked' as it is aluminum, which caustic eats.
I would not recommend Muriatic. Besides the fact it will destroy your core, you will create Hydrogen Gas. Could blow up your garage. Muriatic, like Hydrochloric, is meant for metals, not organics. Wax is not going to be affected by acid, nor is bad antifreeze.
Try a 10 minute rad flush.
Or you could try to find this product we sell called RMI 25
http://www.dfsalesmarketing.com/

Don't know if it will help, but it most definately will Not hurt.
Go to the link and click menu for all the goods on it. Good stuff. Even washes out Irontight.

Good luck

 

I was talking to a neighbor and remembered still having my old heater core which only leaked, so I'll probably have a local shop clean and repair the small leak in that thing. As for the radiator I'm not planning on keeping it unless I can get it cleaned for cheaper than a new one or junkyard one. My biggest concern is for the block and those small coolant passages in the head gaskets.

 

The radiator shouldn't be hard to clean as long as you have heat to it...thermos work by two wires encased in that wax, when the wax melts, theres nothing stopping connection between the wires... voila.. power goes thru... the wax is made to melt at 180 degrees, You should have no issues getting that radiator warm enough... you might have to get a bit creative with water/heat/big a** basin/tub etc.. but all you SHOULD have to do is heat 'er up... pour it out.

 

there is a cooling system flush that you can buy that is left in system for a couple of days or a certain amount of drive time. it only costs about 10 bucks from the parts store. this is not a quick flush.

 

Whatever I put in the system I'm guessing will not be a quick fix. I'm sure that most of the fixes for this will require a bit of time. I still haven't tried any of my ideas and I'm having to wait till I get some money since every last cent that I have right has to go in the gas tank for work. I will try to stop by Advance to see if the have anything on the shelf that will take care of this stuff.

 

Wow that reminds me of the gunk from the old dexcool. Dont buy those "fail safe" thermostats, all thermostats are designed to fail in the open position, and ive heard of people having problems with the "fail safe" ones at autozone. Go to the dealer and buy the right thermostat.

As far as the radiator youd probably have to pressure flush that, you could try a chemical flush but I dont know if it would work. A radiator shop might be able to clean it out if not time for a new radiator. Not terribly expensive sometimes you can find good ones at the junkyard.

 

There was no mixing of coolants at all, brand new from the store.

Most thermos are not designed to fail in the open position.

 

Do you have a a/c supply store near you? They have a product used to clean "A" coils on home a/c units. I have used this before. Take thermostat out and flush as best as you can, add product and water ,follow lable directions for mix, run car about 1/2 hour, drain flush again 2 times replace thermostat and antifreeze. If it is not clean repeat, will get rid of calicum and crud.

 

From looking into your radiator you need to take it out and have it rodded or get a new one. Find a radiator shop and they will tell you if its bad. They should be able to do it while its still in your car so you wont be taking it out in vein. I would strongly recommend to anyone that when you rebuild your motor, you should pull the radiator and get it professionally cleaned and system flushed. they DO NOt make anything out there that you can simply pour in and flush out that will do better than having a radiator shop do it. Its not usually that expensive either. It almost looks like someone poured a bunch of stop leak in there before and its still in the coolant system. I am not saying you did this but maybe a previous owner. Once you get the radiator rotted out, I would then take a hose with water and flush the rest. Sorry for the long post but I have had clogged radiators/cooling systemsbefore and this has been my experience.

Kevin

 

I just found out that most of the radiator shops are using an alkaline solution to boil out the radiators, and when I was searching through that info I also found out that the military uses simple baking soda, which is alkaline, to clean theirs out. They say to use 1lb soda to 1 gal water. The only problem with that is that aluminum is very reactive to alkaline solutions and they also say that a muratic acid solution can be used which is on the other side of the PH scale. I'm looking into this so that I can clean the rest of the system out, not just the radiator.

What I have done so far has been really helpful, which besides replacing the radiator has been to fully drain the system again and replace the coolant with water instead. I then added 2 powdered dishwasher tablets, warmed up the engine, and then drove it around the in-laws house for about 5-10 miles. I came back and drained the system again and rinsed it out. I added more water and then added 3 tablets of the liquid type. I have driven with that in the cooling so far about 45min at temperature but I put that in on saturday. I will probably drive it off and on until saturday again then drain it and put in the commercial cleaner/flushing fluid to clean any residual stuff that the detergent didn't get out. On my drive home from their house I already noticed that the car was running cooler, at least about 10degrees maybe more. Also makes a difference how hard I'm accelerating but for the most part it's running much cooler than before.