Head Gasket or???

Hi all,

Found this forum and need some guidance. Our 2007 Tacoma with 138k overheated on a drive. We pulled over, and I found the reservoir cap was off and contents were steamy. I added coolant to the reservoir and made it to our destination fine.

Then the truck started getting hot again shortly after as I ran my next errand, and I managed to pour more coolant in it, realized it was thirsty and took a whole bottle, and then it didn't overheat again. Later that day, we took it to a shop, and the guy said there was a small coolant leak, like a drop every few minutes, near a part of the engine that would take a month to order/replace. He said if we were just driving around town, then we should be fine if we just keep an eye on the coolant levels.

I also replaced the coolant cap when this happened.

Well, I noticed bubbles in the reservoir, and this was shrugged off as "air in the radiator lines."

There was occasional engine issues, like you'd give it gas and it would be slow to speed up, but these were sporadic over the next month or so.

We drove maybe another 500 miles in the truck until it wouldn't start one day. The same garage said it was a "catastrophic failure" and the head gasket blew.

There is no milky oil when you pull the dipstick. We got a second opinion/compression test, and they said it was the head gasket.

I would really love to fix this truck, but engines for this thing are not cheap.

Considering some reads on this page, is it worth trying to replace the gasket and machine the head?

Is there any way that something else could be going on other than a head gasket failure? The second shop ran the compression test and believed the gasket to be toast, but I've seen muttering about water pumps or radiator clogs causing coolant reservoir bubbles. There is a brown/reddish coloration to usual orange coolant color.

 

Have them do a block test to see if you are getting exhaust gasses in the coolant system. These all seem to leak from the coolant jackets into the cylinders. Another check is to see if you hear air passing through the heater lines inside the cab after parking for a short time and restarting engine.
The early models until 2010 I believe have a bad head gasket design. Ask me how I know

 

With no coolant in the bottom end, there’s a reasonable chance that it is fine, and head gaskets are perhaps all you need. Hopefully the heads are not warped, per several other threads here on TW there’s not a lot of material you can take off to correct that.

The only models with known head gasket problems were the 05 and early 06 models.

 

A few things you should or can do.

First, I'm not sure why your truck overheated in the first place. You never really said why. Was the coolant low? Were you pulling a trailer? You are going to need to figure that out.

Second, you have a mechanic saying you have a leak external to the motor. Head gaskets on these trucks usually leak internally so that is another issue that you will need to figure out.

Third, your coolant should be pink not brown or orange in color. Maybe I misunderstood your comment there.

Lastly, buy a block tester and check for exhaust gases in your cooling system. That's not fool proof and does not guarantee that you do not have a head gasket leak if negative. It came back negative for me but my leak was very small and did not cause any engine issues other than mysterious coolant loss. By an inspection camera with a side view capability. They can be had for around $100 on Amazon. Rent a cooling system tester from an auto parts store like Autozone and pressurize your cooling system. Once under pressure, inspect each of your cylinders for coolant leaking into them. Assuming you have a V6, start with cylinder #6 which is on the driver's side closest to the firewall. Maybe for around $130 or so you can confirm whether or not you truly have a head gasket leak. This is a very small investment compared to the cost of doing a head gasket repair regardless of whether you or a shop does it.