zaboomafoozarg

Hello all,

I've got a 2003 civic LX, 5spd manual, 130k on the clock.

It burns a bit of oil-- has since I bought it at 110k. It loses a bit of coolant, as well. It's overheated (about 3/4 the way up the temp gauge) maybe twice in 6 months.

Compression test results from 2 different test kits on 1, 2, 3, 4 were as follows:

225, 160, 220, ~225
180, 110, 180, 180 (new rental tool from Autozone.)

Not sure why 2 different gauges are giving different readings but the pattern is the same.

Now the odd part: I let it idle for 20 minutes and did a Combustion Gas Leak test on the radiator. It tested fine. I always have heat on the highway and only have heat at idle about half the time. I was getting a random misfire on Cylinder 4, thought it was the coil, swapped it around, and misfire went to Cylinder 2. I bought a new coil and still rarely (only shortly after starting, and only sometimes) get the misfire on cylinder 2.

There's no oil in the coolant, or vice versa. No bubbling in the coolant from gases, either. If I rev the engine, the coolant jumps, but that's all. But I'm pretty sure the coolant was overflowing or getting lost somewhere.

I hooked up my Actron scanner to read the live data. Coolant temps ranging from 185-205. Radiator fan doesn't kick on until about 205, which is concerning.

I'm thinking there may be multiple issues at play here, but for the main thing, I'm not convinced it's a head gasket.

Any suggestions or anything? Any insight would be most appreciated.

GolNat

iTrader: (7)

Is the overflow filing up with coolant?

7th gen head gasket issues don't usually have traditional signs.

zaboomafoozarg

Well, it has some in the reservoir anyway, I believe. It's quite hard to see the level in that bottle though due to the location. I try to keep the system pretty full (not saying I directly fill the overflow reservoir, however-- just as much as the radiator will take) since it burns off and if it gets even a little bit low, the heat doesn't work when idling as much and that's when it overheats.

The level in the overflow does rise when the temperature goes up and was indeed overflowing when it reached 3/4 of the temperature gauge. The intermittency, however, is puzzling.

mikey1

this is a good clue.....now you need to solve the puzzle

find out WHERE the coolant is going,

my bet is your overflow bottle is filling up and literally overflowing with coolant, if that is the case, your head gasket is blown

mikey1

head gasket definitely blown, thats all the evidence i need

zaboomafoozarg

Thanks Mikey1,

Do you think the absence of other indicators is insignificant then?

My understanding (which is limited) was that a blown head gasket would probably cause bad compression on 2 cylinders, but I only have bad compression on 1 cylinder. And there there was no evidence of combustion gas leaking when I ran that test.

I don't know what other diagnostics I could perform, but I'm concerned that if I assume it's a head gasket and tear the head off, it will end up being 2 separate problems instead of a head gasket, lol, such as a bad piston ring for the compression problem and a bad component in the coolant system causing the overheating, especially given the lack of other head-gasket indicators (i.e. no bubbling, no oil-in-coolant or vice versa.) What are your thoughts on that? and then again, I guess my above concerns would coincide with what GolNat said about the usual symptoms of head gasket issues not often being present on 7th gens.

mikey1

no

compression tests mean nothing when diagnosing these engines for head gasket failure, compression could still be 100% fine even WITH a blown head gasket

i am in no way saying that you COULD NOT have other problems, the head gasket may just be one of them,

even if you DID have these issues, neither of them would cause your overflow bottle to puke its guts out

ezone

There's at least a dozen different possible ways a head gasket can fail.

The checks most people think of usually only looks for like one failure mode out of a dozen possible.





These head gaskets repeatedly fail in one particular manner.
There is one specific test I use to prove this failure.

zaboomafoozarg

Thanks Mikey1.

Thanks ezone-- it's one of those days, so I should ask if I am correct in assuming that your last 2 lines, which conflict with the first 2, are said sarcastically as if from the perspective of other persons?

ezone

Um, yeah, no. As sarcastic as I might be, this reply wasn't intended that way. My lunch break was over, I had to cut the reply short.


Your compression test results should probably be addressed first, so you know if it needs a valve job when the head comes off to do the head gasket job.

Does the low cylinder have tight valves? Adjust valves and rerun the compression test. Did the readings come up to par with the others, or not?
If no, then a cylinder leakdown test would be done to see where the leakage is going--if it's going out the intake or exhaust then do a valve job while the head is off.

Now back to the head gasket leakage tests before the head comes off... Prove it's bad:


EDIT: AddingThat's ok.
Rings are probably stuck. Pull the pistons out while the head is off, either free up the rings or replace them.

Your low compression numbers are on #2 (?), so that one should be consistently setting misfire codes.

HTH

zaboomafoozarg

Ah, thanks-- sorry for misconstruing. My brain was operating about as well as that #2 cylinder, lol.

I haven't gotten to the valves yet. I just got done running a wet compression test on #2 though. Added a tablespoon of oil, ran compression, and it jumped up to #180 PSI like all the rest. Blah. Sounds like a ring, alright.

ezone

Seems like a lot

I would have cranked it over a few times before screwing the tester back in, to spread the oil around and blow out any excess.
THEN do the test.
(If you got too much oil in the cylinder it will give a false elevated reading,,,,, and you can "slug" the tester with liquid.)

Retry that cylinder now that it has been cranked and see if the result is different?

Do the exact same to the other 3 cylinders and see if their test results also rise, and note by how much they rise.

(Also, is the tester you got really reliable, or questionable?)


After doing the oily tests, screw the plugs back in and run it a while to get the excess oil burned out.

I would then continue with a leakdown test to make sure about valve sealing ability.


-----


True compression ring problems seem unusual to me, 130k is low mileage IMO, far too early for problems ---unless it's been severely overheated or run with crappy air filtration, swallowing sand and rocks (K&N style?)
Got oil ring problems all day long, but compression rings?

------


Head gasket telltale on this engine is== the overflow bottle level raises, overfills or overflows, while at the same time the radiator goes low.

The system is designed to keep the radiator completely full under all conditions, and when the head gasket leaks it displaces liquid to the reservoir, and lets the radiator level go low..... It cannot pull liquid out of the reservoir as the system cools down after there is an airspace in the radiator.

Overheat comes when the radiator level gets too low.

Other faults can cause the same symptom too (bad cap, burned out neck), but this is what most people can see visually once they know to look for it.


Specific tests can prove a combustion chamber breach beyond a shadow of a doubt.

HTH

Star1967

Bad thermostat , worn belt , bad water pump , warped head , flat spot on the camshaft , bad fan motor/burned out connections, and fouled plugs could cause coolant loss and misfires. Worse case could be a hairline crack in the head or the engine itself. Maybe the coolant bottle itself could have a pin hole in it. have you tried putting a flattened cardboard box under it? As for the oil you might go with a high mileage synthetic.

dinsum

I had same issues but all compression was equal in 4 cylinders, I was not burning any coolant and not mixing any coolant into the oil so I made myself believe that the head gasket was fine but after ripping it all apart it indeed was the headgasket, you could see a little crack in the gasket on the bottom side that allowed some compression to escape into the coolant system, because of its angle the coolant could never get into the cylinder so i was never burning any coolant.

top off your coolant and make sure there are no air bubbles in the system by idling the car and turning your heater on with the coolant cap off for about 10 minutes and topping it off, be sure to only remove the cap when the engine is cool. After this go for a 15 minute drive and bring the car home to cool off (I would drive it decently hard, at least 3-4k rpm), then check to see if the coolant is still topped off right to the top after the engine cools off, most likely it wont be and chances are that your overflow tank will be filled to the top, you will most likely notice when you take the coolant cap off after the engine cools off that you will hear air bubbles escape from the system and that will be your sign that pressure is getting into the system which means headgasket. The crack in the headgasket on my car was small it leaked very little pressure in the coolant system when I drove very gentle, but if I decided to bring the rpm's up to 4k or so it pressurized the system quickly and lost a lot of coolant pretty fast. I beleive the reason your fan is turning on at 205 degrees is because there is air in your coolant system which causes the temp sensor to malfuntion (mine did the same thing), once you top off your coolant and get all the air bubbles out you will notice the fan come on around 185 degrees. I also did not see much change to the coolant when revving the engine with the coolant cap off, it didn't look like it was getting pressurized cause it wasn't climbing or making bubbles, just once in a while I would see a few tiny bubbles

I also heard from a mechanic that the 2003 civic was the worst year for head gasket problems, just do those coolant checks I suggested to get your definite answer

Good luck