nicolaselias

Hi everyone..
I have a 96 Accord EX.. Only mods are the standard I/H/E..
Radiator is OEM but with the two plastic bottles replaced with a brass ... Prestone coolant

For the past few months my vehicle would be running nice and cool but sometimes when you get stuck in traffic or after a hard drive the temp gauge would creep up slowly toward the red mark..
My first step was testing the radiator.. Came back good..
I decided to change the thermostat and replaced it with the OEM part.. Same symptoms..
I was unsure of if the fans were working correctly but those also are fine after testing..

3 Weeks ago, the car overheated up to the red mark so I pulled aside in traffic to investigate.. It looked like my rad cap was faulty and somehow managed to come loose releasing almost all my coolant.. I filled her back up and put a new cap.. No problems there until I got home and realised that coolant was leaking.. Turns out the water pump was gone.
I changed the water pump thinking that this may have been the cause of the symtoms I was experiencing for months, but the new Gates water pump has made no difference to the sporadic overheating.. I just changed the pump 2 days ago and the vehicle is already doing the same thing..
Would never overheat on highway running, but will heat up in traffic or the city.. Usually, once I get moving and air flows it cools down itself...
I did some testing tonight and I realised that if I were to park the car with the engine on the gauge will slowly climb up but oddly if I were to give the car some quick revs it will actually bring the gauge back down.. That doesn't make much sense to me unless my water pump was bad, which it isn't...

Is there something that I am missing in all of this? I even pressure tested the engine wondering if the head gasket was bad but all came back good with almost identical numbers..

I am completely stumped now and genuinely have no idea what else to consider looking for or changing...

MAD_MIKE

You didn't mention it, did you open turn the heater to ON and HOT when you were purging the system of air? Did you get a steady solid stream from the nipple on the intake manifold?

nicolaselias

I would love to do the heater during the purging but my electronic control for the thermostat gave up the ghost ages ago.. Right now, I have it wired up so that the thermostat is bypassed..
Basically once the A/C is on its going to be ice cold.. No option of cool or hot..

MAD_MIKE

So the valve is different on the firewall from manual heater controls?
Even if the controls were broken you should be able to crank that valve open by hand. I highly doubt that valve is water tight.

nicolaselias

Excellent point Mad Mike.. I will give that a shot tomorrow and see how it goes...

Just to be sure I know what I am doing, can you please describe exactly where said valve is?
Thanks

jdmcertified909

the valve should be passenger side near/under your intake youll see two hoses

nicolaselias

Hi everyone..
So, I followed the bleeding instructions and let it flow out of the bleeder hole on the thermostat housing... I let it go for about 10 minutes until the flow of coolant was constant..

I then switched off the engine, refilled the rad, put back on the bleeder bolt and took her for a spin.. Same problem as before..

Basically after some hard driving once I slow down the gauge tends to creep up..
I ran a test as soon as I got home, i sat in the car and just let it run.. I would see the temperature gauge go up to about 3/4 but then come back down slowly.. The fans were running all during this time so it wasn't that the fans switched off..

Is it possible that there is yet more air in the system? Anyone have any more specific tips about purging this air?

Thanks

MAD_MIKE

You bled the cooling system with the engine on?

You open the bleed screw as you are filling the engine with coolant, with the engine off.

From the 'How-To: Replace Timing Belt, Timing Balancer Belt and Water Pump on a F22B1'

nicolaselias

Thanks again Mike.. Excuse my mistake there...

So I bled it with the engine OFF this time, followed the instructions as described but as far as I can tell I did everything correct..
However on my test drive, same exact problem as before..

After that, I tried the really rudimentary way, ie. open the radiator cap, start the engine and let it run until you get a fairly constant stream of coolant coming out of the radiator without all the burps and bubbles.. That never actually happened...

This may be a long shot, but is it possible to have a leak in the coolant channels of the head gasket? I compression tested the engine and it game back good but that wouldn't necessarily mean that ALL of my head gasket is good..
Assuming I had a head gasket problem, what symptoms would my cooling system show?

holmesnmanny

I would redrain all the coolant in the system and open up the thermostat housing to let all the air out. Obviously put housing back on.

Then jack the front of the car as high as you can. Turn the heater dial all the way to full red. Open bleeder bolt on thermo housing. Then fill up with coolant til it starts coming out in a steady steam. Then close bleeder valve, fill up radiator and that more or less should do it.

MAD_MIKE

If you have an external head gasket leak, look for steam/coolant on the external parts of the engine.
You would have smaller bubbles in the system. Stateside you can rent a pressure tester to pressurize the cooling system. If it bleeds down you know you have a leak somewhere in the system.

Pull the plugs, if there are any that are extremely clean or tinged with the same color as your coolant, be it green, orange, blue. Then you may have a leak from cylinder to coolant passage.

That should also show up in a cylinder compression test.

Keep in mind, tiny leaks in hoses/bypass tubes can easily go unnoticed.

nicolaselias

Will go the radiator shop tomorrow and pressure test it.. See what they can find if anything...

The plugs as far as I can tell look fine, but the car does tend to smoke white (water vapour maybe) at startup but stops smoking once it is up to temp...

I will keep you posted as I know more, but thanks so far for all the help

jdowen2

Were you losing coolant? If so, was it in the overflow tank? Could be a radiator cap problem. Have you flushed the radiator?

jdmcertified909

head gasket it is. if you would of told us it smokes white at start up we would of been done with this thread. a honda head gasket failure can be a head ache to diagnose. trust me i know. im a honda tech lmao but on the real i am honda acura certified. but a head gasket die test its expensive but it will tell you if you have exhaust gases in your coolant

nicolaselias

Today's update:
I top up the coolant, start the car.. No white smoke whatsoever from a cold start..
She drives normal for about 20 minutes before the temp gauge starts to creep up..
By the time I make it to the radiator shop, the gauge is almost up to red and coolant is spilling over from the overflow bottle..
Clearly, leaks are not the issue if the pressure is so high.. We still pressure test the system anyway with no problems....

So, with so much air and bubbles in the coolant something has to be going on there..
Next step.. Remove the new thermostat and see if that is the cause...

After that if it makes no difference we look at the head gasket..

nicolaselias

Hi everyone.... I removed the thermostat today and the symtoms once again showed up...
Also it seems to be hardstarting more and more each day....

It most likely is head gasket by this point....

Any tips on other things to look out for or work on if I am taking the head off?

jdmcertified909

youve done a pressure test right to check for leaks. have you done a flow test of the radiator?

holmesnmanny

What were the exact results of the compression test ? Are you losing coolant or not ? Is there any coolant at all in the oil ? Are you blowing white smoke out of the exhaust that doesn't dissipate after a couple feet ?
Can you pull the spark plugs and post detailed pictures of them ?

2jzfreak

I hope you haven't used nothing but water in your cooling system before, or maybe a previous owner had in the past. It rust your cooling system, including your radiator. Take your rad off and see if it looks rusted inside... If it's over 10yrs old I would strongly suggest you replace that too. Also, murrAy (I believe is the brand or murry?) sells a PREMIUM thermostat which flows way better then a stock OEM one due to a bigger opening on the thermostat.. I run that in my 94 ex turbo and it made a difference. Big diff.

2jzfreak

I meant to say DON'T use water only. And make sure if you get 100% to dilute at least to 70 / 30.....

dwllama

I'm doubting it will make much difference in this case but you could also check if the radiator is full of crud externally... bugs, etc all jamming the holes... can cause it not to work right.

nicolaselias

Unfortunately down here in the caribbean none of the rad shops do flow testing.. They just tend to judge by sight and then recommend you buy a new radiator..

Concerning the compression test (which was done before the overheating situation got really bad) all 4 tested around 8.9... I have been trying to get a leakdown test done but same problem, no one where I am located does it..

Concerning the coolant in the oil, I haven't noticed any and I even inspected the old oil I just changed for any sign.. Couldn't see any.
The white smoke in question usually only shows up when I first start the vehicle and dissipates very quickly.. It is hard to tell here though because it is so hot that water vapour doesn't tend to hang around like it does in the US..

I have ALWAYS used a 60/40 or 50/50 coolant mix, usually prestone or genuine Honda in the radiator.. I also had the radiator cleaned out about 2 years ago and have changed my coolant regularly since..

Externally the radiator is actually very clean so that isn't the issue..

Concerning the plugs, I will try to pull them this afternoon and take some pictures...
They are all relatively new (I will post mileage with the pics)

That said, I have been fouling plugs somewhat regularly as of late and all of the seals were changed...

MikesEJ1

change the radiator it may be clogged and is not flowing coolant right,then get the yellow spill free funnel and bleed the cooling system(works best for bleeding coolant)air in the system causes overheating also.If your still overheating better check the head gasket or head warp-age

you said new water pump and thermostat yes?

nicolaselias

Yes was a new themo (which has now been removed, currently running NO thermo)...
New GMB water pump as well...

I really really can't see it being the radiator, because it worked perfectly fine before the water pump crapped out, so why would the radiator instantly be the culprit?
I mean, if I HAVE to change the head gasket i'll get the radiator cleaned out anyway, but that I suspect is not the cause..

nicolaselias

I pulled the plugs today... The two Denso on the right are 5000km (3000miles) old
The other two to the left of it are barely 1000 miles old..

The 2nd from left has some oil on it so that could explain the misfiring when i first start.. Cleaned it up and the car started much better.
I also regapped all the plugs..

What can you people tell from the condition of the plugs and their respective ages?