75 replies to this topic

[Condor]

OK, so I didn't mind replacing some parts just to "be sure" since it is so old,
and I use it as a DD when it is working right. Or rather as of lately, only when it
is not hot weather. These are the parts I have replaced in the past year plus.

water pump, spiral kind.
thermostat, times 4, this one is 170F
radiator cap.
a number of hoses including the main ones (one actually was collapsed, on
the back of the engine).
computer temp sender
gauge temp sender
radiator fan switch
I have confirmed the gauge works using FSM technique.
I have confirmed when it says hot it is hot.
I have confirmed when it says overheating, it is overheating. Gauge works.
radiator
O2 sensor
Dist cap
Injectors
cleaned entire FI system.
spark plugs
Catalytic converter is absolutely free of obstructions
50-50 prestone mixed outside the car then added
new head, pressure and leak tested, all rebuilt professionally.
block cleaned when head off (was not dirty)

Runs at half the gauge which I think is about 200+ on cool days.
(did not have it running for the cold)
Hot days it would go off the chart if I let it.

The fan does cycle on but kicks on at half. Runs about 20 seconds.
It does not stay on continuous when it overheats. (more experiments on this coming)
On warm but not hot days if I run the AC I can keep it at half, kinda.
I guess that is the aux fan running.
But I am certain it would overheat if I drove it further than I am driving.

I drove it in the hot this weekend and it went straight to way overheat.

Certainly I will be making an auxillary switch for the fan coming up.

But that is not the real answer.

I am at my wits end on what is going on and how to fix it.
I should actually be running "cold" with all the above. 1/3 on the gauge max.

I'm hoping somebody can help.
Right now I plan to save up some money and put it into the honda place here.
Not that I expect them to say much more than "we replaced the thermostat it
must be your gauge is bad", like when it broke down at the beach.

Also I need to drive this thing, really.
I can't continue to be the guinea pig of people's theories.
(NOTE I DO DO DO APPRECIATE EVERYONE'S HELP)
But now I'm starting to get advices like
"hey man, try a 195F thermostat, you know, sometimes, its like uh, you know
man, you put the hot one in, and it works great. Just opposite of what you think
you know man yeah"

Well I've been around a while and I have never heard the theory of put the
highest thermostat in to make your car run cooler.

Any help is appreciated.
Funny by the time I have the money to put it in the shop and (I have not had
good luck at any shop in my life) get robbered for nothing it will be cold again.

Thank you.

[dwend]

How much coolant is in the radiator when cold?

Edited by dwend, 18 June 2012 - 09:22 AM.

[Condor]

when cold, the coolant is right to the bottom of the top.
If that makes sense lol.

There is a fill neck and you can see a little pool of coolant when it is cold.
It's maybe a couple of pints from that point to fill to top.

(one of my theories on bleeding has been to overfill, have it go to the
resevoir, then empty the resevoir. After a couple times it seems to get to
a steady level.

[Bubba]

What happens when you run it with the thermostat removed? Does it still overheat?

It is possible that the block is warped (top deck is no longer flat) and this is keeping the head gasket from sealing with the new head. I was rebuilding a 1.3 liter block and decided to take it to the machine shop so they could check it out- the block was right at the service limit for flatness so I had them mill it. The previous owner likely overheated it severely.

There is a chemical kit you can get at auto parts stores that checks your radiator fluid for the presence of exhaust gas (a sign of a head gasket leak/cracked head) there is a color change if there is exhaust residue in the antifreeze. It wasn't very expensive.

[Condor]

I am planning to run with no thermostat this Friday.
I will also go get the kit or on ebay maybe better.

That seems logical though. I sure hope not.
I am so screwed if it is the block. After all that work.....

[stock85]

Do you have/use the puke tank? Water level in it?

My car has running hot issues, which I haven't fixed, but have improved lately. Even on relatively mild days (70 or so) the temperature would go over halfway, sometimes approaching ⅔ up the gauge, when commuting home (2000ft climb, freeway).

The fan would come on, but I would hear the relay click 5 or 6 times rapidly (almost a buzz) before the fan would come on and stay on, likewise for maybe 20-40 seconds.

I did two things:

I took the fan motor out (what a PITA), turned it upside down, and filled the case with WD40 through the drain tube, then ran it straight off the battery with some jump leads for a minute or two to distribute things.

Every connector I unplugged, I absolutely drowned in dielectric grease, and also I used pliers to slightly tighten all the terminals themselves. The thermo switch had a small amount of liquid (coolant?) that almost seemed to be leaking straight out of one of the terminals. I didn't do anything with it, but it did get greased.

The weather has since moved into the 80s, 90s, and 100s. The same climb now will result in just barely over halfway on the gauge, and will nearly immediately drop when the road flattens out. That's with or without A/C.

The relay no longer clicks/buzzes when the fan comes on, either.

I'm thinking maybe the motor was getting a little sticky, resulting in higher amp draw, which combined with old connectors to make lousy connections at important points, keeping the fan from running as long or as hard as it's supposed to. It's been a few weeks now, and so far so good.

I am thankful the gauge isn't horribly dampened like newer cars, which just have 'cold', 'normal', and 'molten' modes.

[bgdsign]

it sounds like you may have a clogged block. The engine blocks can get choked with rust or scale.

There are a few things you can try -

One is "Salt Away" - this is a rust and scale desolver that is used mainly on marine applications & can be found at boat stores or places that deal with wave runners or jet skis. You add it to your radiator water and let it desolve the scale / rust as it runs. It may take a few flushes to knock loose any big chunks of junk.

The poor mans way is to get what I consider to be the greatest product known to man - ZEP Industrial Purple found at home depot. You can also use this to try flushing out your system - BE CAREFUL because this stuff will make aluminum fizz... has a lot of acid & you do not want to leave concentrated amounts on anything too long.

If your block still restricts the flow of coolant it may require dismantling.

[Condor]

I put so much up I think it was easy to miss all I did. Three weeks ago Kaymo took the head off
and cleaned the inside of the block. It was not dirty though. It looked pristine no rust no scaling.
Even the pistons looked in great shape (no little lip at the top like on my MG back in the day).

I will examine the fan and relays on friday. I have been making an effort when I take things apart
(like the dash and other places) to go ahead and put that grease on every connection I can get to.

So I'll move into the engine bay. I actually do not have a spare fan of all things.
(I have several of these cars in the yard)

[Greg Gauper]

You can probably rule out the fan as your problem...
The cooling fan is only useful at speeds below 10-15mph.
Once you are moving faster than that, you have plenty of air flow thru the radiator to keep an engine cool.
FYI - We don't run a fan on the racecar since it is excess weight and actual blocks airflow when at race speed.
With a 'real' temperature gauge, you can actually see the temperature drop from 190+ down to 180 in just a few second when we move from the false grid to form up behind the pacecar. It does not take much air flow to cool our cars.

Drive it up and down the road near your house at 25mph or faster for testing...that way if it does overheat you only have a few blocks to go to get home.

The radiators can and do plug up with rust & sediment. If you can borrow an IR thermometer, check the temperature into and out of the radiator. You can unplug the fan switch and jumper it out with a piece of wire across the two pins to keep the fan on all the time for a test with the car idling. If there is very little temperature difference between the two hoses, you probably have a radiator problem, especially if you have removed the T-stat for a test as this would rule out a stuck T-stat. You might have to bite the bullet and get a replacement.
I run an el-cheapo Modine OEM replacement on my race engine and it cools fine even in 95 degree weather.

If you want to try a safe flushing fluid, remove the radiator and lay it on the ground flat with the cap on. Boil up several quarts of vineager and pour it into the radiator until it is full and let it sit for about an hour, then flush thoroughly with a hose for about 5 minutes. Also try to clean out any gunk on the exterior fins.

Edited by Greg Gauper, 19 June 2012 - 02:57 PM.

[ballade]

Weird
All My CRX's have always run a tad warm on the gauge. Slightly Over the 1/2 then the fan kicks in.
Even my B16A running a HF half rad does the same thing. but never in 20 years have any of my cars over heated.

That said : I've always been a bit nervous. The faster I move the cooler it stays.
One thing I did a few years back. I ran a switch in conjunction with the fan thermo switch. This always kept the car cool in stopped traffic
even stuck on the freeway in LA in July!!!!!!!!!

The OEM fan gave up last year so now I'm running one of those Ebay $15 slim fans with the HF Rad. works fine.

[Condor]

The radiator is only a year old. It is the double max cooling all metal one from rockauto.
That was actually the first thing I replaced.

I plan to put that fan switch on this friday (I got last week did not have time to do it).
That may make it better for me to drive in the heat temporarily but I think over the long
run it only results in me replacing fan motors. Or masking some other problem.

I am going to get the leak down test thing Friday as well.

I dont have the money right now for the exhaust gas tester. Plus it has to be ordered
and won't come.

I am never going to give up.

I would just put it in the shop and put it on my CC or something but after the beach debacle
I just don't want to pay for nothing. (car is fine, your gauge is broken).

I have a multimeter with a temp probe is what I normally use that way I can
touch it to the exact spot. I calibrated it at work (only at 100F, but still, I assume it is semi linear)
and it is only off 4F. Not bad for a $20 ebay thing.

That is how I know when the gauge says overheat, it IS overheat.
I never ran experiments with the radiator so much.

It does seem to me it is a flow problem. I mean this is the second head, same thing.
I would think that if it was a warped or cracked block it would manifest itself to the breakdown.
I drove it quite a bit this winter at 1/2 the guage call it 200+. 6000 miles maybe as I replaced
parts and tried to debug.

I also wonder if that rockauto low bid POS is bad right out of the box.
that would be RARE. And doing the EXACT same thing as the honda one.

I'm just thinking out loud.

[Condor]

I am tempted to replace the guage at this point.

But the thing is, it does move. It does hold steady at a half, kinda, under
certain conditions. I did measure it at half and the motor is too hot.

When it goes over half the motor is hot enough to smell hot.

And it's not like the guage is sending a signal to the fan. It just reports.
Meaning, if the guage was off by X amount and was reporting the wrong signal
to the fan switch it would be messed up. But the fan switch is themometer switch
and comes on automatically.

I DO think it should be coming on earlier though.
But then it just goes to show it is really the head that is hot not the radiator.

I am honestly at my wits end. This has been SO expensive, both in money and in TIME.

The car runs and drives as good as new except for this one thing.
Three years now working myself and with Kaymo.
All I have to do is straighten out my plastics and paint it and I have a super nice car.
IT IS SO FRUSTRATING I OFTEN SCREAM

[ballade]

Wow that is frustrating.

[Condor]

Maybe there is some small creedence to the use the higher thermostat.

Dude here says to put the 185 one back in. Says that I am pushing the coolant
around too fast and there is not enough thermal exchange to cool the engine.

I do not think this is my problem. However, for my first attempt tomorrow I will
run an auxillary switch to the fan and re-install the new 185F thermostat.
It is too late to get a "honda" one, if they still exist. In all honesty I have a problem
believing they are any different. The new honda stuff (that we can still get) is made in China.

I do wonder should I put the OEM radiator switch back in.

[Smokescreem]

I do remember someone here on RPR saying something about using the honda thermostat. Is it 190 F ? For the reason that it works best for the engine .That the ecu is programmed for that temp use. I could be wrong.