krazylol

Some opinions would be great.

Some background.

Bought a used 04 Civic Si ~150k miles, was running fine for about a week and a half to two weeks.

When it started getting cold, I noticed that the car was taking longer than usual to warm up.

To add, the car would hesitate when going above 2,500 RPM uphill (only uphill) as if it were going to stall. We ran some injector cleaner and I lowered the octane gas I was putting in the car and we have not run into this problem since. About 3 weeks or so.

Once the temperature really dropped ~18F degrees or so, the car would have a hard time starting and it sounds like it's giving some kind of misfire. The car stalled out from a warm-start once and gave P0400, 0401, 0402. Since then we've changed the coils and spark plugs and haven't gotten a CEL. However, on a cold start, the car will make an ugly noise as if something were failing.

Onto the more serious problem I have. After a couple of days of running, the radiator will be completely empty, or low, and the reservoir will overflow with coolant to the point where it squirts out from somewhere all over the engine.

The coolant has been flushed twice, at two different shops and the heat will still randomly go out at stop lights/signs. The oil is not creamy and there are no gas emissions in the radiator (passed the test twice) so I have personally ruled out the head gasket. There is also no thick white smoke.

We've taken it to two different shops and they cannot figure out what the issue is. The thermostat was changed recently, brand new OEM. We took the car to a different place who recommended changing the radiator so that's being done right now.

Would anyone here suspect that head gasket is still the problem? I am tired of dropping money little by little into the car since it's too cold to do the work myself.

Has anyone experience a similar issue where it wasn't the head gasket?



Thanks for the input!

mikey1

your personal ruling is incorrect,

you sir have a blown head gasket

Stock 99

I would

ezone

Head gasket.

USA or Canada? Which engine does this car have?
If it's a K engine, it's a buttload more work and probably warped.

You mean P0300, P0301, P0302?

krazylol

Whoops! Yes, that is what I meant.

I am no mechanic by any means obviously. I also believe it might be the head gasket. ugh.


Also it is a USA EP3 with the K20A3.

ezone

Well, based solely on the symptoms you observed, the procedures I would use to diagnose and verify the cause is the same procedure I use on the 1.7 engine, so search for the sticky about 'overheating, common causes' and check out the first post in the thread.


I strongly suspect the engine has been severely overheated at some point in its life. Anything obvious? Front end crash evidence? Aftermarket radiator?

krazylol

Surprisingly enough, the mechanics ruled out the head gasket as there is no sign of overheating. The car also hasn't overheated at all while I've owned it.

The new radiator is aftermarket, yes. The radiator is still pretty full. It's only been one day though. The old radiator will empty out into the reservoir after about 3 days. Another thing to note is that (with the old radiator at least), removing the rad. cap while the engine was cold made a hissing sound, aka pressure.

No evidence of a front end crash but signs of fender benders. I don't suspect it's anything serious.

Thanks for your input and help. I will look into your topic.

ezone

That's not actual testing or proof there is no problem, and you seem to have a significant problem. If you let it get to the point of an overheat situation, it is a huge problem. Your saving grace at the moment may be the bitter cold ambient temperature.


Did you tell your mechanics this bit of information?

Do your mechanics not understand how this particular set of symptoms occurs?
Do your mechanics not understand how to test and prove without a doubt what the cause of this is?


Don't fret, not many mechanics are diligent enough to find the true cause of a problem like this without help from someone who knows, and that's an ego buster for most.
Many just fire the parts cannon, hoping something will stick. Eventually you will run out of money and go away.


-------

Many of us that have had to deal with it extensively already know the most likely answer, that's why we reply the way we do.

My testing methods can give definitive proof, AND pinpoint which cylinders are having the problem.

I don't make my money by guessing at things like this.



In my previous reply I was referring to the radiator that was in at the time you purchased this car.

Now the question becomes, what radiator was just removed? Was it an OE or aftermarket unit?

(Remember, I was looking for evidence of crash damage that could have been a root cause of a major overheat BEFORE YOU GOT THE CAR -- which may have led to the symptoms you are seeing now.)

Do the hood and front fenders have matching VIN number labels on them, or a sticker that says "R-DOT"? Or no stickers at all?

Everyone is familiar with the VIN tag you can see through the windshield and in the drivers door jamb sticker, but each original body panel also has a matching VIN label. Examples:





R-DOT sticker (OE replacement part) example: