Boiling Coolant? (1 Viewer)

[Josh83]

I got home from a 15 minute drive across town with a 30 minute cool down period and then a 10 minute drive back across town. I got out and after a couple of minutes I noticed a noise coming from the 80. Popped the hood and the coolant was boiling. The overflow was almost full but it is still too hot to take the cap off the rad. I searched and didn't find much really. I changed out the typical sludgy mixture last fall for 50/50 red and tap water and the level has not dropped since, so I don't think I have a head gasket issue. What could be causing this? Ambient temp was ~85-90 and I had the AC on. I have an ARB with IPF 800's on it that could be restricting air flow I suppose. This is my first really hot day I have driven the 80, but I know this shouldn't be happening.

 

[Silicon 70]

Thought you're supposed to use only distilled water for radiators?

 

[cruiserman]

You may not have had a head gasket issue then, but it's probable you do now.

 

[Josh83]

I did use distilled water...my mistake. Also, the temp guage was fine when I notice the issue, but I don't know what it was doing during the drive.

 

[Josh83]

Update: Truck is now cooled down some. I checked the oil. The level and color looked ok and no foaming was presant. The oil looked new(only ~700 miles since change). I took the cap off the rad. and it was full and color looked ok. The overflow was at the same level that it has been since I changed the coolant, color looked good in there also.

 

[lovetoski]

Maybe your rad cap is bad. Cheap to replace. It's supposed to keep at a specified pressure, maybe it's letting go too soon - causing coolant to "boil" into the overflow tank. You can get wierd symptoms from bad rad caps.

 

[alaskacruiser]

You may not have had a head gasket issue then, but it's probable you do now.

Probable? I think you're jumping the gun on this one, cruiserman.

Josh- you're probably fine, but do the bubble-in-overflow-bottle-test just to make sure. Check the rad cap and also ensure your rad is not clogged from the sludge you mentioned earlier. Could be something simple like your thermostat?

 

[Josh83]

I did the bubble test and didn't see any bubbles. When I did my rad. flush last fall I ran the water through the system for a LONG time and it eventually ran crystal clear, but there could be sludge still I suppose. The t-stat was not changed when I did my coolant flush, so it could be that. Can I get an auto zone rad. cap or do I need to wait till Tuesdayand get a Toyota cap? Can I drive it like this around town, as long as I watch my temp guage? I have 3 other trucks so I don't need to, but it is my favorite.

 

[Josh83]

OR: Could I put the cap from my 100 on the 80 and see if that works? Just as a test? I assume they would have the same pressure rating.

 

[Rich]

Based on my experience, if you had grey sludge in the radiator, you would not be able to flush it out with the volume and pressure available at home.

I flushed several times, more than 90 minutes total, running Prestone radiator cleaner in between. I had to remove radiator and take it to a radiator shop where they flushed the radiator using a monster high volume pressure pump.

After the shop flush there was no visible sludge in any portion of the core visible from the cap opening, inlet, or outlet.

After a number of months subsequent to the shop flush I saw more sludge accumulating in the radiator, visible from the radiator cap opening. At that point in time in installed a coolant filter. I have been running it for more than a year and at this point in time there is no sludge visible from the radiator cap opening. When I originally removed the radiator the majority of the sludge was on top of the core at the radiator cap end. Some, but much less was at the top driver’s side. None was visible in the lower tank.

 

[dd113]

Use an OEM cap but for short term use any cap will work.

At least 50% of all trucks that come into the shop ahve bad caps that fail the pressure test.

 

[Josh83]

Ok, I swapped out the cap for an Autozone unit and went for a good 1 hour drive ( at a good 10 degree lower temp, admittadly) and saw no issues. I'm going to take it out again today and see what happens, but I really feel like that was the issue. I'll now add a OEM rad. cap to my Cdan order that is growing . Thanks guys!

 

[TX_TLC]

I did the bubble test and didn't see any bubbles. When I did my rad. flush last fall I ran the water through the system for a LONG time and it eventually ran crystal clear, but there could be sludge still I suppose. The t-stat was not changed when I did my coolant flush, so it could be that. Can I get an auto zone rad. cap or do I need to wait till Tuesdayand get a Toyota cap? Can I drive it like this around town, as long as I watch my temp guage? I have 3 other trucks so I don't need to, but it is my favorite.

Another thing to keep in mind is the relative inacuracy of the stock temp gauge. It was designed this way so soccermom's (well they don't actually look at any of the gauges, but you get the idea...your average driver) don't freak out if they see the temp gauge move up high. So basically it isn't going to show "hot" or in the red....until it is TOO hot. This has been discussed many times and there are several guys with a seperate aftermarket temp gauge to get a real reading on their temp.