Last week my 1998 civic lx overheated and the cel came on, found hardly any coolant in radiator and cel was for the temperture switch that controls the radiator fan. Also I had coolant spots below the upper radiator hose where it connects to the engine.
I tested the temp switch and it was no good, so I replaced that and the thermastat also, plus just for safe measure the radiator cap to. I ran the car for awhile and the fan does come on, lower hose gets hot, so I topped off radiator and overflow tank.
The problem I am having is when I checked the cooloant level a few days later I noticed that the radiator was a little low and the resisvor tank now higher then I had filled it, also there is still some coolant spots below upper radiator hose on engine block.
I know that I should have replaced the upper hose but do you think that is the only issue? It seems odd that coolant would be forced into the overflow tank if the car is running at regular temp. (temp gauge in instr panel shows just under half way while driving) No other incidents of overheating so far.
Any help would be much appreciated, this is my first time on a car forum. Thanks
Be sure to closely inspect to your upper radiator tank (plastic) all the way around. Those are very susceptible to cracking and seeping after overheating happens. Hose should be fine pretty much forever if it's original as it is not rubber, but silicone.
Also, beware of your head gasket. It may be leaking as it only takes one overheating to warp the head slightly and cause the gasket to leak. That can cause rapid loss of coolant as well as make the overflow volume go up.
Thanks for the quick reply, I will check both areas like you said. The coolant seems to be collecting on the lower bolt just below the hose, is it possible that air is being sucked through the hose at that point? Anyways I will look into it tomorrow and post again. Thanks
Well all the expansion and contraction of coolant means air could go in or coolant could be pushed out all within a single drive/cool-off cycle.
If you are talking about the bolt just below the upper hose, it's most likely a mounting bolt for the radiator fan. That would indicate (most likely) the seam is letting go between the aluminum body and upper radiator tank.
Scott, the bolt I was refering to is were the hose meets the engine not the radiator. It sorta looks like a thermastat housing but its at the front not the side. As far as coolant in the oil, I have been checking the oil frequently and just gave it an oil change last night and no sign of any coolant.
Is there any chance that the water pump is not working 100%, I say this because I am due for a timing belt? Or is it time for a new radiator, as far as I can tell its the original and I have over 230,000 on this car. I would think that if the head gasket needed to be replaced the car would be showing signs that I am not seeing (running hot, poor mileage, etc) this car is still getting 40 mpg on the highway, runs good not hot. The only other possibility is the front of the radiator where the lower grill is, lots of the fins are tweaked from rocks, and other road debris. Maybe this is causing reduced cooling.
Yes, there is a chance the water pump is weeping away some coolant but I kind of doubt it's loosing all of it there. Check the drainage hole at the bottom of the timing belt cover. If it's damp replace the water pump (and timing belt of course). If not, do a compression test...and a radiator pressure test. Either of those could show a head gasket issue.
Also, if you take off the radiator cap with the engine cool, start it up and see if bubbles come out there. If they do, you did in your head gasket and you'll need to pull the head, have it resurfaced and replace the gasket.
As far as the antifreeze near the engine, I'm guessing the heat did in the gasket there.