Ahhh.. That's good to know. And yes. I jacked the front of the car up and bled the system by removing the cap and by using the bleeder valve. I'm assuming all of the air is out because the coolant coming out of the bleeder valve was a steady stream. No bubbles.

 

There is that, but then after that you leave the cap off and run it with heater on full heat until the radiator fan kicks on at least twice.

I'm sure you did that though by the sounds of it.

Also when the cap was off, when the thermostat opened, especially when the fan kicks on, the fluid drops some in the radiator and you should see it flowing. That helps verify the pump is still pumping coolant. If it seemed almost placid instead of turbulent, your pump fins are definitely compromised.

 

COMPRESSION TEST:

190-200 PSI across the board: )

This was done with the engine cold since everything was unhooked.

 

?

https://youtu.be/Lq_N5wzmzkg

 

Looks to me like your HG is fine. Like everyone else mentioned, the suspicion is the water pump.

 

Really?! Did you see the video? Wouldn't exhaust gases escaping make the water bubble up?

 

It would show up in the compression test and your compression test says it's sealing fine. It appears weird to be seeing bubbles coming up like that but I suppose it could be pulling in air bubbles from somewhere, maybe even the water pump. I would say just pull the water pump and see what it looks like.

It's still possible you have a hairline crack in the block somewhere.

 

Dammit. I wish I could just pinpoint the problem. The compression seemed really good. After I did the compression test, there was faint white smoke like the kind when it's cold outside (or precipitation) This was at full operating temp. That led me to testing the reservoir tube test you seen. OEM Water Pump comes in tomorrow.

 

You will know if the head gasket is failing because the white smoke doesn't dissipate like regular condensation on a cold start and it doesn't go away after the car has warmed up.

 

I did not see the video. However, until you do a block test of said bubbles, you can get air from all over the place. Also being your recovery isn't overflowing and your rad is staying full to the brim, that doesn't sound like combustion going into the water jacket. Coupled with the solid compression on all 4...... HG seems fine.

Also, I just experienced constant bubbles when burping my car on an incline as the fluid would drop below the filler neck when the thermostat opened up and suck in a little air. Thermostat would close and it would spit the pockets of air back out. Wash rinse and repeat.

You need to get a radiator funnel so you can keep the fluid above the filler neck even when the fluid level drops when the thermostat and fan kick open/turn on. Then you shouldn't see bubbles unless something is letting air in, which may or may not be the head gasket.

 

 

Currently bleeding again. Video on the way.

EDIT: I found something very interesting while bleeding for 60 minutes. When the car initially warmed up to operating temp, my fans would only come on every one minute. That one minute gradually turned into every 3 minutes. Symptoms of a bad engine coolant temperature switch?

 

 

In your video you are putting the recover hose into plain water. If your coolant is anything less than 50/50 the boiling point is reduced. If you are running straight water, you are going to be boiling the water regardless which produces air and hot spots in the engine.

Like I mentioned, the bubbles themselves don't mean anything. Block testing those bubbles will tell you more. If the block tester fluid stays blue when you pass that air through it, then you have ruled out combustion gasses. If it turns yellow and you didn't contaminate it with fluid etc, then you've confirmed combustion gasses in your cooling system.

I do like that 2 liter bottle method of capturing the air from the cooling system though. Will make it easier to get readings without contamination.

And lastly, expecting to purge all your air through the coolant recover hose is not the proper way to bleed the system. If that's your method it's bound to leave air in the system.

 

GOOD NEWS:

I jumped the fan switch connector and drove around for about 3 hours. All stop & go traffic; NO overheating what so ever.

I'm kind of unsure where to go from here...

 

The fan is controlled by it's own thermo-switch on the thermostat housing. I would start there.

Also.... If you are using something other than an OEM thermostat, it could be opening up late. Running the fan all the time will likely prevent that from showing.

 

I bought one (thermoswitch) from O'Reilly's today. However, how do you feel about the Mishimoto thermoswitch? As for the thermostat, it is OEM. Straight from the dealership.

 

I have no experience with the thermo-switches. So far all of mine have operated normally with 20 year old OEM switches.

The key is that it operates correctly at the correct temperatures. If it operates a little lower in the temp scale, I doubt that would hurt any. If it operates only at a higher temp than OEM, you are in trouble.

You should probably get the Helms Manual (Factory Service Manual) for your motor if you don't have it already. It has all those specs and how to test the components etc.

By the way, did you ever take the crank pulley off so you could take the lower timing belt cover off to inspect the water pump?

 

Nope. My OEM pump just came in yesterday. I'll probably be installing it along with my Gates timing belt very soon now that I have overheating somewhat under control.

 

 

This stuff isn't rocket science. It's only hard to figure out if you make it difficult.

 

Actually the Mishimoto is more than adequate:

The Mishimoto Thermoswitch Fan Switch replaces your OEM fan switch, allowing your radiator fan to activate at 80 degrees, 15 degrees lower than stock temperature. Installation is simple with direct replacement to OEM switch.

As well, it comes with a lifetime warranty so really is a no brainer.

 

If the rad fan shuts off after a few sec. when engine is overheating the problem is in the rad fan circuit, that could be the ECT switch or the rad fan relay, if the fan keeps running with jumper installed I would replace the ECT switch, if it still cuts out swap out the relay. 94

 

Well guys, something strange happened today.

I installed the Mishimoto Thermoswitch today and took it for a spin.

No overheating for about 30 minutes - 1 hour. So I stop to check if the reservoir had over flowed; and indeed it did.

So I go back into the car and look at the thermostat and see the gauge rises toward the "H". The fan was on the entire time while it was rising, so that's good!

This is intriguing because for the 48 hours I rode around with the fan jumped (constantly running) none of this happened. Are these symptoms of a bad water pump (inspecting it tomorrow)?

 

There is 0 benefit whatsoever running a non Honda fan switch and/or thermostat in a stock system. The ecu and cooling system is designed to operate within a given temperature. Normally the thermostat opens at a certain temperature, while maintaining a minimum temperature, 15 degrees later when the thermostat is fully opened the fan(s) come on.

I have seen many aftermarket cooling system parts fail after only 1 year and 25k miles. Honda cooling system parts last far longer.

When an engine is modified and is putting out excess temperature and the ecu is programmed to work within a different operating temperature then I can see having a different temperature triggered fan switch(in conjunction with a different operating thermostat), but it appears the OP has a stock engine.