Subzali’s 1FZ-FE head gasket repair - turbeaucruiser

[Corbet]

4/6 look great. I’d assume with a new HG the other two are probably back to normal. Unless you see some damage upon disassembly I don’t see a reason yet for more than a HG replacement. Prior to the failure it was running perfect right? Does not sound like you pushed it after. Shut it down towed it home etc…

I feel like old steel block engines are more durable than people give them credit. I had a water pump fail on a SBC in my youth. I didn’t trust the gauge and continued to run it at redline for some time. When I finally had to stop it stumbled and stalled, temp gauge was well past the 260 high temp mark. Being I was in Wisconsin and at a stop sign there was a bar on the corner. I filled the radiator with a dozen pitchers of water and drove her home. Had a water pump slapped in and it ran like nothing happened.

 

[simps80]

you have to take into consideration altitude for compression numbers
for example 128 at sea level is ~110 at 5000 feet
so like your 125 numbers at an even 5000 feet of elevation above sea level are more like ~142 ( 125 x 1.138 )

here’s a snippet of a correction chart:

 

[DaveInDenver]

@subzali, what you're seeing in completely expected with a tired and now blown HG.

On the 1985 I did a few compression checks. My elevation is roughly 4600'.

Before:



After repair. FSM wants 171 psi, 142 min and 14 psi delta. I dorked a lot of things up, too. You'll be fine.

 

[subzali]

Thanks guys for the reminder about altitude correction. I will see what I can see as I tear into it.

Though the white turbocruiser had 150-160 when I did the test a few years ago:

A Tale of Two 80s

And then I did a compression test. All plugs out, accelerator to the floor, about 5 cranks each. 150-160 psi, so feeling pretty good about that unless someone says something. Cylinders 2, 3, and 4 has a little streaking on the exhaust valves, so don't know if that corresponds to the compression...

risingsun4x4club.org

 

[wesintl]

You would really have to do a leak down if you want to see if it's rings or valves, etc in deciding to do a full rebuild or just head refresh.

 

[Corbet]

Like Wes just mentioned a leak down is worth doing before you tear the head off. Looking at your older post it looks like you used the same gauge to do that compression test so that eliminates the variable accuracy difference between two gauges. You clearly had more compression with the other engine assuming you performed both tests under the same conditions.

I didn't do any testing before my rebuild. It was clear my engine was tired even though it didn't knock, smoke or burn excessive oil. To that day I would have driven it anywhere on the continent just more slowly than now with boost. If for some reason you need a bottom end to build that block is still sitting in my garage on a stand.

 

[DaveInDenver]

Won't a leak down at this point only confirm a failed head gasket? It would tell you maybe better where it's leaking, e.g. if you push coolant out or it escapes into the exhaust, intake or an adjacent cylinder. I dunno. I don't see how it's going to give you enough new information to say you definitely do or do not need a lower end rebuild. Head's coming off either way so you will get a good look at the casting for cracks and valve seats, which a leak down could diagnose, too. Probably worth doing just to know but I don't think it's going to give a clear warm and fuzzy on all the rings. With the head off you can get eyeballs on the cylinder walls, too.

 

[subzali]

Won't a leak down at this point only confirm a failed head gasket? It would tell you maybe better where it's leaking, e.g. if you push coolant out or it escapes into the exhaust, intake or an adjacent cylinder. I dunno. I don't see how it's going to give you enough new information to say you definitely do or do not need a lower end rebuild. Head's coming off either way so you will get a good look at the casting for cracks and valve seats, which a leak down could diagnose, too. Probably worth doing just to know but I don't think it's going to give a clear warm and fuzzy on all the rings. With the head off you can get eyeballs on the cylinder walls, too.

I am planning on doing a leakdown just to see what happens. If the gasket is blown on only one cylinder then doing a leakdown on the other cylinders can give me a general idea of the health of the engine and where there might be trouble with rings or valves or whatever.

 

[simps80]

if you need a leak down tester i have a pretty decent one
my experience with rented ones was never consistent so I eventually bought one

 

[Rzeppa]

FSM has 128 psi minimum cylinder pressure and 14 psi max delta between cylinders. Looks like I’m right at those limits. Rebuild?

As noted above, elevation above sea level reduces compression. I have never measured more than 125 PSI at my 7,000 feet even on a freshly built motor.

 

[wesintl]

Won't a leak down at this point only confirm a failed head gasket? It would tell you maybe better where it's leaking, e.g. if you push coolant out or it escapes into the exhaust, intake or an adjacent cylinder. I dunno. I don't see how it's going to give you enough new information to say you definitely do or do not need a lower end rebuild. Head's coming off either way so you will get a good look at the casting for cracks and valve seats, which a leak down could diagnose, too. Probably worth doing just to know but I don't think it's going to give a clear warm and fuzzy on all the rings. With the head off you can get eyeballs on the cylinder walls, too.

Yes for the 1 cyl or if it's blown to another cyl. The rest of the 4 cyls are low it can be an insight into is it the rings or the valves to help decide to rebuild. It's way better than a compression tester.

 

[subzali]

Leakdown test 1-6

Leakage mostly through pcv and dipstick. No coolant system, intake or exhaust leakage though from what I could tell.

Over 25% loss seems bad.

When testing #2, plugged #3 spark plug hole and seemed to be stopping some leaking. Which seems weird.

#1-68% loss

#2 - 46% loss

#3-47% loss

#4-35% loss

#5-42% loss

#6-30% loss

 

[subzali]

I guess there is nothing else to do but pull the head and get after it. A full engine rebuild is not in the cards right now so will have to see what, if any, negative effects there are from low compression/high leakdown results after I get it back together. It ran fine before this. On my 22R-E it burned more oil after the head gasket, so maybe that will happen here too. So be it, for a while, until timing is better for an engine rebuild.

 

[Corbet]

That’s the reality. Do a leak down post HG for comparison.

 

[subzali]

Pulled off the heat shield. As I already knew, the manifold is cracked again at the repair weld location. Shoot.

 

[Inukshuk]

I think I have at least two sets of exhaust manifolds. One for sure. You can have it.

 

[Corbet]

I think I have at least two sets of exhaust manifolds. One for sure. You can have it.

no you don’t.

 

[Inukshuk]

On my 22R-E it burned more oil after the head gasket, so maybe that will happen here too. So be it, for a while, until timing is better for an engine rebuild.

80 oil consumption is usually the valve guide seal. My 93 still burns zero oil after 150,000 miles following rebuild. New seals apparently better than original.
LongCruiser had a head available too

 

[Inukshuk]

no you don’t.

Do I need a better security system?

 

[subzali]

Do I need a better security system?

I also have stock manifolds, but this is not a stock manifold that is cracked...