slim9300

Just kidding. But I will be very grateful.

But here is the prob. I have intermitent pressure in my upper radiator hose. When I say pressure I mean it makes a brand new hose rock hard and bigger then it should be getting, and even with t-bolt clamps tightened all the way down, coolant still finds a way to drip out both ends of the upper hose. The overflow bottle does not fill up and the lower hose never gets nearly as hard. Plus, the car never overheats. I have changed the thermostat (with OEM Honda) and a new 16 lbs. cap, but the problem still comes back. And yes the thermostat is opening. The hose seems to be fine for a few days of driving hard and, or light, but then all of a sudden after a few days it comes back. I suspect headgasket but leakdown showed 3-4% across the board. What could be causing this to happen? Could the head be lifting under load, kind of like some turboed motors seem to do under boost? Could a compression test yield different results then a leak down? As you can see, I really could use some help.

Background info: JDM H22A motor in 95 DC2, 20K miles from me and never boosted, PWR radiator, Car runs perfect, smooth idle, perfect coolant coloration, very clean oil, burns zero oil, no black or white exhaust, etc. I run the stock P13 ecu with zero codes, not even egr. The motor makes great power.

I will be glad to answer any questions. I greatly appreciate the help.

-Conlan

v4lu3s

id also check for any bubbling coming out in the overflow bottle, even a little bit can mean a head gasket that needs to be replaced.

Lewdin' Incognito

Just throwing an idea out there....Could a bad radiator cause this? Like if the radiator is getting clogged up and causing pressure to build up.

britishlude

Yes the radiator would be the first thing on my elimination list as you mention it only happens after a few days, the head gasket theory is correct but I would think if it was head gasket you would have a pressure build up every time you drive the car. What I would do is totally drain the coolant system and pressure flush it through especially the radiator and see what sort of gunge build up washes out, then bleed after filling with water only and see what happens after a drive round then drain again, and finally fill with a 50/50 antifreeze mix and bleed it again, don't forget to at least fill the reservoir tank to minimum when cold.


Modified by britishlude at 2:30 PM 5/18/2006

Lewdin' Incognito

^ Probably a brand new radiator wouldn't hurt.

britishlude

A brand new car would be nicer if only !!!

flyrod

The radiator cap should vent before the pressure gets so exreme. The coolant will expand when the engine heats up, and the cap should vent if the pressure gets too high. So I would check the cap and the fitting where it attaches to the radiator. I suspect that the cap is not compatible with the radiator.

flyrod

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slim9300 &raquo;</TD></TR><TR><TD CLASS="quote">the lower hose never gets nearly as hard. </TD></TR></TABLE>

Both hoses should be at the same pressure, and thus the same "hardness."

darkspector

sounds like a clogged radiator to me.

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">id also check for any bubbling coming out in the overflow bottle, even a little bit can mean a head gasket that needs to be replaced. </TD></TR></TABLE>

Trust me, there is none. And if I let the car reach full operating temp. with the cap off the radiator won't overflow. The fluid level will change a little when the thermostat opens or the fan kicks on, but I am talking like a cup difference. Plus, I think that is normal anyways.

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lewdin’ Incognito &raquo;</TD></TR><TR><TD CLASS="quote">Just throwing an idea out there....Could a bad radiator cause this? Like if the radiator is getting clogged up and causing pressure to build up.</TD></TR></TABLE>

I had this problem with the factory radiator also. It's not the radiator, unless I am seriously unlucky. Plus, if the radiator was clogged, how would the cooling system be working properly in terms of cycling through the head, through the lower hose and back into the radiator? Even when I have high pressure in the upper hose there is fluid in the lower hose.


Modified by slim9300 at 1:17 PM 5/18/2006

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by britishlude &raquo;</TD></TR><TR><TD CLASS="quote">Yes the radiator would be the first thing on my elimination list as you mention it only happens after a few days, the head gasket theory is correct but I would think if it was head gasket you would have a pressure build up every time you drive the car. What I would do is totally drain the coolant system and pressure flush it through especially the radiator and see what sort of gunge build up washes out, then bleed after filling with water only and see what happens after a drive round then drain again, and finally fill with a 50/50 antifreeze mix and bleed it again, don't forget to at least fill the reservoir tank to minimum when cold.Modified by britishlude at 2:30 PM 5/18/2006</TD></TR></TABLE>

Thanks. This seems like a good idea. I have flushed my system multiple times and bled the system every time. But I guess that doesn't mean that there isn't a clog somewhere. How would I test if there was a clog not in the radiator? Since it's intermittent then it seems almost impossible.

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">The radiator cap should vent before the pressure gets so exreme. The coolant will expand when the engine heats up, and the cap should vent if the pressure gets too high. So I would check the cap and the fitting where it attaches to the radiator. I suspect that the cap is not compatible with the radiator.</TD></TR></TABLE>

It might be possible. But it's a pretty standard cap, isn't it?

The cap should open once the coolant reaches a certain temp, not pressure, right? Remember, it's a type-A cap, unlike the factory honda cap. So if the coolant isn't too hot, won't the cap's valve stay closed? I am probably wrong. The cap looks like this:







Modified by slim9300 at 1:49 PM 5/18/2006

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Both hoses should be at the same pressure, and thus the same "hardness."</TD></TR></TABLE>

The lower hose is the "correct" hardness. The upper is not. What would this imply then?

britishlude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slim9300 &raquo;</TD></TR><TR><TD CLASS="quote">

Thanks. This seems like a good idea. I have flushed my system multiple times and bled the system every time. But I guess that doesn't mean that there isn't a clog somewhere. How would I test if there was a clog not in the radiator? Since it's intermittent then it seems almost impossible. </TD></TR></TABLE>


Have you checked that the breather from the neck of the radiator to the expansion bottle is clear of obstruction or debris ? poke some wire through to check that's clear firstly.

slim9300

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by britishlude &raquo;</TD></TR><TR><TD CLASS="quote">Have you checked that the breather from the neck of the radiator to the expansion bottle is clear of obstruction or debris ? poke some wire through to check that's clear firstly. </TD></TR></TABLE>

I replaced it with a new one a few days ago.

slim9300

BUMP

slim9300

Well it been 200 miles and it hasn't done it yet. I replaced the cap, and thermostat again with new factory parts. Crossing my fingers.