I am not the most mechanically inclined... but was inspired by other "beginners" on this forum to go for it. I have been constantly referencing the FSM, Haynes manual, and several re-build threads from yotatech with pictures.

About a week ago I heard a "pop" noise after starting up my truck. It had been sitting in a parking lot for about 10 hours and drove fine previously. I instantly saw a huge cloud of white smoke and noticed that it idled funny.

Brought it home (short 10 minute drive) and carefully watched the temperature. Drain the oil and it looked perfectly fine. Pulled the spark plugs and noticed that the #4 plug was pretty fouled and white. Decided that there was a coolant leak into the #4 piston and decided to tear it down.

Here is where I am at now. Piston #4 is all nice and shiny. The other pistons look pretty typical:





Picture of the #4 head gasket:



I honestly can't find anything wrong. The head gasket looked perfectly fine to me (other than the metal ring coming off around the edges). Don't know if that could cause a coolant leak or not.

The head looks true. I poured water into the air intake and exhaust intake to see if any water leaked out into the water / oil lines. Looked fine. I will be dropping the head off on Monday to have the professionals check for true-ness and cracks.

Can you guys think of anything else I should look for? Picture of my truck for reference:



Thanks for looking. Joshua

 

I had to replace the HG in my '95 last fall, same cylinder started leaking. Easy, cheap job. Cost me a total of about $250, including a new torque wrench

Very nice truck, man!

 

Did you ever figure out how it was leaking? Or did you just throw on a new HG and call it a day?

 

No. Never did. The HG was in pretty good condition like yours. I didnt notice any damage/cracks/marks. Just replaced it, and hasnt been using coolant or over heating since, over 11K miles now.

 

By the way I love your 4Runner... I had a picture of it saved on my desktop for awhile...

 

Whaaat? Thanks I love my runner, too.

I wish mine could be as clean as yours, but then I wouldnt want to off-road it

 

I'd say timing cover as well for the coolant leak, but that wouldn't cause a plume of smoke through the exhaust and it appears the chain guide rail looks intact. But just so you know, that isn't the original head gasket either. It looks similar to the rock brand head gasket that ENGNBLDR sells. Make sure you have that head checked by a machine shop though.

 

Thanks for the suggestion. Its definitely burning white clouds of smoke out the exhaust and my oil looks clean. So I don't think its the timing cover.

I will be dropping the head off on Monday to have it checked for cracks and true-ness. I decided to go OEM on the head gasket for this rebuild. I am hoping this makes the difference...

 

I used OEM head gasket and new OEM head bolts. Wasnt expensive. $54 for the HG, $63 for head bolts, including fast shipping.

 

Very nice runner! Makes me want to trade my truck in and get one.. But im to attached to it. Anyways back on subject i would scratch every bit of old gasket off that block.

 

I hand sanded my block and head over a year ago on my 3VZE and its still holding strong.

250gt to knock down the big stuff
600gt after the big stuff was gone
1200gt wet sand. Took my time and made sure there wasn't and groves and stuff.

Sorry I dont have anything to say on the 22re, I know nothing about it haha. Good luck! Still think your runner is awesome, nice job painting the wheels!

 

Thanks Shawn! Good to see you are still on here. Wow on the sanding... that would just intimidate me. I would be worried about uneven sanding, deep scratches, getting crap in my water lines.

I have been using brake cleaner and the edge a plastic credit card to scrape everything off.

Here is a photo.


Was starting to feel good about the block surface till you mentioned sanding

 

Hey noticed you are in Lane County... where do you live? I really wanted the functionality of a truck myself but I really need 4 doors for my kids.

 

THat ring coming off the gasket was your leak, mine did the same thing. I replaced it and it was good and I overheated mine pretty good.

 

Yes! Thank you. I was hoping to hear that. I will feel much better about the rebuild now...

 

No prob man, I was confused too when i saw it. I highly doubt you have heat cracks, good luck.

 

Different engine (3.0) had the same head gasket problem on the #6 cylinder fire ring, except the split in mine was pretty small compared to yours...maybe 1/4" in length. Not enough to completely drown the cylinder, but just enough to cause the plug to foul at idle. Drove it some 1000 miles like that until I had a chance to replace it. Been 39K miles since (knock on wood) with no issues. I also had the top radiator tank replaced due to some extremely small holes developing. My theory is that the holes wouldn't allow the coolant to stay pressurized causing the coolant to boil over the hottest cylinder possibly leading to HG failure so I had it replaced.

 

Nice looking rig wanna trade? I agree that your leak was caused by ring separating from the body of the gasket. I have seen this on most of the 100k+ mile engines I have torn down.

Also I back you up on your opinion that sanding your mating surface is NOT a good idea. I have NEVER heard of anyone using that method to remove old gasket material on such a crucial surface like your block or head but I have seen people use emery cloth wrapped around a wood block. I haven't tried it because I usually just have the head and block machined but I would put money on it that some emery cloth and 3 in 1 for lubricant would work great. Would work like a wet sand.

I have a head gasket project going on now too....maybe I'll try it first and let you know how it works out =)

 

I work in Eugene but i live in Oakridge. I would use a flat blade razor knife to scratch that gasket off. There like $1 at jerry's. You dont have to wory to much about leaving scratches in the block, it is cast. The head maybe.


BTW! Do not take your head to Caldwell's.

 

Help! I feel sick to my stomach. One of the head bolts near cylinder #4 was really stuck when I was pulling my head. I thought I would try slowly working the bolt back in to see if I could figure out why it was stuck. I heard a crack and then saw this...



I am assuming the block is no good now...