ElliotSiR

I drove my car a total of 300 miles today on the freeway going to see my friend and then coming home this evening. My 1995 Civic DX Hatchback performed great, until I got off the exit a few miles from my house. My coolant temperature shot up very rapidly as soon as I came off the freeway (it had been steady all day). Since it was only about a mile and a half to my house I switched on my heater full blast and just rolled the windows down. The air coming from the blower was very hot so I know the car was infact running very hot. The tempurature then fluctuated between about 7/8th and 1/2 on the guage, fairly rapidly as I drove home. I was wondering if anyone has had a similar experience coming off the freeway after driving 65mph for a long period of time. I'm going to diagnose it tomorrow, I figure it has to be one or a combination of 4 things:
-Thermostat decided to go bad on me and is stuck open
-Waterpump gave out (previous owner changed it and I suspect it's a cheapy Chinese made one not an OEM Honda one)
-The coolant sprung a small leak or has an air pocket or two
-The head gasket had a very minor failure (since I don't feel a misfire or loss of power, this is probably worse case scenario but a possiability after 200k miles and not knowing if it has ever been changed)

Just an interesting occurance, was wondering if anyone has experienced something similar, I'm sure I'll find the problem tomorrow morning, I'm not looking for instructions on what to do just so no one wastes their time typing out a procedure that is second nature to me at this point. Anyone had anything similar happen to them?

Cliffs:
-Drove the car on the freeway for an extended period
-Coolant temp started fluctuating greatly after exiting freeway
-Not looking for a diagnosis procedure, I know what I'm doing and am 100% confident I will find and fix the issue tomorrow, just wondering if anyone has had a similar experience

daonight

Radiator hose colapsed.

ElliotSiR

Possibly, it's too dark to check tonight I'll have to check tomorrow. Only way I can really see it collapsing is from an air pocket, which I stated might be the issue. I won't know until tomorrow.

Townson

im just gonna take a stab in the dark and say thermostat. thats what i'd check first anyway.

SikEj8

The radiator hose can also collapse due to a faulty radiator cap. It relieves pressure out into the overflow tank then allows it back into the cooling system when the pressure retracts. its so simple yet a very important part of the cooling system..check it out

thenext

Just went through the same thing, mine was a blown head gasket. Those radiator caps can be junk too man.


Pull the radiator cap and run it. this checks a few things at once:
-If there is exaust smoke running out the radiator, headgasket
-If there isn't any coolant moving when its up to temp, waterpump
-grab them hoses and see if they are warm to check the stat.

lazlong

Classic symptom of a bad headgasket. Although I would still make sure the fan, stat, and waterpump are working ok.

frankenghia

Its a bad head gasket. When you are driving on the freeway its rushing the fluid throught the system. When you slow the motor down the thermostat gets an air bubble in it and makes the temp sky rocket. I just went through the same thing. It sucks....

thenext

Hey it is a good excuse to check your engine out! It really isn't that hard pulling the head. Mine came off without a fight.

ElliotSiR

What I did this morning:

-Checked for leaks, found none
-Checked hoses, they were fine and attached firmly
-Did a compression test 1-200 2-200 3-195 4-198
-Ran the car on my driveway for approx. 10 min. Fan never kicked on (I know it works, I've seen it working within the past week), upper and lower hoses took longer than normal to heat up (about 3-5min.)
-Heat needle never got past 1/3 of the guage
-Radiator cap stayed cold the entire time

My guess is that either the headgasket has a hairline crack between the oil galley and the coolant jacket (there is some slight "milkshake" looking stuff on the radiator cap but nothing in the oil, could just be really nasty coolant but more than likely it's an oil/coolant mix), and/or there is an airpocket/thermostat/radiator cap issue. I can eliminate the water pump because it's obviously working fine, which is good (about the most expensive part to fix considering I only buy OEM ones from the dealer since I don't trust those chinese made Autozone/Kragen pumps). I have to go do a clutch on a Miata right now, so hopefully I can get back to this either tonight or tomorrow and start pulling things apart. Unfortunately I don't have access to my 40% off parts hook up this week since they're closed, so I may tear it apart but fix it next week when I can get the parts a lot cheaper (considering I only have about 200 bucks to fix this). If it's looking like it's going to be more than $200 to fix it after I get a parts quote, I'm just going to go into my savings account and swap the car, no point in trying to repair a D series when I want to go B anyway.

frankenghia

Dont forget to resurface the head.

ElliotSiR

I'm well aware of what's involved thanks.

I won't know for sure what the problem is until tomorrow when I can dig into it, so I guess I'll pull the head and see if the gasket is actually bad, hopefully not but I'm betting it is. If the gasket is bad I'll have to price out a repair, if it's going to be expensive (more than say $500 in parts/head work to do it right) I'm just going to dig into my savings and swap the car instead.