Oil in coolant?
 

The car is a 2004 EX Coupe, 5 speed, 94k miles. No leaks, not burning oil. I haven't had it for a month yet and I've put about 3k miles on it so far. I drive to AZ twice a month from NM and I ran into some issues this last weekend, and I'm kind of at a loss on figuring them out. Have not experienced loss of power or changes in driving characteristics before or after this last road trip. So..

On Thursday, about 50 miles left of my 400 mile drive I threw a CEL for the vtec oil pressure switch. Oil was low by 2.5 quarts (which definitely shocked me), topped it off and CEL went away the next day. No issues driving around during my three day stay. On the return drive on Sunday, the car started to overheat 100 miles in. I turned the heater on, which did nothing but warm me up. I pulled over to the side since the temp kept going up and when I came to a stop the heater started blowing cold. I turned the car off and popped the hood, immediately smelling coolant. Coolant reservoir had spewed coolant and what seemed like oil all over the place (it was darkish and really greasy). I checked the oil level which had not changed since adding the 2.5 quarts days earlier. Topped off the coolant and continued my road trip. Had no issues after that, drove the remaining 300 miles running at normal operating temp. Worrying about my oil loss and the fact that oil seemed to be in the coolant, the next day I did a compression test. Compression was 185, 185, 175, 190. No coolant in oil, coolant looks green and clean in coolant reservoir. The inside of the coolant reservoir, above the max line, seems to be coated with oil though. I started the car and idled it with the radiator cap off and nothing spewed out, however there seems to be a little smoke coming out of it. Doesn't produce more smoke when revved or anything. I'm planning on doing a leak down test in the next few days.

I've been doing research basically all day, which is only kinda freaking me out. Apparently it could be a crack? I'm really hoping this isn't the case for me. But I also really don't want to crack it open to replace the head gasket if it doesn't need to be replaced. I'm hoping someone on here can shed a little light on this for me and give me some ideas. I'm really hoping I didn't buy a pos. :(

So a little update. I decided to drive it around for a while to see if the issue happens again before doing anything. Car seemed absolutely golden during normal driving. Yesterday I figured I'd run it a little hard, so I ran it through the gears at WOT about three times. Final time I started smelling coolant. I pulled over and my coolant reservoir had puked all over the place and was still full of oil. I babied it home and decided to pull to head to see what I'm dealing with. Head gasket doesn't have any obvious marks on it, but then again I'm not too sure what I'm looking for?

See the yellow/brownish rings round the HG? That's coolant....time for a new MLS (multi-layered steel) head gasket.

Get one from Fel-Pro if you can afford it as they seem to be an OEM supplier for MOST gaskets to Honda and are of very good quality as well. I found a Fel-Pro HG set for ~$100 for your vehicle on RockAuto. Good luck and enjoy the rebuild.

Thanks for the reply, jonsey1886! I actually did replace the head gasket with a Fel-Pro, which fixed my problem. I've had so many issues since then, I forgot to update my post! I actually just replace the alternator on Saturday. It was intermittently charging the battery. My car died half walk between Phoenix and Albuquerque a few weeks ago. I had to get towed to a tiny town 90 miles away, where they claimed my alternator was good but my battery was bad. Replaced the battery, and continued on my way. Same thing happened on the way back but thankfully it decided to start again and get me home. Ran perfectly for over a week and then the alternator decided to completely give out, which is obviously why I replaced it. This has definitely been the worse experience I've ever had with a Honda, this is my first Civic but my fifth Honda. It's been nothing but issues. I guess some people just really don't take care of their vehicles, or I'm just so lucky that things decided to happen right after I bought the car. I'm hoping it's smooth sailing from here on out!

Would that mean the coolant was in the oil?

No, I only had oil in my coolant. It wasn't mixing the other way, thankfully.

A.) What kind of alternator did you replace it with? DENSO is the OEM supplier, if you used one of the parts store generic reman'd alternators get ready to replace it in about a year or 2

B.) Have you done a tune-up since you bought the car?

Tune Up
Oil Change Preferably with SeaFoam Treatment to clean the crud out of the engine
https://www.hondacivicforum.com/foru...uctions-14612/
New OEM Plugs (NGK)
New OEM Wires (DENSO)
New Fuel Filter & Oil Filter (WIX/MANN/DENSO)
Trans Fluid Change (Honda MTF ONLY)

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That was meant to be a joke.

I replaced the alternator with one from the U-Pull-&-Pay junk yard here in Albuquerque, so it's technically OEM. I had it tested and it passed. It seems to be working well. For 30 bucks, I can't complain. Comes with a seven month warranty, so not bad.

Yes, I did do a tune up when I got the car. I don't trust people and their claims of maintenance. Replaced the spark plugs, all the filters and then all fluids were replaced when I did the head gasket. I used all the brands you suggested. I haven't replaced the plug wires though and I've never used sea foam before, it kind of makes me nervous.

Oh, heh. Next time you should probably put "Lol" or "Haha" or something. Sarcasm is sometimes kind of difficult to pick up through text.