Can a Bad Coolant Temp Sensor Cause No Heat
06-08-201007:24 PM #1
Veteran Member 4 Rings 
Fixed my overheating consequence - Bad Coolant Temp Sensor.. Details inside
First I'll say, I made a detailed long thread because if yous search this issue, there are many guesses and issues posed, simply not many fixes. So this is for those united nations-answered questions.
Lately, my issues have been that once up to temp, I've been noticing that my coolant estimate was creeping over the one-half way marking by roughly one/2-3/four of a tick, and then sometimes getting better as I began to movement... So all signs point towards auxiliary fan switch right?
Well I have to say you certainly cannot live without VAG-com/VCDS with this car... I take the real cable and I know some people similar to relieve as much money as they can, only when you go what yous exit of the full version sometimes the 250 seems similar modify for the people that developed a program that helps us so much.
So before I went ahead and committed to the aux fan switch equally the answer, I wanted to effort one last thing... I hooked upward my laptop and measured a block in the engine that would display the coolant temp, there are a few blocks that practice.. I wanted to run across if I put my A/C on (forces the fans to 100%) if the car would still overheat a little, considering that would dominion out the aux switch since the fans would be @ their total output... So as I'yard driving, I detect that the car got upward to temp, then sure enough with the A/C on, fans running, and the temperature in VAG displaying 90-93*C, the needle after being in the middle for a bit began to rise up to where it had been going before, but the temp in VAG was property steady! I was almost convinced that information technology was the aux switch considering many people were then sure, merely thanks to VCDS I replaced the right sensor the first fourth dimension, without whatsoever guesswork. 
Long story short, the sensor I had in there was non OEM, it was installed by ICS Performance in Stamford, CT, and it was nice of them to charge me the dealer price for a non-dealer function. 
This is the sensor they installed, and charged me full 40+ dollars for. It'southward a brighter shade of Light-green compared to the OEM Audi sensor. It'southward only similar the one on ECS's website for 1/2 the toll, it's probably the Meyle.
Today, I got the sensor from my Audi dealership, and although I got buttraped for the toll (45.00 with o-band and prune), just I'g Actually happy it worked and it was the correct piece. Otherwise I would have been out that coin since they don't take those parts back!
ALEX, this was for you buddy.. Y'all and I certainly didn't have the aforementioned trouble, yous seem to be more a candidate for aux. fan switch. 
Daily: C7.five A6 iii.0T | Garage: B5 S4 | Videos
06-08-201007:30 PM #two
Veteran Fellow member Iii Rings
cheers... so u r saying VAST gave me a bad sensor as a part of Stage 3 Kit? :-) cause it came with RS6's, and was replaced by my shop. issues started soon afterwards...
06-08-201007:33 PM #iii
Veteran Member Four Rings
Originally Posted by alexverve 
thanks... so u r saying VAST gave me a bad sensor every bit a part of Stage 3 Kit? :-) cause it came with RS6's, and was replaced by my shop. problems started soon afterwards...
No, I'm saying your issue isn't the CTS 
.. Accept you replaced the aux. fan switch? You mentioned temps over 100*C.. Mine get to 95* at their highest, fifty-fifty on a hot mean solar day... You should get a new fan switch and get a EFK to keep your car cool.
And my sensor in a higher place didn't come up with my VAST fueling kit, ICS Performance installed information technology a few months before I got K04s on the car. VAST supplies OEM from Audi, not that Meyle crap.
Daily: C7.5 A6 3.0T | Garage: B5 S4 | Videos
06-08-201007:41 PM #four
Veteran Member Three Rings
VAST provided an "upgraded" light-green sensor with fueling kit which was installed by my mechanic. now, i did not see which one it was but upgraded in my vocabulary ways none-OEM. after installation, the problem started. my guys swapped both blue fan switch and fan control unit of measurement with another car... none of those 2 worked. so reading past what u said above - the "upgraded" green sensor is most likely the cause. either Myele makes crappy sensor or it is just super-sensetive.
regarding temps, i am not certain what numbers my guys were checking, just at exact center of estimate (with car at however) it read 100 degrees. once it went over eye (never crossed one-half signal betwixt heart and next marker) temps were fluctuating 101-104 range.
06-08-201008:01 PM #5
Veteran Fellow member Four Rings 
Great, i have the aforementioned problem and is nice to know it is the coolant sensor. I volition supersede it when i do my axuliary pump, Total Hose kit and new ICs.
Giac stage 1 279whp-327wtq
TEAM A.C.E. NY
Me: Siri where practice lesbians hang out?Siri : I found 2 Subaru dealers adequately close to y'all
06-08-201008:02 PM #6
Veteran Member Four Rings
VAST provides an "UPDATED" sensor, non upgraded.. Believe me, it's an OEM part !
This is from the description on the site..
This fueling kit is for any ii.7T running k04's or larger. Included is custom VAST programming for use with a Bosch or Hitachi maf sensor. ii.7T's using the Bosch MAF sensor may either use our Bosch programming or convert to the Hitachi programming with the necessary hardware. The fueling kit consists of: Hitachi maf wiring, Hitachi MAF sensor, RS4-Hitachi MAF housing, updated green coolant temp sender w/o-ring/clip , N75 valve, i heat range colder Bosch Platin spark plugs, check valve cap & tie(2001.5-2002 only), Bosch three BAR fuel pressure regulator, Fuel track hardware, RS4 airbox modified for more than flow, RS4 accordian hose w/clamps and Siemens 630cc/min fuel injectors. Please ask on fueling for RS6 turbos or larger.
Either mode Alex, when yous turn on your Air-conditioning, can you confirm that your fan that is located ON the engine is coming on?
Daily: C7.five A6 3.0T | Garage: B5 S4 | Videos
06-08-201008:04 PM #7
Veteran Member Four Rings
Originally Posted by DRA4
Smashing, i take the aforementioned problem and is overnice to know it is the coolant sensor. I will supervene upon it when i do my axuliary pump, Full Hose kit and new ICs.
Glad I can help
Daily: C7.5 A6 3.0T | Garage: B5 S4 | Videos
06-08-201008:05 PM #8
Veteran Fellow member Three Rings
Originally Posted by AudiSportB5S4
VAST provides an "UPDATED" sensor, not upgraded.. Believe me, it'southward an OEM part !
This is from the description on the site..
This fueling kit is for whatsoever 2.7T running k04'south or larger. Included is custom VAST programming for utilize with a Bosch or Hitachi maf sensor. 2.7T'due south using the Bosch MAF sensor may either employ our Bosch programming or convert to the Hitachi programming with the necessary hardware. The fueling kit consists of: Hitachi maf wiring, Hitachi MAF sensor, RS4-Hitachi MAF housing, updated green coolant temp sender due west/o-ring/clip , N75 valve, one oestrus range colder Bosch Platin spark plugs, check valve cap & tie(2001.five-2002 only), Bosch 3 BAR fuel pressure regulator, Fuel rail hardware, RS4 airbox modified for more catamenia, RS4 accordian hose w/clamps and Siemens 630cc/min fuel injectors. Please inquire on fueling for RS6 turbos or larger.
Either fashion Alex, when you plow on your Air conditioning, can yous confirm that your fan goes on that is on the engine?
sorry, i misread. u r correct. updated.
My auxilary fan is on when AC is on. and my machine does not overheats when AC is on....
06-08-201008:15 PM #9
Veteran Fellow member Iv Rings 
Think I'k going to take to supplant my coolant temp sensor. Everything you lot described is happening to me.. cheers
B8.five Monsoon Grey Allroad - Airlift 3H / BC Forged Wheels
Anthracite B5 S4 6MT //J-Fonz Tuned - SOLD
Flickr
06-08-2010x:31 PM #11
Veteran Member Four Rings
The stock sensor on the '00 cars was blackness, the updated sensor is green. That is all that means. VAST uses the updated green OEM sensor.
06-09-201006:53 AM #12
Veteran Member Four Rings
Originally Posted by S4 Big Head
Think I'k going to have to supercede my coolant temp sensor. Everything you described is happening to me.. thanks
Proficient stuff!
Originally Posted by Nitroturtle
Yeah, I'1000 having the exact aforementioned issue so I appreciate you sharing what you found. VAST replaced my CTS when my car was upwards at that place in March, but I'm not sure which sensor they used. I'm going to endeavour to do the aforementioned testing yous did and brand sure earlier I supplant anything, but my symptoms are identical.
Deff. look into it.. Like I said all signs betoken towards aux. fan switch otherwise... It'south VCDS/VAGcom that is literally the best tool you tin can buy for this machine... If y'all went to VAST, they used OEM sensor from the dealer... Unfortunatley, when I want service similar that, I have to drive from CT to MI as I have twice in the past iv months 
. If I were you lot, exercise the testing, lookout the temps.. Come across if they are creeping up and keep going up.. If so I'd say fans... You can exercise the same matter I did, throw the Ac on, make sure all your fans are blowing, then scout. If it still goes past, then y'all may need another CTS.
Daily: C7.5 A6 three.0T | Garage: B5 S4 | Videos
06-09-201007:04 AM #13
Veteran Member Three Rings
Originally Posted by The_Jerbel
The stock sensor on the '00 cars was blackness, the updated sensor is green. That is all that means. VAST uses the updated green OEM sensor.
is in that location is a change the "updated" ane is more sensitive? and reacts to small fluctuations?
06-09-201009:38 AM #14
Veteran Member Four Rings
The dark-green sensor is less prone to failure, that much I know. I'm not certain if there are other changes, or non.
06-09-201009:56 AM #15
Veteran Member Iv Rings 
Is in that location a DIY for replacing the CTS or even the aux fan switch? Thanks for sharing this.
06-09-201009:59 AM #16
Veteran Member Four Rings 
Originally Posted by alexverve
is there is a change the "updated" one is more than sensitive? and reacts to small fluctuations?
no it just doesn't neglect as ofttimes.
and, OP, the symptoms you described actually don't sound like a failed/declining CTS. They usually read low and and then fluctuate wildly between operating temps and really low. Simply going past what I know of CTS failures (too much to exist honest), merely that'due south the mode I hear it described 99/100, not reading hot. Non saying that wasn't your upshot but I'd be surprised if that was actually the cause.
My WTB List:
-Sport (all black) shift surround for 6MT
-Sport (all black) ash tray coverKNaudi'south story
06-09-201010:02 AM #17
Veteran Member Four Rings
Originally Posted by CONTROL I
Is in that location a DIY for replacing the CTS or fifty-fifty the aux fan switch? Thanks for sharing this.
CTS is a pretty like shooting fish in a barrel chore.
-Remove Piano accordion hose/Airbox
-Await for a blackness or green sensor held in by a U clip under where the hose was
-Have out U clip
-Pull out sensor and o ring, replace
-reverse
My WTB List:
-Sport (all black) shift surround for 6MT
-Sport (all black) ash tray coverKNaudi's story
06-09-201010:06 AM #18
Veteran Member Four Rings 
Im my Avant when i bought it last May, had a temp gage consequence, it was not working, bought the one from vast and it works great, information technology was an OEM ane.
2001 S4 TIP STG 3 EPL tune,517 trans store, and Stuff
1998 Jeep Grand Cherokee , beater/off road rig (pending elevator WIP)
2001 S4 Avant TIP Sold to a good homeTurbo's are the Perfect Drug
06-09-201010:12 AM #19
Veteran Member Four Rings
Originally Posted by KNaudi
CTS is a pretty easy job.
-Remove Accordion hose/Airbox
-Expect for a black or light-green sensor held in by a U clip nether where the hose was
-Have out U prune
-Pull out sensor and o ring, supercede
-reverse
Is it any different from a 2000 to a 2001.v? I have a MY 2000.
Also, OP, tin can yous update with the verbal part # to brand this thread complete?
06-09-201010:13 AM #twenty
Veteran Fellow member Four Rings 
HOW Cartel You lot! HOW Dare You lot Accept THE NERVE TO SAY Y'all ARE OVERHEATING! Y'all DON'T KNOW WHAT THAT IS UNTIL YOU'VE PUSHED YOUR CAR ON THE HIGHWAY FOR five MILES (Non that you lot've seen that or anything)! lol
Current TOY
Parted and Torn down:
2013 TT-RS Ibis White - Stock for at present......
Sold:
2010 B8 S4 Phantom Black: Stasis Touring Pause Kit, APR Pulley, APR 93 Octane Pulley Tune, APR Full Carbonio Intake2000 Black 6spd S4
SSP Tuned PJK04 Stage 3
Burned:
2000 S4 Tiptronic (B5)
06-09-2010ten:xvi AM #21
Veteran Member Four Rings
Originally Posted past CONTROL ONE
Is it any dissimilar from a 2000 to a 2001.5? I have a MY 2000.
Too, OP, can yous update with the exact part # to make this thread consummate?
no, its the same.
this, is what you want: http://www.ecstuning.com/Audi-B5_S4-...ture/ES264174/
or this: http://www.ecstuning.com/Audi-B5_S4-...rature/ES1484/
its the aforementioned affair.
oh and I'd mind ECS'due south warning on those pages: WARNING:Installation is simple merely keep this in mind. You are working with a high pressure cooling organisation. Earlier starting work make certain the engine is absolutely cool. This could mean letting the auto sit for several hours before starting work.
My WTB List:
-Sport (all black) shift surround for 6MT
-Sport (all black) ash tray encompassKNaudi'due south story
06-09-201010:21 AM #22
Veteran Fellow member Four Rings
Originally Posted past KNaudi
It was indeed my outcome, as I tested it after the fact with the aforementioned driving, through town, did a 60-130 pull, FATS, and the coolant numbers would rising and cool, but the needle didn't move from center. That's why I made it clear in the beginning of the thread, if you have these issues and search information technology, you'll run into everything BUT this being the cause by and large. I saw a lot of Tstat, aux. fan switch, etc.. Anybody said erratic movement, simply that'southward what it really is if you lot recollect about it. It may not be bouncing around, simply it was sending one signal to the ECU, and one to the cluster. Information technology would move around from one/2 tick to three/iv tick over.
And the second one you posted is the 1 I had, that'due south the OEMe, non OEM. Information technology's Meyle, and information technology's the 1 that broke on my car. There is a reason its one/ii the price.. DON'T BUY that one.. Even Piggie was like, oh yeah man yous can't purchase that ane, they don't piece of work for that long! I can vouch. Information technology was in my machine for two years.
Daily: C7.five A6 3.0T | Garage: B5 S4 | Videos
06-09-2010ten:22 AM #23
Veteran Fellow member Iv Rings
Originally Posted by YZracer
HOW DARE YOU! HOW Cartel You lot Accept THE Nerve TO SAY Y'all ARE OVERHEATING! You lot DON'T KNOW WHAT THAT IS UNTIL You lot'VE PUSHED YOUR Car ON THE HIGHWAY FOR 5 MILES (Not that yous've seen that or anything)! lol
hahaha!! GOD that was funny... I yet have pictures of that on my telephone!
Daily: C7.v A6 3.0T | Garage: B5 S4 | Videos
06-09-201010:23 AM #24
Veteran Member 4 Rings
Originally Posted past AudiSportB5S4
And the 2d one you posted is the one I had, that'due south the OEMe, not OEM. It's Meyle, and it's the i that bankrupt on my car. There is a reason its 1/2 the price.. DON'T Buy that one.. Fifty-fifty Piggie was like, oh yeah human being you can't buy that one, they don't work for that long! I can vouch. Information technology was in my car for ii years.
I guess I'll have your give-and-take for it. I was always nether the impression that they were the same but one with the Audi/VW name attached.
My WTB List:
-Sport (all black) shift surround for 6MT
-Sport (all black) ash tray coverKNaudi's story
06-09-201010:25 AM #25
Veteran Fellow member Four Rings
Originally Posted by KNaudi
I guess I'll accept your word for it. I was ever nether the impression that they were the same just 1 with the Audi/VW name attached.
Yeah if you concur the two, you lot'll see the one I had, and that second one yous posted are the same. They are a brighter light-green compared to the Audi one.. Audi looks similar a shittier light-green, merely it's the 1 that works! ha!
Daily: C7.5 A6 three.0T | Garage: B5 S4 | Videos
06-09-201010:45 AM #27
Veteran Member 4 Rings
Originally Posted by KNaudi
I wish we still had Rep on here, cheers.
Would this be worth replacing equally a precautionary measure at just $27 or is information technology best to merely wait until you lot have some type of heating issue?
06-09-201010:48 AM #28
Veteran Member Four Rings
Originally Posted past CONTROL One
I wish we however had Rep on here, thank you.
Would this exist worth replacing every bit a precautionary measure out at but $27 or is it all-time to just wait until yous take some type of heating issue?
my pleasure.
I'd just wait. In that location isn't a huge problem when information technology fails. Information technology won't injure anything to drive similar that for a bit. I did it for similar 2 months and drove from DC to Chicago 2x earlier I got around to information technology.
await, is your coolant temp reading correctly at present?
My WTB Listing:
-Sport (all blackness) shift environment for 6MT
-Sport (all black) ash tray coverKNaudi's story
06-09-201011:02 AM #29
Veteran Member Iv Rings
Originally Posted by KNaudi
my pleasure.
I'd only wait. There isn't a huge problem when it fails. It won't injure anything to drive like that for a bit. I did it for like 2 months and collection from DC to Chicago 2x before I got effectually to it.
wait, is your coolant temp reading correctly at present?
Yup, everything is 100%. coolant temp is always dead on heart, oil temp is always 1/4 way.
06-09-201011:04 AM #xxx
Veteran Fellow member 4 Rings
Originally Posted by CONTROL ONE
Yup, everything is 100%. coolant temp is always dead on center, oil temp is always ane/4 way.
if information technology ain't bankrupt..... don't fix it.
My WTB List:
-Sport (all black) shift surround for 6MT
-Sport (all blackness) ash tray coverKNaudi's story
06-28-201004:43 PM #31
Registered Member One Ring 
sounds like this is my upshot...coolant temp gauge goes up to 3/4 in hot conditions simply (and when i'm sitting idle, if i bulldoze on the state highway, it drops to halfway), typically to a higher place ninety deg. I rarely drive in hot weather as i alive in San Francisco...just when I practice, the symptoms are the same.
I had a water pump replaced, flushed coolant, and then i'm hoping this CTS is the culprit! i'm glad to have found this thread!
06-28-201005:31 PM #32
Veteran Member Four Rings 
Mike adjacent time phone call me dummy.
-MilitantGrunt- Certified Audi Dealership Technician IG: @disgruntledmeow
-05 R53 Mini Cooper S
-07 997 Turbo
-10 B8 A4 Avant - 6spd swapped / congenital motor / Pag Parts EFR 7163 Turbo Setup.
https://world wide web.facebook.com/Pagparts/
06-28-201005:47 PM #33
Veteran Member Four Rings
The upgraded part is less decumbent to failure but still fails.
07-xv-201011:33 PM #34
Veteran Member 4 Rings 
Originally Posted by AudiSportB5S4
First I'll say, I made a detailed long thread because if you lot search this issue, there are many guesses and problems posed, simply not many fixes. And so this is for those un-answered questions.
Lately, my problems have been that one time upwards to temp, I've been noticing that my coolant gauge was creeping over the one-half way mark by roughly 1/2-iii/4 of a tick, and then sometimes getting better as I began to movement... So all signs bespeak towards auxiliary fan switch right?
Well I have to say you certainly cannot live without VAG-com/VCDS with this motorcar... I have the existent cable and I know some people like to save as much coin equally they can, but when you get what you lot become out of the full version sometimes the 250 seems like change for the people that adult a program that helps u.s. so much.
So before I went alee and committed to the aux fan switch as the answer, I wanted to try one last thing... I hooked up my laptop and measured a block in the engine that would display the coolant temp, there are a few blocks that exercise.. I wanted to see if I put my A/C on (forces the fans to 100%) if the car would notwithstanding overheat a little, because that would rule out the aux switch since the fans would be @ their total output... And then every bit I'm driving, I notice that the car got up to temp, then certain plenty with the A/C on, fans running, and the temperature in VAG displaying 90-93*C, the needle afterwards being in the middle for a bit began to rise up to where it had been going before, just the temp in VAG was holding steady! I was nearly convinced that information technology was the aux switch because many people were and so sure, but cheers to VCDS I replaced the right sensor the outset time, without any guesswork.
Long story curt, the sensor I had in there was not OEM, it was installed by ICS Performance in Stamford, CT, and it was nice of them to accuse me the dealer price for a non-dealer part.
This is the sensor they installed, and charged me full 40+ dollars for. Information technology's a brighter shade of Greenish compared to the OEM Audi sensor. Information technology'due south just like the ane on ECS'southward website for ane/2 the cost, it'southward probably the Meyle.
Today, I got the sensor from my Audi dealership, and although I got buttraped for the price (45.00 with o-band and clip), merely I'm Really happy it worked and it was the right piece. Otherwise I would have been out that coin since they don't take those parts back!
ALEX, this was for you lot buddy.. Yous and I certainly didn't have the same problem, y'all seem to be more a candidate for aux. fan switch.
And so if i had withal issues except my fans were non ever turning on. could information technology be the same problem or should i practise the aux fan switch?
Current Rides:
2000 Toyota Celica GT-Due south Supercharged - 2008 Audi A3 VRT(SOLD) - 2003 Audi RS6 Avant - 2013 Audi Q7 Prestige
2000 Audi S4 Stage 3(SOLD) - 2008 Audi TT 3.2 (SOLD) - 2002 S6 Avant Manual w/ S8 engine
1990 Audi Coupe Quattro(SOLD) - 1993 Toyota MR2 Big Turbo(SOLD) - 2001 Audi S6 Sedan (SOLD)
Cheque Out My Facebook
07-16-201004:49 AM #35
Veteran Member Four Rings 
is this one of the sensors that is to the rear of the engine or the one that is by the lower radiator hose?
GIAC-Ten, STASIS TS,VAST,034 MS
07-16-2010x:08 AM #36
Veteran Member Four Rings
Weird... When my temp sensor failed the needle would leap around quite a bit.
Replacing it was cake. Took a whole xv minutes (for the 1 on back of engine). Brand certain that when you lot pull out the old sensor that you take the o-ring out with it. Mine got stuck in the hole so I had to dig for it with my fingers. Found out most it when I tried to stick in the new sensor with o-ring and it wouldn't seat right. Likewise get new clip. One-time one is probably cooked and brittle.
Funny matter is that the thermostat had failed simply since I alive in FL information technology didn't bear on it. Merely establish out when I collection it to Boston for Christmas that the needle started to drib and stay low the farther north I got! I was similar DAMN, thermostat! Quick solution was to gorilla record the lower radiator openings on the bumper in sections the further northward I got.
00 B5 S4 - K04, Stern Soft MM, Stern Snub, DTS, Neuspeed Rear Sway, Oinkies, GIAC stg 2 XR, Vogtland GT, SSAC copy. Soo... Stg two.31456?
06 Mazda3 - Wife's car and autox car96 Eclipse GSX - Gone
03 Acura CL Type S - Gone
96 Soarer GT - Gone
93 RX7 R1 - Gone and missing her
Source: https://www.audizine.com/forum/showthread.php/368825-Fixed-my-overheating-issue-Bad-Coolant-Temp-Sensor-Details-inside
0 Response to "Can a Bad Coolant Temp Sensor Cause No Heat"
Post a Comment