Toyota Celica Supra Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter · #1 ·
I run a 5mge in an 87 4runner. I just got this head rebuilt a few thousand K ago and recently noticed antifreeze pooling on top of the motor. The crack is about an inch long: between the 4th passenger side head bolt and the hex-head plug in the center of the head (I think it's a plug for a coolant passage..??). But I can't tell how deep it is. From what i've read, cracks are pretty common in these motors and people run them anyways. But, my plan was to drive to Mexico in a couple weeks (where 5mge's are rare) sooo... i'm wondering what my options are. The guy who rebuilt my head suggested a cyramic sealant which may seal the crack but, if the crack is just gonna spread and eventually cause the motor to blow, i'd rather that happen in Canada than some dark Mexican side-road.

So far I'm just leaking a little coolant. My oil is clean. Compression is 140 across the board. No overheating.

Does anyone have experience with these cyramic sealants? Are they just a band-aid or would they prevent the head from cracking further?

Also, can i pull just one head bolt? I'd like to see how far the crack goes but without compromising the new headgasket. I'd also like to pull the plug in the head but i'm not sure what it's purpose is...

A buddy of mine suggested JB weld

Some other opinions would be great. Thanks!
 

·
Registered
Joined
·
622 Posts
I have a whole 85 top end, minus harness and ecu for sale. not that you need all of it but just fyi. pm me if interested in anything 5m. also have a new full 5m gasket set.
 

·
Registered
Joined
·
3,226 Posts
i'd rather that happen in Canada than some dark Mexican side-road.
Mexico is not that bad, well depends where are you going, long highways !!! same as here...

anyway u should blame the guy who rebuilt the head, they supposed to tested for any cracks, if do they should let you know n give you an option to fix it, that happened to my head, they found a crack and they fixed, doing that, new seals, valve job, cleaning n supplies costs around $400 and up.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #5 ·
Don't get me wrong, i love mexico but I won't have a working cel phone on the way down and don't have as many resources (I've never seen a cressy/supra in Mex).

Are you saying the machine shop fixed the crack in your head??

The guy at the machine shop says he'll rebuild another head, if i bring him one, but i'm wondering if i can somehow get away with the cracked one i have already had rebuilt and installed. Does anyone have experience with these cyramic products?
 

·
Registered
Joined
·
3,226 Posts
even if u have a good working number, can u speak spanish??? if yes Orale.

n yes they were able to fixed the crack n they guarantee the job. well depends if u want a quick fix or ...u can find another one n be done with that issue.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #7 ·
So how exactly did they fix the head? Weld it? Presumably my crack travels down the coolant passage and down a head-bolt hole so i'm not sure welding is possible. I'm looking for the best kind of ghetto fix without taking the head off the motor.

On the other hand, it's been driving fine for several thousand K already so maybe if the temp stays normal it won't get any worse.

Is there anyone out there who drives with a cracked head and has done so without problems for a while??

Also, if anyone has used that cyramic stop-leak crap with success please let me know what brand you used and any other hints. Thanks for the replies!!
 

·
Registered
Joined
·
607 Posts
Presumably my crack travels down the coolant passage and down a head-bolt hole so i'm not sure welding is possible. I'm looking for the best kind of ghetto fix without taking the head off the motor.

Your head is cracked probably just like mine did this past summer. I think you will find that it is not leaking from a coolant passage and up the head-bolt like you are presuming. That is what I thought at first happened to my head until I pulled the head and the head gasket was fine. Nor was there any coolant in the head bolt hole. I was finally able to see the crack using a magnifying lens and after the head had been sitting out in the 90 degree sun all day. Crack expanded and I could see it. see post#22 of my thread:
http://forums.celicasupra.com/showthread.php?t=50043

there is coolant just below the spark plug valley floor, so you will have to replace the head. no easy way around it by trying to add a sealer.

sorry,
rick
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #9 ·
Yeah I just got through reading your thread Rick. I can actually see the crack and it's right where yours was cracked. I'm super choked as i just had this head fully rebuilt last summer:32:. I called the machine shop yesterday though and they'll rebuild another one free of charge if i bring them one. Meantime though, i'll just grab a used motor from a wrecker down the road, toss it in and go to Mexico... wayyyy easier, and possibly cheaper, than pulling off & reinstalling a head. Thanks for all the replies.
 

·
Registered
Joined
·
2,164 Posts
way easier to pull the head dude

just undo the timing belt
undo the exhaust mani
undo intake mani
take off head bolts
and your done!!!!
 

·
Registered
Joined
·
3,226 Posts
So how exactly did they fix the head? Weld it? Presumably my crack travels down the coolant passage and down a head-bolt hole so i'm not sure welding is possible. I'm looking for the best kind of ghetto fix without taking the head off the motor.

On the other hand, it's been driving fine for several thousand K already so maybe if the temp stays normal it won't get any worse.

Is there anyone out there who drives with a cracked head and has done so without problems for a while??

Also, if anyone has used that cyramic stop-leak crap with success please let me know what brand you used and any other hints. Thanks for the replies!!

dude take moonpies's advice, take off the head n go to the machine shop, n let them test it, they have to test it for free!!! cause they rebuilt it right? and ask them if can be fix, mine had a crack between the valve seats n the spark plug hole, maybe they can be able to weld it.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #12 ·
Well, I can actually see the crack and it travels from the #4 head bolt to the water plug. Because it's in the head bolt passage, i'm sure it can't be welded. The guy at the shop says he'll build me a new head but the internals will have to come from my cracked head.

if i pull the head, i have no wheels... and the head shop is a ferry-boat ride away (I live in the gulf islands). Then i'll have to find a replacement head for the machine shop to build and there aren't many around this area... either way it'll probably be around $100 for the head, plus ferry fare and gas. Then IF the new head is good, i gotta borrow wheels again to go pick it up, spend another couple hundred on gaskets, install the cams/towers/rockers/lifters/sprockets/timing covers again, time the motor (which is never as quick as it should be). I'm not lazy, i just think swapping in a complete motor is quicker and possibly even cheaper. A straight swap should take 2-3 days total... and i'm done and driving an already-timed/torqued/gasketed motor

The motor is $550 at a wrecker (i have to pull it, but he'll drop the price). It's an '86 in a running cressy (written off for body damage) so i can test compression, warm it up, drive it, check for oil burning etc..

If the motor seems crappy i'll probably just buy the head and do as you guys suggest. Again, thanks for the replies! keep the arguments coming though, if anyone thinks i'm making a bad call, I can be persuaded otherwise!
 

·
Registered
Joined
·
1,198 Posts
Tripod,

That is an awful steep price for a motor that you have to pull. A Pic-a-Part motor should be had for less that $200. Maybe you should just pick-up a head along the way, or better still, just take one with you. With all of the forum members scattered across the country, someone ought to be able to get you a head (on the road somewhere).

If you have no plans to fix it right away, I would run the radiator cap in the half-way position (not tight, not loose). This way it does not pressurize the cooling system and will not spray fluid. I have done this plenty at different times in the past, and it works... The question is, how will it affect the cabin heat in the car?

If you have a head with you, you can change it on the road or in Mexico. Maybe you need to find a member along the way that is willing to help you install the head, and get you on the way...

P.S. Maybe you should list your intended route and travel days...

Best Regards,

Carlos
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #14 ·
Thanks Carlos. If i do get stuck along the way I'll throw out an emergency post for sure. I'm going to the wrecker on Saturday to check out the engine and negociate. If the motor tests well i'll try to get it for around $350. I agree that i'll be paying top dollar but that's how wreckers are up here. Either way, if the engine seems crappy, i'll negociate for just the head and take it to get rebuilt.
 

·
Registered
Joined
·
3,226 Posts
i do have a spare head, which had the same crack, between the seat n the spark plug hole, head alone, no valves, springs, seats. do you want it? pm for details.
 

·
Registered
Joined
·
27 Posts
I bought an '86 Cressida last year for parts. The car was hammered, but the engine ran well, and I figured I'd go through it to have for a spare. Once it was all apart, I found two of those tiny cracks between the spark plug hole and a nearby valve seat. Over the next few months I located and purchased two more used heads. Both have similar cracks. There's no sign in any of them of any coolant leakage into the combustion chamber. I'm not convinced that they are anything to worry about, so I'm going to go ahead and build the engine up with the best of the three and we'll see.
The crack in Tripod's head is another matter. It's on the outside and leaking coolant. At best it's a major PITA. At worst it will lead to a more serious failure mode down the road someday.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #17 ·
Thanks zuprax but i'm in British Columbia and shipping a head must cost a fortune. I'll find something a little more local.

The crack isn't pissing fluid, just slowly, slightly leaking about a half litre every 2 weeks. From the other threads i've read this problem doesn't affect performance at first but eventually contaminates the oil via the headgasket and blows the motor.

After reading up on this problem, it's seems to me that these motors are hella crack-prone. Makes me kinda worry about buying and building another head... in case it has a crack that the pressure test doesn't show... again:32:
 

·
Registered
Joined
·
1,198 Posts
Tripod,

I never really considered this head "crack prone," and I have taken plenty of them off and reinstalled them... I don't know if head bolt torque or torquing sequence affect this at all, though...

Regards,

Carlos
 

·
Registered
Joined
·
655 Posts
re:

Bring it to a shop that specializes in repairing this type of damage. That is what I did with my 6M-GE and the proper way to fix it is to drill out the crack first (to stop it from spreading) then weld it. Shop has to know what they are doing to make sure head does not warp from welding heat etc.... .

Sonny
 

·
Registered
Joined
·
3,226 Posts
Bring it to a shop that specializes in repairing this type of damage. That is what I did with my 6M-GE and the proper way to fix it is to drill out the crack first (to stop it from spreading) then weld it. Shop has to know what they are doing to make sure head does not warp from welding heat etc.... .

Sonny

+1 :thumbsup:
 
1 - 20 of 20 Posts
Top