The 9 Most Common Coolant System Failures on a 3.0T 

Having some coolant spraying from a hose in the front of my motor, took to it audi they told me, water pump. I’m still covered under CPO warranty. Watched this video and was relieved you described exactly was what happening. I’m only at 53K miles also. Surprised it’s a water pump this early on!

You are helping lot of people with your videos keep on going brother

I followed you when I had my B8 S4 and have now went to a C7 A6 and made sure to put the bell on to watch all your content. Doing great and you've helped me a couple times!

Nice video, this should save me a ton of time diagnosing my intermittent noise coming from the engine, after doing some significant maintenance.

Just bought a c7 coming from a slightly modded camaro 🃏very informative sir really detailed. I’m just looking for possible issues I could have with this thing before I fully commit

Hey. Amazing Videos. Thanks so much for putting all this out there for all us 3.0T owners! I missed this video before but just saw it. I’m noticing a very small coolant drop in the reservoir. Is there any amount of coolant loss that is normal for this engine?

Cameron, love the channel. I have a 2016 Audi Q5, 3.0T. I recently replaced the water pump and thermostat. Did not pressure bleed the system but did so using heater core method and turbo bleed screws. When i go about 45 MPH, my heater blows from hot to cold and the temp spikes with an alert. I drop below 45, reset the code and i can drive for days, as long as i don't go above 45.

Awesome channel! Definitely one of the top 5 channels in my list (over 30 channels). Thank you for your excellent explanation and attention to detail. 👍

Thanks for all of the valuable support and help.

I wish you had a video on a C4 A6, but this was solid with some good basic tips. Nice shirt by the way.

thanks so much for these videos. I just picked up my B8 S4 and I love it so much. your videos will be very very helpful in my ownership to keep enjoying my S4. :)

Thanks so much for your video,,,STELLAR ON ALL POINTS, 2010 S5 V6 WITH SUPERCharger, not sure what is going on with car, heater in car is inconsistent to the point I thought I needed a heater valve...intermittent heat since Nov 23....does not heat car until way past the operating temp at 50% on temp gauge...long and short got the car at 94 k miles, carfax indicated thermostat replaced at 90 k, carfax also reported "intake manifold " replaced at 78 k miles. Car now at 104 k....Car purchase by me around 2/23...so since then I have replaced oil filter housing with aftermarket metal frame, updated tuner to ESC Tune with smaller super charger pulley and had to replace rack and pinion assembly on steering since bad leak at seals. Indy replaced trans fluid since I had no idea when fluid replaced at 101, 668 miles...cost was $1090 repair esetimate at 5K AS i DO BELIVE THEY WERE shooting in the dark,,they said" oil mixing with coolant in resevoir, metal flake in coolant as well, could be failing water pump or stop leak"...So long and short no coolant issues until drive to boone, NC up the mountains a month ago withj my 3oo lb kid...showed low coolant level and sure enough..was low...drove down mountain and went to autozone and got antifreeze and filled up resvoir....the temp gauige spiked on these errors withing 10 seconds.....turn off car...restart and error gone and temp gauge back to 50%, strated to go up mountain and temp climbed and I turned around headed back to slat plains in Charlotte with no issues...so then still no issues for a month...........loaded up the reaevoir when i got home that day and I poured out the drivers side near front wheel in a puddle yet maintained level....so not sure if relief valve for overfill or the trannny vealve you brought up...Today on the way to work....temp spiked for 10 seconds.....temp error on dash and then back to normal temp....rpm flutterd a bit through the experience...only errors on car were PO13900...o2 sensor circuit bank 1 sensor 2 slow reponse and 03531, belt bringer motor....at a loss as to temp sensor, thermosat although recently replace, transmission valve or PVC under supercharger....current thoughts are to: pull supercharger, replace PCV, replace temp sensor, replace Tranny coolant valve....Your thoughts???? Thanks in advance Chris

I have a 2009 Audi A4 Quattro V6 3.2L FSI (CALA engine code) and I'm dealing with a coolant leak which is pooling up under my IM. I recently had the coolant system flushed and the thermostat replaced bc the shop I take my car to (when I don't have time to do the repair myself) identified the t-stat as the culprit. At first it appeared they found and fixed the issue, however, not long after the t-stat was replaced, I noticed the coolant level dropping again and immediately checked under the IM and noticed a pool of coolant again. I took it back to the shop and they removed the IM and checked that the bolts holding the t-stat housing had been torqued to the proper spec which they said everything there looked good and checked the coolant pipes and said they couldn't identify where the leak was coming from and suggested to take it to the Audi dealership. I should mention that they also replaced the short hose that connects the thermostat to the coolant crossover pipe on the front, as well as installed a new O-ring on the hard plastic coolant pipe that connects the t-stat to the heater core hose. I would rather not take it to the Audi dealership and thought it may be coming from the crankcase breather valve (PCV/Oil separator) and have already ordered/received the parts to do the repair myself. I know replacing this part would be good preventative maintenance, however, as I am sure you already know it's a pretty time consuming repair and in doing additional research (of course after I received all the parts), I am not finding any facts stating where others have had coolant pooling under the IM that was directly related to the PCV/Oil separator and I want to ensure that the PCV/Oil separator could at least potentially be the cause before proceeding with the repair. I've only been able to find cases where the PCV/Oil separator is linked to mysterious coolant loss which is ultimately found to be contaminating the oil, versus actually leaking from the PCV/Oil separator itself and pooling under the IM. I've checked my oil to ensure this isn't also happening and my oil looks to be in good shape...knowing the leak is coming from somewhere near the underside of my IM, what are the possible culprits? TIA for any assistance you can provide

I have a A6 and loose all the coolant. I can see on the floor the liquid, but start to smoke the engine. The temparature is normal never past the regular.

Thank you for the content! This channel has helped me tremendously.

All your videos really are great and informative. And straight to the point there's no bullshit or nonsense

Super interesting video, thanks a lot! That will help me to diagnose the coolant leak I have on my C6 A6

I changed most of the issues on this list just because or from recalls. 🙌🏾

New favorite channel, helps a ton and I am getting into working on my own car (c7 a7) now. Dudes legit 🤙

thanks for your video cameron, i was out on a joyride today and my a7 c7 decided to leak all it's coolant out. I haven't figured out why, but hopefully this vvideo will help me!

Thank you for the videos. My 2017 Audi a7 just popped the light for "coolant system fault, turn off engine", I went to the body shop and the code they scanned is P1B1C00. However, the temperature is normal, coolant level is normal and there is no leak which makes them no clue. They said it might be the programming issue. Would you please share your knowledge on that? Thank you!!

having heavy coolant loss after operating vehicle (overnight) looks to be water pump but shops haven’t been able to diagnose . would be more than appreciative to get in more contact and use your help to diagnose

I'm glad I'm sub to your channel it's very informative because I have a 13 b8.5 S4 and ommmg I'm having g hurts rn from MeCK problems to coolant luckily the shop I'm working with works on VW and audi mainly so I'm a little happy

That’s very good information I learned a lot I have 2011 Audi Q7 goes overheat in a few seconds and goes back to normal every 40 minutes driving , most likely when I’m in the highway I changed thermostat radiator I checked water pump I couldn’t find anything any help

Thank you for a page that’s finally relatable. Extremely helpful 🙏🏽 Any possible pathways for a P1B1C00 code? Shows coolant pump static. But drove for 2-4K miles with it and engine temp has not fluctuated. Much appreciated 🙏🏽

Good video, currently dealing with cooling issues myself got engine code p2181 and check engine light the other day they appeared before along with a misfire and epc light when i really got on the car one day, but those codes ended up clearing themselves right before I brought my car into the shop. now just the p2181 and check engine light appeared again. Pcv, water pump, thermostat, crossover pipe, lower rad hose,coolant temp sensor are all new so abit tricky to diagnose. I will have to have the shop do an extensive look at the entire cooling system.

I have a 2012 A6 3.0T with a coolant leak that i cant pinpoint. I can see the coolant dripping from the left front corner of the engine. I initially thought the oil cooler was the culprit but saw that the coolant was dripping off of the a/c compressor. Any suggestions? Thanks

i still have big trouble with my cooling system with my A6 C7 2012 3.0L tfsi. AFTER 2 hours of working alone the coolant get up to 120 celsius degree and sending a N signal from the gearbox.

Yess been waiting for you to do relocate the pcv valve

Hi, have you ever known exhaust gases in the cooling system causing to pressurise coolant out of the coolant tank? I’ve just replaced pcv hoping it would cure it. No oil in water runs well no misfires. Could supercharger cores failing cause this? Thankyou 2011 3.0tfsi S5 😀👍

Love the channel! Recently picked up a super well maintained Audi A6. Previously had an SQ5. The water pump on this vehicle was replaced 40k miles ago (when it had about 60k miles on it) but 8 years ago. The car now has a 100k miles so I thought I would be safe for a while. Im still diagnosing it but all signs point to the water pump. Lots of coolant on the ground and coolant under the intake plenum/on the hoses which appear to not be leaking. What are the chances of a water pump going at 40k miles on these engines ? Previous work was done at the dealer.

Thanks! I have a few comments/questions. 1. My water pump just went. I have been getting smells and some white speckling in the engine bay and belts but not a lot of coolant loss. I thought I would have time. Then I got on it one morning and arrived at work with it smoking. I looked an fluid was pouring out. I pretty much lost the contents of my reservoir. I assume it's the pump. I ordered everything from FCP Euro include t-state belts, gaskets, etc. However, I know my PCV body needs replacing (codes, oil burn and some coolant loss), but due to money and the extra time it will take to do that, I'm just going to focus on the water pump and t-stat. I need to get my car back on the road, but removing t-stat will require supercharger removal. Would you just do water pump and belts and wait to do the t-stat when I do the PCV body? Coolant isn't cheap, so I'd hate to have to go trough 4 gallons of it. 2. Where did you find the supercharger coolant pump? I have a 2015 Q5 TFSI 3.0 and it seem no one carries it. Crazy FCP Euro has it for everything but my car/model. 3. I have Blue Driver OBDII with IAT readout and CACT (charge air cooler temp B1/B2). Plus boost, coolant temp, Engine RPM and TCA CINP (turbocharger compression inlet pressure) on the HUD. Is this a viable option?

Cool shirt. Thank you for producing these videos.

Its reassuring knowing its probably not my head gasket and most likely my PCV. I lost a whole tank of coolant in just a few days. not driving the car till its fixed.

Hi 👋🏼 have you ever seen a lot of white smoke coming out of your exhaust? I’m not talking about when the car is cold. Or when it rained before. When googling it I found a few 3.0T with that issue but never any solutions. It’s not losing any coolant. And it gives no fault codes. But the amount of smoke Is still kind of alarming when u can’t figure out what it is! Maybe you know anything! Have a beautiful day! ❤

A free shirt?! Thats awesome

I just bought a 2013 audi a6 and I'm loosing coolant it's not much at all but I do get a sweet coolant smell at the front of the car under the hood but I'm not seeing a leak, the fins on the intercooler are pretty bent as it has been in a wreck but if i was getting a smeel could it be that the car has 87000 miles and I'm stumped any guesses???

Do you have a video showing how to replace radiator on a C7 A6??

Hey Cameron! I only seem to lose coolant when I’m doing wide open throttle on the car and found abit of coolant on top of my reservoir. Can’t find any other coolant leaks, car runs great otherwise in terms of temps.

I have a 2010 Audi A6 with a 3.0 T it was overheating and I change the water pump thermostat PCV and the coolant reservoir and I'm still having overheating issue the coolant reservoir I pressure test it and it is dropping pressure is losing pressure but there is no visible leak and no exhaust smoking but it is still dropping every time I close the cap the reservoir start to drop and the temperature light comes on in the gauge moves up the 3 quarter but cannot figure it out

Hello! Great videos u have here thank you for that. I have a coolant leak it was leaking a lot. I could see it is pouring down. I couldn’t see where it is leaking. But it wasn’t front of the engine it was driver side middle of the engine. But i did have cover on. What do you think is a problem? If it is not my water pump and i had to remove the super charger should i still change my water pump ? I am at 90k miles

Radiator fan? Passenger side went out for me, hoping it’s just a fuse

I’m at 200k on my 2013 Q5. I’m having the PCV replaced and, depending on when the thermostat was last replaced, I’ll swap that out too.

So again picking up one of These in the next couple days. This is my first Audi with the super charge V6. So like I said, any input is greatly appreciated. And I'm not a teenager, so all this messaging back-and-forth and s***Online is hard for me to wrap my head around. Like us, adults are used to like actually having a conversation. Which is like unheard of anymore but if that can happen that would be great, let me know somehow what you think

I’m a check all these today but #9 is the symptoms I’m having

I have a Audi A6 2010 with the supercharged 3L and I'm having a coolant drop but there is no change ichange the PCV water pump and thermostat and still drops

I get the coolant system fault right at startup. I'm thinking to start with the sensor.

Hello, I have a problem with my 3.0T engine coolant system, basically when I drive more than 100 km/h I have info that my engine is overheating, then I slow down and temperature is in normal range. I observed that coolant hose which goes to heat exchanger is very pressurized, is that normal? When I open coolant reservoir plug, the level is raising up and fluid is going out from reservoir. And one more... when I'm on driver seat I hear kind of "fluid flow" behind wheel/dashboard. Tomorrow, I bleed my system according your video and then we see. P.S. You did a great job, keep going :)

2021 Audi S7, bought about a year ago only put on 7k miles and coolant reservoir was bone drive when the light came on. Dealership claims no issues however after refilled it's leaking again. pressure tests say no issues, any thoughts?

Timely video - great content thanks. My coolant has been dropping very slowly, the engine temp has been around 200-218F. The shop is in the process of replacing the pcv but you pointed out that it could be the inter cooler. Is 5-15 misfires in cylinder 3 over 30 min drive avg speed of 45mph considered an issue related to the inter cooler.

Hi, my car is loosing coolant when is in operation at 90*C , when i go to work 2 miles away is not loosing, do you have any idea what it can be? Thanks

Hah, just got diagnosed headgasket failure at local Audi dealer. I sent my car to another countrys audi dealer to fix it and they said that there is nothing wrong at engine. There were only air at the system and thermostat was fully open.

I need some advice for my 06 A3 Quattro 3.2 overheated last night and started running rough

Hope you could please help me, I got a 2009 A5 with the 3.2L, well I fill up the reservoir up to the max and after driving around I come home park it and when I come check on the coolant level after sitting for a little while the coolant level have dropped to min or below min. What could it be do you know?

Great video. One thing you forgot to mention was that plastic pipe that feeds into the thermostat housing that cracks and leaks

Do you have to drain the coolant to replace the coolant temperature sensor?

i have a 2014 audi s4 and it does not leak coolant at all but it just looses coolant out of no where

Hey bro I have the P190D 190D code on my 3.0 engine Audi s5 , Is that the auxiliary water pump ? Appreciate any help please

Hey Cameron, I have been watching your channels for quite some times now and you gave a lot of good advices. I have 2014 Audi A7 and recently I changed PCV Valve, thermostat, water pump, remove inner coolers on the supercharge, and drained the radiator and refilled the radiator fluid using pressure filled method. I have two issues i cannot solve, 1) I still get the vacuum pressure at the oil filler gap after the PCV valve replaced and 2) I have no heat when I push auto regardless what temperature I set until I crank it up to Hi setting, then I can hear and feel the heat. I can adjust the heat fan speed, temperature, and vents manually and it works just not in auto mode. The AC runs fine, no problem at all so I know all the components work. I think it may be something with adaptation or basic setting that i may have messed up. Do you have any suggestions I need to look or check, thanks in advance.

Good day Cameron. I came on to your page to find out about some coolant issues today; which I watched these problems. So my coolant warning came on omw home today. 1. no engine light🤞🏼 had 2. no leaks 3. I did winding up changing my coolant sensor which was kinda corroded. But my warning ⚠️ is still on I do have a P3 gauge it’s running at 175F-180F hasn’t spiked up. Any ideas want it can be?

hey just watch your video and i need your help with my 2009 s5, videos about it right now will be be posting them within a week, lets keep in touch.

I noticed this morning a puddle of coolant on the ground. Started the car and seen “turn off engine and check coolant levels. I turned off and looked under hood and seen the coolant was all the way to the bottom. I did see Coolant splashes below the left side of the coolant can all around the coilpacks. I also see it dripping off the front under carriage cover, and along the bottom right side. Any ideas of where it could be leaking?

I have 3.0t 2016 Haase a leak I don't no if is water pump or coolant pipe the rons n top water pump have 70.000 mile what is the more come n on that

I have code po118 high circuit fan is running high and code for coolant temp sensor, I got the part but have no idea where to locate on my b8 s4

I think and hope it is my pvc this helps alot man

Can you make a video installing a blow off valve?

Cameron, Thanks for the video, my man. You have no idea how much you've helped me to date. However, I'm stuck with my coolant leak. I'm losing a ton, and I can see where it's coming from on the bottom, but I can't trace it from the source due to how tight everything is packed. I'm almost to the point where I'm about to remove the supercharger, etc. and just start replacing stuff, but do you have any suggestions first? FWIW, I do have the schwaben vacuum filler tool for coolant, and I have taken the stuff apart before. Just not excited about doing it again...I'm guessing I've either got a leak somewhere related to the hard plastic coolant pipe in the valley under the supercharger, or else maybe the thermostat or the PCV, the breather valve, maybe, or even the water pump. However, I just replaced all of them about two years and 20k miles ago...so. Any suggestions? As I said, it's nothing obvious from the suggestions in the video. You can see where it's dripping down from at the bottom, but I can't trace it back up. I can link a video if it helps, but bottom line, I've got to get this leak resolved. It's not the supercharger, the reservoir, the coolant pump (insofar as I can tell--plus the leak is opposite side of the engine bay from it) or any obvious hoses.

Off hand thank you for these videos. My favorite channel on youtube now. My A7 has about 47k miles its a 2016. It started leaking some coolant and looks like it’s coming from the thermostat. I found part nr 06E121018K, should i also replace the housing and gaskets for the thermostat? I’m going to replace water pump, the tube under the supercharger, and the coolant pipe that i believe connects to the heater core. Any help would be greatly appreciated.

Can any tell me what’s wrong wit my car it told me shut engine check coolant but then I got home my wheel tighten up a lil then I got out seen coolant leaking then popped hood had some coolant came back out it was all on the ground any idea?

Im facing overheating issues on My A6 2.8 2012 not on normal speed bus when it goes to 80km/h or above. And waterpump and Thermostat is also working ,coolent level is also maintained and no leakage ,What you can Suggest?

I am thinking about buying an a6 with this motor. The dash says coolant system failure… any ideas?

Great video!

Dont know if you’ll see this but did you like that rkx inlet hose? Did you notice any more whine, is it rigid enough for a tuned engine?

Hey buddy I have a 2011 A6 3.0 sc it only overheats when in motion and it's bubbling back through the reservoir what's your take on it

Hello from Ukraine! Nice content, BRO Thank you!

That #audishirt is awesome

Hi my coolant temp fluctuates between 70-90C at times and my oil temps have been cooler than normal (always within 1-5C of my coolant temp instead of the usual 102-106C). I do get some air when I remove my reservoir cap, could air trapped in the cooling system be the cause of this? Changed my thermostat, pcv, supercharger coolers, waterpump, coolant pump and many hoses recently.

i have a coolant leak from the left side of the engine, leaks rapidly. i’m not sure if it’s from the thermostat. but it leaks from underneath from the passenger side. hoses don’t seem ripped i guess. any help 🙏🏼

Hey man! appreciate the video! I’m having an issue of coolant disappearing. No puddles forming, no white smoke coming out of exhaust, no sign of coolant in the oil. Any thoughts of where to look?

hello my friend, replace the PCV, water pump, valve cover gasket, the intake inlet butterflies, and today I noticed that the temperature of the cooling liquid reaches 107 degrees, is it normal?

Thanks for another instalment of 3.0T international 😂

Hey Cam My 2012 a6 3.0 is running fine but I’d love to do some replacement just because I don’t want them to go bad. My plan is to replace the pcv, water pump and thermostat. Anything else??

Keep getting bank 1 too lean / rich, I just clear it and it comes back in a week or two any tips?

Okay quick question so on my a6 my rad fans kick on max speed when I turn engine off, also when I open any of the doors, and also if I unlock or lock the doors with key. My question is it never did this before what is likely the cause of this? Thanks!

Anyone had their heater core fail? Mine smells like shit and it seems the window is starting to get foggy.

When you divorced your coolant did the iats drop heard there isn’t much difference I’m sure you have stats

Thanks. Glad I didn't buy the S5 cabriolet. No car is worth unreliability at my age.

Hello, I’m trying to buy an Audi A6 2012 with 131k miles in it and the car looks in great condition, the guy who selling it says he is the second owner and previously owner was a Lady, so It’s my first German car to buy and with that mileage what to look for and what advice you can give me please, it will help me not to do mistake or anything such. Thank you a lot.

Where is the pcp location at

Hi was wondering if u could help me I’m not getting power to my aux coolant pump ,fuse is good I’m getting p192700 open circuit aux relay not sure where else to look thanks

Good content. Question. If my coolant level went down about half an inch and i got a soft code for PCV. Is that a dead giveaway that my PCV is bad? I have an sq5 with the same engine. Hope you can help.

Audi A7 P1B1C00 coolant pump mechanical malfunction Any ideas? WATER Pump, thermostat replaced

😢Awesome channel

Why does my Audi radiator fan turn on every time I open or close a door?

Can the supercharger intercoolers leak coolant on the ground?

Does anyone know the definitive center bore size of the hubs to put rims on a 2013 A6 Quattro. I am looking for 19 rims and I see many sites saying 60.6 or 60.5? I hope someone here will know for sue. Thanks

What does a pcv regulator performance code mean?

Hello Cameron. I have a 2013 A7 that after having the timing chain and gears replaced close to $9000.00, I started having cooling leaks immediately afterwards. The shop says it is nothing they did and I could not afford to keep putting money in for them to check. I'm a pretty decent mechanic so I pulled the super charger off since that is where he said the leak was coming from. I replaced the thermostat, heater core pipe on top of the motor, and the front crossover pipe. Got it back together and found that it was still leaking from the front. I changed the water pump since it appeared to be from there now. Shortly after changing it I got a leak again. Coolant is pooling up on top of the motor. I pulled the super charger again, capped the hose and pressure tested it and I can see the coolant building up on top driver side. Nothing leaking out of heater pipe, no visible leak from the thermostat. Is it possible to be leaking out of the PCV valve? I checked and there is no coolant in the oil. It's driving me crazy.

So quick question would you take this car on a 13hr drive with your family for a vacation? Like do you feel comfortably enough with the reliability on this platform to take it on such a road trip?