so I've been fighting an overheating issue with my CRX for the last few months. I've replaced the thermostat, flushed the radiator and used a cleaning system by preston in it, replaced all sensors/switches ,rad fan relay and radiator cap and everything seems to be working correctly but car will still overheat after driving for about 15+ mins and then coming to a dead stop (takes about 2 mins for temp to start increasing, and then within about 30 secs temp is in red). fan turns on at 195 degrees but doesnt seem to be enough to keep engine cool and it will slowly creep up until the check engine light comes on (210 degrees). On highway speeds no problem, I can drive for 45 mins straight on highway with temp never reaches even midway. when I purchased the car it came with a massive pulley connected to crank, with NO A/C or Powersteering, and also has adjustable cam gears, which I doubt have anything to do with the under driven components. so as a test, I waited till the temp went into the red the other day (approx 215 degrees) and then I rev'ed the engine to around 2500 rpm's and left it steady there and within secs the temp started to decline all the way down to below the mid level point. so based on this I'm assuming my water pump is either bad, or has been slowed so much by the pulley system that its not flowing coolant fast enough to keep engine cool at a dead stop. So, what would you guys suggest I do in order to keep engine running correctly, my first thought was a larger/better radiator fan (I'm currently using a half sized alum radiator and 1 large sized radiator fan that came with the vehicle... probably something off ebay) any particular fan you guys would recommend using with a B16? new one or maybe a factory unit from a different vehicle?

 

hey, waterpump is driven by the timing belt, no external pulley will change that ratio. are you using the stock rad ? if so, you are probably dealing with a stopped up rad. check your coolant pressure and/or flow while the engine is running. ran into this in the old days (i'm old) when racing ovals. changed rad, inst a good t'stat (oem in this case, from the dealer, period) and a new rad. avail at napa for around $125. gotta repl mine soon, too. good luck
dave

 

well I did run the prestone radiator cleaning in my car for a few days about 1 to 1 1/2 hours worth of driving and then drained it, but didnt use garden hose to flush the system out, guess I will drain it and flush with hose. maybe just take off the whole radiator and check for corrosion, b/c when I replaced the thermostat there was quite a lot of corossion on the metal thermostat housing, mostly on the outside where rubber hose connects to metal housing but also some on the inside. is a half sized radiator sufficient for cooling a B16? b/c i know factory is full sized.

 

sounds to me like the water pump is shot

 

sounds like a clogged radiator. Take off one of the radiator hoses and put a flashlight to it and check for corrosion. If there's a fair amount of corrosion, replace the radiator. It's cheap and fairly easy to do depending on your mechanical ability. Then test your cooling system and go from there.

 

Get a full size radiator. The DA integra one should fit.

 

You sure the fan is spinning the right way? Checking the waterpump is worth a shot. I replaced one that the fins actually oxidized away to little nubs. When you flushed the rad, how quickly did it drain?

 

Bingo. The fact that revving the motor cooled the engine temperature makes believe this is true as well.

If you've ruled out an air bubble in the system, there is likely a blockage in your radiator core.

 

we have replaced many with the fins eaten away and have same symptoms as being described by OP - when they get really bad, they look like the one on the right

 

sweet jesus how does that even happen???

 

to rule this issue out, let's make sure I did this right...
in order to bleed the system u run engine with radiator cap off on a elevated service, such as a drive way with the front of the car higher then rear. then run it until car heats up, then fill coolant to the very top correct?



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fan is sucking air through the radiator onto the engine, same way it would flow during driving. and when I flushed radiator it took like 10 mins to drain but thats because on my radiator it a spicket like connector on the bottom that only opens to a maximum amount and drains through a pencil sized hole. after draining it I filled it with a gallon of water and let it drain that out too, just to be sure it drained out all the cleaning product. but I think I should have taken the garden hose to it :/

 

update: spoke to my mechanic and he said he can use a temperature sensing gun (it uses a laser light and you can point it at different objects to tell their temp) on the radiator in different areas once the car is brought to operating temp, to see if there is drastic temp difference along the face of the radiator. he said if there is around a 10 degree difference in one spot of the radiator compared to another spot then most likely the radiator is clogged somewhere. so will try that on Wednesday and get back to you guys, thanks for all the information!

 

teh impeller can also loosen on shaft + just spin. (took one off an D16A6 not too long ago that did that,it was prolly cranked with ice during cold weather) It would overheat,then run normal,then overheat again til h20 pump r+r'd... G'luck!

 

it happens partly because we are supposed to use distilled water in our cooling system for one. Not changing it in a timely manner and using the wrong coolant are usually contributing factors. All of the ground straps should be properly attached as well. It helps to save all aluminum parts.

 

update: so I tried bleeding the system with fingers crossed and it seems it had a few air pockets in the upper radiator hose I had to squeeze out and it was about a quarter gallon low on antifreeze. drove it around twice now and let it sit running for 10+ mins and no issues. I hope its fixed! woot!

1 question tho:
my overflow tank/reservoir is not air tight, the top of the cap is cracked open on one corner, will this effect the cooling system in any negative way? now I'm thinking the sytem might still be airtight because, the rubber tubing from the radiator top neck ( below the radiator cap ) runs into the top of the reservoir cap and then the rubber hose runs down to the bottom of the reservoir tank where it is submerged in coolant. so as long as there is no air leaks in hosing running from radiator to reservoir tank the system should still be pressurized correctly no?

 

You should have read the directions on the bottle.
Most tell you to flush out the water with cleaning agent and then FILL with water.
Then, with the heater on, run the engine for a while and then drain all of that out.... rinse repeat as much as you want until you feel satisfied that all the stuff is out.
(Take the radiator cap after you open the radiator drain - the water will come out a lot faster)
Garden hose water is fine for flushing.
Distilled water for when you are done so you don't corrode and get build up.

http://www.prestone.com/products/print/424?popup=1

 

I did all that, drained half of coolant, put in cleaner, drove for a few days, drained radiator completely, flushed with gallon of water, then filled with distilled water and water wetter.
.....but the thing I forgot to do was run car until it got hot WITH THE RAD CAP OFF to allow the thermostat to open up and pull water into the block then fill up again with distilled water and push the air out the system by squeezing the top rad hose.

so now anybody that runs into this issue after flushing a radiator will know what NOT to do lol

 

Ah... ok!
Didn't get that from your original post.

 

so going back to my original question,

On my overflow tank/reservoir the top of the cap is cracked open on one corner, will this effect the cooling system in any negative way? now I'm thinking the sytem might still be airtight because, the rubber tubing from the radiator top neck ( below the radiator cap ) runs into the top of the reservoir cap and then the rubber hose runs down to the bottom of the reservoir tank where it is submerged in coolant. so as long as there is no air leaks in hosing running from radiator to reservoir tank the system should still be pressurized correctly no?

 

The system pressure is maintained by the radiator cap, having an open reservoir isn't going to effect anything, besides coolant splashing out.