Hi all, Just did a thermo and full flush on the XJR. Looking good. Bleeding the system with the screw on the res tank and even have the car angled up to exaggerate the highpoint on the bleed. That said.... holy crap how much air is in the lines? On bleed Number 1 (which is as far as I got before rain opened up on me) I had the system flowing, topped off, and bleeding for like 20 minutes. I buttoned it up as I was getting soaked. When the rain subsides (2 days now in LA and we melt in the rain) I will bleed it again. That can I get a recommendation on how long that screw will throw air and the occasional coolant spew (LOTS OF AIR). Any ETA or thoughts? Thanks and let me know.

 

Sounds like you might have a breach in the system where air is getting back in.

 

Yes but where? There are no coolant leaks anywhere at the moment. Other than a blown head gasket which seems unlikely as the car was running in top form before the thermo replacement. I would think it would have to be a major air suck to create that amount of non stop air? Any thoughts as to where that much air could rush in?

 

You have the radiator cap on right?

When I did my thermostat I only had to bleed once & top up. So not sure why you should have this sort of issue...

 

Is your aux heater pump working?
It may have been air trapped in the heaters
Did you have the heaters on when you bled the system?

Here is how i do it

1. Raise the front so the reservoir is the highest point (ie above the s/c full port)
I use car ramps to do this
2. Fill the system, trun on ign so both the aux and s/c pumps are running.
Dont run the engine at this point
3. Leave it 10 mins for the coolant to circulate and top up if below full
4. Open the bleed screw and instal the cap
5. Run the engine up to temp with heater on full, monitor the coolant temp
Let it run for a few mins after it's up to temp so your circulating with the thermostat open
6. Let it fully cool, close the bleed screw, top up again and lower the front

PS I dont use the gauge to monitor the temp but use Torque on android.
I also set the alarm at 99C so if the ere is a problem im alerted
This let me do other stuff while the car idles up to temp

I find most of the air is extracted by running with the engine off and the 2 pumps running not need the bleed screw at all abut to be sure I do that anyway because it the factory procedure

Cheers
34by151

 

Thanks bro, I will try that. Did not turn the aux pumps on as per above just started the motor.

Will run it through like you have it above and see how it goes. Thanks again!

 

When I did my flush and fill, I opened the supercharger coolant fill plug while I was filling to let the air out. Never an issue with bleeding after that whatsoever.

Something to think about.

 

You don't need to remove the S/C fill plug if you raise the front on ramps as the fill plug is no longer the highest point.
All the air then ends up in the resevoir as it the highest point now
Running both pumps with engine off pumps/forces out most of the air without even running the engine. There will only be a minor amount left that is handled by normal bleeding.
On more than one occasion I have skipped opening the bleed screw altogether.
Just bleed via the pumps, top up, replace cap, run engine to temp, coll and top up


Cheers
34by151

 

Can you mix water with the coolant or should it be 100%?

 

I got the Jag Coolant however I used it all up.

 

OAT coolant should be mixed with water 50% coolant 50% water.

Good luck.

 

Also there is a tsb, ill dig it up if needed, that states 50% oat coolant and 50%water
It makes a specific point not to use distilled water just tap water

I always use premix 50% oat myself

Cheers
34by151

 

FYI, If your air bleeder ever starts to leak on the coolant expansion tank, like mine did recently by getting a small crack in the rubber O ring that is on it from age, there is a rubber O ring that you can easily replace. The O ring is #48 size and has the dimensions of 16mm CD x 10mm ID x 3mm Wall thick. Mineard's sells one for only $0.59 cents.

 

Thanks all for the replies. Thermostat replaced. The old one felt weak but not stuck, however I bled the system much better. My High Fan problem has gone away. All is right with the world and the cooling system. Thanks again for all the advice.

love this forum!!