FormulaIntegra

So, last spring at a race, I lost the coolant bleed screw on my 95 Civic (D16Z6). Noticed the temperature spike, and immediately slowed down and pulled into the pits. There was steam coming out of the tail pipe, so we replaced the head gasket (with a Felpro from Autozone) at the track, and ran the race the next day with no further problems (or steam).

Fast forward to last December (first time I fired up the car since that race), I noticed more steam coming out of the tail pipe. Pulled the head and straightedged it, and found it to be about .012" out in between the 2 and 3 combustion chambers, and about .005" out near the front edge of the head. Also, the intake manifold gasket had failed where the thermostat bypass hose ports through the IM into the head. Replaced the intake and head gaskets with brand new stock Honda factory ones, and had the head resurfaced back down to being perfectly true. I straightedged the top of the block, too, and couldn't get a .003" feeler gauge to slip under anywhere, so it should be in good condition.

However, once I put everything back together, refilled the fluids, and fired it up, there were massive amounts of steam coming from the tail pipe, as well as coolant streaming out of the mating surface between the head and the block. I killed the engine only after a minute or so, and when I pulled the spark plugs, the #4 cylinder had a ton of coolant in it. When I pulled the valve cover, it was obvious that there was a very large amount of coolant mixed into the oil. So, I've pulled the head off again, and plan on having it pressure tested, although I can't visibly see anything wrong with it, and I was meticulous about re-assembling everything last time, so I can't figure out what could cause this kind of issue. Everything was assembled following the Honda factory manual to factory torque specs (ARP studs to spec with 40w oil torqued to the correct spec for that lubricant, although there seems to be a fairly large disagreement on the internet as to what is the correct spec, I went off the ARP website)

I know the mating surfaces were clean, and it was a brand new headgasket still in the sealed package. Does anyone have any ideas of something I could have missed or not done properly? There definitely wasn't any debris inbetween the mating surfaces. I followed the proper torque sequence on the head studs, doing it in stages as the manual describes. I just can't figure out, if the head was machined back to tolerance, how it could have been leaking the way it was, which was worse than when it was still warped. Any help would or ideas would be appreciated. It's starting to become aggravating, but I don't want to just give up on this motor. I'm going to have the head pressure tested on Monday, and talk to the machine shop (racing engine machine shop) to see if they have any ideas, too. TIA.

night

ARP's with moly should be like 72ish lbs off the top of my head, so with oil... would be more.

dirty19

iTrader: (1)

Hmmmm did you torque the bolts in the correct pattern?
I know you used the manual.
Some people dont use the torque pattern, and sometimes the result you got is what happens.
How about the water pump?
Did you check it for free movement?
If it seized your going to get the same result.
Definately get the head pressure tested.
Let us know what you find out.

VTECIntegra9

do you use the dowels? 12thou and 5thou between different cylinders seems to be beyond spec - if you milled the head good but you may also have issues with your cam wear and the head after torqued down may still be warped even tho it looks true off of the car. Only other thing I can think of is a crack in the head that hasnt been spotted. At this point is it possible to try a different cylinder head? Rather than chase a problem over and over?

And what dirty said. Good Luck! Ever since I pulled my head it's been leaking and it's true :-/ But just a tad of oil from the return so who cares - I just keep topping it off!

FormulaIntegra

I straightedged the cam bearing journals, and none were out, so I'm believe the warp was just around the water jacket openings. As for the dowels, when I pulled the head the first time, there were only two dowels on the 2nd and 4th studs on the intake manifold side. Should there be two on the exhaust side as well? I can get those easily from my local dealer. The head's currently at the machine shop getting pressure tested, so I should have some more info tomorrow. As for the torque spec, the ARP website says 10mm studs get 84 n•m (or 62 lb-ft), but like I said, the message board consensus varies greatly on whether torque should be to shop manual spec (58 lb-ft), or as high as 80 lb-ft. I did follow the tightening sequence by the book, dirty, so that shouldnt have been an issue, but I did notice my exhaust header flange didn't square up to the head like it always has before, so I'm not sure if something else is out of alignment.

night

he asked about the dowels because if a head has been cut enough the dowels at original height can hold the head up. since it is off now, before you reassemble, take them to a grinder wheel and trim em down a mm or two.

dirty19

iTrader: (1)

Did you check the water pump for free movement and leaks?

chikin pickle

Get the block decked. That's the only missing link assuming proper installation.

mc-integra111

Get a new head.

https://honda-tech.com/forums/acura-integra-6/rebuilt-engine-now-smoking-something-cylinder-1954758/

I had a similar issue where everything seemed correct, yet the engine still leaked. I still don't know for sure, but I believe that head had some kind of microscopic crack in it that couldn't be found off the engine. New head (really a used head, just new to me), no problems. The offending problem head is now a nice display piece at work.

FormulaIntegra

Yes, Dirty, the water pump spins freely. No issue there. Discovered that there are only supposed to be two dowels, and they are on the exhaust manifold side :bonk: Even though they fit on the two of the studs on the intake side, the head gasket holes aren't big enough on that side, so it's impossible I installed them incorrectly. I talked to the machine shop, and they said the head pressure tested just fine, with absolutely no leaking or cracks evident. I asked him about the dowels being too long due to the resurfacing, and he said as long as the resurface indicators (those cast button looking things that tell the machine shop the absolute minimum they can mill a head down to) are still there and within spec, the factory sized the dowels accordingly so they couldn't bottom out. Now, he said, if one of the dowels bound or got cocked on it's seat, it's possible. The only other thing I can think of is that the factory head gasket I used has a grommet that's awfully close to the edge of the mating surface, and if I try, I can actually get it to sit up on the lip, so it's plausible that I pinched it and that's what caused the leakage. The only other thing the machine shop said was to get the part number for the ARP studs for that engine, and call them directly to get a proper torque spec. I'll be putting it all back together with a Felpro headgasket this weekend, with the proper torque specs from ARP, and if it doesn't leak, I'll be at Willow Springs in a couple weeks. If it's still effed up, I'll be pulling the engine and dropping in my other race motor. Wish me luck, and I'll update you guys with how it goes.

Good read on your thread, Jared. Sounds very similar to mine. My head was pressure tested to 80psi at 210*F by the machine shop, and they said it held pressure perfectly, so, although the thought of a crack opening up at temperature crossed my mind, it's been eliminated as a possibility. I just hate junking something without finding a smoking gun. Thanks for the help so far, guys. I'll keep you updated.

night

ya, the gasket copper rivet was a problem when people were learning hybrid vtec swaps, but I would never think about on anything else.

mc-integra111

So was mine (I guess I forgot to add that part to that thread). I still remember what the machine shop guy said > "You know how when you are really, really looking for a leak, you can usually find one ... well, I couldn't."

For reference, the combustion side head surface temperature will be anywhere between 300*F and 600*F (at full load).

VTECIntegra9

My other comment about the dowel pins was that although some people do without them for some reason, I like how they align the head gasket with the block/head... and also helps ensure that you're alignment is correct when mating the two. Best of luck, glad there are no cracks, and I have a good feeling it will work out for you now - sometimes just doing it over again fixes the problem you couldnt find - although frustrating - the hell with it, it works!