S14 SR Thermostat Issue

[speedfiend]

Well I recently installed a 1 piece Greddy intake manifold on my S14 sr and now my thermostat is not opening.

Here's the run down. Thermostat is a Nismo unit that was installed brand new and has 500 miles on it. I have removed it and put it in a pot of water to test it and it does in fact open properly so I know it is functioning. Thermostat was installed with the bleed thru hole up. Now when I installed the intake manifold I deleted all of the coolant lines that were originally below the intake. I now have one single 7/8" loop that runs from the back of the thermostat housing to the large port on the manifold. All other coolant lines have been blocked. Also, the water pump is brand new so I know things are good there.

Could it be possible that the water pump is creating enough pressure in that loop that it is actually holding the thermostat closed? Basically the pressure being more than the spring can overcome on the thermostat? I can grab the loop and it does have a good amount of pressure while running even with the radiator cap off. Or have I created another issue by deleting and blocking off all the lines that used to run thru the throttle body and such? Or do you think I'm fighting a stubborn air bubble? I've never had a problem bleeding the air from the system prior to this though.

Any help or ideas on this would be much appreciated.

Cameron

[S14rebuild]

Seems like you have an air pocket stuck around the thermostat causing it not to reach temp and open up. Could be a cause do to the hose you deleted. What i would do is open a hose thats connected to the thermostat housing and bleed/burp it. Add coolant as it bleeds out the air, then reinstall the hose. Repeat till no air is trapped in the system.

[speedfiend]

Seems like you have an air pocket stuck around the thermostat causing it not to reach temp and open up. Could be a cause do to the hose you deleted. What i would do is open a hose thats connected to the thermostat housing and bleed/burp it. Add coolant as it bleeds out the air, then reinstall the hose. Repeat till no air is trapped in the system.

Thanx for the reply. I would think an air pocket big enough to prevent the thermostat to open would bleed through the hole at the top of the thermostat. But its worth a shot. Maybe ill try that this weekend.

[S14rebuild]

Anythings worth a try.

If it worked before, then go back to what u changed.

[brndck]

this
https://www.tooldiscounter.com/product/lisle-spill-free-funnel-lis24680?gclid=EAIaIQobChMIyIzpyYrw5gIVsRx9Ch0oNgD IEAQYAiABEgLCPPD_BwE

[speedfiend]

this
https://www.tooldiscounter.com/product/lisle-spill-free-funnel-lis24680?gclid=EAIaIQobChMIyIzpyYrw5gIVsRx9Ch0oNgD IEAQYAiABEgLCPPD_BwE

Sorry but not following how a funnel will eliminate air pockets. Does this setup create some sort of suction on the cooling system or something? Ive never had a problem filling my cooling system in the past 15 years on these motors and not getting air pockets. First time for everything i guess. Ill try purging the system more this weekend and see if that helps.

Still no mention of how I have my coolant lines deleted and the single loop so I assume most don't feel that that could be causing the issue?

[jedi03]

i agree...it shouldn't, but a pocket of air could be trapped...does your heater blow hot? and what are you seeing that the thermostat isn't opening?

[speedfiend]

i agree...it shouldn't, but a pocket of air could be trapped...does your heater blow hot? and what are you seeing that the thermostat isn't opening?

The car does not have a heater, which is why i have the loop below the manifold. Im seeing rising temps even when both fans are on, no heat build up in the lower radiator hose, and no movement of coolant in radiator to indicate flow from one side to the other past the thermostat.

[jedi03]

understood, that definitely sounds like its stuck then...and you have movement of the coolant? AK waterpump is pushing coolant?

[dct223]

If you taken out the thermostat and it worked in hot water... Then it has to do with something with your plumbing. If there is not hot coolant going to the thermostat than it will not open to allow flow through your radiator. Check LC-10 to LC-13 in the SR FSM.

[speedfiend]

Well I drained most of the coolant today and put a vacuum on the system and refilled it via the vacuum set up but still no luck! Not sure where to go from here. Might throw a new thermostat in just for shits and giggles and see if it works. Thanx for the suggestions guys.

[jedi03]

just run without! will just take a little longer to warmup

[S14rebuild]

Sounds like ur not getn coolant circulating to the thermostate, blockage, something is wrong.

[Jorgs_7]

Are you implying the engine is overheating...?

if you just are feeling the radiator hoses - put a piece of cardboard between the radiator and fan shroud. Then try again.
Stock clutch fan & SR20 with a large alloy radiator will rarely allow the thermostat to open at idle.

[speedfiend]

Are you implying the engine is overheating...?

if you just are feeling the radiator hoses - put a piece of cardboard between the radiator and fan shroud. Then try again.
Stock clutch fan & SR20 with a large alloy radiator will rarely allow the thermostat to open at idle.

Yes if I were to let the car continue to run it would over heat. Im running dual FAL fans and with both running temps continue to climb.

I have talked to some good buddies of mine that run dwarf cars with 1000cc sport bike motors and they have had similar thermostat issues. Since they delete all the unnecessary coolant lines to run in the cars they kept getting an air pocket. What they did is installed a "purge line" near the thermostat. Once the motor comes to temp they open the line and allow the air to be pumped out holding the line higher then all other elements of the cooling system. I am going to try doing the same off of the coolant port I have blocked off behind the thermostat housing. This is the only spot air could be trapped and effecting the thermostat.

Ill keep you guys posted as I plan on doing this this weekend. Hopefully it works!

[S14rebuild]

Yes if I were to let the car continue to run it would over heat. Im running dual FAL fans and with both running temps continue to climb.

I have talked to some good buddies of mine that run dwarf cars with 1000cc sport bike motors and they have had similar thermostat issues. Since they delete all the unnecessary coolant lines to run in the cars they kept getting an air pocket. What they did is installed a "purge line" near the thermostat. Once the motor comes to temp they open the line and allow the air to be pumped out holding the line higher then all other elements of the cooling system. I am going to try doing the same off of the coolant port I have blocked off behind the thermostat housing. This is the only spot air could be trapped and effecting the thermostat.

Ill keep you guys posted as I plan on doing this this weekend. Hopefully it works!



Pretty much what i said....

[jr_ss]

Alright Cameron, what did we figure out this weekend?

[speedfiend]

Alright Cameron, what did we figure out this weekend?

Unfortunately, nothing really. Tried to do the purge line but the fitting I had here wasn't the correct size so no go there. I did hook up a crossover line from the manifold back to the little nipple off the main pipe coming from the block behind the water pump. Was hoping this would help equalize pressure in that loop and possibly create an escape route for the air but no luck.

[s13 @ fullboost]

Sorry but not following how a funnel will eliminate air pockets. Does this setup create some sort of suction on the cooling system or something? Ive never had a problem filling my cooling system in the past 15 years on these motors and not getting air pockets. First time for everything i guess. Ill try purging the system more this weekend and see if that helps.

Still no mention of how I have my coolant lines deleted and the single loop so I assume most don't feel that that could be causing the issue?

If you use that set up It will not make a mess. The water/coolant will now be higher up than engine. Air will travel to the highest point. With that funnel you can hold the R.P.M.'S at 3k & let the water pump help move all the air out. When your all done leave the funnel on & let the car completely cool and it will seriously eliminate all air trapped.

Tech tip fill the funnel 1/4 of the way to leave room for expansion. Then start the car & let it do its thing.

[dct223]

That funnel bleeding system is a good tool, I always use that. Pro tip if you do, clamp off your overflow line. Otherwise you end up just filling your overflow tank.

You leave the funnel connected to your radiator as you are bleeding the system, not just to fill. Like what fullboost says it makes the coolant highest point as well as allowing the coolant to expand and contract as your engine heats up and cools down pending what kind of cooling fan system. IE myself running E-fans on a thermostat the coolant will expand and fill up the funnel and as the fans come on and cools, it contracts down back into the radiator. Also giving a bunch of revs help burp and get rid of more air in the system while your engine is running.

None of that matters if you are having issues with the thermostat not opening and lower line staying cold. Like I mentioned before.. If everything worked properly before removing coolant lines and installing new intake manifold, it probably has to do with something in your plumbing. Could try a stock thermostat to double check as well.



If you use that set up It will not make a mess. The water/coolant will now be higher up than engine. Air will travel to the highest point. With that funnel you can hold the R.P.M.'S at 3k & let the water pump help move all the air out. When your all done leave the funnel on & let the car completely cool and it will seriously eliminate all air trapped.

Tech tip fill the funnel 1/4 of the way to leave room for expansion. Then start the car & let it do its thing.

[speedfiend]

Well i went ahead and purchased one of those funnels to try out this weekend as well as a little more engine ice. I don't think the funnel is going to work seeing as my issue is around the thermostat area and lower hose but its worth try. Deleting all the lines has definitely been the cause of this issue. Just a matter of figuring out how to get it to purge and no replacing all the lines is not an option. Ill let you guys know how it goes this weekend. Thanks a lot for all the advice.

[dct223]

FYI If its a similar kit to mine, I had to double up on a rubber O ring to get the cap to properly seal. I'm running a koyo rad

Well i went ahead and purchased one of those funnels to try out this weekend as well as a little more engine ice. I don't think the funnel is going to work seeing as my issue is around the thermostat area and lower hose but its worth try. Deleting all the lines has definitely been the cause of this issue. Just a matter of figuring out how to get it to purge and no replacing all the lines is not an option. Ill let you guys know how it goes this weekend. Thanks a lot for all the advice.

[speedfiend]

FYI If its a similar kit to mine, I had to double up on a rubber O ring to get the cap to properly seal. I'm running a koyo rad

Gotcha im also running a Koyo so thanx for the heads up.

[onehundredoctane]

I don't know if this has already been covered; but did you double check the orientation of the thermostat?

The hole with the jiggly bit faces up so air can get around the thermostat while your bleed the coolant system.

EDIT: noticed OP is from way back (2002), so he likely knows this tid bit, but maybe someone years from now will find it useful lol

[speedfiend]

I don't know if this has already been covered; but did you double check the orientation of the thermostat?

The hole with the jiggly bit faces up so air can get around the thermostat while your bleed the coolant system.

EDIT: noticed OP is from way back (2002), so he likely knows this tid bit, but maybe someone years from now will find it useful lol

This is actually a new post, your looking at my join date. Anyways, yes I have made sure the little hole is up when the thermostat was installed.

[LoSt180]

Wish we could see a picture of how you have things ran. Should have 3 ports connected if you're deleting the heater core and throttle body connections.

The large one on the intake manifold is the return from the head, this should loop out and connect to both the ports behind the thermostat housing. Basically should have a T in that loop. Then you'd just cap off the lines that are supposed to go to the throttle body (or loop those together also).

Hopefully you still have some of the hard pipes around, easiest way is to cut those as needed.

Here's a picture I found in another thread after a quick search, should give you an idea to compare your setup with.

http://givemeshred.com/wp-content/uploads/2013/06/givemeshred-s13-sr20det-coolant-line-simplification-2.jpg
https://zilvia.net/f/showthread.php?t=644900

[speedfiend]

Well I pulled the thermostat and cut the little nipple out of the pass through hole to guarantee pressure wasn't holding it closed. Connected the funnel setup and jack the front end way up. Slowly filled the system until there was coolant resting in the funnel. Then I proceeded to squeeze the upper and lower rad hoses purging the air out. I was able to get alot of the air out just by doing this. Started the car and let it get to temp. A ton of air purged while it was getting to temp! Once to temp I checked the lower hose and low and behold it was HOT!!!! Thermostat was finally open! I let shut the car off and let it cool for a bit an restarted it. It purged a few more little bubbles and that was it. You can see the flow of coolant and when i squeeze both lines you can feel the flow of coolant through them so its good to go FINALLY!

Big shout out to all those who posted up their ideas and helped me with this one!

[S14rebuild]

Glad all worked out for u..air pockets are such a pain. Now drive and enjoy the car!