Whether you have a blown head gasket due to your Honda DOHC B18 engine overheating or from abuse, it’s never a good time. Excessive problems with your head gasket can lead to oil and coolant mixing, or your engine consuming oil or coolant at a very fast rate. Quick fixes like turning your heater on, carrying around water or coolant or even trying to keep your cooling fans running, these things all delay the inevitable task of replacing your blown B18 head gasket.
Today we’ll be showing you how to fix a B18 blown head gasket in a 1997 Acura Integra LS with a B18B1 in it. Although the instructions for a B18C1 will differ, you’ll be following almost the same exact instructions.
For a guideline on what the differences are between a LS and GSR water pump / timing belt and cylinder head bolts, check our VTEC wiring guide as well as our How To on building a reliable LS VTEC.
Symptoms of a Blown Head Gasket
- Milky oil
- Engine consumes oil rapidly
- Engine consumes water or coolant rapidly
- White smoke from exhaust pipe
- poor engine performance
- misfire or missing cylinder
For more on how to diagnose a blown head gasket, check our FAQ here. In order to fix your B18 blown head gasket, you’ll have to remove your cylinder head and have it serviced. While having it serviced, you should have the machine shop deck it to make sure it’s 100% completely flat and free of any deformations caused by heat or stress.
Installation of a new head gasket will restore the seal between your cylinder head and engine block. Before you get to this point however, you’ll have to remove the timing belt assembly as well as your B18 head.
Before beginning our how to fix a B18 blown head gasket guide, you will need to disconnect the negative terminal on your battery. Once you’ve got the battery disconnected, drain your oil and coolant. Always discard of your used oil and coolant safely and follow your local state’s regulatory rules and mandates to disposing this waste. For some good tips on how to stay safe while working on your vehicle, read our Safety guideline for some helpful reminders.
To start our How To fix a B18 blown head gasket, begin by removing all the 10mm nuts that hold your B18 valve cover in place.
Remove all of your spark plug wires but do not disconnect from your distributor. Undo the two 10mm nuts up front on your B18, making sure to note the engine ground located on the drivers side of the engine.
As you begin to remove the 10mm nuts, undo the PCV hose shown here. Disconnect and let it hang as you continue to work your way around the valve cover.
Remove this 10mm bolt that holds the front power steering line bracket to the valve cover. Once you have this bolt removed, swing your B18 power steering line out of the way.
After you have the valve cover loosened, remove the 12mm bolts that secure the ignition distributor in place. If your DOHC engine has severely overheated, as this one has you may find your valve cover tough to break loose. Try to use a dead blow hammer or a piece of wood as to not damage or crack your aluminum valve cover.
Unplug and remove the entire distributor with spark plug wires and set carefully to the side.
Now that you can reach the engine coolant temperature sensors a little better under your distributor, go ahead and unplug the idiot light as well as the ECT.
Disconnect the heater hose lines and radiator coolant lines on this side of your cylinder head while you are here. If you’ve drained enough oil and coolant, the mess you are making on the floor should be minimal.
Let’s take a break from that side of the motor by heading over to the cruise control unit. Unplug the cruise control by undoing the plastic clip and connector. With this cruise control module unplugged, you can now remove the 10mm bolts so that you can access the B18 engine mount.
Remove this deep 10mm bolt as well as the upper bolt shown below.
After removing the final 10mm bolt located near the B18 motor mount, you can flip the cruise control box up and rest it against the upper portion of the engine bay.
Disconnect your Manifold Absolute Pressure (MAP) sensor as well as your Throttle Position Sensor (TPS), you can choose to disconnect your Idle Air Controller (IAC) as well and depending on your year of B18, your Intake Air Temperature (IAT) as well. If your IAT sensor is located midpipe of your intake snorkel, disconnect before removing your intake.
After disconnecting your intake locate your throttle body butterfly located in the diagram above. Depress downward to open your throttle blade and free your throttle cable. Take caution as to not warp or stretch your throttle cable or bracketry in any way.
Remove your valve cover and take a look at how bad the damage may be. The smell will be a strong indication of how badly you have warped your B18 engine.
We’ve cut our old timing belt but if you wish to keep yours intact for some reason, you’ll need to wait until you are nearly complete with our How To Fix a B18 Blown Head Gasket guide. Skip ahead to removing the front timing cover, crankshaft pulley and lower timing cover to remove your old timing belt whole.
Start removing the cam cap bolts to your DOHC B18 engine, loosening outward going in. You should try to remove these bolts to complete the cam cap in reverse sequence as you tighten them.
If you are repairing a blown head gasket on a B18C1 or GSR engine, you must first remove the cylinder head girdles that run across the valvetrain. It’s just a bit different, but not by much. Remove your B18 cam caps to loosen and free up your camshafts.
If you have a tough time of it, try raising the bolts until the threads bite and push to help “wiggle” the caps out. Never attempt to loosen or remove cam caps without all of the cap bolts removed and B18 cam caps loosened. Improper removal of your camshafts may lead to damage which could ruin more than a blown head gasket.
Take out your oil dipstick and remove the 12mm bolts that hold your heatshield to the B18 exhaust header. There’s a tricky one that’s difficult to reach that’s shown a bit better below.
Remove your exhaust header heat shield and start loosening and removing your 12mm exhaust nuts. These are iron so take care not to cross thread or otherwise damage the stud in your cylinder head.
You’re about done with the removal part of our How To Fix a B18 Blown Head Gasket article, and now you’re ready to start removing your DOHC camshafts. Again if you are working on a VTEC version of the B18 things will be slightly different, check our GSR Timing belt How to for more information if you need help.
Remove your camshafts and arrange your cam caps in order. If they get mixed up you can tell which way they line up according to how they are stamped.
Take your old rockers and B18 valvetrain parts out of your cylinder head keep them safe or take them in a bag to your machine shop to have them cleaned.
Open your fuel door and turn open your gas cap before disconnecting your fuel return line. This line is marked with red lettering and is connected to your fuel pressure regulator at the end of your fuel rail. If you are working on a B16 or B18C1 things will look a bit different, but the return hose is unmistakable. Always use caution around fuel or fuel fumes, check our safety guidelines for more details.
Unclip your fuel injectors and loosen the 10mm nuts that hold the fuel injector wiring harness tray to your fuel rail. If your IAT is mounted in your intake manifold as a B16 or LS would, disconnect that before flipping the entire harness up and out of the way.
Now that your fuel return line is loosened, loosen the banjo feed to your B18 fuel rail and remove the end. Do not lose the washers and remember to keep the proper sequence with the slotted washer on the outside of the bolt.
Remove the coolant lines to the back of your B18 intake manifold, as the usual caveat also applies here if you are working on a B16 or GSR engine the manifold disconnect procedure will look quite a bit different. Again, check our How To guide on the GSR Timing belt for more information on disconnecting your intake butterflies and intake manifold from your cylinder head.
We won’t be doing that however, because you can remove the cylinder head with the intake manifold still attached. There’s a very difficult set of bolts that holds the bottom of your B18B intake manifold to the back of a bracket on your engine. This is the one big challenge to learning How To Fix a B18 Blown Head Gasket, because these bolts are very hard to remove.
Once you have these bolts removed, you are almost ready to lift and remove your B18 cylinder head for service. The last thing holding your intake manifold back is your Idle Air Controller. Disconnect the engine harness from your DOHC IAC and then disconnect the 12mm bolts that hold it to the back of your intake manifold.
Make sure not to lose your IAC gasket, because your B18 will have a hard time with idle if you don’t have this gasket in place.
Now remove the front 12mm bolts to your power steering pump. Don’t bother with the bracket as we’ll be removing that with the cylinder head.
Don’t forget to remove the lower bolt as well.
Now pull your power steering pump and pressure line to the side and out of the way. With this removed, you can move on to removing your headers which is the next part of our how to fix a B18 blown head gasket guide. There is one 14mm bolt that holds a bracket to your B18 shortblock that must be removed for you to free your headers.
Gun off the cylinder head bolts in reverse sequence and discard them. As they are yield to torque (YTT) bolts they are useless once you’ve tightened them down. Your almost done with our how to guide on repairing your overheating cylinder head. Remove the long 10mm bolts that hold the upper timing cover to your cylinder head. Your cylinder head should be ready to be removed after your exhaust headers are taken off.
Disconnect this 14mm bolt that we referenced before that holds your exhaust manifold in place and then you can move your headers off your exhaust studs as shown below.
Pull outward on your headers to remove from your cylinder head. Rest your headers against a floor jack or wood to support your B pipe and exhaust pipe.
With a friend on either end of your B18 cylinder head, lift up and remove the head gently. There’s quite a few things you’ve got to clean now starting with your shortblock. Clean your shortblock using a razor to give your newly prepped B18 cylinder head a good chance to seal.
When you’re done cleaning the shortblock surface, you should have a clean prepared DOHC shortblock to put your new cylinder head on.
Now remove your intake manifold from your cylinder head, as well as your coolant ports and engine temperature sensors. Have a machine shop inspect and service your B18 cylinder head by decking it flat and have your compression checked. We’ll be upgrading to a set of ARP head studs, and we recommend it even for people who just want to drive their Integra from point A to B. They’re relatively cheap and reusable in case something with your How To Fix a B18 Blown Head Gasket project goes wrong.
Stay tuned for the next part of how to fix a B18 blown head gasket DIY guide, where we install the new cylinder head and show you how to do a B18 timing belt job. Have any questions about our DIY guide on repairing a blown head gasket? Let us know below.
