PT Cruiser Forum  
Advertisements
       

Go Back   PT Cruiser Forum > General Forums > General PT Cruiser Discussions

PT Cruiser Forum

Advertisements
Air generated in cooling system eventually causing overflow

 
Like Tree7Likes

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 20 Mar 2018, 03:11 pm
rsrocket1's Avatar
Fanatic Cruiser
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 761
Default Air generated in cooling system eventually causing overflow

I've been chasing a loss of coolant problem for the past 4 months and I think I've narrowed it down to maybe a hotspot in the engine which is causing local boiling.

I'm getting small bubbles up the filler neck when running with the Spill Free Funnel and after a week of driving, eventual fill up and overflow of coolant out of the reservoir.
  • Coolant system pressure check - negative
  • Exhaust in coolant check - negative, liquid stays blue over many tests
  • Flush and reverse flush engine and heater core - done several times, once after a week with 2 cups of Cascade dishwasher powder dissolved in hot water added to tap water in the system.
  • Compression check - ~ 130 +/- a couple psi on each cylinder
  • Bypassed the heater core, no difference

So not likely air leakage from the overflow system (I can put my hand on the filler neck, squeeze the upper radiator hose and suck all the coolant back by squeezing and releasing the upper radiator hose while doing the same with my hand over the filler neck).

Not likely a leak in any other part of the coolant system

Not likely a blown head gasket or warped head

I switched to a 180F thermostat and this week I ran the A/C full time in order to keep the fan running on high speed 100% of the time. This was the best result ever as the coolant level dropped only from the top of the filler neck initially to the bottom of the upper radiator hose after a full week of driving. All of that coolant was sitting in the reservoir. No net loss of coolant.

Note: after flushing the heater core the first time, many small flakes of Moroso (Irontite) Ceramic engine sealant flushed out. This was used last August to stop a heater core leak and it worked great. I still get > 150F hot air out of the vents. All flakes were essentially powder when I touched it.





Except one big chunk that came out of the heater core on the first flush:



This looks like it had actually hardened into a ceramic chunk.

So I wonder if any of the Moroso/Irontite could have solidified this hard within the cooling passages in the engine enough to block coolant from flowing up the engine but allowing coolant to flow down into the super hot chamber and boil generating gas that then pushes the coolant out into the reservoir?

In the video you can see that as the engine heats up, the coolant gets pushed up into the funnel until the thermostat opens up, then it goes back to normal level. This is probably when the coolant is getting pushed into the reservoir. Is that a sign of blockage in the engine cooling passages?

Fast forward to 2:20 to see this happening. This is with a 195F thermostat



If that is the case, how can I clear up the blockage? Would removing the head get me a clear shot to bust up the blockage? Is there an easier way into the lower coolant passage like maybe through a freeze expansion plug? Can I snake something from the water pump opening? I know I have to essentially do another TB job in order to take off the head but I'd like to exhaust all other possibilities first.

Thanks
Reply With Quote
  #2 (permalink)  
Old 20 Mar 2018, 04:42 pm
Cool Cruiser
 
Join Date: Sep 2015
Location: Phoenix AZ
Posts: 283
Default Re: Air generated in cooling system eventually causing overflow

I'm not quite sure the purpose of the "funnel" rig shown... have the cap pressure tested along with your regular cap. the one on the rig may be junk.. with that being said, its still sort of working the way a closed system should work, just much more volume. any dang shop worth a crap would help a customer with 4minutes to test a cap or two for free.

so with the regular cap your o.f. reservoir fills up and over flows out the top?

this is why stop leak stuff doesn't work. in the future for a heater core leak id bypass it first or figure out a way to just seal the heater alone but wether or not it would stay in the core is a gamble.

not sure what good dishwasher cleaner would do at all, that's a new one. id take those flakes and experiment with proven acids/vinegar/ or what ever in a clear plastic cup and go with the one that dissolves it. test it, find the best one, screw the directions or danger to aluminum, and let the solution sit in the engine a LONG time- making sure theres no air, then just pressure flush the block with Both hoses and thermos off. you might just be jamming the junk somewhere else when you are flushing it. then do the same with the radiator- what ever order, just don't let one system dry w/o flushing it! (youll find a way, they make rubber caps that big, or make it)

try to use a container to catch some of the flush so you can see junk coming out. then, flush again and again, put back in the stock thermos, fill with HOAT, not oat, do one last pressure test and drive off to the sunset..

p.s., always assume a test rig or gauges may be incorrect or not working...along with new parts like thermos or caps. test them. I cant remember if its impossible to install the thermos upside down. anyone?

Last edited by rambojoe; 20 Mar 2018 at 04:47 pm.
Reply With Quote
  #3 (permalink)  
Old 20 Mar 2018, 04:52 pm
Obsessed Cruiser
 
Join Date: Aug 2014
Location: Thousand Oaks, CA
Posts: 7,335
Default Re: Air generated in cooling system eventually causing overflow

Also make sure the hose between the cap and the reservoir is not leaking. If it is you will get air in the coolant system.
pt06 likes this.
__________________
If at First You Don't Succeed - Try, Try Again
Reply With Quote
  #4 (permalink)  
Old 20 Mar 2018, 05:41 pm
rsrocket1's Avatar
Fanatic Cruiser
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 761
Default Re: Air generated in cooling system eventually causing overflow

Thanks for the responses and suggestions Joe,

Quote:
Originally Posted by rambojoe View Post
I'm not quite sure the purpose of the "funnel" rig shown... have the cap pressure tested along with your regular cap. the one on the rig may be junk.. with that being said, its still sort of working the way a closed system should work, just much more volume. any dang shop worth a crap would help a customer with 4minutes to test a cap or two for free.
Already tested the cap, holds 18 psi all day long (well, at least 5 minutes) and it obviously opens (coolant gets blown into reservoir). I've swapped between 3 different caps. 1 is 2 years old and the other 2 are brand new.

Quote:
so with the regular cap your o.f. reservoir fills up and over flows out the top?
Yes.

Quote:
this is why stop leak stuff doesn't work. in the future for a heater core leak id bypass it first or figure out a way to just seal the heater alone but wether or not it would stay in the core is a gamble.

not sure what good dishwasher cleaner would do at all, that's a new one. id take those flakes and experiment with proven acids/vinegar/ or what ever in a clear plastic cup and go with the one that dissolves it. test it, find the best one, screw the directions or danger to aluminum, and let the solution sit in the engine a LONG time- making sure theres no air, then just pressure flush the block with Both hoses and thermos off. you might just be jamming the junk somewhere else when you are flushing it. then do the same with the radiator- what ever order, just don't let one system dry w/o flushing it! (youll find a way, they make rubber caps that big, or make it)
The diswasher soap is supposed to remove any hard water scaling and if there is any mixture of oil in the coolant, it is supposed to emulsify it and carry it away when you flush the system out after letting it run for many days. Plus it is made not to suds like a regular soap. It didn't seem to make any difference in my case.

Looks like there is a way to do a pressure flush with a contraption that uses shop air and a water source. I do believe that my flushes are very low pressure/flow. I hook up a garden hose with a nozzle pressed against a 5/8" I.D. vinyl hose clamped to the heater inlet/outlet and it flows about 2 gallons per minute. I've tried pulsing the water to try to "water hammer" the coolant system, but I think the pressure/flow rate is just too low. I don't have a powerful enough compressor so I may need to pay a shop to do this.

BTW the radiator is one year old this month and there seems to be plenty of cooling capability in it when the T-stat is open. The temperature runs rock solid at 174F while driving down the highway at 65 MPH. First thing in the morning, it climbs to ~195, then when the T-stat opens, it drops to the high 160's then oscillates until it reaches a steady state of 174. When I had the 195 thermostat in there, there were a few times that it got up to 240F before opening up the first time. When I dipped that thermostat in boiling water, it opened reliably and closed when I pulled it out and let it cool. That T-stat ran at a steady state temp of 194F.

Quote:
try to use a container to catch some of the flush so you can see junk coming out. then, flush again and again, put back in the stock thermos, fill with HOAT, not oat, do one last pressure test and drive off to the sunset..
Yeah, that's what I've been doing. Using a 2 gallon clear plastic jug to catch the outflow.

Here's a picture from my earlier heater core flushes. I've replaced the 1 gallon container with a 2 gallon clear plastic wide mouth jug that fits in the airbox cavity and shortened the hoses quite a bit.



Quote:
p.s., always assume a test rig or gauges may be incorrect or not working...along with new parts like thermos or caps. test them. I cant remember if its impossible to install the thermos upside down. anyone?
I believe the thermostat is supposed to be installed with the pointy side up and the wax pellet down and the jiggle valve closest to the tab pointing toward the engine (away from the right front corner of the car). If it's not and I've been doing it wrong all this time and it fixes it, I'll be the happiest guy on this board.
Reply With Quote
  #5 (permalink)  
Old 20 Mar 2018, 06:55 pm
Cool Cruiser
 
Join Date: Sep 2015
Location: Phoenix AZ
Posts: 283
Default Re: Air generated in cooling system eventually causing overflow

I wouldn't get too caught up with the fancy engine gauge readings (but it would be interesting to know what the water temp reads when the dash shows the normal needle a hair below half) sometimes having the basic crappy temp and idiot oil lites makes life a little simpler, if you get my drift.

hose pressure is fine, point is to experiment with the particles in a cup till they dissolve then just use that. hell, a zep degreaser will eat/etch aluminum but you would have to neutralize the action. I bet 3 days of straight vinegar would do it,i don't know- ive never used this stop leak stuff. that's your job.

I'm almost 100% positive its not possible to install upside down (thermos). if you calibrate a cooking thermos at 212f (they all are adjustable- twist the dial) and a 195f thrm opens at 195f, then don't worry about the digital gauge reading so high. I know you know this crap...

last, I meant test the pressure cap on that weird funnel thingy... keep it simple, and you will work less and find out if you need to yoink the head. everyone will agree on one thing, water jackets are easier to super clean while its together!! just don't work crap from one area to the next. isolate the components. and remember, the head passages are huge but the gasket only has small transfer holes... time for supper!
Reply With Quote
  #6 (permalink)  
Old 21 Mar 2018, 03:35 am
Senior Cruiser
 
Join Date: Jan 2013
Posts: 1,266
Default Re: Air generated in cooling system eventually causing overflow

rocket; The thermostat gets placed with the large 'spring' pointed downward. The little valve on the thermostat gets rotated in line with a notch on the upper housing.

Water heating up in a pot of water on a stove will create air bubbles at much less than 212 degrees. In a PT engine, these air bubbles float to the top of the head. It requires a few cold/hot/cold cycles to purge this air out of the system. The upper seal of the radiator cap is what holds a vacuum that sucks the coolant from the reservoir tank back into the engine. Keep reservoir tank filled with HOAT [50/50] at about 1/3 full.

The radiator cap must be on and the heater core cannot be blocked for this to work.

Good luck
Reply With Quote
  #7 (permalink)  
Old 21 Mar 2018, 11:28 am
rsrocket1's Avatar
Fanatic Cruiser
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 761
Default Re: Air generated in cooling system eventually causing overflow

Thanks PT06.
Yes, that's the setup I have with the thermostat. So it's working as it should. Unfortunately, it seems that the PT thermostat setup causes the thermostat to stay closed much longer on the first cycle because it lets cool water from the upper radiator hose to sit against the top of the thermostat. Plus any air under the thermostat cannot get past the jiggle valve if it is flat on the bottom because the pressure will hold it closed tight against the thermostat plate.

I think I have good flow through the heater core. With the setup shown in the photo above with the clear vinyl hoses as I can fill the container just as quickly with water going through the heater core as I can with the hose dumping straight into the container plus I get good hot air through the heater (at least 156F) with the car in motion. The temp goes down to the mid 130's when stopped at a stop light. This was with the A/C off of course.

Early in November I was getting a very noticeable babbling brook sound coming from the heater core when accelerating under load with 1 or more passengers in the car or with a really heavy accelerator foot. The first reverse flush plus filling the heater core completely with coolant before reattaching the heater hoses to the engine eliminated this. I think air was trapped in the heater core and maybe a partial constriction prevented all the air from getting purged. It may have come from that ceramic "rock" that came out from the first reverse flush.

It's strange because with all other cars I've seen when I've started the engine with the radiator cap off, the only difference between an open and shut thermostat was that I could see coolant flowing when the thermostat opened. It may be because the thermostat is sitting right above the water pump and when it cracks open, the small opening squirts water up and out of the filler neck until the thermostat opens completely.
Reply With Quote
  #8 (permalink)  
Old 21 Mar 2018, 01:06 pm
Handy_Cruiser's Avatar
Obsessed Cruiser
 
Join Date: Oct 2013
Location: Arkansas
Posts: 10,427
Default Re: Air generated in cooling system eventually causing overflow

This all sounds a lot like a clogged radiator to me. In that case, the air pockets are likely coming from hot spots where the coolant can't properly flow. The coolant at the temp senor is staying cool so you don't see this on the gauge.

If me, I'd remove the radiator and flush it with a steam cleaner. I'd also check to see how fast water can flow through it. The problem is that water can likely still flow through the upper part of the core but may not be flowing at all in the lower part. As a very general rule of thumb, a clogged radiator gives trouble while running down the road at speed but often doesn't when the car is just sitting and idling. And sometime you just can't tell until you try another radiator. I'm not saying go buy one. I'm just saying it's something to look at.
__________________
Reply With Quote
  #9 (permalink)  
Old 21 Mar 2018, 02:05 pm
rsrocket1's Avatar
Fanatic Cruiser
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 761
Default Re: Air generated in cooling system eventually causing overflow

Thanks Handy. The radiator is new (one year old) and I don't think it is obstructed. If the weather holds up this weekend, I'll try a flow test. It's easy enough to remove the top and bottom hoses and get a big bucket.

A few months ago I questioned you about drilling holes in a thermostat that already had a jiggle pin. It didn't seem to be needed but while thinking about it over the past few weeks, I might get another T-Stat and try it to see if it makes a difference. As a quick test, I removed the jiggle pin on a 195 thermostat, but that hole was much too big and the engine took forever to warm up and I actually got a MIL code saying engine too cold for too long (P0128). This was on a 45 degree morning and it didn't solve the coolant loss problem. I might get another 180F thermostat and drill a much smaller hole than the jiggle pin hole like 1/16" or smaller.

That's just a patch and isn't fixing the cause though.

I'm looking for other possible reasons for what I think is localized boiling or if there is any other reason for the coolant to get lower in the engine and rise in the reservoir of a sealed system with no head gasket issues. If removing the head is the only way to tell for sure, then I'll resign myself to doing a HG job. It shouldn't take more than a weekend and hopefully just one day.
Handy_Cruiser likes this.
Reply With Quote
  #10 (permalink)  
Old 21 Mar 2018, 03:41 pm
Cool Cruiser
 
Join Date: Sep 2015
Location: Phoenix AZ
Posts: 283
Default Re: Air generated in cooling system eventually causing overflow

that's why I suggest dissolving the seal crap with a aggressive medium... heat transfer could very well be the ticket. until you do what the others suggest and etch the metal in the passages... it just wont work. the big hint is- the engineers made it so you don't (shouldn't) have to modify a thing... talk to a radiator shop, they have good chemicals!
Handy_Cruiser likes this.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
My Cooling System: I hate it! Hoser General PT Cruiser Discussions 16 22 Dec 2016 07:33 pm
Help with cooling system!! Osufan64 Tech & Performance Forum 3 29 Oct 2013 01:09 pm
03 gt turbo cooling system...help !!! SteveisKoolaid General Turbo Discussions 5 26 Jul 2013 10:00 pm
cooling system ? cllwyrc Tech & Performance Forum 6 25 Apr 2010 10:35 pm


All times are GMT -5. The time now is 01:10 pm.




Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors