My main question is:
Can tap water cause radiator fluid to foam?


Like my title indicates, the problem is my truck is getting hot.

I can drive along in traffic and everything is fine, but if sit in traffic or wait at a drive thru, the temp needle slowly starts to move and will eventually get to the "H" mark.

More info:
The thermostat appears to be working. I can see fluid flowing by looking down the radiator neck. (Replaced thermostat a year ago)

I also assume that the water pump is working since the water is flowing and I hear no bearing noise or any sounds indicating that it is failing. (Besides I replace the water pump about 6 or so years ago.)

Heater works (blows hot air)

Radiator fluid color seems normal.

==========================

Ok, now on to the issue with the foaming radiator fluid, which I imagine is the reason for the overheating. I understand that a blown or a problem with the head gaskets could cause foaming. I truly hope that is not the problem, since I replaced my head gaskets a year ago. I had the heads machined flat before replacing and torqued the head bolts as specified in the instructions that came with the gaskets.

There is no radiator fluid in my engine oil. The oil actually looks pristine.
There is no white smoke or anything visible coming out of my tail pipe.

So I'm hoping that a head gasket isn't the problem. Yet, I have foaming radiator fluid.

I read in another thread here that a guy was having a foaming problem, but he throughly flush his cooling system and that solved his problem. So it got me thinking that adding tap water instead of distilled water could possibly cause foaming. Additionally, I never noticed a problem with my temp (and I religiously look at my gauges) until I added a couple quarts of tap water to my overflow reservior, which got sucked up by radiator.

So, could adding tap water be the cause of my foaming problem and thus my overheating?

 

test your fan clutch. Allow your truck to heat up to operating temperature just sitting in the parking lot with the engine bay open. Turn of the truck and go look at the fan. If it continues to spin more than 2 revolutions before it stops you have a bad fan clutch. if that is not the problem then burp the cooling system. If both those don't work try the flush and get back to us with results.

-Dimitri

 

Most of the fan clutches when working properly make a terrible air noise when you first start them in the morning for a couple of seconds. If your's doesn't, that may be another sign the clutch is bad.

Overheating in town means a airflow problem

Overheating on the highway means a coolant flow problem.

 

Fan has no clutch, just mounted to a belt hub. So when the engine is running, the fan is spinning, when the engine is off, the fan doesn't spin.

I burped the system as well as I know how without actually picking the truck up and patting it on its back.

I will flush next. I just bought Prestone's Flush'n Fill Kit, so I will be using that with the addition of their Super Flush chemical.

Thanks Dimitri and Franklin2.

 

I should mentioned that I just drove for 30 minutes in 98 degree heat, but no overheating. When I got back home I removed the radiator cap. It was foaming.

So I'm thinking this foam is being pulled through the engine. When on the highway the radiator fluid is flowing good enough to keep the engine cool, but when at idle, when the flow is slower, the foam is acting sort of like an air gap, causing my temp gauge to peg out. And once I head down the road again, the temp drops to normal.

Well, I will flush now and only worry about other horrible possibilities later if it doesn't work. Thanks again.

 

I should mention that the foam is white.
And it has no combustion odor that I can detect.
Also the foam disappears after the engine cools. I can look down in the radiator neck and the fluid looks clear.


Started flushing but my radiator drain **** is giving me trouble. I can't close it. Since I broke one in the past I know how to fix it, but it's dark out now. So hopefully I can finish flushing tomorrow and give an update.

 

Just a thought...Is there alot of fins bent over on the radiator, or anything? The fan would have alot of trouble pulling air through the fins if there is. The only other thing that may be going on, is some sort of restriction in the system, like an excessive amount of corrosion in either the block water jackets, or the radiator itself. That might explain the foaming....

Frank

 

Foam indicates combustion leak into the system ... Get a test kit to see if you are getting combustion gases into the cooling system. Sounds like a blown head gasket or a crack.

-Enjoy
fh : )_~

 

also make shure you have a proper shroud, that makes a world of difference

 

Gordon Freeman,

Welcome to the forum!

Usually, when something like this suddenly starts, it can be related to something breaking or something having just been replaced or altered. In this case, depending on where you are located, you may have had marginal cooling capacity for some time and now with the current heat wave [102F here today with predicted 114F heat index] your cooling system cannot remove the excess heat?

Have you checked the v-belt [serpentine?] for correct tension?

 

**UPDATE**

Well, sorry for the delay. Like I said earlier, my radiator drain **** broke. It took me a day and a half to find a drain ****. (That's what she said.) **** on Napa for crappy service, **** on Autozone for discontinuing my drain ****, and HOORAY! for O'rielly Auto Parts for carrying it in stock. I bought two.

Anyway, I finished flushing my coolant system.

First, I back flushed it with that Prestone Flush Kit.
Second, I used Prestone's Super Flush chemical. (Idled with it for 10 minutes then flush.)
Third, I used Prestone's Super Cleaner. (Drove with it for about 4 hours then flushed it.)
Forth, I back flushed again with Prestone's Flush Kit.

And yes, it did flush out some stuff, but nothing surprising. I never once said, "Dang, look at all that stuff coming out!" I said, "Hmmm, that's it?" and "Oh, there's a little more."

I'm not sure if my foaming problem is solved yet. However, during my 4 hour Super Cleaner drive (see third step above), I never came close to overheating. My temp was pretty steady the whole time. But I should mention the high today only reached 83 degrees outside, as opposed to 98 degrees when I was having my trouble. Also, tomorrow will be the first chance I have running it without chemicals it and with flushing complete, so I will check for foaming then.


As suggested by me above and at least one other person responding to this thread, my foaming could be pointing to a failing head gasket or a cracked head or block. Therefore, a combustion gas leak test was duly noted and performed.

Combustion Gas Leak Test
Three test came back NEGATIVE. Negative is good.
If there is combustion gas in the system, the test fluid turns from blue to yellow. The test fluid stayed blue for each of the three test.

I know, I was expecting a big fat Yellow POSITIVE too!

I should mention that I performed the test when the outside temperature was around 80 degrees. As mentioned above, I had my foaming and overheating issue in much hotter temps.

Therefore, I will perform the test again and check for foaming tomorrow when the temp is expected to be 94 degrees.

I want to thank everyone for your help and replies. I made sure to check everything that was suggested by you all. So, thanks again.

I will give another update tomorrow, that is, if I don't have any trouble with my drain ****.

 

I often have trouble draining my ****.

...oh come on I had to

 

**UPDATE #2**

Performed Combustion Gas Leak Test again, but in warmer outside temperature.
The result of the test was the same as the first! Fluid stayed blue, so no combustion gas in my cooling system.

Still not satisfied, so I performed the CGL Test for a third time. I tried to duplicate the conditions as when I had foaming and overheating trouble. I drove for about 40 minutes in 94 degree heat and went thru a drive thru. I didn't overheat this time. And when I got back, I did the CGL test. Again, the result of the test was NEGATIVE, same as the first two times. The fluid stayed blue.

And just in case you're curious, yes I did test to find out if the fluid would turn blue to yellow. You test it by blowing into the airlock. I blew thru the airlock for a five seconds and it turned yellow. Compare that to around 20 minutes of total time testing it over the radiator neck. So, I'm confident that there is no combustion gas in my cooling system.

Th foaming problem has been noticeably reduced, however I am currently running just water.

Next, I plan on putting in a new thermostat and make sure my coolant hoses are in good condition and tightly clapped down.

After that I will perform yet another CGL Test before adding radiator fluid.

I will give another update once complete.

And, Dimitri, you are correct. You had to do it. And I must admit, it was fun asking women at the auto parts store for a drain ****. "A drain **** you say? Oh, drain ***** are on aisle four."

 

Cooling info worth a look:

April 2002 Troubleshooting Professional Magazine: Automotive Cooling System Maintenance and Repair

Pretty good reading.

 

**UPDATE #3**

Well, I just replaced my thermostat with a new one. The old one was stuck or failed open. It was the Failsafe brand. It was only a year old. How ridiculous is that? I can recall not wanting to buy it, but it was the only thing Autozone had in stock at the time.

The new one I got from NAPA, from their Premium line.

Anyway, I put in the new thermostat and checked the coolant hoses and connections. I saw one spot on my upper radiator hose that got rubbed on by the belt pulley thingy. There wasn't a coolant leak, but I'm wondering if air was being sucked in and caused my foaming issue. The spot in question appears high enough not to leak fluid but it seems possible it could be letting air in the system. What do you think?

I wrapped up the spot with electrical tape. I have yet to refill and run the engine, since I want the thermostat gasket seal stuff to harden properly first. So I will test all this out tomorrow. Until then...

Almost forgot to thank TrucksNamed"PHIL" for the excellent info link. Thanks, TrucksNamed"PHIL"