CODE P2181 check engine light question

[breez6777]

my light has been on for about 2 weeks now and i can't figure out why,

code from autozone states, cooling system performance, low coolant level probable cause (coolant isen't low) failed radiator or water pump (it's not overheating and has been at the same temp for years) and lastly check ECT sensor and i changed that last week (coolant temp sensor)


anybody have any advice on this?

[Jetta02AWP]

my light has been on for about 2 weeks now and i can't figure out why,

code from autozone states, cooling system performance, low coolant level probable cause (coolant isen't low) failed radiator or water pump (it's not overheating and has been at the same temp for years) and lastly check ECT sensor and i changed that last week (coolant temp sensor)


anybody have any advice on this?

When my car threw this code the waterpump went within a couple hundred miles.

Miles?

[KCISRViTG10]

You said you've replaced the coolant tempature sensor so that's rulled out.

Are both the fans working?

- Turn the car on
- Put the fan on and push the a/c button.
- Are both fans working? If not, there's your problem.

Quick easy way to check water pump and thermostat:

- Put the fan on with temperature set to hot.
- Does heat come out readily from the vents?

If not, Probably the water pump is gone. If it does, likely the thermostat is gone

[breez6777]

When my car threw this code the waterpump went within a couple hundred miles.

Miles?

86,000 timing belt's been done just not pump.. by me at least i bought it with 70,000

You said you've replaced the coolant tempature sensor so that's rulled out.

Are both the fans working?

- Turn the car on
- Put the fan on and push the a/c button.
- Are both fans working? If not, there's your problem.

Quick easy way to check water pump and thermostat:

- Put the fan on with temperature set to hot.
- Does heat come out readily from the vents?

If not, Probably the water pump is gone. If it does, likely the thermostat is gone

i seen this online and checked, yes both fans are working and when i place on heat, it comes out normally..


so possibly thermostat?

[Jetta02AWP]

86,000 timing belt's been done just not pump.. by me at least i bought it with 70,000



i seen this online and checked, yes both fans are working and when i place on heat, it comes out normally..


so possibly thermostat?

Geez, who replaces the timing belt and not the waterpump. The $100 part is definately worth it when going in there to do all that work

[breez6777]

Geez, who replaces the timing belt and not the waterpump. The $100 part is definately worth it when going in there to do all that work

lol true dattt, oh well my bad

[turbo3jetta]

water pump and thermostat should have been done. either can cause that code. honestly the water pump should have been replaced with the t-belt. especially since they are plastic and are known to crack/fall apart... t-stat should be done just because its pretty much tired out by 100k. mine went out at 110000. i know t-belt replacement is expensive but its cheaper than buying a new engine or a new car...and if you know your way around a car you can do it yourself

[breez6777]

water pump and thermostat should have been done. either can cause that code. honestly the water pump should have been replaced with the t-belt. especially since they are plastic and are known to crack/fall apart... t-stat should be done just because its pretty much tired out by 100k. mine went out at 110000. i know t-belt replacement is expensive but its cheaper than buying a new engine or a new car...and if you know your way around a car you can do it yourself

i think the thermostat is what im doing next, what are the symptoms of a bad water pump though? my car is not overheating or ever has and the temp gauge is constant

[Jetta02AWP]

water pump and thermostat should have been done. either can cause that code. honestly the water pump should have been replaced with the t-belt. especially since they are plastic and are known to crack/fall apart... t-stat should be done just because its pretty much tired out by 100k. mine went out at 110000. i know t-belt replacement is expensive but its cheaper than buying a new engine or a new car...and if you know your way around a car you can do it yourself

The thermostat is a 20 minute job is you follow the DIY from one of the Audi forums (should be in the FAQ/DIY) using the right combonation of extensions and a u-joint on the ratchet and you don't have to take out the alternator. This was the first thing that I did and it turned out to be the waterpump

edit: here is the link for the thermostat replacement
http://forums.audiworld.com/showthread.php?p=16925102

[breez6777]

The thermostat is a 20 minute job is you follow the DIY from one of the Audi forums (should be in the FAQ/DIY) using the right combonation of extensions and a u-joint on the ratchet and you don't have to take out the alternator. This was the first thing that I did and it turned out to be the waterpump

oh geez that sucks, do u know of any symptoms ?

[turbo3jetta]

the car doesn't have to overheat necessarily in order for the pump to be suspect. the engine may get hotter than normal under load, and it can overheat. remember there may be some propellers left on there that haven't broken off. it will fail on you if it was not replaced. its just a matter of time. i'm not trying to scare you and i hope i don't come off like that. just trying to be as factual and informative as i can.

[Jetta02AWP]

oh geez that sucks, do u know of any symptoms ?

If you change the thermostat, while you have the old one out you can stick your finger in there are feel the waterpump impeller and if you can turn it, it has most likely separated from the shaft. The impeller in my car did not fall apart but there was spider cracks around where the plastic was pressed onto the shaft and at any RPM but idle the impeller would basically stop spinning. It came pretty much without warning. I was driving home from work and out of nowhere the temp spiked and started beeping at me. I stopped and the temp would drop back down to normal. Start moving again and it would start to overheat again.

The spider cracks around the shaft were allowing it to spin under little pressure but as soon as I put the car under a load the impeller would stop spinning and the car would overheat

[travis.rudd]

the car doesn't have to overheat necessarily in order for the pump to be suspect. the engine may get hotter than normal under load, and it can overheat. remember there may be some propellers left on there that haven't broken off. it will fail on you if it was not replaced. its just a matter of time. i'm not trying to scare you and i hope i don't come off like that. just trying to be as factual and informative as i can.

Agreed. Plus you should probably do your waterpump anyways, even if it isn't what is throwing the code. I know I had a magnaflow catback on my old GTI and it caused this code and the CEL to come on every now and then, but it would just go away.

But again, this was after I had already replaced the thermostat, water pump, and looked into any other culprit, so if you don't have an aftermarket exhaust, or done a cat-delete or something...then I would replace all parts you need to anyways, because you eventually will have to, and you might as well before something actually goes out

edit: you will most likely know if it is your water pump

[turbo3jetta]

^ this is very true. i have seen this before as well as chunks missing and the whole impeller missing. OP just replace it and save yourself the trouble. or do the t-stat first and check the water pump as previously suggested. but honestly it will most likely fail before the next t-belt is due.

[breez6777]

the car doesn't have to overheat necessarily in order for the pump to be suspect. the engine may get hotter than normal under load, and it can overheat. remember there may be some propellers left on there that haven't broken off. it will fail on you if it was not replaced. its just a matter of time. i'm not trying to scare you and i hope i don't come off like that. just trying to be as factual and informative as i can.

oh no i completley understand and appreciate it i know of this already i guess i just been overlooking it b/c everything seemed fine for so long

Agreed. Plus you should probably do your waterpump anyways, even if it isn't what is throwing the code. I know I had a magnaflow catback on my old GTI and it caused this code and the CEL to come on every now and then, but it would just go away.

But again, this was after I had already replaced the thermostat, water pump, and looked into any other culprit, so if you don't have an aftermarket exhaust, or done a cat-delete or something...then I would replace all parts you need to anyways, because you eventually will have to, and you might as well before something actually goes out

edit: you will most likely know if it is your water pump

i have a magnaflow catback and 42 dd downpipe & highflow cat WITHOUT the o2 sensor spacer lol but it was on for like 3 weeks with no check light on so i thought i just got lucky and didnt need 1

[travis.rudd]

oh no i completley understand and appreciate it i know of this already i guess i just been overlooking it b/c everything seemed fine for so long



i have a magnaflow catback and 42 dd downpipe & highflow cat WITHOUT the o2 sensor spacer lol but it was on for like 3 weeks with no check light on so i thought i just got lucky and didnt need 1

ya I had mine on for almost 6 months before the light came on, I replaced everything, even though when I got to the thermostat, and sensor I came to find they already had practically brand new ones, but oh well, and I had replaced my pump previously so I knew it wasn't that. So it had to be the o2 sensor and my exhaust system. Like I said though ,it was on an off, but mostly just annoying to look at. If you do all the maint and it's still there, you can get a vagcom and clear it out if you want, I did, but it came back a couple times. Then it just shut off, and when I sold the car it was still off, but I let the buyer know about it. So idk, just annoying more than anything, as long as that's all it is

[breez6777]

ya I had mine on for almost 6 months before the light came on, I replaced everything, even though when I got to the thermostat, and sensor I came to find they already had practically brand new ones, but oh well, and I had replaced my pump previously so I knew it wasn't that. So it had to be the o2 sensor and my exhaust system. Like I said though ,it was on an off, but mostly just annoying to look at. If you do all the maint and it's still there, you can get a vagcom and clear it out if you want, I did, but it came back a couple times. Then it just shut off, and when I sold the car it was still off, but I let the buyer know about it. So idk, just annoying more than anything, as long as that's all it is

yeah i dont think its anything bad i just dont like the idea of it being on just incase some bad **** happens and i drive it normally like its not.. what code will it throw from the 02 sensor not being spaced?

[travis.rudd]

yeah i dont think its anything bad i just dont like the idea of it being on just incase some bad **** happens and i drive it normally like its not.. what code will it throw from the 02 sensor not being spaced?

Ya I hear ya. If it's anything REALLY bad it will flash, instead of be a steady light. The code is still 2181 From the O2 sensor I think, it's really an emissions thing that unless you live in a state that cares, isn't even anything to worry about. It will prob go off on it's own if you have already taked care of the aforementioned problems

[breez6777]

Ya I hear ya. If it's anything REALLY bad it will flash, instead of be a steady light. The code is still 2181 From the O2 sensor I think, it's really an emissions thing that unless you live in a state that cares, isn't even anything to worry about. It will prob go off on it's own if you have already taked care of the aforementioned problems

yeah i live in new mexico right now where their are basiclly no laws lol but im going back to new york soon and have to get everything fixed

[Parsons]

Bumping this thread for an answer, got the p2181 today. Temp is normal, both fans run, heat comes out when I turn heat on. Pump was replaced 10k ago (at 80k) with metal impeller. So its the t-stat or the ECT?

I will search how to do the ECT, just wanted to know if it could be anything else.

[Jazzydub]

Bumping this thread for an answer, got the p2181 today. Temp is normal, both fans run, heat comes out when I turn heat on. Pump was replaced 10k ago (at 80k) with metal impeller. So its the t-stat or the ECT?

I will search how to do the ECT, just wanted to know if it could be anything else.

I'd start with the CTS (cooling temp sensor) especially if it's not a green top one. Both parts are cheap and the CTS is easier to replace. Takes like 10 minutes.

Kind of a shoddy picture but gives you an idea of it's location.

[Parsons]

I'll take a look at that first. I really don't want to do the T-stat because its a pain in the ass and everything seems to be working fine outside of the CEL.

[Jordangerous]

I had this issue today also. I had it happen a year or so ago and was told it was the coolant temp sensor. Had it replaced, light came back on the next day, had it replaced again under warranty, light came on again a few days later. Brought it to a guy I trusted more and had it replaced and it has been off for a year. Came on today on my way home from work after just giving the engine some gas. Got the code cleared from the auto parts store and didn't come back on after driving around. I will have to get the water pump and timing belt soon so maybe that was my issue this time? Stupid generic CEL codes....

[Parsons]

So apparently I've been driving around for a month now with this CEL. I stopped at an acquaintance's house today who has a vagcom, returned p2181, coolant system. So same thing as a generic scanner.

I guess I'll order an ECT sensor, though it reads normal all the time. My current one IS a green top also.

[Parsons]

Day before new one arrives, CEL goes off on its own...seriously? I suspect it will return.

[mcmmotorsports]

Guys, I get the same code on my '04 1.8 Jetta.

Replaced the CTS
Car does NOT overheat.

At operating temperature, I turn on the A/C and my fans don't immediately turn on.
HOWEVER, they do turn on and cycle for about 10-15 seconds at a time then turn back off again.

Thoughts?

[engineman98]

I have been getting p2181 for months on my jetta changed water pump thermostat and temp sensor. The more research ive done I have found lots of other people with the same issue. I have read a bad coolant mix will cause this also. Mine only gives me problems in the colder months after that it goes away for the summer. I just clear the code and keep driving mine since draining the coolant system and refilling with g12 costs too much imo to fix this little cel.

[Elvir2]

I got that code on My R32. I only got it when the weather was super cold. Once it warmed up it went away on its own.

Elvir