Basically its an overheating problem.
Ok, this is an ongoing problem, and I REALLY need to find a solution soon or I'm going to drive my Lude off a cliff (probably with myself inside)

Links to other posts that I have made about this topic:

https://honda-tech.com/zerothread?id=1098735
https://honda-tech.com/zerothread?id=1095437
https://honda-tech.com/zerothread?id=769783

History: (This might be boring, but I wanted to include everything that I can think of that might ahve even the slightest effect on the cooling system)

Bought the car (92 Si h23a) about 4 years ago (260k klms), and it's always run a little warmer than I thought was normal. But living in Australia, I didn't think much of it. The only aftermarket parts on the car were a 2.25" exhaust and some dodgy aftermarket headers.
Started to start getting the car ready with a few performance parts, lightened the flywheel, rebuilt clutch with brass button variation.
About 3 years ago it started to run much hotter.
About 2 years ago I spun a big end bearing. It then took the next 18 months to rebuild. I basically tried to set the car up for FI, with Darton sleeves bored to fit 89mm JE 9:1 pistons, crower billet rods etc. I also had to replace the crank (and re-nitrated it), however it looked to me as if the journals (?) on the replacement crank were bigger than the original. Water pump, radiator cap and thermostat were replaced. They sent the radiator in for pressure/crack testing and it passed.
6 months ago got the car back from the mechanic. Really noticed that it overheats (ie can't drive more than 3klms without it hitting the red zone on the cluster). Added Hondata with new ecu, only run the car on 98 octane unleaded. Only managed 85kW at the wheels.
1 month ago I took it to a different mechanic (he used to work for honda for 17 years) and he did a diagnosis on it. He found that the radiator cap was jammed shut, replaced it and it seemed to work alright again, for about a week, and now its hot again.

Other info:
one thing I have noticed and its been bugging me is that when the car overheats (and it'll go all the way up to the red bar) i can turn the car off and straight back on again and it will only read half way on the gauge. However it does go up quickly(within a minute) again.
Also, the thermo fans do work, but they only seem to come on at odd times. Sometimes they will come on when it goes one bar over half way, and the car will cool down again. but most of the time it wont come on even when the car is in the red. Sometimes it will come on after the car has been turned off for up to 2 mins.
Also, AC is FUBAR, it worked sparadically before the rebuild, but now it only blows very hot air.

The only things I can think of now are that maybe there is an electrical problem... or that perhaps the guys who did the rebuild installed the headgasket the wrong way up (i've heard that that can block off a few of the water channels through the head/block) Or maybe I just need a new radiator. I am happy to buy a good aftermarket one if I know for sure that it will solve the problem.

Please don't hesitate to throw up any suggestions or further questions.... I am really at a wits end with this... its breaking my heart, I love my lude, but i can't drive it.

 

bad temp sensor? bad thermo switch?

 

Hey man,

I am not sure if you tried this already but take the thermostat out completely. Run it and let me know how it runs.

Oh, great write-up. That was done perfectly!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrettyLude &raquo;</TD></TR><TR><TD CLASS="quote">bad temp sensor? bad thermo switch?</TD></TR></TABLE>

Is there any way of testing to see if its one of these? (other than buying new ones and installing them)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AndyD &raquo;</TD></TR><TR><TD CLASS="quote">take the thermostat out completely. Run it and let me know how it runs.</TD></TR></TABLE>

I asked if it was a good idea to take out the thermostat in one of my other posts, and the verdict was that it needs to stay in. I'm willing to give it a try as a test, and report back on my findings if you don't think it'll hurt the engine in any way. I'll try it this weekend.

 

A new thermo switch is not very expensive like 12 dollars. Fixed a simillar problem in my car

 

when we ran our race car with no thermostat it overheated within minutes.

have you tried taking a temp reading with a different gauge?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by preludeguy_92 &raquo;</TD></TR><TR><TD CLASS="quote">A new thermo switch is not very expensive like 12 dollars. Fixed a simillar problem in my car</TD></TR></TABLE>
Sorry to sound like a n00b but that's a different part to the thermostat isn't it?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">when we ran our race car with no thermostat it overheated within minutes. </TD></TR></TABLE>
I have heard that it is important to keep the thermostat, because even when it's open it still restricts water flow. This may sound bad, but it allows the hot water time to dissipate heat in the Rad...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">have you tried taking a temp reading with a different gauge?</TD></TR></TABLE>
Haven't tried a new console gauge- i'd say that will be one of my last resorts (allong with an aftermarket Rad.) because I imagine that it would be quite a costly exercise... But the mechanis had one of those laser thermometres on the engine and he said it was in fact running too hot (although I wasn't actually there, so i've no idea what the exact reading was...)

Thanks for the posts peeps, keep em coming!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">when we ran our race car with no thermostat it overheated within minutes. </TD></TR></TABLE>

HAHAHAHA, you are kidding me, right?? There is NO WAY the car would overheat if there is no thermostat. Why do you think companies put fail-safe features on the thermostat that keeps it open when it fails??

 

To test the thermo switch/fan switch check the resistance to see if its out of specs.

You could also plug in a different gauge and check the temp sending unit to make sure its working right.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AndyD &raquo;</TD></TR><TR><TD CLASS="quote">HAHAHAHA, you are kidding me, right?? There is NO WAY the car would overheat if there is no thermostat. Why do you think companies put fail-safe features on the thermostat that keeps it open when it fails??</TD></TR></TABLE>


no this jsut shows you dont have a clue actually. the thermostat is there to regualte water flow, if it flows too fast, such as with NO thermostat, thn water never has a chance to cool down in the radiator. it HAS to flow slow enough to pass heat to aluminum in order to work. even all the way open a thermostat restricts water flow.


In our case we removed the thermostat because we listened to a jack *** like you, and though we were running a 1 inch thick radiator that was the saize of an integra radiator for an all motor D series engine we had boilover after ever pass we made with the car, and got thrown off the track for leaking on it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Arch-Angel &raquo;</TD></TR><TR><TD CLASS="quote">
I have heard that it is important to keep the thermostat, because even when it's open it still restricts water flow. This may sound bad, but it allows the hot water time to dissipate heat in the Rad...</TD></TR></TABLE>

you are exactly right, we learned that the hard way.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Arch-Angel &raquo;</TD></TR><TR><TD CLASS="quote">
Haven't tried a new console gauge- i'd say that will be one of my last resorts (allong with an aftermarket Rad.) because I imagine that it would be quite a costly exercise... But the mechanis had one of those laser thermometres on the engine and he said it was in fact running too hot (although I wasn't actually there, so i've no idea what the exact reading was...)
</TD></TR></TABLE>


ok well the thing that the mechanic did was more what i was talking about. jsut getting a second measurement to make sure the gauge was reading right.


Have you ever had your head surfaced and pressure tested?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">Have you ever had your head surfaced and pressure tested?</TD></TR></TABLE>

nope, but I have a h22 head sitting in my garage. My plan was to do the H23 Vtec and then boost the hell out of it... Do you think the head might have something to do with it? I don't think it was really touched during the rebuild... could there be some damage there that is causing the car to over heat? Slightly bent valve maybe? (I really don't know, jus throwing out ideas)

 

well i had a swap that was in my wifes civic a few years ago that had similar symptoms to yours.
it ran prety well, but had a temp gauge that went all over the place, it would go up and down seemingly at random, but most often when the rpms went up. we replaced the radiator, thermostat, any temp sensors and so on. did a compression test that was good.

finally one day i noticed a little bubbel come out in the overflow tank off hte radiator. then a few minutes later saaw a second one. turns out the head gasket had let loos, but was ONLY letting exhaust into the coolant.

i pulled the head, had it surfaced and pressure tested, put a new head gasket on and since then ahve not had a single issue out of the car.

thats why i asked about the head, since if it had done this before and after the block build that would explain it possibly.

 

one thing to check (as others have said) is the temp switch for the fan. It's on the pass side of the block and has 1 wire going to it IIRC. There should be two sorta below the VTEC selinoid, it should be the one more towards the firewall. Put a meter on it, and see if it switchs when the guage indicates about half way up. If it does, check the relay and fuse for the fan. If it doesn't, that's most likely what's up with the fan.

(Sorry if the wire location is off or whatever, I'm recalling back a few months to when my friend and I wired up a JDM H22A into a 95 ciivc EX)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rjr162 &raquo;</TD></TR><TR><TD CLASS="quote">Put a meter on it, and see if it switchs when the guage indicates about half way up. If it does, check the relay and fuse for the fan. If it doesn't, that's most likely what's up with the fan.
</TD></TR></TABLE>

Good idea does anyone know what actual temperature the fans are meant to kick in? also, what is the normal operating temp meant to be?