jibs

So I've got a 98 civic Y8 220k miles, all stock.

For a long time now it seemed to lose a little coolant. About a month ago the heater hose blew. I replaced it along with all the other hoses. Two weeks later, the radiator developed a huge leak where it's crimped together. I replaced it and thought nothing of it, car was otherwise running fine.

The other day the outside temp was pretty cold. Started it up and drove off. The temp climbed to normal pretty quick, which struck me as odd. 5 minutes later temp was high and then lost all my coolant through the reservoir.

Got it home, top it off and let it run and there is an insane amount of pressure in the cooling system.

Did a compression test and first time got 150-150-180-150. Last time I checked a few months back they were all 150 across the board. Check it again a second time it's 150-150-145-150. Not really definitive IMHO, but...

Checked the stat - it was working fine on the stove.

Pulled the oil fill cap and there was tan, milky sludge inside the cap.

I suspected it was the head gasket. Take the head off. Now here is my dilemma. I was hoping to see conclusive "ah-ha!" Evidence of there being a head gasket problem. However, I'm not seeing it. The gasket doesn't appear damaged. The valves and ombustion chamber on #3 maybe look a little cleaner than the others, but not much.

I'm wondering how obvious should the blown gasket be?

Emeraldbomber

Some you can hardly see. Its just a gasket, if its off by a tiny bit it will leak. Replace it and then if it still happens troubleshoot again.

aavtec

Dont just replace the head gasket, take the head to a machine shop and have them check if its warped. Then get the head surfaced even if its not warped to avoid leakage. Do it right the first time so you dont have to do it again.

furious94ls

Replace the thermostat

jibs

So just an update.... Took the head to a local machine shop. This shop does machining for a lot of local dealer service departments, including my Honda dealer.

They are charging me $90 to disassemble, clean, test for cracks, reassemble with new valve seals.

Milling is an extra $65. So $155 total, which I didn't think was too bad. The bad part is he said it might be 5 days. Oh well.

The machinist looked at the head and pointed out where it looked like The problem occurred. He also said he very very rarely sees a Honda head that is cracked. In fact he said "It just doesn't happen". It has to get really hot to crack.

I asked what I should do with the block to get it ready. He said the cast iron sleeves - gently clean them with a razor blade. Then clean the surface with BRAKE cleaner. He said brake cleaner isn't petroleum based and won't leave a oil or residue that interferes with gasket sealing.

I asked about copper spray on the headgasket. I have read conflicting opinions on that, and was interested in his take on it. He said "Absolutely not. ". The spray will interfere with the gaskets coating, and its ability to seal. Said put the gasket on dry, torque it down and it's good. No retorqing needed.

He ordered my gasket set for me so he'll have the valve seals when it's time to reassemble.

So now I wait.

jibs

Final update. Picked up the head from the shop. He said it was warped .005. Max I think is .002.

Gently prepped the block with a razor blade and Sea Foam. Used a shop vac to pull liquids out of bolt holes. Cleaned the gasket surfaces with brake cleaner.

Used a Fel-Pro head gasket. Reused the original head bolts. Torqued them to factory spec in 4 steps.

Also replaced the timing belt, tensioner and water pump

All together I guess this cost me about $500.

Running good now no more over heating.