Coolant temperature too high

[Broke18SQ5]

Yes the thermostat is a PITA, technically you have to pull the front clip into service position to replace, pull out the metal tube that runs in front of the thermostat, One bolt on top two on the bottom of the pipe. The bolts are not visible and extreme amounts of dexterity and small arms are required to remove without pulling the whole front clip back.
After that pipe is out 3 bolts hold the thermostat in. The top left bolt is not visible. I would only do this yourself if you've been doing this awhile.

[Broke18SQ5]

Is the thermostat hard to change on these cars? I think I might need one as well.

Edit.. the fans are going full blast as soon as I turn the car on and stay on for the duration of the drive.

Above is for you sorry I didn't tag you.

[tliu91]

Yes that is the correct part. Yes I will get more information and pictures for you as soon as I get off work.

Fcp euro part

https://www.fcpeuro.com/products/aud...RoCaIwQAvD_BwE

Were you able to get more info and some pics?

[R/TErnie]

Thank you guys for sharing! having the same issue.

[andrei372]

I just went through this exact situation about a month ago. There's actually a TSB on it. They changed the water pump, thermostat, and re-flashed my ecu (and erasing my APR tune in the process). Said it was good, drove 5 miles down the road and overheated again. Long story short, it ended up being the coolant control solenoid.

Hope this helps, good luck getting your car back on the road.

Hi there. Do you happen to know the TSB number ? I want to relate this to my dealer and get it fixed. Having same issue, changing the thermostat did not address it. Thanks !

[pixelated808]

On my 2018 SQ5, I get the alert "Coolant temperature too high. Let engine run while vehicle is stationary." which will randomly pop up when driving on the highway but I've not seen my oil temp go over 233F and the coolant bar always stays right in the middle. Ran my obd11 app and it pulls "P13EF00 - Coolant temperature sensor for engine block Temperature too high Intermittent" @broke18SQ5 - is this your experience? I am planning on getting the air injection valve from FCP Euro - but wondering if that was a long term fix for you? I figure this is the first step before replacing a thermostat or ultimately water pump...

[qcrazy]

Switching valve is the common failure on these cars. Too many people inadvertently replace perfectly good water pumps. Dealers are more than happy to run up hours on warranty claims.

Unplug the vacuum line from the switching valve and you'll find out real quick. I have a spare switching valve in my glove box.

[JonnyBravo!]

I had this same issue and took my SQ5 into Audi. They diagnosed it as a faulty coolant reservoir. So I replaced that and it seemed to fix the issue, except the alert did pop up once after the replacement. I'm going to replace the valve as well, just in case. I'm just glad it wasn't the thermostat or water pump.

Just FYI, I purchased the valve for $18 on eBay:

https://www.ebay.com/itm/174956356464

[JonnyBravo!]

Update - I'm replacing the valve now and I can see what appears to be really old coolant (maybe mixed with oil?) under the old valve. I think I had a two-part problem, faulty valve and coolant reservoir. Hoping this resolves the issue once and for all.

[silverback85]

I am getting the "Coolant temperature too high. Let engine run while vehicle is stationary." message on my instrument cluster still. Have 65k on my S4 and just replaced the water pump, thermostat, solenoid valve, normal fan conditions and new coolant. Anything else I should be looking at?

[JonnyBravo!]

I am getting the "Coolant temperature too high. Let engine run while vehicle is stationary." message on my instrument cluster still. Have 65k on my S4 and just replaced the water pump, thermostat, solenoid valve, normal fan conditions and new coolant. Anything else I should be looking at?

Coolant reservoir? That helped me in addition to the solenoid valve.

[ts8467]

The valve is the correct solution however the part isn't listed correctly under any part distributor and is nearly impossible to find.

The part number for the valve on the vehicle is 037906283. Which is listed as a secondary air injection valve on FCPEuro for $27. And you can also buy it from oriellys auto under interchange part number 667-108 for 149.99 and can confirm both parts are the same number, identical, and work.

Part 037906283 has been used in tons of audi/vw vehicles over the years but still says it won't work when you put in anything 2018+for a vehicle search this is incorrect and it is the same part for the 3.0 Turbo sq5/s4 (not supercharged)

Part is easily changed on top of the passenger cylinder head.

I have the same issue- coolant temp alert after a couple of minutes of driving (doesn't happen when sitting in park)> when this occurs AC stops blowing cold air as well (assume this is to allow engine to cool as when thermostat is stuck)>. turn the car off once the fans turn off i check the coolant tempo and it isn't hot. I ordered the valve as you mention, but I can screw up about anything when it comes to trying to fix a car. Any videos you are aware of instructing how to change the valve- not seeing anything on youtube?

[Ebbsnflows]

As of this morning I have this exact same issue. 2018 SQ5 with 28000 miles on the clock. Driving along and the check engine light came on first...then 15 mins later, the alert telling me to "pull over and leave the car running", popped up. The fans were running full blast, despite just cruising along at 50 mph. My coolant levels are perfectly normal and all gauges are reading within normal range. When I got home I used my OBD11 to pull the code: P117B00 (Sensor for Cylinder head temperature). There does seem to be a TSB for my model and year: https://static.nhtsa.gov/odi/tsbs/20...72961-0001.pdf

Despite that I'm still thinking I might attempt to swap the Vacuum solenoid valve that was posted above (ebay and FCPeuro). For $18 it's worth a shot to avoid a trip to the dealership.

[Ebbsnflows]

Update: Ordered and replaced the switching valve / vacuum solenoid on the passenger head. No joy. Took it for a drive immediately afterwards and warning / CEL popped up 5 mins into the drive, along with Fans running full blast. Starting to think I'm yet another victim of the Thermostat fails.

[staticuxo]

Coolant reservoir? That helped me in addition to the solenoid valve.

perhaps i missed it but can you elaborate on the coolant reservoir? what was the issue with it? i swapped the switching valve with no luck.

i keep getting the coolant temp warning while showing normal coolant and oil temps. it even does this on cold starts when the engine is not warm.

it's been at elite motorsports for 2 days while they are trying to diagnose without jumping right to replacing the thermostat and/or waterpump.

thanks!

[JonnyBravo!]

perhaps i missed it but can you elaborate on the coolant reservoir? what was the issue with it? i swapped the switching valve with no luck.

i keep getting the coolant temp warning while showing normal coolant and oil temps. it even does this on cold starts when the engine is not warm.

it's been at elite motorsports for 2 days while they are trying to diagnose without jumping right to replacing the thermostat and/or waterpump.

thanks!

When I took it to Audi, they diagnosed it as a faulty reservoir (wasn't holding pressure). So I bought a new reservoir and swapped it out. It seemed to help - the car was drivable again and the alert only popped up once or twice afterwards. I replaced the valve as an additional measure and that completely fixed it. The alert never popped up again. Might be worth a shot - $150 vs $1,000+.

[SWS5]

When I took it to Audi, they diagnosed it as a faulty reservoir (wasn't holding pressure). So I bought a new reservoir and swapped it out. It seemed to help - the car was drivable again and the alert only popped up once or twice afterwards. I replaced the valve as an additional measure and that completely fixed it. The alert never popped up again. Might be worth a shot - $150 vs $1,000+.

Thanks for sharing this gives me something to try

I just got a 2018 s5 and got the same alert. I too changed the coolant reservoir because the first alert was a low coolant level followed by hi temp alert all while the coolant temp showed normal via the temp bar gauge and the coolant level was good. After I installed new reservoir the low coolant light went out but the hi temp warning stayed. I cleared it as I figured it was left from the initial fault, drove 1 mile and got the temp too high, let car run while stationary.

2 Questions- I assume the 2019 Sq5 has the same 3.o v6 turbo as the 2018 s5, can you confirm that ?
Also, I see you are in California, if you are in southern cali where you go to get work done on your SQ5. Im looking for a good shop besides the dealer.
Thanks in advance

[qcrazy]

SQ5 and S5 have the same engine.

Does the overheating warning go away when you idle? But come back as soon as you start driving?

[slws4]

Was going to post that it was the solenoid for sure if your water pump and t-stat was replaced. Same issue on my end. But i found the answer on the forums instead. I simply just plugged off the solenoid and essentially kept it open always LMAO. and it worked fine. Car has did multiple runs 4+ hours constant and no issues with overheating.

[staticuxo]

i'm still dealing with this. the shop changed the thermostat and i did the switching valve/solenoid.. no luck. they said they pressure tested it so it wouldn't be the reservoir.

is there there another sensor that can only be accessed by removing the turbo? this is what i'm being told is next to replace.

edit: looks like it's this:
https://www.ecstuning.com/b-fae-part...79919523b~fae/

[qcrazy]

There is another valve that can fail.

It is called the coolant shut off valve on the B9. This valve is also vacuum actuated via a different solenoid. This is a problem on the 4.0T's, so I expect it will also be an issue here as well at some point.

20221101_222845.jpg

This solenoid can be tested via VCDS. It will actuate the solenoid. Since the system does not indicate position, all one can do is activate the solenoid and listen for clicking. If no clicking, the solenoid is stuck.

The alternative is to disconnect and vacuum line (from the shut off valve) and plug the vacuum line and see if the problem goes away. While that sounds easy, access is pretty bad to that vacuum line.

[S4_kas]

Hi. Did you ever get to the bottom of this ?
I'm having the same issue. On the highway the light comes on for a second then goes off. Fault P13EF00 - Coolant temperature sensor for engine block Temperature too high is stored. So far have changed the temp sensor and the solenoid valve for the water pump. Any advice would me much appreciated. Thanks in advance.

[S4_kas]

Pretty much as @pixelated808 has described. Did you ever solve this ?

[kharma]

There is another valve that can fail.

It is called the coolant shut off valve on the B9. This valve is also vacuum actuated via a different solenoid. This is a problem on the 4.0T's, so I expect it will also be an issue here as well at some point.

20221101_222845.jpg

This solenoid can be tested via VCDS. It will actuate the solenoid. Since the system does not indicate position, all one can do is activate the solenoid and listen for clicking. If no clicking, the solenoid is stuck.

The alternative is to disconnect and vacuum line (from the shut off valve) and plug the vacuum line and see if the problem goes away. While that sounds easy, access is pretty bad to that vacuum line.

Interesting... this is exactly where I am seeing coolant residue on my SQ5. Initially it appeared to be the reservoir cap per the dealer, but the issue persists after swapping that and the switching valve on pass side. I would also note I have only seen coolant low warnings, never over temp.

[qcrazy]

Hi. Did you ever get to the bottom of this ?
I'm having the same issue. On the highway the light comes on for a second then goes off. Fault P13EF00 - Coolant temperature sensor for engine block Temperature too high is stored. So far have changed the temp sensor and the solenoid valve for the water pump. Any advice would me much appreciated. Thanks in advance.

Which sensor did you replace? There are three separate coolant sensors on this car. My post/diagram above shows all three sensor locations.

If it is only occurring on the highway, I would take a look at the solenoid for the shut off valve. Solenoid may be starting to stick. Overheating on the highway is a pretty classic symptom for this valve on the 4.0T.

Here is some more info on the shut off valve. The solenoid (N489) is pretty buried ...

Screenshot_20221105-144523_Drive.jpg

[trentr98]

I had my coolant temp too high light come on after a couple miles of driving 3 days ago. It happened while going up a slight hill at ~40 mph and the temperature rapidly climbed (7 lights on the coolant temp gauge). I pulled over immediately and let the car cool down and then proceeded to get back home, during which the light didn't come back.

The next day, I took it for a test drive and the light never came on, even after lengthy driving.

Then yesterday, the same issues as day 1 appeared. I've since purchased the part mentioned earlier in this thread (037906283) from Amazon and will be installing it myself. If this doesn't work, I'll bring it to the dealer since it has a warranty (just has a deductible of $300 so would prefer to do it myself).

Also, I never got a low coolant warning, but after opening the reservoir the floater is definitely way below the minimum line. Not sure what that means, but I'll keep you all updated on if I can fix this.

[venomS5B9]

At the beginning I only had the yellow light "Coolant temperature too hot -> in YELLOW" (without an error message in the error memory) ... after that I first exchanged the "037906283 solenoid" and it worked for a while.

But recently I got a message again "Drive malfunction -> yellow warning sign" then read error "P004900 Turbo turbine overspeed -> in yellow" and after restarting the engine it was gone, but the car now has much less power and the error is reproducible (MAYBE THIS IS ALL CONNECTED??) (have own thread, look below LINK).

After further driving I now get the error message "Coolant temperature too hot - IN RED" "this time there was also an error message inside -> P13EF00 Engine block coolant temperature sensor Temperature too high". To be on the safe side, I replaced the pressure converter because it was making strange noises (part number: 06M906609A) and the problem is still there. Can the engine block coolant temperature sensor be bad?

Has anyone else changed the coolant reservoir or thermostat and had success. :) Don't want to buy/swap any parts all the time that aren't useful. :D

https://www.audizine.com/forum/showt...5#post14844875

Audi S5 Sportback 2018 B9 113000 km 034Motorsport Stage 2

[trentr98]

Wanted to give an update to my last post - swapped out the solenoid and it seems as of right now my problem is fixed. Drove the car hard for about half an hour after warming up with no more issues.

As for the solenoid swap itself, space is tight and for me it was easiest to remove the intake box/hose to get a bit more space. Aside from that, you can use a flathead to get the hoses off the solenoid pretty easily.

venomS5B9, how long did the solenoid swap fix the problem before you got the red error?

Editing to add that it's been a couple days without any problems now. Hopefully this is all I needed.

Editing again to add that it’s been about 2 weeks without any problems so this seems to have been a permanent fix!

Sent from my iPhone using Audizine Forum

[venomS5B9]

just 1 month

[c99]

Truth could be simple. It's blown head gasket.

[venomS5B9]

Everything is possible, but do you think everyone here has a blown head gasket?

[c99]

Of course not, it comes from this:

... I can see what appears to be really old coolant (maybe mixed with oil?) under the old valve. ...

[Requiescat]

This is a stock failure, tune won't make any difference.

It's like being in an HOA. Technically you can install that flagpole in the front yard but you're going to go through hell to prove that you can. Having a tune and trying to get warranty work will always be a struggle, even if every rule in the book says that you're covered.

[pixelated808]

@S4_kas

Sorry for a late reply to this thread. I had this error and replaced the valve. I cleared the errors in the computer - drove on a hot day, the error happened one more time, but then I cleared it, and has not come back since. I have been driving w/ the new valve a few months now. The old valve was pretty clogged up FYI.

[venomS5B9]

Guys! https://www.youtube.com/watch?v=otfln0yBGwM Keep watching from that point min. 09:45! Maybe we all have this problem and its leaking from here?

[Haz]

I just got this same problem today. 2018 S5 Sportback. Fan always on high. Temp wrose for a bit once on the temp gauge to 100 instead of it's usual 90. Message comes on to park and idle. I have an Audi warranty still so I'll call and try to get it to the dealer soonest. I'm in Toronto and it's below zero Celsius right now, odd that this happened when it's so cold out.

I read through this thread to see if there was a definitive solution or common root cause to this issue but it seems we're all still looking for the same answer. If anyone found the fix please help. I'll update you as I navigate this.

[chengsm101]

There is another valve that can fail.

It is called the coolant shut off valve on the B9. This valve is also vacuum actuated via a different solenoid. This is a problem on the 4.0T's, so I expect it will also be an issue here as well at some point.

20221101_222845.jpg

This solenoid can be tested via VCDS. It will actuate the solenoid. Since the system does not indicate position, all one can do is activate the solenoid and listen for clicking. If no clicking, the solenoid is stuck.

The alternative is to disconnect and vacuum line (from the shut off valve) and plug the vacuum line and see if the problem goes away. While that sounds easy, access is pretty bad to that vacuum line.

I’m also getting coolant temperature warning, fault code I get is P13EF00. Reading the live data from my OBDeleven, the temperature sensor of cylinder block (I suspect it’s the G694..?) is giving much higher temp (250~300F) Temp gauge on dashboard stay at middle. Checked both solenoid valves for water pump and shut-off valve and I can hear click sound from both. Since this is the only one sensor gives high temp, and it’s reading correct after car stayed for overnight. Should I start considering I got a faulty shut-off valve? The temp reads high even when car leaves in idle speed. Really appreciated if anyone can give any suggestion.

[chengsm101]

@S4_kas

Did you finally figure out what caused the issue? Appreciated.

[qcrazy]

I’m also getting coolant temperature warning, fault code I get is P13EF00. Reading the live data from my OBDeleven, the temperature sensor of cylinder block (I suspect it’s the G694..?) is giving much higher temp (250~300F) Temp gauge on dashboard stay at middle. Checked both solenoid valves for water pump and shut-off valve and I can hear click sound from both. Since this is the only one sensor gives high temp, and it’s reading correct after car stayed for overnight. Should I start considering I got a faulty shut-off valve? The temp reads high even when car leaves in idle speed. Really appreciated if anyone can give any suggestion.

What you are explaining sounds like improper function of the switching valve. However, when the switching valve "fails" it is almost always caused by a bad vacuum solenoid. It is interesting that you heard it clicking, but I am not sure I would believe that.

The best test is to disconnect (and plug) the vacuum line leading to the solenoid. Then go for a drive. If that fixes your issue then replace the solenoid valve, when convenient

I had to do this exact thing while on vacation in another one of my Audi's. Not fun on the side of the road.

[chengsm101]

What you are explaining sounds like improper function of the switching valve. However, when the switching valve "fails" it is almost always caused by a bad vacuum solenoid. It is interesting that you heard it clicking, but I am not sure I would believe that.

The best test is to disconnect (and plug) the vacuum line leading to the solenoid. Then go for a drive. If that fixes your issue then replace the solenoid valve, when convenient

I had to do this exact thing while on vacation in another one of my Audi's. Not fun on the side of the road.

Do you mean the solenoid of shut-off valve? I tried to Test it through OBD and I do hear the clicking… And I’m not sure if I can touch to the place…let me try anyway. And BTW do you know the part number of this solenoid valve? Is it same part as the one for water pump?