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Think I have an air lock, please help.


Wyntersun

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I have just drained the coolant out of the rad by taking the cap off and undoing the little white screw plug at the bottom.

 

After all the coolant had drained into a bucket, I unclipped and pulled the top and bottom hoses off to get any remaining fluid out. Screwed the little white plug back in.

 

Got the garden hose and put it in the top inlet of the rad and flushed out with clean water out of the bottom outlet.

 

After about after 5 mins of this, I stopped the water and put everything back together. Hoses back on, top & bottom, cleaned expansion tank and but that back. Filled tank to about half, and started filling the rad back up with Toyota coolant. When I could see the fluid reaching the top of the rad I turned engine on, put heaters on max and waited for the coolant to drop so as I could fill back up.

 

The gauge on dash got to half way as per normal, but the heaters still blowing cold air!!

 

I put the rad cap back on as the coolant had started to splutter out of the top. Top hose is to hot to touch and bottom hose is stone cold.

 

Is this an air lock? and how can I solve this?

 

Thanks

 

*after thinking about it, I didn't pour the new coolant in very slowly in to the rad.

 

**would fitting a 1.3 bar rad cap be any better than the 1.1 I have fitted currently. Just that I have a 1.3 sitting in the garage new.

Edited by Wyntersun (see edit history)
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Let the car cool down, take the rad cap off and run the car with heater on full hot, keep running the car with the rad cap off whilst slowly topping up the system, you will lose some coolant out the rad cap, this is mostly the air escaping from the system, once the car is at its operating temp raise the revs to approx 2000 rpm still with the cap off, you will lose a little coolant so top it up as you go, this is the best way to shift an airlock in the system.

 

Keep checking the heater as when the air lock moves it'll blow hot then top up the rad and fit the cap, then re fill the expansion tank approx half full.

 

There is no need to drain any coolant you already have in there !!

Edited by Dnk (see edit history)
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Cheers Dnk,

 

I will do that shortly.

 

Thanks

 

Would having a 1.3 bar cap be better than a 1.1bar?

 

Every supra ive bled up i've done this way with 100 % success, i'd personally go with a stock rad cap to be honest.

 

It would pay you to put the coolant in an easy to pour out of container, i use a clear plastic 1 litre jug with a nice spout so you can slowly add more cooant as you go. Its hard work doing it out of the 5 litre containers and tends to glug everywhere !

Edited by Dnk (see edit history)
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Yeah, it wasn't until after that I remembered that you need to pour it in slowly as mine was gluging in!

 

So follow what you said and all should work out ok?

 

Yes unless ofcourse theres something else wrong like the heaters blocked or the stats not working correctly.

 

I use the little pouring jug as its just much easier when your actually bleeding the air out, its ok to glug it in when you 1st fill it:)

 

Also when you get heat out the vents you will possibly notice the level drop in the rad so just top it up to the neck and run for a few minutes to get all the air out.

Edited by Dnk (see edit history)
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All done and sorted, cheers for all the info guys :)

 

Blowers blowing hot air now and rad nicely filled up and expansion filled half way. When it cooled down the rad took some coolant out of the expansion. From half way to about a quarter way down. Sound about right?

 

Thanks

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...When it cooled down the rad took some coolant out of the expansion. From half way to about a quarter way down. Sound about right?

 

Yes, that's right, it's self-bleeding. Now just watch the expansion tank over the next few days and keep it topped up to 'max'.

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Another top tip is instead of using cold water added to the anti freeze use hot tap water or boiling water , mix it with your anti freeze and then fill the rad ,this way you open the thermostat striaght way and get out nearly all the air before you start the car, and its loads faster to get up to working temp to . Rich.

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Another top tip is instead of using cold water added to the anti freeze use hot tap water or boiling water , mix it with your anti freeze and then fill the rad ,this way you open the thermostat striaght way and get out nearly all the air before you start the car, and its loads faster to get up to working temp to . Rich.

 

Isn't that dangerous for the block? (Hot water coming into contact with the cold block?) Genuine question, it might be OK. :)

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When fully draining the sytem you need to remember the block drain plug,just under and to the rear of the stock turbos, it is often missed. To refill I used to cut off the top 150mm of a 2L fizzy drinks bottle. The treaded part screws in to the stock rad neck really well.I f ill the systrem untill it wont take any more, leaving the bottle in place and run the engine. I just keep it running so I can watch the bubbles come out and top up as necessary. Leaving a few cms of coolant in the bottle neck is not a problem, I cartch most of ther excess coolant in a bit of rag. I used to use a screw in valve on one of the heater maxtix feeds, not dont it this time, something I need to do,as it makes system bleeding so easy.

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I think it came from a scrapy, Vauxhall IIRC. We put one on the RB engine we put in a 200SX, as the heater matix feed was the highest part of the system. It was so easy, fill the car run the engine so the thermosta opened, undo the bleed screw, get a satisfying hiss of air, then the splutter of coolant, job done.

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  • 8 months later...

I am mid-coolant change.

 

I have opened the little white stopcock thing at the bottom of the rad to drain out the coolant - its very brown..

 

I am filling the rad via the top with just normal tap water and have not turned the car on yet..

 

After I have "flushed" it a few times using this method of drain out and refill with clean water will it be okay to turn on and let run for a minute or two to open the thermostat and get some of the coolant within the block circulated so that can be flushed / drained etc using the same method.. or isnt that such a good idea?

 

I am trying to flush it because I dont want to connect up the new heater matrix and have old coolant circulating around it.

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