Few questions about head gasket failure / overheating issues

[tournique-cheese]

Hi there
Just picked up a 3rd gen with 220,000 km on the clock.

Previous owner was selling because of failing headgasket, when I went to drive it home (4 hour drive) anticipating constant overheating I was pleasantly suprised to drive it 150km before having my first overheat going up a hill.

It was the circumstances of the overheat that got me thinking it might not be a head gasket:

1. overheat happened IMMEDIATELY, aka it was at normal operating temperature on the gauge, then IMMEDIATELY ramping to the redline (I stopped the vehicle immediately as well).

2. Radiator was loose in rad. support, the bottom bolt was missing and the entire radiator angled backwards, causing or being symptomatic of PINCHED coolant hoses on both top & bottom of motor.

I used a ziptie to secure the radiator into the support, gave the vehicle 45 minutes to cool down and then drove the remaining distance home (including some gnarly big hills) without overheating...

Oil looked clean and not contaminated, oil cap looked good, coolant had some evidence of having rad fix added (copper colored particulate).

Going to work on a compression test and full run down but having gotten the flu I figured I'd ask the gurus here if that sounds like head gasket failure, or maybe I got lucky and bought a vehicle with a misdiagnosed HG failure.

 

[ThorInc]

White smoke coming out of the tail pipe on a cold start?

 

[tournique-cheese]

None whatsoever on startup in the morning, but I definitely saw some the first time I started it up. It didn't stick around or plume or anything, if I hadn't been prewarned "head gasket" I would have thought it looked like regular exhaust for where I live.

 

[gonzo97]

I recently purchased a 96 and had a mechanic friend of mine take a look at it, he actually smelled the coolant and could smell a tad bit of a gasoline smell, he mentioned, if i were you I would do the head gaskets before the completely go out on you. He was right.

So what I am suggesting is maybe try and smell the radiator and see if you can smell any gasoline type smells.

Hope this helps.

 

[ThorInc]

here are a couple of threads to peruse for more info:

http://www.toyota-4runner.org/3rd-gen-t4rs/119105-head-gasket-symptoms-starting-show.html

http://www.toyota-4runner.org/3rd-gen-t4rs/[email protected]

A search list on this forum, ignore the first couple of links:

http://www.toyota-4runner.org/gsear...sues.html#post2514222&ref=&ss=7061j3423677j20

 

[gamefreakgc]

I've also purchased a 4Runner with "head gasket" issues. I was able to tell right away it was not a head gasket, it did lose coolant but not into the engine.

A coolant pressure test kit is very helpful here. It's better if you can do it warm (please don't burn yourself with hot coolant though) but cold will do as well. A loss of pressure or a blockage will cause overheating as well.

 

[Black798]

How were you able to tell it wasn't a head gasket? I have a similar issue where I slowly lose fluid from the overflow tank. I don't have any coolant in the oil or vice versa. I've only seen white smoke once and it was after I washed the undercarriage pretty heavily. I also checked all the cylinders and none of them are washed. There's also no visible external leaks.

 

[gamefreakgc]

How were you able to tell it wasn't a head gasket? I have a similar issue where I slowly lose fluid from the overflow tank. I don't have any coolant in the oil or vice versa. I've only seen white smoke once and it was after I washed the undercarriage pretty heavily. I also checked all the cylinders and none of them are washed. There's also no visible external leaks.

A coolant pressure test kit. It applies PSI to the cap and forces fluid out. For my application, it was leaking from the water pump under the timing belt cover which is what I suspected. It only did it when hot though but I could see the messy coolant at the bottom of the engine all crusted and slimy looking.

Just had another 4Runner I parted out that was losing coolant (guy said it didn't leak at all, but the reservoir was empty so....). The radiator had a crack and was leaking but was pretty obvious.

 

[JBurt]

You can also send some engine oil to blackstone labs for an analysis. They can tell you a lot.

Blackstone Labs

 

[NegroTundra]

Sounds like you lucked out cheese. I'm a bit nervous as my 99 with 203k on the clock has outta nowhere started shaking pretty good on cold start up for 5-10 seconds before all smooths out. No white smoke, no washed plugs, but still, im not comfortable with it. Seems I'm very slowly losing coolant. Have done a lot of little things (cleaned IAC, new MAF, new O2 sensors, etc) in past two weeks using the shotgun approach, but nothing yet. Guess I'll keep driving it till she pops

 

[mckennar]

...maybe I got lucky and bought a vehicle with a misdiagnosed HG failure.

Yeah I'd also replace the radiator cap as some preventative maintenance.

And perhaps burp the cooling system.

Also, there are 2x ECT sensors (ok one sensor for the ECU and one sender for the gauge). Pull ECT from your ECU via an OBD scan tool and see if it jives with what you're seeing on the dash next time you have this issue.

Good luck!

 

[ThorInc]

You can also send some engine oil to blackstone labs for an analysis. They can tell you a lot.

Blackstone Labs

^^^ solid advice!