head gasket replacement - advice needed

[Atticus]

All:

I have a '97 FZJ80 (165,000 miles) that is currently getting the HG replaced. No overheating (of which I am aware), just a rough start up and idle that would stop as soon as the engine got warm, and I took it in immediately. Failure at #6 cylinder.

Anyway, here's the predicament: I got a call from the mechanic today who says that he straightedged the block and that there is a spot between cylinders 2 and 3 that is, according to him, about .5mm out of spec. That is, apparently Toyota allows for 2mm of deviation, but he is reading 2.5, maybe a little less. He wants to pull the block and get somebody to shave the deck. He also says that he may not give the full (2 year/24,000 mile) warranty on the repair if I don't have the block decked. I asked him what warranty he will give me on the work, and he's going to think about it and call me back tomorrow.

I am a half banana kind of guy. I can change my oil, replace belts and the fan clutch, etc., but nothing that major. I don't have the knowledge or expertise to tell him what to do, but I simply cannot afford at this point to pay the $1500 or more that this extra step will require.

I appreciate any help with this. If I have left out some important information, please let me know.

Thanks,
Jay

 

[landtank]

are you sure about the half millimeter error? That's a s*** load in terms of flatness.

 

[Atticus]

are you sure about the half millimeter error? That's a s*** load in terms of flatness.

Well, I thought that's what he said. I just tried to call him, but the shop's closed. He said that Toyota allows for a 2, but that I had almost a 2.5. I thought he meant 2 mm and 2.5 mm, but I may be wrong.

Now that I think about it, it's got to be like .2 mm and .05 mm.

 

[OGBeno]

it's got to be like .2 mm and .05 mm.

That sounds just a little bit better--not much--but better.

I'd want to see confirmation of this--i.e., go to the shop and have him show you exactly what he is "seeing."

-o-

 

[Atticus]

That sounds just a little bit better--not much--but better.

I'd want to see confirmation of this--i.e., go to the shop and have him show you exactly what he is "seeing."

-o-

I guess I'll have to do that tomorrow afternoon.

 

[Chaldaean]

I'd want to see confirmation of this

x2

Don't be intimidated about going to visit your truck. It would be the next step if I were you.

 

[Atticus]

Does anybody know what the tolerance specs for flatness on the block are? If it's .02, then we're talking about .025 here.

I really appreciate everybody's help with this. I'll let you know how my visit with the mechanic goes.

I've got to say now that I'm pretty firmly in the "hg as pm" camp now. My truck has been out of action for two weeks tomorrow. It's been a clusterf*ck.

 

[cpg]

.15 mm (.0059in) block side
.10 mm (.0039in) manifold side

 

[Atticus]

Thanks!

 

[Beowulf]

.15 mm (.0059in) block side
.10 mm (.0039in) manifold side

Jay,
Maximum warpage: 0.05 mm (0.0020 in.) There are diagrams in the FSM that detail where to measure, how to measure, as well as the tolerance. Note that the above tolerances posted by CPG in reply #8 are for the cylinder head, not the block.

If you are looking for an informed opinion on whether or not to have the blocked pulled and shaved then PM powderpig (Robbie) and get his take. He has done a lot of recent jobs and some he has sent out for block work and others he has used Mylomar (sp?) as an alternative. He will have to describe the process as I am not familiar with what he has done.

-B-

 

[cpg]

Jay,
Maximum warpage: 0.05 mm (0.0020 in.) There are diagrams in the FSM that detail where to measure, how to measure, as well as the tolerance. Note that the above tolerances posted by CPG in reply #8 are for the cylinder head, not the block.

If you are looking for an informed opinion on whether or not to have the blocked pulled and shaved then PM powderpig (Robbie) and get his take. He has done a lot of recent jobs and some he has sent out for block work and others he has used Mylomar (sp?) as an alternative. He will have to describe the process as I am not familiar with what he has done.

-B-

Sorry for the wrong info.

 

[IdahoDoug]

Robbie is an excellent source. I did not know he has pulled any FZJ blocks for block head surface work, and was going to post that I'm skeptical your block needs it as I've never heard of anyone's needing it. Heads, yes. Blocks no. But I'd love to hear from Robbie on this - do your best to contact him and it's time well spent.

DougM

 

[Atticus]

I'll PM Robbie as soon as I nail the mechanic down on the correct measurements and see the block for myself, because I am well aware of his expertise on the subject. Also, thanks again for the help. I really appreciate. The pdf was way beyond the call of duty, Beo. Thanks.

 

[powderpig]

Beo is right on as far as the block specs. I would also be a little uneasy to pull the block for only one spot that has a .0025 spec. Of course this depends on where it is at. If the fire ring area is compremised then you have a good chance that you can have a failure.
You said you are doing this as a preventive maintance? And there was a problem at #6, not at the place that is low(between 2 and 3). Is there any signs of problems at this spot(carbon build up)? If so then maybe it could lead to a problem.
I have used recently Hylomar to seal out coolant leaking around the block areas to help prevent etching of the block more. I have only done this on blocks that I feel have a chance of lasting. A area for the fire ring to seal on is important. I will attempt to start a thread soon(maybe this weekend) to show some pics and stuff and start a thread for discussion on this.
Remember also that all feeler guages are not as accurate as one would like. Has this mechanic used a Mic on his feeler guages to see real value of the thickness of the guage?
But bottom line is if you trust this mechanic, and have no reason to question his judgement. Then why are you posting this up, to find fault with his diagnosis or try to save some money. Also if he does not want to warranty the job, Is this going to be a problem. Will he still do the best job he can, or will he just slap it to gather?
If the head is goign to be milled to have it as flat as possiable(which if we remember Toyota does not recommend). having a block .0025 out of spec should not pose that much of a problem. There are many different thoughts one can suggest, with out seeing the block my self or real good pics. One can only have specualtion.
Good luck with your choice.

 

[sleeoffroad]

First check that your mechanic is talking in mm or thousands of an inch. Most likely the latter.

 

[Atticus]

Beo is right on as far as the block specs. I would also be a little uneasy to pull the block for only one spot that has a .0025 spec. Of course this depends on where it is at. If the fire ring area is compremised then you have a good chance that you can have a failure.
You said you are doing this as a preventive maintance? And there was a problem at #6, not at the place that is low(between 2 and 3). Is there any signs of problems at this spot(carbon build up)? If so then maybe it could lead to a problem.
I have used recently Hylomar to seal out coolant leaking around the block areas to help prevent etching of the block more. I have only done this on blocks that I feel have a chance of lasting. A area for the fire ring to seal on is important. I will attempt to start a thread soon(maybe this weekend) to show some pics and stuff and start a thread for discussion on this.
Remember also that all feeler guages are not as accurate as one would like. Has this mechanic used a Mic on his feeler guages to see real value of the thickness of the guage?
But bottom line is if you trust this mechanic, and have no reason to question his judgement. Then why are you posting this up, to find fault with his diagnosis or try to save some money. Also if he does not want to warranty the job, Is this going to be a problem. Will he still do the best job he can, or will he just slap it to gather?
If the head is goign to be milled to have it as flat as possiable(which if we remember Toyota does not recommend). having a block .0025 out of spec should not pose that much of a problem. There are many different thoughts one can suggest, with out seeing the block my self or real good pics. One can only have specualtion.
Good luck with your choice.

Hi Robbie. Thanks for the post.

I did not do this as PM. My headgasket blew. One day, I had a hard start, and white smoke coming out of the exhaust. I shut it down, and started calling local mechanics to see if anybody had done a 1fzfe head gasket before. This guy, who runs a reputable shop, said that he did. I don't have any reason not to trust the guy, but I've never used him or his shop before.

According to the mechanic, failure was at #6. However, after they cleaned the surfaces, they straightedged the block and found this flatness issue on a different part of the block (b/t 2 and 3, he says). I am going to the shop this afternoon to get a better idea of what he is talking about.

As for the warranty, I wanted the warranty because I wanted some comfort that his shop did the job right initially. I figured that anything that went wrong would probably show up pretty quickly. He and I spoke this morning, and he says that he cannot warranty the head gasket job. I told him that I understand, but that I wanted him to stand behind the work that he could control, such as other parts of the job not directly involving the head gasket. He agreed to that, so I'm happy with him, and feel like he's trustworthy. Maybe I'm wrong, but who can tell? He seems honest, so that's all I can go on.

I'm not trying to second guess him, or to do a job like this on the cheap. I'm just trying to get enough information to make an informed decision. That being said, I really appreciate everybody's input.

I'll post up again after my meeting with him, and post pictures if I get the chance to take some.

Thanks,
Jay

 

[Atticus]

First check that your mechanic is talking in mm or thousands of an inch. Most likely the latter.

Will do, Christo. I'll post up more this afternoon.

Thanks.

 

[Atticus]

I went to the shop today to see for myself. The head is perfectly flat. The block has a low spot on it between cylinders 3 and 4, in the middle of the block between the two cylinders. As in right dead center in between cylinders 3 and 4. According to the FSM, maximum warpage is .0020". I've got just a shade under .003" of warpage. No jagged edges or noticeable pitting at that place, or carbon build-up. Everything else looks great. Very little pitting anywhere on the block, no other flatness problems, etc.

So, it seems to me that my options are these:

1. Go ahead and finish the repair with the new gasket. If I do this, the mechanic will not warranty the work.

2. Pull the block and have it machined flat.

3. Buy a used engine and replace the engine.

4. Buy a new block and/or complete engine.

5. Sell the truck for parts.

2 and 4 are both out. I don't want to machine the block if I'm not supposed to do that, and I sure as hell am not buying a new block for the truck. That leaves options 1 and 3.

I'm about 95% leaning toward option 1. I watched the mechanic measure the gap, and I'm not 100% sold on the accuracy of the "shims" he was using or the straightness of the bar, but I have to have some faith in the guy.

I welcome anybody's thoughts on this.

Thanks,
Jay

 

[bhmmapping]

I would go with number one and be happy. If you had done the job yourself you would never have known about it. It sounds like he is doing everything by the book and I assume you are using factory parts so I wouldn't think the warranty is necessary. If you decide to go with number five let me know, I'll trade you a nice running 3fe powered 92 with an intact head gasket.

 

[NLXTACY]

Back in the day when I was rebuilding engines we had a straight edge we used all the time. It was one my uncle actually paid some scratch for. Not just a piece of straight steel. I was told never to drop it. Well I dropped it cleaning one of the tear down counters. When he sent it back to be checked it was .005" off just from landing on its corner.

My uncle built race motors along with everyday engines and was ANAL and having an accurate straight edge.

What I will also say is that by the time the 80 series blocks were needing work we ONLY ever got a head to do. I never worked on an 80 block before my uncle shut down the doors.

Just saying.