1998 4-Runner Blown Head Gasket...Need Advice

I'm working on a 1998 Toyota 4-Runner with a 3.4L V6 and 5-speed manual transmission. This vehicle has 175,000 miles on it and has been very well taken care of throughout its life. It still looks brand new. About 2 weeks ago my wife was driving it home from work when it began running a bit rough and seemed down on power. At this point the 'check engine' light had not come on and all gauges including the coolant temperature looked just fine. When she arrived at home I was waiting and could definitely tell that something was not right. I took it around the block and she was correct with her assessment that the vehicle had a problem. During my short drive the 'check engine' light finally came on but all gauges still looked good. I did not have a code reader for this older vehicle but it seemed to me that the problem was catalytic converter related. The exhaust system was beginning to rust and needed to be replaced anyway so I changed out everything with new, quality parts from the exhaust manifold back to include the catalytic converter and both oxygen sensors. After replacing the entire exhaust system I started the vehicle only to find that the problem was not fixed. As the vehicle idled and began to warm up more and more steam began to come out the tail pipe indicating to me that at least one cylinder was ingesting coolant. The engine only ran for about 5 minutes before I shut it off.

I want to stress that this vehicle has never overheated at any time in its life. We really like it and would like to extend its life but we know this will be an expensive fix. I needed to get it in any way for a timing belt change and to fix some oil leaks on both valve covers but I'm wondering what I'm really into here. I know that it's hard to tell until it gets ripped apart but to me this seems like a blown head gasket at best and something cracked at worst. Any advice is appreciated.

 

Check your oil cap, is it milky? Or even the radiator overflow box, any oil in it? That will be your biggest clue to head gasket.

 

Did you have to add any antifreeze lately? Is the radiator full along with the overflow?

 

Good chance it’s the head gasket. Disclaimer I’m usually excessive. Pull the motor break it down to the short block, clean it up, perform timing belt replacement and replace all gaskets plus the radiator. I had a similar issue on a 5.0 mustang I bought several years back. Fought with the lower intake gasket leaking. After I fixed that one of the head gaskets blew...pulled the motor and the cylinders were so scored and pitted I put a different engine in from a pick n pull. I still broke that motor down and did a complete rebuild. Like I mentioned excessive. Good luck in your endeavors.

 

I bought my 96 with 180k on it. Same issue. Oil was never milky and it smoked. There was just a pin hole leak in it. Two days of evening work and a rebuild kit from Rock Auto and I was good to go. Unless you wanna sell it?

 

I'm in the same boat. what I did is found a donor with 130k. Going to do a mild rebuild on top end gaskets and put her in. then I am going to rebuild the old motor from bottom up for a backup.