Hi all!

I'm having a similar issue and I can't understand what's going on. This is on an accord 95

The thing goes like this. I start the engine and it warms normally., but the gauge never passes 3/8.

After driving for like 20 minutes, I notice the gauge becames....strange. Instead of the gauge rising a little over the half and the fans starting, the gauge stays below half and reacts when I step on the gas. Sometimes, if I reach temperature where it fans usually start, I can see the gauge rising (instead of reacting to accelerating the engine).

First I though that the gauge was not working, but it actually looks like I'm not having good water pressure.


Things that happen to this engine so far:
* I bought it almost a year ago and back then I replaced the radiator (and cap) and t-stat. So it's new
* About a month ago, I broke the timing belt while on the route at about 80M/h. Because of this, I replaced all the valves, gasket, the head was flat.....a lot of things were done to the engine.
* 3 month ago I replaced fans relay.
* 2 weeks ago I replaced the radiator cap and the water reservoir. I live in Argentina and there few parts for this car, specially the not so common ones (like reservoir or wheel caps, things like those)
* yesterday I replaced both radiator hoses

so, I have replaced almost all the colling system, and still I'm having low presure.

I checked the hoses after driving. I can notice both are hot. I notice that the water boils in the reservoir (another thread says it may be the rad cap, but I checked it and it's working properly).
Also, fans are not starting while driving (as I explained above) and are not starting when I turn it off. I did try the shorcut where the t-stat goes, and both start.

At this point, I'm not seeing any leakage (I did saw before replacing the cap and hose, recently). I'm not noticing loosing large amounts of water (since some water boils, I expect that boiling water to be lost somehow). I'm not burning oil and I'm not seeing it with water. I'm not seeing smoke (wheter gray, black our white) in the exaust.

At this point, I'm entirely lost =( . All I can think now is that the gasket was not put correctly and is loosing pressure there. But why when the water is how? why the fns don't start? and why the gauge behaves so strangely?!??!



PS: sorry if I'm stealing this post. This looks similar to my issue and, while it doesn't says if it was fixed, it's been long since updated.

PS2: I'm not native english. I'm from Argentina and parts and mechanics are pretty expensive lately. I spent a lot of money after breaking the timing belt and bringing the reservoir and rad cap. I would like to test everything that can be possible before asking a mech to check the gasket.


Thanks!

 

Moved post for better response. Don't tag a new item onto an ongoing thread, it just confuses everyone.

If no coolant is being lost, you may have a faulty thermostat.

Otherwise most likely explanation is combustion gases are entering cooling system through a faulty head gasket (i know it's new, but improper installation is not unknown). That would be reason for boiling in the coolant reservoir. There is a chemical test that can be performed on coolant to detect combustion gases.

good luck

 

Hi TH, thanks for your response

Sorry for the long response, but I wanted to test and try before bugging here.

So, I've 'fixed' the gauge funkyness. Luckily, it wasn't the gasket. The thermo-switch B was kind of loose. I tested if it worked fine (which it did), but it had some plastic debris inside so I cleaned it. I also find that a mass wire, plugged about 4" 'deeper' from the thermo-switch B was also kind of loose. Pluggin this wires the gauge now works fine

However, now I have noticed something different. When I leave the car idling, the gauge range from a little below half-mark to a little above. When I drive in avenues or higways (usually no more than 60 MPH), temperature stays a little below the half mark. Now, when I drive for about 20 or 30 minutes in city traffic, temperature rises from half to 3/4 of the gauge. The fans work when driving, but maybe they don't start soon enough? I also noticed that fans don't keep running when I turn off the engine and sometimes the water boils a little bit (I'm assuming because of the overheat).

PS: I know fans won't start when turning AC on, since the AC system had a leakage and lost all the gas


Thanks!

 

X2 for a leaky head gasket. Was the block checked for flatness when the head gasket was replaced?.

 

Hi Roader.

It was flatted when replacing the gasket. Coolant is normal, so I'm not sure anymore it's leaking. I'm thinking I should replace both thermo-switches, is there any way to test them?

 

The thermo-switch in the thermostat housing is the one with authority while the engine is running, so you should probably ignore the one at the upper radiator hose.

Also, that switch should be set to run the fan when the temperature gets a bit above normal. Your description sounds about right. When driving along, the temperature is about 35% or 40% of the gauge. Stopped in traffic it should climb a bit, maybe 60%, then the fan comes on. Pretty hot now in Argentina? We have about 10.F now, so maybe we aren't thinking about summertime behavior.

 

Hi Jim

What you say is not what's happening to me. It idles around 45% - 55% and when in traffic goes from 55% - 75% (but I've seen some spikes at 80% and this is what scares me).

Yes, it's summer and hot here. Not as hot as Australia (same latitude and usually same weather), but during these summer days we're around 86 to 100 °F.

I'm still find odd that fan don't turn on when I stop the engine.

BTW, where is the temp sensor?

thanks!

 

There's 2 temperature "sensors" & 2 fan-switches.

On the side of the head, there's 2 temperature sensors, sorta below the distributor. One has a 2-wire connector - that's for the engine controller. Next to that is a 1-wire sensor for the dashboard temperature gauge.

In the thermostat housing (follow lower radiator hose back towards firewall) is a fan-switch that has authority while the engine is running. This one should run BOTH fans.

In the upper radiator hose nozzle against the head, is another fan switch that has authority after the engine is shut off. This runs only one fan, usually for several minutes after turning off the engine. It has a higher setpoint, so doesn't ALWAYS come on.

Getting up to 80% would probably make me nervous too, but really the dashboard gauge isn't the most accurate thing either.

 

Testing the fan circuits...

After the car has been turned off for a couple hours, unplug the fan switch at the upper radiator hose. Short the 2 pins on that wire with a paperclip or some little piece of wire. Turn the key ON (I don't think you actually need to start the engine). Now when you turn the key OFF it should make ONE fan run. If you were to leave it running, there's a timer to shut it off after 10 or 20 minutes. That checks out the circuit, timer, fuse & relay.

Put that back together & find the fan switch back on the thermostat housing. Unplug the wire and short between the 2 pins of that wire. When you turn the key ON, that should cause BOTH fans to run. If that's good, then the circuit, fuse, & relays are OK for that one. In that case, it leaves the fan switch itself so maybe it's turning on at too-high temperature.