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How to check for cracked head?


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Hey all,

 

My 91 2.2 legacy was burning coolant. I replaced the head gaskets and had the heads machined. Put them back on, and it seemed to be fixed, but a couple weeks later I seem to be burning coolant still. And pretty quickly at that... I am going back in there and I was curious if there was a good way to check for cracks, other than having a shop pressure test it. I only ask because the nearest shop is 50 miles away and it'd take a while for them to do it. Other than a visual inspection, what should I try? I'm kinda afraid of maybe a creak between an intake/exhaust port and a cooling passage. The combustion chambers all looked real good.

 

I honestly think that the problem was in me not torquing something correctly, or whatnot, but I want to be thorough this time through.

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On that note, for tightening head bolts-

 

"Tighten the cylinder head bolts to the following specifications:

 

*Tighten all bolts in sequence to 22 ft. lbs. (29 Nm).

*Tighten all bolts in sequence to 51 ft. lbs. (69 Nm).

*Loosen all bolts by 180°, then loosen an additional 180°.

*Tighten bolts 1 and 2 to 25 ft. lbs. (24 Nm) for non-turbo engines and 27 ft. lbs. (37 Nm) for turbo engines.

*Tighten bolts 3, 4, 5 and 6 to 11 ft. lbs. (15 Nm) for non-turbo engines and 14 ft. lbs. (20 Nm) for turbo engines.

*Tighten all bolts in sequence 80–90°.

*Tighten all bolts in sequence an additional 80–90°."

 

When I do the final 80–90° turn, about how many ft/lbs will that be? Last time I don't think I went that far because I felt like I was overtightening them. These instructions also said not to exceed 180 in total. I know on other cars I've seen instructions that say something like, "do not exceed 60lbs" or whatnot. Anyway, I was just curious.

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i forget - do EJ's have coolant ports in the intake manifolds like EA/ER series engines? if so, make sure you're not loosing coolant there.

 

also - are you sure it's loosing it internally? coolant system operating properly (when full!)?

 

you didnt' have the heads pressure tested before, which means you probably didn't have the heads machined either.

i'd entertain the idea of doing the job right this time and having the heads machined and tested. if the heads are good then you'll have to wonder if the engine is good.

 

how bad did this thing overheat? did you buy it with blown gaskets?

 

be sure to use Subaru gaskets this time. what did you use the first time? yours is older so i'm not that concerned but if you had a newer EJ engine i'd be questioning anything but a Subaru gasket.

 

also...might be simpler to just find a good used motor, they're a dime a dozen. i bought one for $150 two years ago in great shape, 100,000 miles, 6 month warranty from a yard, and it's in great condition and runs well. put lots of miles on it since then. i'd rather do that than mess with this motor any more if you can find reasonable deals around you. where you're located i'd think engines are everywhere like out here.

Edited by grossgary
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No, the intake has no coolant passages.

 

As the second sentence of my original post said, I DID have the heads machined the first time. It wasn't until I got them back that I found out that they didn't pressure test them. It was my first time of working with this new shop. So, like I was saying, I didn't want to ship the heads all the way back there just for the pressure test.

 

This time, as well as last time, Subaru gaskets were used.

 

Anyway, I never got an answer to my questions which was if there was a decent way to inspect the heads for a crack, other than a visual inspection... I hope this post clarifies any questions that can help me, but I don't need the advice of "having my heads machined" or, "use subaru gaskets", these things I know. I've done a bunch of head gaskets in the past, but this time something didn't work right, so I am going back in and just wanted to double check that the heads were good. As of right now, they look find, so I am just going to reinstall them.

 

And as for my second question, I was just curious about the final torque to not exceed since that is the way I've seen it done on Chevys, Mitsubishis, and other cars...

Edited by gijoe985
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No, the intake has no coolant passages.

 

As the second sentence of my original post said, I DID have the heads machined the first time. It wasn't until I got them back that I found out that they didn't pressure test them. It was my first time of working with this new shop. So, like I was saying, I didn't want to ship the heads all the way back there just for the pressure test.

 

This time, as well as last time, Subaru gaskets were used.

 

Anyway, I never got an answer to my questions which was if there was a decent way to inspect the heads for a crack, other than a visual inspection... I hope this post clarifies any questions that can help me, but I don't need the advice of "having my heads machined" or, "use subaru gaskets", these things I know. I've done a bunch of head gaskets in the past, but this time something didn't work right, so I am going back in and just wanted to double check that the heads were good. As of right now, they look find, so I am just going to reinstall them.

 

And as for my second question, I was just curious about the final torque to not exceed since that is the way I've seen it done on Chevys, Mitsubishis, and other cars...

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relax. why complain or pop an attitude because of some questioning? particularly after something wasn't done right the first time. your ego doesn't really need to be dependent on this thread.

 

if you suspect (or want to find) a leakage in the combustion chamber a leak down test might point in the right direction (i chose ambiguous words on purpose). it's not meant for exactly what you're after but depending on what you're looking for you might find it.

 

i don't think you'll find EJ engines to have invisible cracks, so if you don't see it you're probably golden.

 

a visual inspection should easily determine if there are cracks in the heads. there should not be any cracks in an EJ engine (unlike older Subaru engines where cracks are considered nominal).

Edited by grossgary
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Does Subaru use stretch bolts on the cylinder heads? That could be a reason for a maximum torque value. (Or not, I have no idea just throwing it out there :-p )

 

They make dyes that you can use for checking for hairline cracks in aluminum. I'm not sure where you get it though.

 

I would think that improper torquing has lead to premature failure of the gaskets in this case.

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Gary, my apologies if I was short. I was a little frustrated when I got on and I didn't want to deal anything. I've been on the forums for a long time and I've seen complete morons as well as gurus. So I shouldn't be surprised, when starting a thread like this one, that someone would have questions about what was done.

 

Either way, I was partly mad because my old machine shop always pressure checked heads after machining. I guess after being pampered for a few years I didn't even think to ask the new place if they did the same. So I was just frustrated to think that I did all that work to find out that they machined my cracked heads... We'll see...

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i guess give them credit for not billing as much as they could have.

 

no - Subaru does not use TTY (torque to yield) bolts, subaru head bolts are reusable.

 

if it's a bad leak i've seen coolant lying in cylinders before. in the older EA/ER motors you can peak down the holes with some superb lighting, not sure about EJ's as i've never had to try that.

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Now that you mention the head bolts. That is something I am trying this time. I was first told that the bolts were reusable. So the first time I did reuse them. But then I was told that the bolts were NOT reusable. So the difference is that this time I will be using new bolts. And after looking at the torque specs, it looks like what you'd do on torque to yield bots. The whole, tighten, then loosen, then tighten, then turn x°... Whether it is the new bolts, or the added meticulous attention, hopefully we'll be golden.

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Now that you mention the head bolts. That is something I am trying this time. I was first told that the bolts were reusable. So the first time I did reuse them. But then I was told that the bolts were NOT reusable. S

 

I already mentioned the head bolts, not TTY, completely reusable.

 

I would take a mental note of whoever told you not to reuse them and make sure not to listen to them again for Subaru related information because they are 100% incorrect.

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I already mentioned the head bolts, not TTY, completely reusable.

 

I would take a mental note of whoever told you not to reuse them and make sure not to listen to them again for Subaru related information because they are 100% incorrect.

 

Alright. Note taken. I'll admit I'm happy that I have the new bolts, namely because I was uncertain, and this gives me more peace. And not that I necessarily doubt you, but I'd rather have them and you be right, than not have them and have you be wrong. Either way, I've got them now and I hope to see some improvements.

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I hope to see some improvements.
i'm sure it'll be fine, it's very rare to see repeat head failures, like never. most of us have never had one, so to have two in a row would be odd indeed.

 

the goob that told you not to reuse them is wrong:lol:. a source for reliable information is important, what happens with the next question? i'd save yourself the trouble and cash and not bother asking "person X" subaru specific info, he obviously is clueless and even worse he "thinks" he knows.:eek:

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So... my problems have worsened. I started it up and now the oil has mixed with the coolant (didn't before) and it is actually dripping off the back side of the head. I'm selling the car. This is ridiculous. I was so careful to get this right. Torqued the heads exactly as described above. I've never had this happen before... :mad:

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So... my problems have worsened. I started it up and now the oil has mixed with the coolant (didn't before) and it is actually dripping off the back side of the head. I'm selling the car. This is ridiculous. I was so careful to get this right. Torqued the heads exactly as described above. I've never had this happen before... :mad:

 

Well, stupid question, but, did you check the block for any cracks?

Your heads may be fine but the overheating may have torched your block.

 

Twitch

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Well, stupid question, but, did you check the block for any cracks?

Your heads may be fine but the overheating may have torched your block.

 

Twitch

 

Just a quick visual inspection. Either way... someone else's problem... soon... hopefully

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