Hey Gang,

Need some advice here... I have been running my 1994 Honda Civic DX (D15B7) with a minor headgasket leak for about two years. The headgasket leak pressurized and burst the radiator. I replaced the radiator, and now leave my radiator cap loose to prevent the radiator and/or coolant hose from bursting. I boil off about 1 cup of coolant every 400 miles. The engine does not overheat unless I boil off over 3 cups of coolant. This happened once. I saw the temp gauge spike, stopped, and topped off coolant before anything nasty happened. The engine runs okay, but I've noticed a 10% decline in fuel-economy from 42MPG to 38MPG.

Anticipating the need to rebuild, I've started accumulating components... I've got an MLS headgasket along with all the other necessary gaskets (intake/outtake/etc), water pump, timing belt, timing belt tensioner, and ARP head studs. Recommendations online are to have the head milled before reinstalling.

Can anyone recommend a good Milwaukee-area machine shop for milling a D15B7 head? How much should I expect to pay? How long should I expect to wait? Is there any other work I should have done while the head is off?

I found King Motorsports online. They charge $90 to mill a head. Is this reasonable?

King Motorsports Unlimited, Inc. - CNC Heads, Valve Jobs, Head Porting & Milling

Thanks!

 

Closest guys I know are in the NW burbs of chicago. As for what work you want to get done, I personally wouldn't get a valve job done on that old of an engine unless you're confident of the bottom end. Really depends on how you view this car. If it were something I want to last I'd probably pull the entire thing and do a full rebuild.

Furthermore, you shouldn't be driving without a radiator cap. Your system needs to be pressurized to prevent boiling throughout the system. Pressure raises the boiling point. You're risking hot spots and damaging the block. And it sounds like your old radiator cap was bad because it should never allow that much pressure to build up to pop the radiator, the system should be shooting air out your overflow tank before it damages the radiator.

 

Thanks for the response!

I hemmed and hawed over whether to bother fixing such an old car with 200k miles. I wound up deciding that I couldn't get another car with such good fuel economy unless I bought a brand new hybrid for $25k. That's a lot more $ than a $500 headgasket job.

That's an interesting observation about the radiator cap. You're right. The cap should have blown off pressure before bursting the radiator. Strangely, even after replacing the radiator (and cap), the upper coolant hose expanded to twice its normal size as soon as I started the car. I unscrewed the radiator cap, and the upper coolant hose deflated like a balloon. It's possible the new radiator cap would've released the pressure as designed, but I wasn't ready to chance bursting the hose or the new radiator. I left (and continue to leave) the radiator cap loose.


Understanding that an un-pressurized system will lead to boiling, hot spots, decreased mileage, and rough idling, I've got it in mind to replace the headgasket to prevent exhaust from over-pressurizing the cooling system. Hopefully that'll let me get another 100-200k miles out of the car. Hopefully by then there will be cheap vehicles on the used car market that get 40MPG+. Seriously... In 1994 we're able to make a 40MPG+ vehicle with a 1.5l engine that lasts 20 years. In 2012, the best fuel economy non-hybrid uses a 1.3l and still only gets 37MPG combined!?

I digress...

If my goal is to get another 100k miles out of the car, should I bother having the head milled? Not a valve job... Just milling the deck to make sure it's flat and smooth. One school of thought is that the head must be warped if the headgasket is leaking. The other school of thought is that the original headgaskets uses on 5th generation Honda Civics were garbage. They'd deteriorate between the cylinder wall and coolant chambers easily. The new MLS headgaskets will work much better.

Wha'd'ya think?

 

Since it sounds like you may have overheated it, it is worth taking to a shop to get the head checked for flatness. As far as milling it, I wouldn't get it milled unless the head was warped. People mill heads to increase compression, I dont think you really want to do that unless necessary. However, you do want to have the head resurfaced to the OEM specs prior to installing the HG....the surface roughness requirement also applies to the block.

A PITA if you're doing this yourself and dont have a machinists straight edge, but you also should have the block checked for flatness because of the overheating issue. I know it sounds like overkill, but there's nothing worse than the HG popping only after a few months. I'm also in the subaru world and blown HG's are a lot more common on those boxer engines, so I've seen a lot of quick and dirty HG replacements gone bad, essentially wasting a ton of money.

And one last thought, if you plan on taking this 200,000 engine another 100,000 miles, I probably would consider the full rebuild, with a valve job since you already have it torn apart. At 200,000, you're probably close to being due for one...and it would also likely find any cracks in the block if they happened to occur from overheating....just something else to consider since you dont definitively know its the HG at this point.

 

I highly suggest American Imports in Menomonee Falls. (Just North of Milw.) American Imports Inc. | Home Page
That's the only place I would take my 93 coupe. They are honest, reasonably priced, and they do great work.

King Motorsports will do the work too, but it'll cost you. They're more of a performance shop.

If you go to American Imports tell them a guy with a white 93 Civic that defected to an Audi sent you.

 

Thanks for the referral Danomatic93, but...

American Imports in Milwaukee responded to my inquiry about resurfacing and/or machining by saying...

"We do all kinds of engine work but anything that needs machining we sublet out. Thanks for contacting us though."

Any other recommendations?