As title says my 1987 4Runner blew a head gasket at 20k on rebuild.
Bought a long block a year ago from a local rebuilder that I've heard good about. I installed longblock myself.

Here's some pictures of the head gasket. Was hoping maybe somebody could help me figure out maybe why it failed.. I know nothing about head gaskets.

To me it looks pretty clear it failed between water jackets on 2 different cylinders.

Is it cheap head gasket? Improper installation? Or do I need to just slow down a bit lol? Yes I torqued to spec before installation and after after 1000 miles as per the engine builder told me to.

Truck never overheated. Ran flawless. Just started blowing lots of white smoke so I parked it until I could tackle it (knowing it was most likely HG.)

Thanks for any input much appreciated. I want it to be done right this time so I hopefully don't have to do this again in another 20k..

 

Do you mean short block ??

Long blocks come with the head .

Unless you bought it all in pieces in which case it is just parts

As for the failure sometimes you never can tell it could be a few things.

Slight flaws in the head gasket

Block or head not completely straight

Only a few thousands might cause a issue.

Some thing caused the head bolts to give a false reading when torqued

Over the years I had a few that it just happened never could figure it out I figure Mr Murphy and his daughters may have been the cause

 

Looks like a good quality metal HG.

Are those scuff marks in the bore from overheating?

Was the original engine replaced for a blown gasket also?

 

No I meant longblock. I bought it complete block and head ready to go valves, rocker assembly everything already installed.

And yes I have a factory HG ready to go in.

Ill just try to do everything by the fsm and hope all goes well.
Thanks for the input wyoming9

 

original engine through a rod through the block at 145k factory engine

It the. Sat for 15 years in my dads shop and he gave it to me. So I put the longblock in.

I noticed those scuff marks as well. It never once overheated. The second it started blowing smoke was right when I pulled into my driveway. Pulled it in the shop and parked for a couple days before I could tear into her. I have an aftermarket temp gauge. Never broke 195 zuk

 

Here's some pics of the bottom side.

 

The whole exhaust side of the HG is smoked.. That whole side you can see every indentation from head and block. Is it possible that side was over torqued? Just doesn't look right to me

 

I would chaulk it up to a crappy gasket. That looks like excessive deformation and garbage lamination. 20k is not that much running for such a crappy looking gasket. If your just doing the head gasket go with an OEM. My 2 cents.

 

^^^^
He is dead on. If it's a near stock motor OEM Toyota gaskets tend to live for a long time. I would stay away from the hard core aftermarket gaskets unless you are having the block and heads both surfaced.

 

i was leaning towards the same thing... I could tell the difference in quality between this gasket and my Toyota OEM HG. Got her all back together and she's running great.