ever hear of air/pressure in the coolant system causing a car to miss?

i either had the strangest problem ever or i just dont know what i thought i knew about cars.

so i have an 04 pt turbo. 133k

i have been having this problem where it will lose power while driving. i stop. turn the car off and back on again immediately and i can drive away like it never happened.

i have a 10 mile drive from my house to work each day. it never does this malfunction on the way to work. so i drive to work. park it for 9 hours and on the drive home it happens. the thing is it always happens on the little side street about 500 feet from where it was parked. do the off/on thing and it is fine.

i put a cam sensor on it. still doing it
throttle position sensor. still doing it
pcv valve. still doing it
new plugs. still doing it

so a few days ago i got a new problem. the temp gauge was going from mid point where it should to almost on the red and back down.
did it on the way to work and on the way home.

i checked the coolant and it was just a touch low. i have had it apart though doing a lower intake manifold gasket months back and i had to take the hoses and # off so i may have never had it topped off. no leaks to speak of.

so i top off and start the car with the radiator cap off. immediately, within not even 10 seconds the coolant is bubbling and rolling and spilling out, not boiling. bubbling.
it should not be doing that 10 seconds after i start it.

so i cap it and wait for the temp to rise and open the bleeder. did this a few times and took it for a long drive. didnt overheat.
next day i drive it around my house for about 10 miles and park it. did not overheat. started it in the evening and drive it and it did not overheat or do the loss of power problem.
sunday same thing. no problem with either

today same thing. to work and back. no overheating and no loss of power.

this is the first time in months that it has not had the loss of power.

i can not wrap my head around how air/pressure in the system would cause that problem.

obviously if you blow a head gasket you will get coolant to leak into your combustion chambers. i say this cause clearly coolant makes its way in.

what about air though?

i am wondering of there was so much pressure in the system that air under pressure was making its way into my combustion chamber on my way to work and when i turned the car off the pressure was trapped so when i took off at the end of my shift it always lost power on me a few hundred feet from where it was???

this kind of makes sense to me but not really..

make sense to any of you?

either way the car is not doing this problem anymore after months of doing it and the only thing different is i bled the coolant system.

i dont think this should have fixed that problem but it seems to be fixed.

any comments welcome

taking the rugrat to the park so i will respond in a bit

If 'air' is blowing out of your coolant when the car is running, chances are you've got a head gasket leak. That's exhaust leaking into your coolant during combustion- when the pressure is at its highest.

Grab some PH test strips- I forget what exhaust does to the coolant, but IIRC it should be around 7. if it's far off in either direction it could be from exhaust leaking into the coolant.

edit:
since your coolant was down, there's also the chance it leaks into the engine a little bit.
If you have a boroscope (I got mine for $8 on ebay, plugs into my phone) you can pull the spark plugs out and look inside the cylinders. If one or more of them is shiney clean, you've got coolant getting in there. It vaporizes and steam-cleans the carbon out of the cylinder.

a reply to: lordcomac

that makes sense but i feel like it was just air trapped in there from previous work i did.
it was no more than a cup if that low. overflow had coolant in it.

as i said i had had it apart months ago and put on a lower intake manifold gasket. to do this job i had to take upper intake off. upper hose off.
when i was finished i did not bleed the system. this makes me think that air got trapped in there.

if it is a head gasket then i should still be having the problem(s) and i am not.

make sense?

i feel like i was sucking air for a long time before i realized there was an issue. here is that story

months back out of nowhere the car started to make the loudest noise/whine you have ever heard. so loud and high pitched in fact i could not locate it when i had my head in there cause it sounded like it was coming from everywhere.
i got some carb cleaner and started spraying around and when i sprayed the corner of the lower intake manifold it sucked a little vacuum and quieted right down. obviously a manifold gasket.

i took it apart and there were 2 gaskets on there. i had already had the car about 2 years at this point. so if it had 2 gaskets on it that means it was leaking the entire time i just never noticed until it got to that point where i could hear it.

so i was leaking vacuum. then i tool it apart and fixed it. had the hoses off and never bled the system.

of course you could be right but wouldnt you expect my problem to still be there?

also i see no smoke coming out of the pipe. i see no coolant leaking anywhere.

also if it were a head gasket i would expect to see some problems quite often. i only saw the problem when i started it after work. once i turned it off and turned it back on i could drive for 50 miles and no problems.

i wouldnt expect a head gasket to behave this way.

to be fair i dont expect what i did to fix it either.

figured best to talk it out


thanks

Whenever you have a substantial air or gas bubble in the coolant loop (whether it’s from a head gasket leak or not) the coolant temperature sensor will produce an erratic signal because sometimes it’s immersed in the liquid and sometimes it’s not. You’ve already reported that happening. The coolant temperature is one of the measurements that the ECU uses to calculate how much fuel to inject. If the temperature measurement is off, then the mixture richness will also be off. That, by itself could cause the engine to misfire.

Some engine blocks are a lot more difficult to fill with coolant than others. Some of them require pulling a vacuum at the radiator or the overflow reservoir in order to get rid of all the trapped bubbles. The first thing I would do is to make absolutely, positively sure that the engine block and all the hoses and the heater core are completely filled with coolant. I would bet that will make the problem go away, at least for a while. If the coolant system develops air bubbles again and the misfire comes back, then there’s obviously a leak that needs to be located and fixed. It could be a head gasket, a heat exchanger, or any one of a number of sources.
a reply to: TinySickTears

How high were you when you did the intake gasket?

Seriously though, I'd do a pressure test on the cooling system, either a vacuum test(which will both show if there's a leak and fill the system without air getting in, or a positive pressure test which can be done with coolant still in the system and identify if there is a leak).

You can probably rent the tool from a local auto parts place.

a reply to: 1947boomer

thanks man.
that makes me feel good

makes sense with the repairs that i did and having hoses off would allow air to get trapped in yes?

a reply to: 1947boomer

Yup, I've never had issues with coolant systems after I picked up this guy.

www.amazon.com...=sr_1_1?ie=UTF8&qid=1531171160&sr=8-1&keywords=uview+air+lift

Lot cleaner work too, suck it down, check the gauge, put the hose in some coolant and it sucks it right in.

originally posted by: MisterSpock
How high were you when you did the intake gasket?

Seriously though, I'd do a pressure test on the cooling system, either a vacuum test(which will both show if there's a leak and fill the system without air getting in, or a positive pressure test which can be done with coolant still in the system and identify if there is a leak).

You can probably rent the tool from a local auto parts place.

not at all... surprise i know

i remember doing the job. early on a saturday. before the smoking began.

does what i laid out make sense to you?

originally posted by: TinySickTears
a reply to: 1947boomer

thanks man.
that makes me feel good

makes sense with the repairs that i did and having hoses off would allow air to get trapped in yes?

A lot of engines are pretty complex with cooling systems, some have 3 or 4 bleeders with a few of them being impossible to get it.

I'd try to get your hands on the vacuum tool.

a reply to: MisterSpock

i will check tooltopia and see what they have

a reply to: TinySickTears

You could probably rent one, but if you do any amount of work on cars I'd buy it. After buying mine, I wished I had bought one years ago. Great tool, real good bang for the buck and will save money in the long run. No more filling a system to see if it leaks.

originally posted by: MisterSpock
a reply to: TinySickTears

You could probably rent one, but if you do any amount of work on cars I'd buy it. After buying mine, I wished I had bought one years ago. Great tool, real good bang for the buck and will save money in the long run. No more filling a system to see if it leaks.

if i can get one for the right price i will buy it.
i have a pretty extensive tool inventory. i just dont enjoy working on cars anymore and try not to do it if i can help it.
ever since i lost the finger it bothers me cause i will be feeling around and bashing my stump and it is #ing painful

Anytime that you replace hoses or change coolant you have to "Burp" the system. If you don't the air bubbles will cause overheating as you described. The procedure to burp it is to run it without the cap on and let the burps happen. Sounds like that is what you did (just a little late).

originally posted by: bluesjr
Anytime that you replace hoses or change coolant you have to "Burp" the system. If you don't the air bubbles will cause overheating as you described. The procedure to burp it is to run it without the cap on and let the burps happen. Sounds like that is what you did (just a little late).

i hear ya
technically youre supposed to run it with the cap off and the heater on. when the thermostat opens up you need to give it a little gas to suck some coolant through. top off and then cap

technically



its one of those procedures that i never really followed and never had a problem with.

also the repairs i did was many months ago. strange the problem just presented itself

a reply to: bluesjr

My 300zx has a very sensitive cooling system, with 2 of everything it's very prone to having air trapped in the system. In the past, it was a mess getting them out. With the cap off getting it to operating temp and racing the motor to make sure there wasn't air in there was a mess. Vacuum tool is the way to go, no more floor dry and getting st those bleeders on the back of the block.

Just my shade tree mechanic idea.
You likely got air in the system during the intake job.
As said above, an air pocket formed somewhere, in a bend/dead spot near a sensor.
As the air heated and expanded, this pocket of air expanded, and the expanding air caused a pressurized ''plug'' that effectively slowed or stopped coolant flow thru that area. It may be 1 of 2 scenarios:


1 --- The trapped air pocket is at/near a sensor, giving a false reading.
2 --- Air pocket is fairly large, and sensor is elsewhere

Either way, the sensor is giving a false reading, no?
(I had an old Dodge Shelby Charger, w/ a 2.2 turbo, This happened to me a couple times)

First, check the turbo, and if it has one, the inter-cooler. Plumbing for it, oil lines, etc. If turbo system/loops has issues, it may be the problems. The turbos on the earlier Chrysler products weren't the best.

remove radiator cap
get engine to operating temp
open pet cock and let drain, allowing engine to cool while petcock open, keeping cap off also.

close petcock, fill w/ clean water and a cooling system flush/cleaner
Use something like this

run till 'warm' w/ cap off
replace cap
take for short drive, varying rpm, getting engine up to operating temp
let cool
remove cap, open petcock, drain.

close petcok.
fill w/ premixed antifreeze, leaving cap off
run till warm
top off while running
replace cap

maybe take lower hose loose at lower end, instead of opening petcock, if hose end is lower.

Good to go !

Please excuse grammar/spelling.......day started at 4 am, its now 130 am

Good luck!

a reply to: TinySickTears

Possibly a stuck thermostat

originally posted by: GBP/JPY
a reply to: TinySickTears

Possibly a stuck thermostat

Don't appear so.
Car had no issues again today

another day home and back without a problem

i say its fixed

a reply to: TinySickTears

Check your plugs. If they have a white residue on the electrode, you have coolant leaking. I bet something is amiss with that intake gasket you replaced. May need to tear it apart again and replace once more. That's the only reason your coolant would bubble when you fired it up. It happens, either a defective gasket or possibly a cracked manifold.