Coolant System Failure after PCV, Water Pump, Thermostat R&R - Please help me

[ChiliS4]

Looking for some help here. My wife is very disappointed in me, just spent Mother’s Day weekend replacing PCV, Water Pump and Thermostat. All OEM parts from FCP.

I manually bled the coolant using 034 bleeder screws and partially removing the water heater pipe. The car was parked in the driveway and the temp gauge in the car stayed 50% the whole time.

Went for a quick test drive (4 minutes around the neighborhood) and the temperature gauge all of the sudden started climbing (almost to the red) and I got the coolant system failure code. I had the heat on max the entire time and it never blew hot air.

I shut off the car and noticed the coolant reservoir had gone from the max level marking to the minimum one. Checked the supercharger bleeder screws and coolant was right there. Topped of the tank, turned the car on (after maybe 2 minutes) and the temp gauge was right back on its line right at 50%. Tried another trip around the block but gauge started climbing again.

I feel like the engine never felt very hot and the vents were blowing cold air.

What am I missing? Bad thermostat (would the heat be blowing very hot if thermostat was faulty)? Did I ruin something doing the PCV? Could air in the cooling system cause temp spikes?

If I blow another weekend my wife will never let me start modding the car (112,000) miles 2013. Please help, I was planning on some scheduled maintenance before doing the intake, exhaust, tune.


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[maksym]

Looking for some help here. My wife is very disappointed in me, just spent Mother’s Day weekend replacing PCV, Water Pump and Thermostat. All OEM parts from FCP.

I manually bled the coolant using 034 bleeder screws and partially removing the water heater pipe. The car was parked in the driveway and the temp gauge in the car stayed 50% the whole time.

Went for a quick test drive (4 minutes around the neighborhood) and the temperature gauge all of the sudden started climbing (almost to the red) and I got the coolant system failure code. I had the heat on max the entire time and it never blew hot air.

I shut off the car and noticed the coolant reservoir had gone from the max level marking to the minimum one. Checked the supercharger bleeder screws and coolant was right there. Topped of the tank, turned the car on (after maybe 2 minutes) and the temp gauge was right back on its line right at 50%. Tried another trip around the block but gauge started climbing again.

I feel like the engine never felt very hot and the vents were blowing cold air.

What am I missing? Bad thermostat (would the heat be blowing very hot if thermostat was faulty)? Did I ruin something doing the PCV? Could air in the cooling system cause temp spikes?

If I blow another weekend my wife will never let me start modding the car (112,000) miles 2013. Please help, I was planning on some scheduled maintenance before doing the intake, exhaust, tune.


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Did you use the vacuum thingymathing to fill the system? I believe the SC screws and heater pipe are for the final bleeding after you filled the system with the proper tools.


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[LowKeyLoki]

Sounds like you still have air trapped in the system. I believe on the B8.5 there is a vacuum line connecting to the water pump, double check that connection. Here is a link from ECS that has the proper manual bleeding procedure near the bottom of the manual:
http://bd8ba3c866c8cbc330ab-7b26c6f3...stallation.pdf
Unless your leaking coolant somewhere in a large quantity it is most likely just air locked. I’d highly recommend buying a vacuum bleeder if you plan on working on your own car a lot, saves a lot of headache and tells you if you have any leaks. ECS tuning or Amazon or harbor freight have them for around $80

[ChiliS4]

I did not use a vacuum to fill the system, but I will order it.

I do remember attaching the small vacuum line to the little arm of the side of the water pump.


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[maksym]

I did not use a vacuum to fill the system, but I will order it.

I do remember attaching the small vacuum line to the little arm of the side of the water pump.


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How would you excuse working on the mother’s day though? ;)


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[ChiliS4]

Wife said she wanted the car project finished for Mother’s Day. So the fail on the test drive was very disappointing.

I’m going to order the vacuum bleeder BUT, there was coolant flowing out of both supercharger bleeder screws and the heater core pipe… where is the air bubble if it’s not at those high spots? Would air bubble cause temp gauge to spike?


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[maksym]

Wife said she wanted the car project finished for Mother’s Day. So the fail on the test drive was very disappointing.

I’m going to order the vacuum bleeder BUT, there was coolant flowing out of both supercharger bleeder screws and the heater core pipe… where is the air bubble if it’s not at those high spots? Would air bubble cause temp gauge to spike?


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ECS manual linked above seems to indicate the spots are in fact NOT the highest spots of the system as it instructs to extend the reservoir up. I thought there is something in the design of the system that prevents manual bleeding period, but the manual seems to think it is possible.


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[ChiliS4]

Vacuum bleeder is on order.

I used OBDeleven in the driveway today. Cleared codes and monitored coolant and oil temps at idle for about 15 minutes. Coolant temps steadily climbed to 120C (until I shut it down). Oil temps were about 75C. Interesting to note; temp gauge on dash did not follow temps on OBDeleven very closely.

Hard to believe some air trapped in system is the culprit (again no heat from cabin vents and hoses were not hot to touch) but I’m keeping my fingers crossed.

Updates to follow. I will try to document, hopefully another forum member can learn from my mistakes.


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[S4'ed]

If air prevents coolant from contacting the thermostat, it will never open.

[jbain2]

Having just done this, the pressure bleeder is the way to go. You’ll need an air compressor that can generate at least 90psi. Assuming it’s the standard pressure bleeder. But it works well. When using you should see the main hoses collapse under appropriate vacuum and they will expand as you fill. You will need to drain the coolant before doing this for best results.


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[Gr8nrg]

Sounds most definitely like air is trapped. The vaccum bleeder is best but as mentioned, you really need compressed air to generate the vacuum. While it will get rid of enough to make it safe to hammer on right away, there is always air trapped somewhere and can take days of checking and bleeding.
If you use the manual method, bank on days of checking and bleeding as you have to use some erratic movements in order to free up the air trapped in some spots.
You have potentially 5 locations to bleed.
1. Aftermarket heat exchanger if dual pulley+. Not all but most have bleed screws.
2.The Heating core loop.
3and4.The SC screws (left and right).
5.The coolant reservoir.
The lowest first, and for the reservoir can help to get that driver's side of the care a little higher than the SC.

Good luck. Keep cool.

[Midnight_Rider]

Goin through the same - can't even wrap my mind around this number. something was leaking, and looks like PCV value wasn't seated right or seal failed... water pipe was leaking... shop couldn't even tell me where it was leaking - told me everything was leaking.

[ChiliS4]

This evening I drained the coolant per demonstration on FCP euro YouTube video, did the vacuum bleed (held 23 PSI for 5 minutes), cracked the supercharger bleeder screws and the car still overheated

I did not bleed the heater core. The instructions I read said something about using a funnel in the overflow tank but I figured I wouldn’t have to do that with the vacuum bleeder?

I feel like it may have just started to boil over today, not good. The heat was blowing HOT.

After turning the car off and looking under the hood (everything looked fine) I could tell the secondary water pump was running.

I had to give up for the day to get something else done. So about 5-10 minutes later (car should still have been hot) I had to move the car so I could close the garage and the heat was blowing cold air. When I parked in my uphill driveway it sounded like a leaking pipe right where the heater core lives.

Does anyone have a step-by-step DIY on a coolant system flush? I never had the running water behind the dash noise last weekend… Did I install a defective thermostat or water pump? Am I reaching for straws here? Did I install something incorrectly?


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[ChiliS4]

Tried bleeding the heater core this morning. Parked with nose downhill. At idle there was a weak stream at the weep hole on the heater core hose. It held temperature at idle when the fans came on.

When I turned around so the car went nose uphill, the temperature gauge spiked?!

I melt the car cool off for a while then drove into the garage. Seems like it will hold temperature at idle but not when revved up some. When I turn it off I can tell a secondary water pump runs and each time I try to bleed the heater core a tiny amount of air comes out the coolant comes out with some pressure. Coolant level in reservoir tank seems to fluctuate between minimum and maximum. OBDeleven is telling me ‘mechanical pump failure’ once the car temp gauge gets to 3/4.

I’m really at a loss here… vacuum bleeder yesterday seemed to work well.

Any suggestions guys? Perhaps the shroud in the water pump that lets the car heat up quickly is failing? Cracking the bleeder screws on supercharger releases coolant with some gusto so I’d imaging the pump is working.

I have no idea how to test a thermostat but it’s brand new.

Doesn’t appear to be consuming or leaking coolant.

Heat at vents doesn’t blow hot when coolant and oil temps are at operating range (or above).


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[jbain2]

Are you holding the throttle at 2k and then intermittently revving it to 4-5k? That will force the thermostat open and coolant through the heater core.


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[LowKeyLoki]

My guess is that the vacuum line leading from the water pump either isn’t plugged in to the correct solenoid or the solenoid isn’t functioning. Did you mark the vacuum lines with tape or sharpie before you removed them? Check this thread about the water pump, someone mentions it acts as a valve to cool the head and that theirs was overheating due to a bad solenoid.
https://www.audizine.com/forum/showt...mp-Vacuum-Line

[LowKeyLoki]

“All B8.5 S4 have this style pump. Vacuum is supplied to the water pump which causes a round plastic piece inside the water pump to block the impeller and stop coolant flow. By doing this the engine warms up a lot quicker.“
From the same post linked above.

[jordan7982]

My only little bit of input is to bleed your system per C7owners video. Seems like you've done that though minus bleeding at higher than idle.

Idk what the odbeleven code is saying you have a faulty pump, but if there's a numerical code (pXXXX) related to it, i would search that code on here or the b8/b8.5 s4 FB page.

It very well could be something with your tstat, since you dont have overheating at idle but only when you drive. Seems like a control issue and not a raw hardware input (flow blockage, faulty pump).

You may be entering "take it to a mechanic" territory with this. Could do some research based on your location of best indy audi shops.

EDIT: forgot to add the video link
https://www.youtube.com/watch?v=hc7uoln2u5s

[ChiliS4]

Are you holding the throttle at 2k and then intermittently revving it to 4-5k? That will force the thermostat open and coolant through the heater core.


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I’m working by myself so no, not bleeding at RPM. I can get some help and try that. But I’m a little doubtful because as soon as I move the hose back coolant comes out? Thermostat opens based on heat, not RPM correct?

Does anyone know how to confirm thermostat is opening and closing? At what temp? OBDeleven has temps from 2 different gauges, not sure where they are located in relation to thermostat and radiator…


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[ChiliS4]

“All B8.5 S4 have this style pump. Vacuum is supplied to the water pump which causes a round plastic piece inside the water pump to block the impeller and stop coolant flow. By doing this the engine warms up a lot quicker.“
From the same post linked above.

I’ve thought of this, but, coolant is happy to come out of bleeder screws and heater core hose when cracked open. I’m guessing water pump is moving coolant around at least enough to squirt coolant out of the bleeding points.

I looked into the code, seems like the car throws the same code when temps get too hot, regardless of reasons. If I clear the code and run at idle it won’t fault. Only if it gets too hot.


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[jbain2]

I’m working by myself so no, not bleeding at RPM. I can get some help and try that. But I’m a little doubtful because as soon as I move the hose back coolant comes out? Thermostat opens based on heat, not RPM correct?

Does anyone know how to confirm thermostat is opening and closing? At what temp? OBDeleven has temps from 2 different gauges, not sure where they are located in relation to thermostat and radiator…


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Turn the heat on high. Leave the reservoir cap off. Everything else should be closed. Hold the throttle at 2k then intermittently blip the throttle up to 4-5k. That will force coolant and residual air through the system. That’s all assuming you’ve done the bleeding proceed from low to high. Exchanger, supercharger bleeders, and heater core.


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[hardfive]

Or just have them peg it at 3k for 3-5 min why you open and close the sc bleeder screws.

Your issue is not having a team mate. Trapped bubbles need a lot of persuasion.

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[ChiliS4]

Sad update, took the car out of the garage, heard a hissing sound, pulled the dipstick and noticed a significant vacuum

Pulled the oil fill cap and it was also under vacuum

Not sure if something went wrong doing PCV valve or if original problem is exacerbated because it got hot trying to bleed the system.

Out of time for tonight. Will drain the oil tomorrow.


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[ChiliS4]

Sad update, took the car out of the garage, heard a hissing sound, pulled the dipstick and noticed a significant vacuum

Pulled the oil fill cap and it was also under vacuum

Not sure if something went wrong doing PCV valve or if original problem is exacerbated because it got hot trying to bleed the system.

Out of time for tonight. Will drain the oil tomorrow.


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Okay now seeing some crankcase vacuum is normal… I’m jumping the gun on that post.

Still not sure why it’s overheating. Will try bleeding this weekend.


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[Midnight_Rider]

There is a leak. Likely either the upper coolant/water pipe, breather hose, or bottom coolant pipe is leaking if the O'ring seal wasn't seated correctly. There is a good chance that PCV or thermostat housing wasn't installed correctly, and it's leaking.

I would look on the bottom to see if there are sign of leak - white stuff.

[ChiliS4]

Update to my overheating!

Tried the 2,000 RPM bleeding procedure. Appearance of ‘steam’ coming out the exhaust pipe. Not too bad but noticeable.

Bled the system and let it come up to temp, smoking the entire time.

Pulled a plug this morning and it appears to be burning coolant. Pulled supercharger and there are no noticeable areas of coolant leaking.

I’m considering ordering new intercoolers. If that doesn’t fix it, I will probably tow to a mechanic or dealership.

Would a leaking intercoolers cause overheating? I know coolant burns hot but I would imagine the cooling system would be able to keep up. IMG_2281.jpg


If a coolant pipe were leaking, how would it get into combustion chamber? Intercoolers or head gaskets?


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[LowKeyLoki]

How old are those plugs? Looks more like lean running looking at that tip. Do you smell coolant burning from the exhaust and is it white? You didn’t mention if it was overheating or if the temp gauge was in the middle. If you coolant were being burned in one of the cylinders it would be running rough or throwing a misfire on one of the cylinders. When you removed the SC did you see any brown or orange deposits around any of the intake ports or on the valves? You need to post more pics when your taking stuff apart to give people a better look at what you have going on. Take picks of the SC ports and inter coolers, could have damaged one removing or installing SC. At this point though it sounds like you might be in over your head and might be better to tow to an Indy shop, in the end it will probably be cheaper and less of a head ache vs throwing money at parts/potential solutions.

[LowKeyLoki]

Looking back at your posts and problems I still suspect that your water pump isn’t functioning properly. You say you vacuum filled it and it held, which means the whole system should be filled with coolant so when you crank it and it starts to warm you go to bleed the SC screws then the heater hose you would still have coolant flow out due to expansion and heat/pressure. So I suspect that the OBD code you were pulling was correct in that the water pump wasn’t circulating correctly or at full duty. Possibly the solenoid controlling the clutch on the water pump is causing it to stay open or the clutch/water pump is faulty and can’t provide the correct flow. Try removing the vacuum line from the water pump and plugging the vac line to see if the water pump goes to full cycle. Or put a mighty vac or hand vac on the water pumps vacuum line when engine is off and listen for clutch engagement

[ChiliS4]

Update

I had a bubble in the coolant somewhere.

Chris from CS Motorsports helped me out huge. He recommended I use shop air to remove ALL of the coolant before using the vacuum bleeder.

Hard to believe (I tried to bleed the system 4 times prior, twice with the vacuum system) but I’m back on the road. Hopefully someone learns from my mistakes!

[S4'ed]

How did you use "shop air" to remove all the coolant?

[tomsgtr]

Here's a tip for anyone using those vacuum filler for their cooling system. This applies to all makes and models.

The first thing is to make sure the cooling system is empty of coolant. That means radiators and engine block. If theres a large amount of coolant inside the system, theres a chance of an air pocket trapped.

You need a strong air compressor with a lot of CFM to pull vacuum to properly fill the coolant system. The vacuum method does not get rid of all air. You will still need to manually bleed the system. When manually bleeding the system, the engine needs to be at operating temperature.

If any case, while it was overheating, I would have attempted to crack open those bleeders and watch the coolant stream out until I can see an air pocket come out.

[ChiliS4]

How did you use "shop air" to remove all the coolant?

I have a $99 pancake compressor. I rigged it up to one of the rubber fittings in the vacuum kit at the expansion tank and disconnected a hose from the oil cooler. Let her rip until nothing coming out the hose.


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