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Anyone else have trouble keeping air out of cooling system?

Posted: Sun Apr 03, 2016 3:29 pm
by touretta
Hey everyone, new guy here. Been lurking around for a while and usually find what I need by searching but I am puzzled by this one. Working on a 90 base 2.2 car and I have not been able to keep air out of the cooling system after replacing the heater core a couple years ago despite bleeding the system multiple times. I can usually get one or two drives out of the car after bleeding before the gurgling comes back in the heater core. The car was overheated when the heater core blew so I suspected a head gasket but it has passed both a block test and pressure test, the entire system holds rock solid pressure with the car warm or cold. The only thing I have not tried is parking the car on a really steep hill to try to get the heater core past level (since it is angled up with the inlet and outlet at the bottom), I have tried jacking the front of the car as high as possible but have the same results. Any ideas on what I might be missing? Thanks!

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Mon Apr 04, 2016 9:13 am
by ifixalot
Pressure from the compression stroke and combustion cycle is much higher than a cooling system pressure check so I don't
think your test, does not rule out a head gasket. With the cap off and the engine idling, do you see bubbles coming out
of the cooling system? Did you ever find the cause of why the car overheated?
I never owned a 4 cylinder but I used to jack my daughter's 90 way up on the passenger side to get the air out of it.

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Mon Apr 04, 2016 9:18 am
by themixer
I actually had the same thing happen to me with a heater core replacement with my 2.2, it was due to a crack in the head so i hope that isn't your issue

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Mon Apr 04, 2016 10:39 am
by 3X00-Modified
On a 90 2.2 you have a non pressurized expansion tank correct? If so I would make sure that the line that feeds that is sealed properly and will pull coolant back in the system upon cooling. When the car heats the coolant obviously expands and some will be discharged into that tank, upon cooling if the line, tank, or cap are at fault it can pull air back into the system vs the coolant it overflowed. This could be creating the air pockets your speaking of.

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Mon Apr 04, 2016 9:25 pm
by touretta
ifixalot wrote:Pressure from the compression stroke and combustion cycle is much higher than a cooling system pressure check so I don't
think your test, does not rule out a head gasket. With the cap off and the engine idling, do you see bubbles coming out
of the cooling system? Did you ever find the cause of why the car overheated?
I never owned a 4 cylinder but I used to jack my daughter's 90 way up on the passenger side to get the air out of it.


I used a block tester as well and the test fluid did not change color which is a good test, I may try this one more time. With cap off I get bubbles early on as the air purges out then they subside after a few cycles of the thermostat, I may get an errant bubble every now and then if I continue to run it but nothing constant. The car overheated when the heater core let go and blew all the coolant out, girlfriend was driving the car and didn't catch it until it got hot. I might try jacking just the right side to see if that helps.

themixer wrote:I actually had the same thing happen to me with a heater core replacement with my 2.2, it was due to a crack in the head so i hope that isn't your issue


Me too but it's starting to not look so good.

3X00-Modified wrote:On a 90 2.2 you have a non pressurized expansion tank correct? If so I would make sure that the line that feeds that is sealed properly and will pull coolant back in the system upon cooling. When the car heats the coolant obviously expands and some will be discharged into that tank, upon cooling if the line, tank, or cap are at fault it can pull air back into the system vs the coolant it overflowed. This could be creating the air pockets your speaking of.


Correct it is non pressurized. Good idea! There is a clamp on the hose at the radiator end but I will have to check the tank end.

Thanks everyone! I'll give it another go tomorrow.

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Sat Jun 18, 2016 7:49 pm
by touretta
Cracked head it was, had a small crack from the spark plug to the intake valve. I now have a question about head bolts and torques. My 90 2.2 actually had head bolts with the integrated washers for an 87-89 2.0 so I am wondering if I should put a set of those back in instead of the 2.2 bolts without washers. I have a set of both and the 2.0 set seems to be a better fit for the head, it is a carryover from the 2.0 after all. My next question is torques, the 87-89 has a different torque than the 90 which has a different torque than the 91-later. I don't know what it is about the 90 that makes it a bastard child, the 90-91 should have the same heads and bolts. Any ideas? At this point I'm inclined to go with the integrated washer bolts and the 90 oddball torque value, heck I may even measure the stroke to make sure it actually is a 2.2 and didn't get swapped for a 2.0 at some point.

Re: Anyone else have trouble keeping air out of cooling system?

Posted: Sun Jun 19, 2016 4:40 pm
by 1988GTU
I'd go ARP if deciding which hardware route is spinning up a conundrum situation.