EA288 Cooling system bleeding

[sootchucker]

Hi TDI Fam-

recently drained and refilled my cooling system. what a mistake....

i have used an airlift 550000 to fill my system... but i am still feeling like the system has air trapped since the car still runs hot at times. i have a VCDS and i was able to locate an informal procedure that bleeds the cooling circuit and then a second procedure that bleeds the low temperature circuit, found on this link.

Bleeding Cooling system on motor EA288

Hello , I will change my crankshaft and water pump on my audi A5 engine type EA288, and I would like to know the exact procedure to properly bleed the cooling system with my VCDS, it's necessary as Elsawin says. I have seen some explanations on the net, but often incomplete, or in languages...

forums.ross-tech.com

does anybody know if this is accurate / or how in the hell to actually bleed this type of system?

thanks in advance...

 

[ticaf]

did you run the car with max heating on? and how thorough of a drain did you do ?

 

[sootchucker]

yes. i will never know the quantity of what was removed at this point though

 

[15TDICommuter]

Hi TDI Fam-

recently drained and refilled my cooling system. what a mistake....

i have used an airlift 550000 to fill my system... but i am still feeling like the system has air trapped since the car still runs hot at times. i have a VCDS and i was able to locate an informal procedure that bleeds the cooling circuit and then a second procedure that bleeds the low temperature circuit, found on this link.

Bleeding Cooling system on motor EA288

Hello , I will change my crankshaft and water pump on my audi A5 engine type EA288, and I would like to know the exact procedure to properly bleed the cooling system with my VCDS, it's necessary as Elsawin says. I have seen some explanations on the net, but often incomplete, or in languages...

forums.ross-tech.com

does anybody know if this is accurate / or how in the hell to actually bleed this type of system?

thanks in advance...

How warm is the car getting? What is the coolant temp you're seeing?

 

[sootchucker]

230+ and then I cut it.

 

[sootchucker]

still looking for people with experience bleeding the CVCA. I have ran both the cooling system bleed and low temp circuit bleed three times. still having issues... or a nasty air pocket!

 

[JM Popaleetus]

PM me your email address and I'll send you a .pdf of the repair manual for the engine. Section 19 is the cooling circuit.

 

[sootchucker]

PM me your email address and I'll send you a .pdf of the repair manual for the engine. Section 19 is the cooling circuit.

i am familiar with the circuit itself. what i am not familiar with is the process of bleeding this complicated circuit. ive run both programs in VCDS, but i still think i have a pocket of air somewhere. ill keep running the bleed programs i guess.

 

[oilhammer]

Just curious, did you monitor your coolant temp data prior to messing with the system?

Was there a reason you drained it?

Is there any DTCs currently?

 

[capt_slow]

Have you tried the vacuum fill method? Probably worth spending the $$$ for the tool and compressed air source do it properly.

 

[sootchucker]

Just curious, did you monitor your coolant temp data prior to messing with the system?

Was there a reason you drained it?

Is there any DTCs currently?

I was not monitoring temp data before messing with the system. but the gauge never moved from the middle once it was heated up no matter what.

the reason I drained it... I hit a pile of dirt that broke the auxiliary radiator. its been replaced and system has been vacuum filled.

I will check for DTC's now but the last one I had was for one of the pumps dry running...

 

[pedroYUL]

Are you still running the variable speed water pump? Perhaps that's not working right when the car gets to temp.

 

[sootchucker]

Are you still running the variable speed water pump? Perhaps that's not working right when the car gets to temp.

the only thing i have not tried is bleeding the low temp circuit with the car running at temperature.

 

[pedroYUL]

the only thing i have not tried is bleeding the low temp circuit with the car running at temperature.

I mean, all of the coolant system is still heavily reliant on the water pump. If for whatever reason (impeller loose, solenoid sticking...) the water pump is not moving coolant, then that would explain your symptoms.

I did the timing belt recently, quite a bit of coolant drained that way, but my new pump is metal impeller/fixed speed. I just had to fill thru the reservoir and never had an issue, but also never ran anything dry on the radiator side.

 

[sootchucker]

I mean, all of the coolant system is still heavily reliant on the water pump. If for whatever reason (impeller loose, solenoid sticking...) the water pump is not moving coolant, then that would explain your symptoms.

I did the timing belt recently, quite a bit of coolant drained that way, but my new pump is metal impeller/fixed speed. I just had to fill thru the reservoir and never had an issue, but also never ran anything dry on the radiator side.

keep in mind there are two cooling circuits on the 15 TDI's. the engine cooling circuit and the low pressure circuit which handles the water cooled intercooler. at some point in the system, they loop and feed off of eachother.

 

[pedroYUL]

Have you seen coolant flow into the bottle at temp? That's the most simple test to make sure water pump is working

 

[sootchucker]

Have you seen coolant flow into the bottle at temp? That's the most simple test to make sure water pump is working

all three pumps are functional. i have bled it via VCDS programs a few times, but i guess there is still some air trapped in there i need to force out. what a PITA....

 

[JM Popaleetus]

i am familiar with the circuit itself. what i am not familiar with is the process of bleeding this complicated circuit. ive run both programs in VCDS, but i still think i have a pocket of air somewhere. ill keep running the bleed programs i guess.

all three pumps are functional. i have bled it via VCDS programs a few times, but i guess there is still some air trapped in there i need to force out. what a PITA....

Yeah, that's why I tried to give you the repair manual that tells you how to properly bleed the system, which requires pressure bleeding.

But you do you.

 

[sootchucker]

Yeah, that's why I tried to give you the repair manual that tells you how to properly bleed the system, which requires pressure bleeding.

But you do you.

i have sent you a message with my email. sorry, i wasnt entirely sure what you were referring to at first.

 

[pedroYUL]

I'm not talking about VCDS sending a signal to the water pump solenoid. What I am saying is, have you disconnected the water hose to the reservoir and seen coolant flow into it, when engine is at temp?

Again, it could be that the silly plastic impeller at the water pump separated from the shaft, which was a common occurrence (I read) with earlier TDIs until most clever suppliers of this fine site decided to offer just full metal impeller pumps. It could also be that the signal is sent to the solenoid, but it is stuck and VCDS (you) think that the water pump is then working but it's not.

 

[sootchucker]

I'm not talking about VCDS sending a signal to the water pump solenoid. What I am saying is, have you disconnected the water hose to the reservoir and seen coolant flow into it, when engine is at temp?

Again, it could be that the silly plastic impeller at the water pump separated from the shaft, which was a common occurrence (I read) with earlier TDIs until most clever suppliers of this fine site decided to offer just full metal impeller pumps. It could also be that the signal is sent to the solenoid, but it is stuck and VCDS (you) think that the water pump is then working but it's not.

mr popaleetus was able to direct me to the proper coolant fill procedure... which i followed with the potential unfortunate exception of failing to activate the coolant system filling/bleeding function BEFORE filling coolant via vacuum system.

 

[sootchucker]

popaleetus, question for you...

do you have any idea what program is required to be run BEFORE adding coolant to the car? i am not clear on what basic functions make up the cooling system filling/bleeding function of ODIS

 

[DirtyDub]

PM me your email address and I'll send you a .pdf of the repair manual for the engine. Section 19 is the cooling circuit.

Can you send me this?

 

[sootchucker]

just to close this one out for those who don't care, but hopefully this helps somebody in the future.

there is a one way valve that must be opened when filling these engines with a vacuum tool. otherwise you will never get this car bled. don't even bother. $160 at the dealer and its a done deal.

disappointed VCDS couldn't help me here (I gave up on trying to find anything related to said valve) but we shall further learn!

 

[RIP TDI]

just to close this one out for those who don't care, but hopefully this helps somebody in the future.

there is a one way valve that must be opened when filling these engines with a vacuum tool. otherwise you will never get this car bled. don't even bother. $160 at the dealer and its a done deal.

disappointed VCDS couldn't help me here (I gave up on trying to find anything related to said valve) but we shall further learn!

So the dealer bled it and told you about the valve? Any details on the valve?

 

[sootchucker]

Well to open this up again, it’s still not fixed.
The dealer didn’t mention anything about the valve, I read about it on my own.

seems bleeding this motor is next to impossible!

 

[sootchucker]

So the dealer bled it and told you about the valve? Any details on the valve?

the dealer didn't tell me about the valve - its well known that these engines have several one way valves... one of them I believe is electronically controlled. search "coolant shutoff valve"

I just drove 25 miles. highway speeds of 75+ seem to recreate the issue of the car wanting to run excessively hot.. if I cruise around 55-60 on the side roads.. temp on the gauge stays normal 70% of the time, creeps up until I let off the throttle a bit and then settles back down. heater on full blast helps manage driving the car around.

the plot thickens

 

[adjat84th]

I used a vacuum tool to fill my system back up after swapping the engine, and it got over two gallons in before it ran out of vacuum. After it stopped pulling coolant via vacuum, I reapplied vacuum to the system again by clamping the bottom hose of the bottle so that all vacuum was coming through the bleed hose. That way vacuum would open all the check valves, and it ended up allowing to fill the bottle at least one time. Haven't had to add any in 300 miles. Impressive tool that was well worth the purchase! Also, I didn't run the electric charge cooler coolant pump to "bleed" because of how well this went.

I deleted the rear electric pump as well since I went with a non-variable timing belt pump during the swap. Less lines on the back of the motor!

 

[RIP TDI]

I used a vacuum tool to fill my system back up after swapping the engine, and it got over two gallons in before it ran out of vacuum. After it stopped pulling coolant via vacuum, I reapplied vacuum to the system again by clamping the bottom hose of the bottle so that all vacuum was coming through the bleed hose. That way vacuum would open all the check valves, and it ended up allowing to fill the bottle at least one time. Haven't had to add any in 300 miles. Impressive tool that was well worth the purchase! Also, I didn't run the electric charge cooler coolant pump to "bleed" because of how well this went.

I deleted the rear electric pump as well since I went with a non-variable timing belt pump during the swap. Less lines on the back of the motor!

Which vacuum tool did you use?

 

[adjat84th]

@RIP TDI the Schwaben brand. It's the cheaper one that you have to apply vacuum, and then swap over the fill tube. The more expensive setup you don't have to swap out pieces, just turn off the extra valve.