Hi folks, three weeks ago I just finished my first ever head gasket job, and it was a success!

The car is a bone-stock 1995 Civic EX coupe with the D16Z6 engine and an automatic transmission. Cute little cars, these coupes. One of the small coolant lines had split, and fortunately the driver of the car shut down the engine in time. No emulsion in the engine oil, fortunately, but the car was consuming coolant (had to top it up every 30 miles). Took off the head and yep, coolant in the cylinders. Noticed it was not the original head gasket, so someone had been in this engine before. Cleaned things up, verified head straightness (it's good), and planned next steps. Included among those next steps were a new timing belt (Continental) and OEM water pump; might as well, since we're in there anyway.

Got a new head gasket, new head bolts, new intake manifold, and new exhaust manifold, all Mahle. Did it by the book (Honda Civic Service Manual), while leaving the intake and exhaust manifolds in the car. All mating surfaces were cleaned with first acetone, then isopropyl alcohol. Bolts got some motor oil on 'em, per the Service Manual. Got things lined up and ready to torque down. Really wasn't that bad...

...UNTIL...

...I was doing the final torque-down of the head bolts. Got everything to 36 lb-ft and began the final torque-down. Was doing it in the proper sequence. Well, the first head bolt was torquing down nicely, and then it all of a sudden got looser. Yep, stripped head bolt threads. My guess is that whomever did the previous head gasket installation tightened things too much and weakened the threads. What to do now? Obviously an insert of some sort is called for.

So, do I use Helicoils or Time-Serts?

I went with the Time-Sert. Yeah, the kit's expensive, but I like the idea of a solid steel insert. Some threads here on Honda-Tech mentioned that the race guys use Time-Serts, and that sounded good to me. The drill bits that come with the kit are of high quality, too. Did all ten head bolt holes, just in case. Might as well since I'm in there anyway (do it right, do it once). Doing the Time-Serts was the longest part of the job.

After that, everything bolted in and torqued down very nicely. Filled and burped the coolant system with good ol' 50/50 Prestone. Drove it short distances around town to build trust in the car. Car's fuel mileage went back up to where it should be. Car's temperature is staying right where it should. Finally drove it on a 2-hour freeway cruise where the speed limit is 70 MPH. I had the car's cruise control set at 68, and the car did great.

How'd I learn how to do this?

1.) Reading this forum.
2.) Watching YouTube videos.
3.) Reading the Honda Civic EG Service Manual.

So, thanks to all of you who've posted threads on this subject. While I was at it, I also totally overhauled the front suspension and put new rear struts in, plus a lot of other things (tires, all fluids, VTEC solenoid oil gasket, engine mounts, turn signals, Denso radiator, instrument cluster LED upgrade, and so on). And yes, every last coolant line in that engine bay is now brand new! Yep, even the heater core lines and new heater core valve. All hoses are either Genuine Honda or Made-In-USA aftermarket. Furthermore, this car now does not leak one drop of oil. It should now give another 200,000 miles of service with basic maintenance.

I was surprised by how difficult this job *wasn't*. Just take it methodically, do proper preparations, pay attention to detail, and take pictures beforehand. That's how I knew how to hook everything back up afterwards.

 

Yep, sounds like an old Civic..lol.
Anyway, sounds like you took your time and research to do it right. These cars are great to learn on.
Did you use a precision level and feeler gauge to measure flatness?
Did you bring bring the head to a machine shop to check for flatness, cracks, valves leaks, springs compression, valve seals?
Did you replace the timing belt tensioner?

I used stacked helicoils for a stripped head bolt on a '98 EX a few years ago. Fortunately, it was just the one stripped block threads and the stacked helicoils worked very well. I've read on many forums that Time-Serts are even better quality than helicoils, and especially involving future access. I currently have a '95 EX with a JDM B20/LS head.

 

Awesome great job!

 

You're right, they are great to learn on. First time for everything, and Hondas rock for maintenance. And nothing like studying up before making such an attempt.

I did not take the head to a machine shop, but my mechanic buddy, who's done a lot of Hondas, Toyotas, etc. does have the precision level stuff, so I had him take a look at it. He gave it his seal of approval, and I trust him. I can tell you this: the car runs great at this point. He's been using Helicoils for years on head bolt threads and likes 'em. The Time-Serts are even beefier, and I don't mind a little overbuilding of things as an insurance policy.

I *did* replace the timing belt tensioner, along with the belt itself and the water pump.

This was a good experience, because my '94 Civic LX with the D15B7 + manual trans will be getting a D16Z6 upgrade, possibly this year. This is the car that I will also eventually be putting a Go-Autoworks turbo kit on, for perhaps 180 to 190 HP at the wheels. The idea is to update its power levels to what today's 4-cylinder cars are putting out. For fun. And to learn. Oh, that D16Z6 engine, since it will be getting turbocharged, will also get Time-Serts in all 10 holes, just in case. Might not be necessary, but a little insurance never hurts. It's intended to be a good, solid, reliable daily driver with a little extra oomph.

Someday I may do a B-series swap like your car has. Will work with some more D-series engines first and get good at those before I tackle a B-series.
Thanks! Turns out I was off by a tooth, though, with the camshaft timing, and I had read the timing light wrong (it's an adjustable timing light). Oops. That explained the slight engine knocking and the relative lack of performance, especially at higher RPM's.

It's apparently rather easy to be off by a tooth with these cars, so I fixed it, and highway gas mileage went from 31.12 mpg to 36.36 mpg, averaging 68 mph (speed limit's 70). Acceleration's better now, too, and the knock's gone. City mileage should go up a lot from the 20 it had been. :-)

Lesson learned there as well. All about learning. Should I make that mistake again in the future, I'm now better at detecting it.