ss04

EDIT: At the request of s2kVTAK, I have edited this thread with more urgency for HIS situation. Mine is all sorted out. Anyone that has any advice that they can offer s2kVTAK I'm sure he'd appreciate it.

SS04 - Problem solved

s2kVTAK - NEEDS HELP!


Hey guys,

I'm hoping you can shed some light on the problems I am having. I have done a lot of searching and tried everything that was mentioned. I recently installed a Mishimoto radiator. Install went smoothly, fit nicely etc. I refilled the top rad hose, attached it the radiator, filled up the radiator, filled up the reservoir appropriately etc. I bled the system with the car level, with both bleeder points. Seemed great.

Today on my way to work, the temps were spiking and I had no heat in the cabin. The top rad hose was very hot, the bottom ice cold. I got home after doing some long reading. Jacked up the front end as high as I could, bled it again, first with the cap off, both bleed points, got a lot more air out, and suddenly my heater started working again! Great! I was happy. The bottom hose was also warm and was definitely getting warmer - as if the thermostat had opened. I then shut the car off for an hour or two, fired it back up, and then let it idle. The lower hose remained cold the the touch, while the top hose got HOT. Same with the top of the radiator. Heat in the cabin was working as normal.

Ideas? I have yet to see anyone post with both a cold lower hose combined with HAVING heat in the cabin.

This is a 2004 with only 30,000 KMS on it. Thanks in advance guys.

~Cam

ss04

So I took it for another drive.

No temperature spikes, heat works great, and still, the bottom rad hose is cold to the touch, top one is hot. The top of the rad is very hot, bottom of the rad is cold.

ss04

I should also mention that when I had the front jacked up, and was bleeding the system - the fans would cycle.

However now that the car is back on the ground - the fans aren't cycling - even when the temp gauge is at operating temperature.

Maybe there is still air in the system?

s2kVTAK

okay i have a mishi too and im having this problem EXACTLY! top hose hot as fawk! and bottom cold the top of the rad. if hot! i havent felt the bottom. i have a huge thread made trying to figure this problem out, except we were on the track of a head gasket except i couldnt get it to fail a lithium test (test for detecting hydrocarbons) no that my car has been in and out of the shop for about 2 months straight i have re thought my problem and i dont think its a HG.

back to when my problem originally came to sight. my thermostat started sticking, so i popped it out and sure enough it was in pretty bad shape. replaced it with a non-OEM t-stat. problem solved, for about 3 days. suddenly i have the side effects you are describing and we start to scratch our heads. we perform a leak down test and we do have leak down on cyl. 3 so i take it to my mechanic and have him check it out to comfirm. he does leak down after leak down and lithium test after lithium test and all negative for problems.

so now we are up to present. now is when i start to suspect the t-stat and think since its not an OEM for some reason its not functioning properly. so i start to think it out. i have seen that J's racing had an issue with the Mishimoto Alum. Rad. in the fact that it was making too much heat transfer and not allowing the motor to even get up to regular operating temp. i believe that this is not allowing the thermostat to heat up enough to open fully causing the spike in temp. im not a mechanic, but this has got to be atleast on the right track and since the OP is having trouble with his mishi. rad. too there has to be someting in common.

my side effects are the same as the OP as that i will get a huge spike in temp and loose heat. go home raise the nose of the car and bleed out air from the system, the heat starts to work after that. i drive the car for a while and then it starts over again. sometimes i have heat and sometimes not. it actually goes in and out. one thing that doesnt make since to me is that this only comes up if i drive the car hard and take it to vtec and on to about 8500 rpms. if i just drive the car normally and stay under about 5000rpms it doesnt happen and wont until i start to drive it harder again. i believe that vtec has something to do with this weird situation.


again like the OP please help this problem is getting to the point where i want to sell my S cuz i cant afford to keep searching for this problem.

wuttheheezy

odd. i also have a mishi rad, and exactly the same symptoms like the op.. i also did a re-bleed, but that didn't seem to work.. but the funny thing is that i only had the heat spike once i got on the highway, but driving local it was perfectly fine.. so i park, open the rad cap and rev the car to 3-4k rpms for almost five minutes at a standstill.. all of a sudden the heater finally started working, so i started to drive around on local streets first, after feeling pretty confident i decide to take it back on the highway where the problem typically shows itself.. drove for about 30 minutes.. everything was perfect... no more heat problems... it's been about a month now and no signs of that heat issue anymore..

ss04

Well my cabin heat issue seems to be solved... the issue now is that the coolant is not circulating as the lower rad hose is ice cold and my fans aren't cycling - and they would be controlled by the fan switch not engaging because the entire lower area of the rad is cold

either I have a bad rad - which I doubt, or my thermostat isn't opening - this is what a local tech has suggested to me

any other thoughts guys? I'm glad to see I'm not the only one with similar issues

jwkim

We had problem with over-cooling with this rad.
It seems like its popular the problem with much thicker rad.

Run aftermarket (lower-temp) thermostat, or drill few little holes on stock thermostat to allow some water flow.(This is what we did on our race car)

ss04

Well I'm at a point now where I'm going to disconnect the lower rad hose to see how well the coolant flows through it - eliminate the possibility of a bad rad (very doubtful as it's brand new)...

So if I'm draining all the expensive honda fluid I bought I might as well pull the thermostat while I'm at it

I'll boil it to see if it opens, if it does then it has to be an over-cooling issue. The ambient air temps outside are freezing (0 degrees Celsius) so that could be contributing to it as well.

Mugen112

If it is an over cooling issue, you can take a simple approach. I know this is going to sound tacky, but get a piece of cardboard from a box and put it infront of your rad. See if that helps with your problem. If that fixes your issues, then I would assume jwkims advise of getting the lower temp thermostat would be a solution. Good luck.

ss04

Would over-cooling have the same symptoms of what I'm experiencing?

The top of the rad is super hot, I cannot hold my hand against it. The bottom of the rad is cold to the touch. The fans don't cycle.

I'm convinced that my heat wasn't working because of air in the system. But now I'm at a stand still here trying to figure what else is wrong.