It was bound to happen - after 10 years of driving 3.0s it looks like I'm finally doing a head gasket. Bought hastily not knowing of the clogged cooling system, previous owner had recently done a HG but said as I was driving off it could use another coolant flush (read 23 flushes). It has overheated twice while I was driving around town testing it, once seriously while a buddy was driving it back for me, and who knows how many times while the PO was beating on it post HG change.

Doing a leakdown test later today to see if the HG is behind the overheating but I feel like since the heads have been overheated many times, I already have to do a knock sensor, don't know what gasket was used, and seeing the crap work that was done to the truck in other areas I should probably continue on post KS swap and do the HGs.

I've read that the maximum amount of material that can be removed from these heads is .010" but I have no way of knowing how much material has already been removed, or even if it has ever been milled at all. Does anyone know what the height of a brand new head is, that I should be looking to stay above -.010" after milling? The FSM doesn't seem to say.

 

Do you guys who've done a HG on the 3.0 take your chances with the clearances? Any way anyone can think of that I might be able to find out, calling a dealer (though it seems unlikely they'd know/help if the FSM doesn't say) etc?

Leak down test confirms blown HG between cylinders 3 and 5, bubbles in the coolant on both despite leak percentage under 7% on all cylinders. Now I'm wondering if the PO actually had the HG done or just bought the parts, sold them without the box and threw the empty box in the back. New FIPG around water outlet too though.

 

Give Todd at Engine builder a email.

Check with what ever shop might be doing the machine work.

 

It's possible the PO installed the head gaskets incorrectly, thus blocking some of the cooling passages. From reading on this forum, that's a relatively easy mistake to make and could account for the original overheating, which now has led to HG failure.

 

Got it all torn down today in a marathon session. Went pretty smooth.

Thanks. I was going to order the bolts from him so I'll ask when I do that. Plan is to use his Topline bolts and the Ishino gasket kit from elsewhere. OEM gasket according to partsgeek and cheaper/easier than sourcing everything individually from Toyota.

My concern with trusting a machine shop is that I moved recently and don't have any connections for one here. It could be in the interest of an unscrupulous shop to mill it and get paid regardless of clearances and potential future engine trouble, rather than sending me off to buy a head from a national rebuilder, as was the backup plan.

Nailed it. The PO said it was his buddy who did the HG. It might be giving the guy too much credit to say it's an easy mistake to make; l I had read elsewhere that it only affected one passage, it's actually something like 8 passages where the holes don't line up.



2 EDTA flushes and a couple hours of running water through it and I still have this much gunk in the system, how does that even happen...









Some significant deposits on the valves. I take it that if I buy a valve job from the machine shop they'll clean all that up for me. Kinda hate to mess with them since the compression and leakdown test came back so good but it probably shouldn't be run like this for another 100k.



Good news! Although it looks like the last guy cleaned the surface with a roloc and was none too careful with it, I was unable to fit even a .002 gauge at any point under a straightedge. It was not milled last time either so a shop should be able to take a few thousandths off to clean up the surface without issue.

 

I always keep the old gasket for comparison and a reference. I have seen holes not punched out in some replacement gaskets. One of the most difficult problem I had was on a Ford was the head gasket water passage not punched out.

For other gaskets as well and this is on a 22re Throttle Body.
Copied...
When using aftermarket gaskets, double check all holes are punced in. A good practice to get into anytime swapping any gasket.


Here you can see the hole I added.

 

thats a really good idea, I bet you wished the PO would have done that!!!

 

from what I've seen the MS should take about .010 off the head, 10 thousandths

 

I think that's the maximum allowable by Toyota before you start needing head shims and such. I asked the machinist to take off just a few thousandths if he could, and he said he probably wouldn't even need to take that. Forgot to ask what he actually removed. Also forgot to ask Ted at Engnbldr what dimension people should be looking for, I will do that and edit post #1 one of these days. He was on vacation when I got my bolts so had to get them elsewhere.

Not that the dimension matters to me anymore because if this #*&@#^$ thing blows again I'm swapping in a 3.4. The saga continues at - https://www.yotatech.com/forums/f116...theast-283508/