22 replies to this topic

[1g Supremacy]

Well, tonight, I trucked on down to AutoZone, got a new thermostat (And some ricey blue corner lights. Sometimes you have to satisfy that ricer in you, even if only for a few hours.)..

Well, I THINK I put the thermostat in right. My friend pulled it out, so I'm not really sure how it went in. But it seemed to fit in nice and neatly. I bolted the housing back on, put the coolent back in..started the car.

Nojoy.

Temp needle rose and rose until it was just barely out of the red. At that point, I turned the car off. Smoke, or steam, was coming from the rad cap and the surrounding hoses.

So, this makes both the fan switch and the thermostat I've changed.

I touched the hose going into the thermostat housing. Ice cold. No coolent is flowing. Fan is still not coming on, which is kind of telling me no hot coolent is making it back into the rad.

There are no coolent leaks.

So, what's next? Break down and replace the rad? Water pump maybe? That'll practically replace the whole cooling system.

[Gumby]

i would say replace the water pump, and flush ur rad

[Madkore]

Sounds more like a plugged radiator.

Waterpump would either be loose and loud, or seize.
Did you replace the WP the last time you replaced the timing belt?

Was the car running hotter than usual prior to this more severe overheating problem?

[1g Supremacy]

Was the car running hotter than usual prior to this more severe overheating problem?

The car didn't run at all prior to the more severe overheating issue. It's been doing it since the mechanic put the EW5 in it. He also replaced the timing belt, but I'm not sure if he replaced the water pump. He's a skilled guy..Highly recomended..so I'm sure it's something he checked.

How can I test the water pump to see if it's working?

[Madkore]

The WP is driven off of the timing belt.

If the car runs, it probably works fine. There is no real way to check since it's behind the timing cover and you can't tell if the bearing is going bad even with the WP exposed. Older Civics (G1 and G2) you could just grab the WP pulley and wobble it to see if the bearing was loose since it was exposed and driven with the crank pulley.

This is why most dealers will replace the WP at the same time as the Timing Belt. There's really no additional labor, just the price of the WP. Cheap insurance because if the WP seizes, you are almost guaranteed to bend valves. Very expensive.

Honda WPs seize, but don't lose their cooling fins or disintegrate(some WPs do), in which case it would be really really loud.

Make sure your T stat is in the right way first.

General rule of Backyard Mechanics: The person who removes a part from the car should reinstall the same part, and should definitely pay attention to the proper orientation of the part.

Sounds like a plugged radiator if you are getting no flow at all. Especially if the car didn't run for a long time. And it sounds like everything else is OK. But again, double check the T stat. And make sure all of the electrical connectors on the right (passenger side) of the engine are connected properly to ensure proper fan operation.

How many miles does your car have? Radiators can lose significant flow around 100,000K. Your could try draining the coolant and disconnecting both radiator hoses. Check the inlet and outlet tubes for blockage. Put a garden hose in the inlet and see if the water comes out the other side. No flow, no go.

[Surestick]

Have you tried replacing the rad cap? If it doesn't hold pressure you will over heat (and it's cheap so you've got nothing to lose).
Make sure you don't have any leaks in any coolant hoses (you mention steam coming from "the surrounding hoses") as that will mean you aren't holding pressure as with a bad rad cap. Sometimes the leak will only show when the system is pressurised so try & isolate where the steam is coming from.

The first time I changed the T-stat I didn't put the gasket on properly, it fits around the end of the T-stat & I had it between the T-stat & the "cover" of the T-stat housing (real smart I know) it leaked of course & took me a while to figure out.

Are you sure you got all the air out of the cooling system? If not done properly you can get an air bubble in the head that can cause cooling problems.

[myheadhertz]

Most of the time, water pumps don't stop circulating water when they go bad. They leak or start making noise.

An air bubble in the block near the thermostat will keep the thermostat from opening before the engine overheats.

Before you replace the water pump, please try this...

Drain the radiator down a bit and then open the bleeder bolt (located near where the top radiator hose attaches to the block). With the bleeder fully open, add coolant until thr radiator is full and fluid is running out of the bleeder bolt without air bubbles. Shut the bleeder bolt (not too tight!). Squeeze the top radiator hose to burp air, add some coolant, squeeze the hose again, add coolant, repeat until you get bored. Now see how it runs. Good luck. This procedure worked for me.

[1g Supremacy]

I'm pretty sure I got the thermo in there right. I got the o-ring around it without a problem, and I fit it in the whole..I didn't feel any grooves or anything for it to fit into..so as far as I could tell it just kind of presses in and is pressure held?

I'll definately try purging the system of air bubbles.

How much coolent should I drain from the rad?

And what is the common procedure for refilling the rad? As far as I can tell, the overflow tank doesn't open, so I was just puring it back down the rad cap. And that took forever. I want to avoid that if I can.

[kenny86si]

I know from my experience w/ my crx that a bad radiator will throw you of track in finding a heating prob. I did the whole thermostat thing and no difference, it would get hot idling and going on far drives. After pegging the gauge one time far from home I got fed up and shortly there after replaced the radiator. what a huge diff.. The car runs at 1/4 temp constantly when it used to run at 1/2 or a little under since purchase and it solved all my heating problems. not saying thats yours but I couldn't stand fighting that gauge no longer.

Try bleeding the system:

My manual says this : loosen the cooling system bleed bolt to purge air from the system. When coolant flows out of the bleed port, close the bolt and refill the radiator with coolant up to the mouth. To purge any air trapped in other parts of the system, set the heater control to Hot, start the engine, set it to fast idle and allow it to reach normal operating temperatures. DO NOT tighten the radiator cap and leave the heater control in the hot position. When the engine raches normal operating temperatures, top off the radiator and keep checking until the level stabilizes; then , refill the cooling resevoir to the full mark and tighten the radiator cap.

and pull that thermo back out once more to double check its correct install(install the thermostat with the pin towards the thermostat housing outlet). Then go from there. Good luck

Edited by kenny86si, 19 January 2005 - 10:18 PM.

[myheadhertz]

Kenny's procedure for bleeding the system is excellent! I'd just like to emphasize that you should have the bleeder bolt open from the very start - while you are filling the radiator. Open the bleeder bolt first, before you do anything else. (I'd drain about a quart out of the radiator before starting the bleeding routine.)

[1g Supremacy]

Victory is mine!

The new rad cap seemed to be the keystone. Fan fires up, Coolent's flowing, everything's working. Now let's hope it stays that way.

Guage is at about 3/4, but from what I hear that's normal. It idled for over an hour (Before it started tor un out of gas), and never climbed above 3/4...so I'm sure it'll stay about there.

Thank you all for your help. I may go ahead and bleed the system anyway if I get bored.

[r49crx]

Victory is mine!

Guage is at about 3/4, but from what I hear that's normal. It idled for over an hour (Before it started tor un out of gas), and never climbed above 3/4...so I'm sure it'll stay about there.

just my .02,,, but you might want to keep an eye on things. 3/4 sounds kinda high to me. ,mine runs at 1/3 & very rarely goes above. might want to think about relaceing or at least rodding out your radiator.



good luck!
frank

[Surestick]

Good!

3/4 is a little high as indicated above. You might end up replacing the rad but it's an easy job.

When you put the thermostat in you put it with the little loose pin thingy up right?
It has to be up so that air can bubble past the thermostat as you fill the system with coolant.

Funny, I was having these exact same probs & had the exact same questions a bit more than a year ago when I got my 'Rex... I knew nothing about them then & this thread just made me realise how much help this board has been and how much I've learned thanks to it.

[1g Supremacy]

Yeah. It's 'up'. I felt around inside the cavity a little, and it felt like it had two indentations. I kind of put 2 and 2 together, and the O-Ring had two little flanges..so I lined up the flanges on the o-ring with the indentations in the cavity..Yay me. But it's working, thank God.

I'll replace the rad for sure. A 20 year old rad that sat in the desert for 10 years is probably far from clean. I just wanted to get the system working. And it is.

Thank you all for your help. You've been great.

[Greg Gauper]

The stock radiator works just fine, assuming it is in good condition. They do plug up over time and this does hurt cooling efficiency, and yes, this can cause you to pull your hair out. I ran hot (190-195 on a 'real' gauge) my last year of running in ITC class before I replaced my 10 year old radiator. I then put a new, stock unit (actually a Modine replacement) and my temps never got higher than 180 with the stock OEM T-stat (180 degree) including one very hot July race (mid 90's).

Fellow racer Bob (1st Gen Boy) ran into the same problem when he hit the track with his 86 CRX Si that hadn't been sitting for several years. It too ran hot in the first race in April, but then he installed a new radiator and his temps have been fine ever since.

The stock radiator works fine for modified racing as well. I believe Kirk runs a stock unit on his full prep GTL car, and I haven't had any overheating problems with my 'limited prep' Production motor. In fact, I have been battling the exact opposite problem....I'm running too cold! Ever since Jay jinxed me and caused my brand new OEM T-stat to stick closed, I have experimented with blanking sleeves, modified aftermarket T-stats, etc, and still end up having to tape off half the grill to get the car to run hot enough (shooting for 170). Without the tape, I ran 150 on a hot 90 degree summer day at Indy Raceway Park!

FWIW - after screwing around last year, I have decided to give the OEM T-stat another shot. I'm going to take a chance and assume that the stuck unit was a combination of a fluke and bad karma from Jay