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Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011781 11/04/10 04:28 AM
Joined: Aug 2008
Posts: 125
builthatch Offline OP
Wheeler
ok, well i ended up just ordering it all from advance auto as the prices were practically the same. everything is due here tomorrow. the head was checked and surfaced. it was indeed warped, i need to find out how much was milled but apparently it was not a lot. i don't know about these, but on a honda once you get past 30 thou from milling things can get hairy. but most of the time when surfacing they take off like 5 thou (in my experiences).

it looks like i should have this thing back together by the weekend, which would be awesome because i REALLY miss it. thanks all for your help, we'll see how the assembly goes.


'87 swb 5spd 2.6L Montero, >150k miles. Pretty much bone stock as purchased from user ToddStidham1, 'cept some Hella 500's, 700's and Hella ECE headlight conversions.

6'4", 315lbs
Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011782 11/05/10 01:29 AM
Joined: Aug 2008
Posts: 125
builthatch Offline OP
Wheeler
well...

my friend picked the head up from the machine shop since i was busy. i looked at the surfacing job, which was fine, but i studied the head further and noticed that there ARE cracks between the valves; the most complete crack is cyl #2. there seems to be another forming on cyl 3. i only had my blackberry so i took the best pics i could with it. all are of #2.

[Linked Image]
[Linked Image]
[Linked Image]

so...this is the pickle i didn't want to be in. when it is all said and done, i'll be spending a pretty penny. i am feeling like i should just cut my losses and sell the truck, but i am SO partial to this thing. it has been so fun over the past 2+ years. i feel like i could probably sell it for a few hundred and cut my losses, and just buy something else with the money i'd save not fixing it. i know it will need a clutch soon, and who knows what else will go bad considering its age. i dunno...this is a toughie.

i guess it will ultimately fall on how much a new head is. there seem to be a lot of options and all are expensive, haha. it seems the cheapest deal is the clearwater hesd, which shipped will probably be closer to $450. i'm guessing, i don't know, but that seems to be the case.

Last edited by builthatch; 11/05/10 02:34 AM.

'87 swb 5spd 2.6L Montero, >150k miles. Pretty much bone stock as purchased from user ToddStidham1, 'cept some Hella 500's, 700's and Hella ECE headlight conversions.

6'4", 315lbs
Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011783 11/05/10 02:44 AM
Joined: Jan 2001
Posts: 13,649
fasteddy Offline
Web Wheeler
*****
all seasoned 2.6 heads will have a crack there. Unless it reaches the water jacket, you just ignore it. I assume the machine shop pressure tested the head, right? Those cracks close some with heat, and most are not a problem for a long time, often 100's of thousand miles.


Not responsible for advice not taken...
Re: symptoms: pick a problem! (headgasket?) [Re: fasteddy] #1011784 11/05/10 02:51 AM
Joined: Aug 2008
Posts: 125
builthatch Offline OP
Wheeler
Quote
all seasoned 2.6 heads will have a crack there. Unless it reaches the water jacket, you just ignore it. I assume the machine shop pressure tested the head, right? Those cracks close some with heat, and most are not a problem for a long time, often 100's of thousand miles.


thanks.

so that isn't the cracking that these heads do when they fail? i was under the impression for some reason that it was in that area.

it looks like it goes all the way to the valve seat, is that normal?

i will talk to the machine shop tomorrow about pressure testing it.


'87 swb 5spd 2.6L Montero, >150k miles. Pretty much bone stock as purchased from user ToddStidham1, 'cept some Hella 500's, 700's and Hella ECE headlight conversions.

6'4", 315lbs
Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011785 11/05/10 03:51 AM
Joined: Jan 2001
Posts: 13,649
fasteddy Offline
Web Wheeler
*****
Every 2.6 head I have ever pulled with over ten thousand miles on it has those cracks. If you overheat it enough, it will continue to crack there into the water jacket, and then you have to replace it or get it tig'ed up. eventually it will crack thru, just from work hardening and thermal cycles.


Not responsible for advice not taken...
Re: symptoms: pick a problem! (headgasket?) [Re: fasteddy] #1011786 11/05/10 04:19 AM
Joined: Aug 2008
Posts: 125
builthatch Offline OP
Wheeler
Quote
Every 2.6 head I have ever pulled with over ten thousand miles on it has those cracks. If you overheat it enough, it will continue to crack there into the water jacket, and then you have to replace it or get it tig'ed up. eventually it will crack thru, just from work hardening and thermal cycles.


hopefully i'll never overheat it!

BTW, can a head be pressure tested w/o removing the valve train? i was under the impression NO, so i assume he didn't pressure test it since it is all together. i'll find out tomorrow what's doin'.

thanks again mayne!


'87 swb 5spd 2.6L Montero, >150k miles. Pretty much bone stock as purchased from user ToddStidham1, 'cept some Hella 500's, 700's and Hella ECE headlight conversions.

6'4", 315lbs
Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011787 11/05/10 04:42 AM
Joined: Jan 2001
Posts: 13,649
fasteddy Offline
Web Wheeler
*****
Most of them leave the valves in place, and use a pressure plate and head gasket to check the combustion chambers. Missed a crack in the exhaust port that way once. Kept losing coolant and having a hissing sound fromd the exh mani at shutdown...


Not responsible for advice not taken...
Re: symptoms: pick a problem! (headgasket?) [Re: fasteddy] #1011788 11/05/10 08:35 AM
Joined: Dec 2006
Posts: 445
A
airbats801 Offline
Mudrunner
not much of a crack, just make sure you dont overheat and there probably wont be a problem for a very long time. I've had much bigger cracks on that on engines that ran perfect.


8 Starion SHP, 87 mitsubishi van, , 81 galant g54bt, 78 lancer g54bt, 1965 Mitsubishi Debonair Deluxe
87 swb montero offroad pkg goin g54bt with sr locker 33x12.5 dual bouncy.
Re: symptoms: pick a problem! (headgasket?) [Re: airbats801] #1011789 11/06/10 04:11 AM
Joined: Aug 2008
Posts: 125
builthatch Offline OP
Wheeler
Quote
not much of a crack, just make sure you dont overheat and there probably wont be a problem for a very long time. I've had much bigger cracks on that on engines that ran perfect.


thanks. i'm still sketched out though. my luck typically doesn't jive with the sort of positivity you guys are relaying my way ; )

i dumped the head off at my regular machine shop. he's going to pressure test it and if it is good, tank it to clean it up. at that point, i guess i'll have to pop the caps up a bit for some lube - i might be running on antiquated info but i've never had an assembled head tanked, which means i'd have to start a cam dry. i've never done that, new or old. old cams get some clean motor oil, new cams get red lube and conventional in the crankcase. anyway, that is the least of my worries at this point.

i hope this head is not trashed. i'll know monday.


'87 swb 5spd 2.6L Montero, >150k miles. Pretty much bone stock as purchased from user ToddStidham1, 'cept some Hella 500's, 700's and Hella ECE headlight conversions.

6'4", 315lbs
Re: symptoms: pick a problem! (headgasket?) [Re: builthatch] #1011790 11/06/10 08:26 AM
Joined: May 2000
Posts: 6,132
K
Kevin C Offline
Trail Leader
****
The area between the valves compresses when hot and open up when cold.

The hotter the engine, the greater the compression on the thin metal between the valves.

Another factor is how hot your exhaust gases are. Retarded timing, poor fuel mixture bring up the exhaust gas temp and dump a lot more heat into the head.

Basically, a poor running motor can shorten the life of the head.

My experience is similar, they all crack. Its all about the number of heat cycles and how extreme that determine how long it it before the crack reaches the water jacket.

Most heads have a hairline crack by 60,000 miles. The 2.6 is not the only motor that does this.


87 Turbo Intercooled Raider, roller cam, torsen rear diff, LSD front diff, lockup auto with modified converter, V6 brakes, low transfer case gears...
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