'93 Temperature Gauge - Overheating
 

All - I am looking for some advice:

I recently got into my Civic and when i put the key in the ignition, the temp gauge automatically registered as high as it could go (it had been sitting in the garage for 2 days - i.e. not hot).

So I went to Autozone and bought a new thermostat and a temperature switch (Autozone.com part #TU121). I know that I installed the thermostat correctly but the temperature switch - I am not sure if this is the correct piece of equipment. It definitely only needs one wire and this is should be the sensor on the engine block closest to the firewall which sends the temp to the gauge. So i replace the sensor (after draining and refilling radiator fluid) but now when i drive it, the temp will stay fine for a while and then it will fluctuate, going up and down sometimes 3/4 up the way of the gauge.

Any ideas??

Thanks.

It may help to bleed the cooling systems as detailed in post #2 here.

Sounds like the gauge is messed up.

Ok - Now i have just driven the car again simulating traffic to try and get the cooling fan to come on - but to no avail. I drove the car until the temperature started to increase (above average and climbing) but no fan.

I then hard wired the fan by wiring it directly to the car battery and the fan comes on, so i am not sure what i should try next - maybe replacing the cooling fan relay in the fuse box??

Now any more ideas?

if all ur wanting is the fan to work u can jump a wire frmo the fan motor to the relay wire for when u turn on ur blower motor the fan comes on... this way u kno the fan is working...

whats next?
 

I posted this detail in another spot, but thought i would add some more detail here so maybe i can get some closure on this 3 week old problem - tired of driving of my truck once and for all....


I recently got into my civic and it had been sitting for about 4 or 5 days and cranked it up and started driving. I looked down after a few miles and my temperature gauge was pegged at high. I immediately pulled over, checked the coolant & it was fine. So then I let it sit all day and night and checked the gauge with just power to the instrument cluster (via a 2 click key / ignition turn) and the gauge pegged out at high again. So here are the things that I have done to try and correct the issue:

1 - Replace the Coolant Temperature Sender (the sensor with 1 connector that sits right below the distributor)

2 - Replaced the thermostat (after a drain prior to pulling thermostat and then refill of engine coolant after replacement ensuring a proper bleed using the bleeder bolt - pretty sure)

3 - Replaced the Cooling Fan Relay (in the underhood fuse box)

4 - Replace the Radiator / Cooling Fan switch (thermostat housing) - and i now have confirmed that the fan comes on and does its job


So now what i find is that i can ride down the road for a bit and the gauge will start to increase ever so slightly about 2/3 the way on the gauge on the high side - like after driving about 45 mph (now my speedometer does not work due to a faulty VSS - another issue though) but then when i slow down it will drop down a little bit to exactly half way on the gauge.

If anyone has any ideas - i would love some help - i have even tried a different thermostat to ensure the temp specs were consistent with Honda OEM....

Will a new radiator help? I think that is the only coolant system piece i have yet to replace?? or do i need a new water pump or how do i even check that?

thanks in advance for the help - i love these forums....

Overheating Issue
 

I just wanted to check to see if anyone has read this posting and has any ideas???

Do I need to check the compression for a blown head gasket??

Also - I called one mechanic just for an estimate for a head gasket replacement and he said it would cost around $1,000 and his quote - "those things won't stay fixed"....is this true??

He also said a head gasket replacement was a tough job to do - just trying to get some thoughts - i am not a great mechanic, but i know enough to be dangerous....

Yet Another Update
 

This is another update to this problem - I removed the spark plugs today for the compression test and found that the plugs (#1 & #2) were very oily - #1 was essentially covered in oil - does this mean anything different or help diagnose? I did not run the compression test yet as i will try to wait a bit for a response from the forum....

Sorry - Forgot to mention
 

1 more thing - could all of this just be the result of my ignition timing not being set properly? I did have to take the distributor off to get to the temperature sensor. If i did not set it exactly back correctly, could this be causing my problems?

Compression Test Results
 

So i ran the compression test this morning....when turning over 7 cranks, each cylinder is at approx. 160 (give or take 1)...when turning over 10 cranks (i.e. max compression) - each cylinder is at about 170, so i dont think it is a head gasket....

I tried the bleed again by letting the engine warm to normal temperature and then use the bleeder bolt to get any air out...i just accelerated the car until a steady stream of radiator fluid came out, so i dont think i have an air bubble....

I also read a lot of forums that said to check the coolant at the radiator neck for bubbles for signs of a head gasket issue and there were no bubbles there either, so not sure...

what is next???