[jwkiss0]

My wife was waiting in the school when the check engine light came on and the temperature guage spiked. She turned it off immediately. I checked it out and the radiator lost some fluid. It lost the amount in the overflow tank. I refilled the overflow. After it sat we restarted it and it ran very rough. Turned it off and towed to mechanic. He thinks heads/head gasket but he didn’t do any testing. How can I troubleshoot this? I figured I should start with a cylinder leak down test. Any other suggestions?

[jgue467]

Could pull plugs and check for coolant, I'd start with #3 (middle right side).

It is the most common starting point for leaks and cracked heads, it takes very little 'overheating' to crack a head on these, ask me how I know.

[gamefreakgc]

Odd that it failed so quickly. When it is running do you get any smoke out the exhaust? That's the easiest sign with a significant gasket leak. Sure does sound like it if you are losing coolant AND it is running poorly but it is an expensive repair if you cannot do it yourself so make sure you are absolutely sure before you spend the money.

[jwkiss0]

Originally Posted by gamefreakgc

Odd that it failed so quickly. When it is running do you get any smoke out the exhaust? That's the easiest sign with a significant gasket leak. Sure does sound like it if you are losing coolant AND it is running poorly but it is an expensive repair if you cannot do it yourself so make sure you are absolutely sure before you spend the money.

I have not run it for even a couple minutes after the episode. I don't know if it would smoke if it ran longer, but none so far. The coolant leak was due to the radiator I believe since it was all over the hood and front of the engine. Last oil change they said the radiator was discolored and would probably need replacement in the near future.

[jwkiss0]

Originally Posted by jgue467

Could pull plugs and check for coolant, I'd start with #3 (middle right side).

It is the most common starting point for leaks and cracked heads, it takes very little 'overheating' to crack a head on these, ask me how I know.

I plan to pull the plugs and check them when I get it home. They wanted way too much money at the shop to do this work. I honestly think the guy working there wanted my 4Runner. He offered me $1,500 for it.

Did you pull the heads and do the repair yourself? If so, did you do one or both heads and did you go remanufactured or new?

[jwkiss0]

Originally Posted by jgue467

Could pull plugs and check for coolant, I'd start with #3 (middle right side).

It is the most common starting point for leaks and cracked heads, it takes very little 'overheating' to crack a head on these, ask me how I know.

Your 4Runner is super clean. I thought mine looked good but I think yours looks better. That is a sharp ride.

[gamefreakgc]

Originally Posted by jwkiss0

I have not run it for even a couple minutes after the episode. I don't know if it would smoke if it ran longer, but none so far. The coolant leak was due to the radiator I believe since it was all over the hood and front of the engine. Last oil change they said the radiator was discolored and would probably need replacement in the near future.

Oh I think I missed that part. I am aware of the discoloration that happens with the original radiators, that means the plastic is being stressed and about to fail. Kind of like if you bend plastic and it starts to turn white where you've bent it. I suspect it failed at the seam between the top of the plastic and the top of the fins on the inside edge as the coolant likely sprayed out (it is under pressure) and hit the fan and splattered about. Sorry to hear it failed so quickly but I suppose your mechanic did warn you about it.

I agree that it should not be ran in that condition. Replacing the radiator is a relatively simple job and only a few bolts. The only tricky part is taking the fan off the fan hub as it likes to move around as you try and get a wrench on it. If you can get a DENSO/Toyota replacement and new upper and lower hoses (don't reuse the old ones as they molded to the shape of the old radiator) you can get it up and running again at your house. I realize you did have it towed to the mechanic though so you might be on the hook to have him replace it. At least then we can see if the head gasket did indeed blow or if it was only the radiator.

[JBurt]

Loosing coolant is one thing, and you can run it without any coolant for a few minutes. I agree that the radiator replacement isn't a bad job, and a new koyo or denso isn't too expensive.

If you suspect a bad HG, you can get a combustion gas leak detector. Autozone has it as a loaner tool. It'll tell you for sure if you've got exhaust gases in your coolant system, which means you've got a bad HG.

Timmy just did a 7 part series on replacing a bad head gasket.

Here's the autozone link

https://www.autozone.com/loan-a-tool...-gasket-tester

[jwkiss0]

Originally Posted by gamefreakgc

Oh I think I missed that part. I am aware of the discoloration that happens with the original radiators, that means the plastic is being stressed and about to fail. Kind of like if you bend plastic and it starts to turn white where you've bent it. I suspect it failed at the seam between the top of the plastic and the top of the fins on the inside edge as the coolant likely sprayed out (it is under pressure) and hit the fan and splattered about. Sorry to hear it failed so quickly but I suppose your mechanic did warn you about it.

I agree that it should not be ran in that condition. Replacing the radiator is a relatively simple job and only a few bolts. The only tricky part is taking the fan off the fan hub as it likes to move around as you try and get a wrench on it. If you can get a DENSO/Toyota replacement and new upper and lower hoses (don't reuse the old ones as they molded to the shape of the old radiator) you can get it up and running again at your house. I realize you did have it towed to the mechanic though so you might be on the hook to have him replace it. At least then we can see if the head gasket did indeed blow or if it was only the radiator.

I was actually planning to have the radiator replaced next week because it was a convenient time. Unfortunately it didn’t make it that far. Do I need to replace the radiator before I do any testing?

[jwkiss0]

Originally Posted by JBurt

Loosing coolant is one thing, and you can run it without any coolant for a few minutes. I agree that the radiator replacement isn't a bad job, and a new koyo or denso isn't too expensive.

If you suspect a bad HG, you can get a combustion gas leak detector. Autozone has it as a loaner tool. It'll tell you for sure if you've got exhaust gases in your coolant system, which means you've got a bad HG.

Timmy just did a 7 part series on replacing a bad head gasket.

Here's the autozone link

https://www.autozone.com/loan-a-tool...-gasket-tester

Thank you for the link. Do I need to replace the radiator before I can use the combustion gas leak detector? The engine did not want to run very well after the episode. Am I risking any further damage by running the engine to use this tool? Is this better or worse than a cylinder leak down tester? Do both give me the same answer? Thank you for the help.

[jwkiss0]

Originally Posted by jwkiss0

Thank you for the link. Do I need to replace the radiator before I can use the combustion gas leak detector? I am assuming the engine needs to be running to use this tool?

I am new to the site. How do I find the videos Timmy put together on replacing head gaskets? Please don’t say the search tool because I don’t seem to have much luck with it.

[thegipper]

His videos are posted on youtube and can be found here.

I would replace the radiator, refill the system then you can try the combustion gas tester. Keep in mind that the fluid will only change color if the the leak is pretty bad.

Keep an eye on the temp gauge and don't run it back into the red and you shouldn't do any further damage. . A leak down test looking for bubbles coming out in the radiator is a more reliable test for a bad head gasket in my opinion. Timmy has a video on how to use a leak down tester also.

Good luck

[gamefreakgc]

Originally Posted by jwkiss0

I was actually planning to have the radiator replaced next week because it was a convenient time. Unfortunately it didn’t make it that far. Do I need to replace the radiator before I do any testing?

Yes because if there's air getting in the cooling system through a leak in the radiator you cannot do a coolant system pressure test or a combustion gas leak test. At this point you know it's not any good so it has to be replaced either way.

That's a bummer you had planned for it but the radiator had other plans. I had that happen to me with the clutch on my old Toyota. I noticed a crack in the clutch bracket and was starting to deform. Found a shop that would repair it and while driving there the bracket broke and fell on the carpet. Kind of hard to drive a manual transmission without a clutch pedal.

[jwkiss0]

Originally Posted by thegipper

His videos are posted on youtube and can be found here.

I would replace the radiator, refill the system then you can try the combustion gas tester. Keep in mind that the fluid will only change color if the the leak is pretty bad.

Keep an eye on the temp gauge and don't run it back into the red and you shouldn't do any further damage. . A leak down test looking for bubbles coming out in the radiator is a more reliable test for a bad head gasket in my opinion. Timmy has a video on how to use a leak down tester also.

Good luck

Thank you for the link. I have watched his videos before. I used them to fix the door lock actuator. He does a great job. Do you know of a good source for the radiator?

[jwkiss0]

Originally Posted by gamefreakgc

Yes because if there's air getting in the cooling system through a leak in the radiator you cannot do a coolant system pressure test or a combustion gas leak test. At this point you know it's not any good so it has to be replaced either way.

That's a bummer you had planned for it but the radiator had other plans. I had that happen to me with the clutch on my old Toyota. I noticed a crack in the clutch bracket and was starting to deform. Found a shop that would repair it and while driving there the bracket broke and fell on the carpet. Kind of hard to drive a manual transmission without a clutch pedal.

That’s very aggravating when that happens but what can you do? I drove a manual for a long time and it is very difficult without the clutch.