320k and head gasket appears to be leaking

I had my vehicle sold before having over heating issues and loss of fluid after driving more than an hour or so. Anyway, after changing thermostat, cap, water pump, and a good flush it was running without problems. I drove 2 hours today and just before getting to the dealership to put a deposit down on a new double cab long bed and get an appraisal. My truck overheated. Then started pissing fluid out of the overflow and all over the engine bay. Now I am kinda screwed. First even if I buy new it will not be in for a couple of months and I work an hour one way to get work. Second, is it worth to get head gasket fixed at the mileage. Just so I can sell it at a fair market price instead of lowballing dealer offer. Not blaming dealer at all. Alderman Toyota in Rutland VT had offered me my dream truck in Blue Crush at $200 bucks above MSRP and were willing to remove lift and aftermarket items Such as lights wheels tires and either install my new bilstien 6112s and leaf pack on new truck or let me sell them to make up the difference of their offer and do the work of bring my old truck back to stock for free.

 

I would do a used engine swap, drive for awhile to get your finances back up, then sell it on used market like CL. You can get a used Tacoma/FJ engine on eBay for around $3k-$3500. I wouldn't spend $$ to repair the HG on an engine with 320k miles.

 

Sure you didn’t just get a bad thermostat/cap…?

 

Good point, OP get some coolant tested for exhaust gases, you might get lucky and it be something small.

What year? 05-06 and early 07's were kinda known for worse head gaskets.

 

or…. the radiator might be blocked.

Monkeying around with the thermostat/pump, and a less than perfect flush, can knock crud loose that jams it up.

 

This^^^^^

If your truck overheats on long drives only its your radiator.

 

I have today off, and I can get another thermostat and do another flush. My question is would it be best to deal with possible radiator blockage. Do I pull radiator and deal with it separately or just do a normal flush? I would have to order a radiator.

 

Before you pull the radiator, did you bleed the coolant?

 

Yes. I just picked up a new thermostat and plan on draining everything and getting new stat in. What next?

 

A bad cap could cause a couple things. Not holding pressure will cause coolant to spit into the reservoir prematurely excessively. Not holding pressure reduces the boiling point of the coolant.

 

I have a new cap

 

Diagnosing an issue, I like to do the easy stuff first ruling out possible causes.

If you have an ir thermometer, warm up the engine, check the radiator hoses to see how well your radiator is pulling heat out of the coolant. You could also check if the thermostat is opening and closing by checking around the thermostat housing. Once you figure out where to check, you’ll see the temperature reach a certain point circulating in the block, the thermostat will open then the temperature after the thermostat will go up until it goes back down and closes.

If the radiator isn’t working efficiently it might be externally dirty, dirt and bugs in the fins. They make cleaner wands you attach to a garden hose, or you could make your own, or you could remove the radiator and blast it clean with water.

If you have a pressure tester you could test the cooling system for leaks, see if it holds pressure. If it doesn’t hold pressure, a possibility is a head gasket. Then you could also test your new cap with it. Then you could pull the plugs to see if you now have coolant on top of any pistons.

Next doing the test with the block tester to check if exhaust gasses are bubbling out of radiator is fairly unobtrusive.

Give the fan a spin. It should feel somewhat stiff, not free spinning like an alternator pulley. If it feels too free wheeling it could be a worn fan clutch.

You can’t always see milky oil by looking at the dip stick. Drain the oil, see what it looks like.

Before you change the water pump, take the belt off, spin the pulley. It should feel smooth, not notchy. Pull the pulley up down side side in out. It should not be wobbly. The weep hole on the bottom shouldn’t be leaking.

I’m hoping it’s something simple.

 

Thank you. I changed the water pump and fan clutch at the same time. All the pulleys looked good. I also did block test that failed ( I contaminated first test with antifreeze). That was right after it had overheated and was still bubbling due to air pocket. Right now, it passed 2 tests and was easy to bleed out a few remaining bubbles after doing a fill then an individual flush of block, radiator, and heater core. Before this flush and new thermostat plus cap it was nothing but constant bubbles. I would really like to know how to check if radiator is clogged or not working.

 

Something else to look at is inside through the cap hole. If you can see the core, you might see a bunch of deposits on it. Which is why I only use either premixed or mix with distilled water on my vehicles. There’s that cleaner stuff you pour in and drive around. I tried it years ago, it removed maybe 30-50% after leaving it in for a week.

I suppose another thing to try is to take both hoses off the radiator, stick in a garden hose it the upper hole, see if it flows out the bottom hole freely or just trickles.

When you flushed, did lots of rust or chunks come out?

If it’s all buttoned up, I’d say run it, keep an eye on the temp gauge, recheck the reservoir level in a day or two.

 

warm the engine up and, carefully, run your hand all over the radiator… it should be hot, all over, no cold spots.

 

I did use a garden hose on radiator. No chunks and is flowing both ways

 

you can still have a clogged ‘sector’ and coolant will seem to circulate normally, but the radiator’s effectiveness may be significantly reduced.


I blew a head gasket on a ‘99, dumped in a bunch of Barrs leak sealer to get it home, replaced the head gasket, thermostat, water pump, repeatedly flushed it all out (I thought)…


Weeks later while tooling down the interstate listening to the radio - BOOM, blew the neck right off the radiator, put a dent in the hood and I nearly crashed in the total visibility blackout…


when I took the sawzall to the old radiator it might have had one or two square inches that weren’t completely jammed with gunk.

 

Man, what a day. I ended up taking a run to the Texas Roadhouse about 20 miles round trip. At the R House I was able to put my hand on radiator and it was a little warmer at the edges, but not very much. I did notice hose clamp at thermostat needed to be adjusted. Drove home with no problems. Got home ate my steak and when readjusting clamp, I lost some fluid. No biggie but the hose at thermostat on right was cold compared to the somewhat hot hose on the left. Then when I went to refill everything started spitting out of the radiator opening and would not let my get any fluid in. I pulled the hoses and hit the block with a flush. Then I was able to do a proper fill. Hose on right at the thermostat not really warm compared to hot left side.

 

Sounds like you’re good. Getting that final burble of air out. You could top off the reservoir to the cold after sitting overnight. Or to the hot line of course when it’s warmed up.

 

Radiators can seem to flow ok with a garden hose but be seriously down from the original gallons per minute design.
If you have a radiator shop around they can check/clean it for you. Probably with 320K they will tell you "it just fell apart when we hit it with the pressure" however.

These infrared thermometers are really inexpensive anymore and a useful troubleshooting tool. When measuring the radiator you should see a steady temperature drop from the hot side to the cold side and it should be quite even top to bottom also.

Something to note: Some materials will read an incorrect temperature. For example you might get widely different readings from an aluminum water outlet and the black hose attached to it even though they are approximately the same temperature.
The black hose will be a more accurate temperature.