Rep Power: 0

Recently, I've run into a lot of trouble with my car (2001 honda civic ex, 167k, 5 speed). First, I could not get the egr system to work properly, tried 2 different new egr valves to no avail. I tried cleaning the passages, computer was reset several times, still would throw a check engine light (insufficient flow code) usually after 4-8 restarts or x # of miles driven. It would also studder/buck at 30mph no matter what I did.

Then the cat converter clogged up completely allowing basically no acceleration at times. Replaced that and the car ran great. Tried hooking up the egr system again and it worked fine for a little longer then threw a check engine light with the intermittent bucking. EGR has been disconnected since march.

Now my car is randomly starting to overheat once its on the highway after approximately 2 hrs of driving. Despite the problems listed above, I never had a single problem with overheating with this car. Even with the egr disconnected it still ran fine, no issues even with a clogged cat converter. It always reached operating temp correctly with no issues.

Basically, the car will run excellent for approximately two hours on the highway. As soon as a get to the point where I have to slow down from 65 to merge with traffic or get off the highway, the temp gauge starts fluctuating in the middle for a few minutes then starts climbing rapidly. Turning the heat on causes the temp to drop but it will try to climb again randomly at highway speeds. Once I'm off the highway, the car will try to overheat at stoplights or if I drive too slow. If I put my foot on the gas, the temp drops to normal.

I've already checked my coolant, basically it forces a ton of coolant into the overflow tank, leaving the top half of the radiator empty starving the cylinder head for coolant. There is also a thin layer of oil always at the very top of the coolant overflow tank when this issue occurs. However, it doesn't mix with the oil and the coolant isn't milky? There is also oil visibly covering the engine after this occurs as well (front of engine block, rear of block, oil pan, near egr valve, etc).

I'm not sure just a blown headgasket could cause this because the car should be overheating sooner if that is the case? I tried running the car hard for an hour on the highway, it would not overheat. It will never overheat on a trip that has a lot of stop/go even if driven for a few hrs either. Just after a long/straight highway trip thats 2hrs almost exactly. It almost seems like there is a crack in the cylinder head that opens up or maybe another issue? Could the egr valve cause this problem as well? I already tried cleaning the passages and letting it soak in TB cleaner overnight and it still doesn't work for long? Thanks

 
Rep Power: 313

Yea your heagasket has failed... click on the link in my signature to get more info as to why.

 
Rep Power: 235

When you do the headgasket take the throttlebody and intake off and clean the EGR passage(s) behind the intake. Chances are the EGR passages inside the block being clogged are what has lead to cat and headgasket failure. When the EGR or PCV doesn't work right it throws off the air/fuel ratio in the computer causing the engine to run lean. Which would lead to headgasket failure and/or burnt valves and rings. Once you get the heads off you're gonna have to have them at least inspected if not machined. Whoever you have inspect/machine them will be able to tell you exactly what needs to be done to them. If the rings are bad you might as well get a new engine- average cost salvage is about $500 for one with 70-100K.

 
Rep Power: 0

Fixing it is going to be a problem. I can't do it myself, no time, money's very tight, no tools or a place to work on it, and frankly no patience for that kind of work anymore after my last car. My boss was screaming at me for taking two non-consecutive days off in June so asking for more time off isn't an option plus my schedule changes frequently. Sadly, I can't afford a second beater car nor can I carpool or take public transit to get to work. Besides, I've done one in 2005 (1.8 SOHC motor) and would not do it again, it just takes entirely too long to fix it properly even with help and the right tools.

I'm SOL for now so the only thing I can do is drive it as is until my situation gets better or buy a new car in a few months with less problems. I read on here that people drove their cars with this problem for many miles (one guy said 168xxx to 224xxx?) so it can't be that big of a deal. I can buy coolant and tolerate pulling off the road and adding coolant frequently. Most of my driving isn't highway so I never noticed this problem until this weekend when I drove to the shore.

Are there any other tips to keep this thing going? Running without a t-stat, straight coolant, different radiator cap, ghetto rig both fans to run all the time, anything? Does anyone know how long it takes for the air to build up or how frequently I should add coolant? Thanks for the help.

 
Rep Power: 235

OK, I feel ya. We've all been there. Just try to baby it. And try not to drive it more than 2 hours.

Don't run without a t-stat or straight coolant. A different cap and rigging the fans won't help much if any. Check it at least twice a day- before you leave for work and before you leave work. If it's overheating, pull over and let it cool off. Then add as warm a water as you can find. DO NOT add cold water. Just keep a jug or 2 of water in the car.

*Be very careful pulling the cap on a pressurized cooling system when it's hot. You think a burn hurts, wait until you get one with antifreeze in it. This is from experience.

 
Rep Power: 0

Cool, I'll just keep an eye on it for now and take it easy. I check it at least once now and I'll carry some warm water with me for now on. Would it be better to run just water or use a 50/50mix and add warm water every now and then? This would be distilled water right because I think regular tap water is corrosive?

Also, what would happen if it was run without a t-stat? I'm assuming it wouldn't really solve the issue anyway since combustion chamber gases force the coolant into the reservior. Just curious because I already have a check engine light from a disconnected egr valve. Thanks for the help

 
Rep Power: 0

I had the very same problem on my car and it was the head gasket (overheat issue) and valve seals (oil consumption issue) I drove it for a year like that. Sounds exactly like my situation, when I did the head gasket i found that there was a line about a 1/4" wide from the combustion chamber to the coolant gallery, where the black head gasket coating was gone and all that was left was the polished metal center.

my theory is that when the piston compresses that little section acts as a reed valve, forcing air into the coolant gallery and pressurizing the coolant side. Once the pressure gets approx 16 psi pops the rad cap and outs goes the coolant into the overflow. do this a couple of times and the coolant is too low to register on the coolant temp sensor which does not register steam and the engine fan cease to work.

Its not a very big job I did it on a saturday about 10 hours roughly, but you would want to change your valve seals waterpump, timing belt and tensionor, at the same time. with regular hand tools few specialty tool and the Honda manual. I did not get the head machined tho as it was within spec.

driving without a thermostat is a bad idea... the engine will never get up to proper temp and eventually will cause other problems. If you continue driving it the damage will vary... worst case scenario warp your head or the block or hydraulic lock stuff like that.

I would make sure the coolant always full. and make sure that the coolant is not getting into the oil. Check your dipstick alot coolant in the oil it will cause a bad... knocking sound.

I just kept filling mine up til i got fed up and fixed the problem.
good luck!

 
Rep Power: 313

10 hours for one person could take days for others... but whatever.. you can't say its not a big job because it is lol... its not overly hard but for the average DIYr its pretty complicated.

 
Rep Power: 0

true... i wouldn't go at it without the service manual tho!