1988 CRX Si, 186k miles, D16A6, fresh rebuild with about 1,200 miles on it.

Out of the blue this weekend coming back from an autox to car starts to overheat rapidly. I get out and pop the hood to find a HOT upper water pipe and a COLD lower water pipe. I fiddle with it and make a couple of very short attempts to drive it. One time while pulling back onto the road, I spun the tires and got a bit of wheel hop and the gauge shot down like a rock, but after about 500 yards, started to climb again. Luckily we had someone towing in our caravan and we put my car on the trailer to get it home.

I figure that something is clogging the system and that its the radiator since its only 17 years old and one of the few things I didnt replace in the rebuild. Pop the new radiator in there and nothing has changed. So I figure its the T-stat, so I go and buy a new one at NAPA. Pop it in and nothing changes, overheats in like 10 mins.

So we take the T-stat out all together and it gets close to operating temp and the temp gauge mysteriously falls to its lowest point (almost like it quit working) and after about 10 mins of idleing gets close to operating temp and holds. I let it idle for about 20 mins and shut it down for the night.

WTF is going on here. It sounds like something is itermittently clogging and unclogging the cooling system or the water pump is only working sporadically. The water pump is new, but is NOT a OEM Honda pump (Autozone special). I think I need to replace the water pump with a OEM pump but wanted some opinions before I did.

TIA!!

 

was the timing belt done the same time as the waterpump? i would also check the actual temp of the coolant flowing through. get a heat gun and see if your car is actually overheating. if your temperature sensor for your gauge is not working correctly you could be getting the false readings. if the car IS actually overheating, double check the thermostat first - sometimes they do come defective from the box, and then check the waterpump. good luck.

 

maybe your headgasket. imo

 

When the motor is cold, With the T-Stat out, take the rad cap off, and see if the water is flowing, if it is, then your water pump is fine, and its doing its job, so is everything else. I would say your temp reading is false. Also do the fans kick on?

Also, Turn your heater on full blast if it starts to heat up and see if that cools it down a little, Turn on the heater full blast. keep your motor reved up. See if that cools it down.

 

Check the new thermostat it is possible you got a bad one.I always check my new ones in hot water with a thermometer.

 

test the thermostat in hot water and drop it in like a pot on a stove and use a thermometer to get to the specified temp when the thermostat opens. Its probably 180 or 210 degrees and if it dosnt then its faulty and get a new one. Also did you get all the air bubbles out of the cooling system? If that dosnt work it might be the head gasket and do a compression test. Also another way to check the head gasket is to see if theres water in your oil by checking the dipstick.

 

I have put 2 new thermostats in.

Timing belt is new.

There is no water in the oil.

We had the infared heat gun, with the Thermostat in, the upper hose would get close to 200° and the lower one would only get to 75°. Its not a faulty gauge reading either. The water was boiling out of the top of the radiator.

WRT flow thru the radiator. It only seems as if we have flow when Tstat is out.

How should the water flow in the system

Does it pump out of the upper hose thru the radiator thru the lower hose and back around. Or is it the other way around.

I just cant help but to think that the $25 autozone pump is crap.

 

Make sure you aren't installing the t-stat backwards.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sporkcrx &raquo;</TD></TR><TR><TD CLASS="quote">Make sure you aren't installing the t-stat backwards.</TD></TR></TABLE>

It can only go in one way. The spring is point toward the water pump.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ecugrad &raquo;</TD></TR><TR><TD CLASS="quote">

It can only go in one way.</TD></TR></TABLE>

That's a negative.

 

https://honda-tech.com/zerothread?id=434232

 

Ok, I read the link and it sounds ohhh so similar to my situation.

So what is the correct way to install the t-stat? I have the spring facing the drivers side of the car:


Passenger Side---------------------------------------------------------------Drivers Side

 

Mine was doing the same on my B20vtec and after replacing everything that mattered, (I thought) it turns out that a new radiator cap fixed my problem. It needs a certain pressure to work properly. Try it out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ecugrad &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I read the link and it sounds ohhh so similar to my situation.

So what is the correct way to install the t-stat? I have the spring facing the drivers side of the car:


Passenger Side---------------------------------------------------------------Drivers Side
</TD></TR></TABLE>

That is the correct installation for the thermostat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by action38 &raquo;</TD></TR><TR><TD CLASS="quote">Mine was doing the same on my B20vtec and after replacing everything that mattered, (I thought) it turns out that a new radiator cap fixed my problem. It needs a certain pressure to work properly. Try it out.</TD></TR></TABLE>

All of my testing was done last night without the radiator cap on to "burp" the radiator. Although, it will do the same thing with the cap on.

 

i had the same problem. i was going out of town to visit my sister and the car started to overheat when we finally got off the freeway. once we started moving it would fall down. it kept doing this and we had my sisters bf's uncles take a look at it. they said that it could be my thermostat and said to take it out and let the coolant flow freely. we took it out and took the car around a couple of blocks. it worked for now. we had to drive 4hrs back like that. about 3hrs into the drive the car started to overheat again, this time on the freeway. we had no choice but to call someone to pick us up. we towed the car the next day and installed a new waterpump and even reinstalled the old thermostat. it ran fine ever since. sonce we were using the old thermostat, it had to be the waterpump. thats my guess from my own experience.

 

A new water pump is on the way, thanks for the help!

 

Just an update for the archives, the new water pump (Honda OEM) fixed the problem. A friend and fellow CRX owner had the same problem with a water pump from Autozone.

 

Nice! I love when people update with the solution. Moral of the story, waterpump go with oem!