Rep Power: 0

My daughters 2000 civic is overheating. It does this only after its been driven for about 10-15 minutes under moderate loads (speeds up to 35 mph)

I read this thread:
https://www.civicforums.com/forums/3...reference.html

My question is that my symptom is slightly different then out lined by many here. When the car is idling, it warms up just fine and I get heat from the vents. After driving, when I saw the gauge jump up to 3/4 full deflection, I turned on the heater to attempt to supplement the cooling capacity. To my surprise, I only got cold air.


When I got home, there was a fine misting of coolant in the Engine compartment, so it was difficult to pinpoint the origin. (The car was bone dry when we started and it was still completely full from the work I did the night before. The reservoir was also where I left it.)


I heard a HISSING sound and traced it to the hose that goes to the heater valve. If I flexed the hose, the sound would go away. If I released the hose it would hiss. I assumed it is bad. The hose is plugged in right below the distributor. (This will be fun to remove)


I am in the process of replacing the upper and lower radiator hoses as well as this engine to heater valve hose. Since I'm there, I will also be dong the thermostat.


Q - Why did I not get heat when it started to over heat?
Q - Is there a coolant flow chart for the 2000 civic that shows the flow of coolant through the engine and heater?


Yes, I'm hoping it's not a head gasket, but what do you guys think? Can one hose and a thermostat cause this?

 
Rep Power: 518

The hose rupture alone is a big problem. Fix the oil leak at the distributor, that's the usual cause of soaking the hose in oil.

Overheating could cause head gasket breach issues.

Fix the known problems first, refill and bleed the cooling system completely,
then see how it goes.

 
Rep Power: 0

Well, the hose below the distributor was really soft, ballooned and had a crack in it. Definitely bad.

I replaced the hose, t-stat and flushed the system as best I could, bled the lines as best I could (on a hill and let it warm up and watch the bubbles come to the top for about 20 minutes.

Since I had to remove the distributor, I replaced the gasket (o-ring). I did not see any signs of the actual seal failure are there was no oil when I removed the distributor cap. Oddly enough, there didn't seem to be any oil leaking from the distributor. It was pretty clean. There was a lot of coolant as the hose was bad.

Took it for a test drive around the block, some close by back roads and then a quick 4-5 mile sprint across the interstate since it was not over heating. It never did. Total drive about 20 minutes.

I let it cool down and topped off the radiator. My daughter is driving it home now and I am very apprehensive. I know what I did was needed, I only hope it was the cause. I am so concerned that it will over heat on her 20 minute drive home.

Wish me luck.

 
Rep Power: 518

That O ring is what usually leaks oil to ruin the hose below it. Rubber hoes get soft and mushy when soaked in oil.


I'd say to monitor the level in the reservoir daily for a while. Mark the reservoir level with a cold engine, then each time it is rechecked it should be at near the same temperature (i.e. cold after siting overnight) the level should always return to the same point.
If the head gasket breached, it will slowly expel liquid from the radiator into the reservoir but won't be able to suck it back in from the reservoir as it cools.
The reservoir would slowly fill up while the radiator slowly goes low.
......If the breach is tiny, it could be several hundred miles before it displaces enough liquid from the radiator to compromise cooling capacity..

Depending on weather, it might have to lose less than a quart out of the radiator before anyone notices it getting hotter than usual. These systems don't have much reserve so any loss could become critical.

Good luck!

 
Rep Power: 0

Well, my daughter got home! No issues....


Here is an image of the hose that appears to have been the culprit. I do see evidence of oil, but unless the overheating "steam cleaned" the area it looks pretty clean, just full of antifreeze. It also does not look like I have a huge oil leak at the distributor either.


Here is the new hose and slightly broader view of the area.


I want to test the anti freeze in a few days, and check the timing with a gun and see where I go from here.

Thanks for helping.

 
Rep Power: 0

Will do! Thanks, I'll post if it turns ugly or of this appears to fix this overheating issue and I dodged a bullet.
I will see if I can get a compression test or read up on how to check for head gasket leaks.

 
Rep Power: 518

Someone may have replaced the O ring before you, but the hose still looks like it was oil damaged.

If the O ring was brittle and broke when you tried to remove it, it was likely original. If it was still pliable, it's probably been replaced at some point. Seems like we used to replace those starting around 75k or so for leaking.

If you lined up the distributor on the dirt outlines of the bolts, it should be close enough for government work. I usually make a chisel or scribe mark across the housing and head so I can put it back exactly where it was.

 
Rep Power: 133

Should this thread be moved to the 6th Gen section?

 
Rep Power: 0

Absolutely the hose was oil damaged. No questions. I just did not see the amount of oil I was expecting, and as my images show, the area of the distributor was fairly clean and not oil covered. (I didn't clean it before I took the picture)

The o-ring (AutoZone calls it a gasket) was flat and brittle and cracked when I took it off. For a few seconds I thought I had the wrong o-ring to replace it.

I did what you said, I drew lines on the casting exactly where you show the yellow alignment marks for all three bolts. I also made sure to not disturb the distributor once is was out. It went back very easily and the car cranked and started perfectly. Idles and runs fine.

My daughter reports that the car is back to normal and had no issues taking her to work on her 20 minute commute to and from work. I still want to monitor the fluid levels and over flow for a few days as I honestly think I did a hack job of flushing and filling it back up.

 
Rep Power: 0

Did I post this in the wrong section? I thought "Fix-it forum" would be appropriate?

 
Rep Power: 518

I moved the thread already.
96-2000 is 6th generation Civic, you originally had it in 7th gen.

I also unghosted a post I hadn't seen earlier.

Compression test won't find a head gasket problem on this.

Months. Regularly. A small breach could take a thousand miles to make itself known.
Changing coolant levels will be the early warning of a problem, but someone has to be able to watch it.


Werd:
https://www.civicforums.com/forums/3...reference.html

 
Rep Power: 0

Thanks for moving the thread, didn't think I made that mistake. Sorry!


When I said compression test I meant pressure test, the link you provided was the one I had read. A blown head gasket from what I gather can show itself by pressurizing the chamber and watching for bubbles in some fashion.


My little girl (She's 20 lol) is good with cars. She likes to change her own oil and has been there with me when I did numerous brake jobs and does he own basic maintenance, (filters etc.). She will have no problems watching this.