OK, I am sure I am over analyzing this, but here it goes. To start I have a B18 engine. My car has been running fine in hot weather recently. Yesterday it was hot and I got stuck in traffic. As soon as I stoped I notice the temp went from around 210 (where it normally is) to 220. This concerned me. I was close to home though so I drove the last few minutes and pulled in my garage. When I got home I noticed the fan was on. I know my coolant temp gauge doesn't match when the fan turns on and off, but it shut off and the engine still read 216 and quickly climbed back to 220. 216 seems a little high for the fan to be turning off. I don't know for sure that the thermostat was working, but I do know the radiatior was hot, so it was open at some point if not always.

Today I opened the radiator to see if the fluid was low. I noticed when I opened it the rad made a sucking noise as if it was under vacuum. I also noticed some bits of what looked like a gasket floating at the top. The coolant was not low. Any ideas?

I plan on stopping at autozone and getting a thermostat tonight, but those typically fail open from what I have read.

 

Replacing the thermostat is a reasonable idea given that it is a cheap part.

If you think the fan switch located on the thermostat housing might be bad, uncouple the 2P connector and connect the two terminals with a jumper wire. This will make the fan run whenever the key is ON. If this prevents the overheating, then replace the fan switch.

 

To start, I guess maybe overheating was too strong a work. I am not exactly sure if 220 is too hot for this engine. I just noticed a step change as to where the engine was running on hot days. It use to run at 211 not it runs 220-221.

This weekend I changed the coolant, thermostate, and fan switch. I know the water pump is working. All this and it still does the same thing.

 

Did you bleed the cooling system?

 

No I did not bleed the system. I just let it run for a little and kept filling it. How do you bleed the system?

 

Does a B18 engine have a bleed bolt for the cooling system? It's usually located where the upper radiator hose attaches to engine.

 

when was the last itme you flushed your cooling system? :-D

 

I dont know if I have a bleed bolt. I will check tonight. If I have one how do I properly use it. Do I just open it up and close it when fluid starts coming out? Does it need to be running?

When you refer to flushing the cooling system are you talking something other then drain it all and refill it with new coolant, because that is what I did this weekend.

 

Bleeding:

1) Push the heater lever to MAX heat and then do these steps:

 

No, I mean hooking up a garden hose to it and actually doing a flush with some pressure going through it. That should clean out the garbage that floats around in there.