Can anyone tell me. will removing the coolant temp sensor (the one that sends the reading to the ecu)possibly cause an air lock?

Just want to know before I swap in a new one.

You bleed the system.? they can be a cunt to bleed, is the rad fan kicking in on idle?

Sorry erin not sure i get what you mean. Are you saying i would have to bleed the system after swapping out the coolant sensor?

I've read that this sensor cold possibly be the cause of my miss if faulty+a lot of posters on mr2oc recommend putting a new one in with miss type issues. They are only 15euro from camskill so thought id try it as its a cheap fix.

If the system.needs to be blead after though i might get anto to do it for.me as i wouldn't have a clue how to do that.

....sorry I should why do you suspect theres an airlock in the system?

Not that i can tell. The temp gauge always sits nicely at slightly below 9o'clock. Anto did a bleed on the system a while back so thereis no reason there should be an air lock.

However, from what I've been told, the sensor that sends the coolant reading to the ecu, not the dash, can cause the type of issues Im having cos that dictates fueling etc.

I don't.know if this is causing my issues but its on my list of 3 things to check. 1) sensor 2) timing 3) compression.

What i was asking is if i remove the old sensor to put in the new one, am i at risk of causing an airlock? Im confident i can swap the sensors but not confident i can bleed the system.

After reading my original post i see that i didn't make myself very clear-sorry.

Mister Two wrote:
Not that i can tell. The temp gauge always sits nicely at slightly below 9o'clock. Anto did a bleed on the system a while back so thereis no reason there should be an air lock.

However, from what I've been told, the sensor that sends the coolant reading to the ecu, not the dash, can cause the type of issues Im having cos that dictates fueling etc.

I don't.know if this is causing my issues but its on my list of 3 things to check. 1) sensor 2) timing 3) compression.

What i was wondering is if i remove the old sensor to put in the new one, am i at risk of causing an airlock? Im confident i can swap the sensors but not confident i can bleed the system.

The sensor is on the radiator...if I remember correctly it will require a drain of the rad...but I was changing out the radiator so needed to swap this over.

Leave your car idle (with heater off in car!) for a couple of mins and if the rad fans kick in then the sensors working.

If its sitting at 9oclock thwen the cooling appears to be fine.

Im nearly certain it sits in a water pipe just below and left of the throttle body and near coolant (gauge) sensor and oil pressure sensor. The radiator is at the front of the car is it not. Im on my phone at the minute but il locate a picture of the sensor i mean and post it up.

Mister Two wrote:
Im nearly certain it sits in a water pipe just below and left of the throttle body and near coolant (gauge) sensor and oil pressure sensor. The radiator is at the front of the car is it not. Im on my phone at the minute but il locate a picture of the sensor i mean and post it up.

Ah the thermostat? If your getting 9 o clock on the gauge then that should be doing its job...no harm in replacing it before it fails but it will require an air bleed if you do.

_KUNENA_BBCODE_HIDEIMG

the sensor im talking about is the green one which is responsible for sending the reading to the ecu and is responsible for fueling etc.

it has nothing to do with the reading on the dash/gauge-thats the grey sensor to the right on the same pipe no?

Sorry man, I know this is a little confusing. Bottom line, i cant remove this sensor without a bleed afterwards!

Mister Two wrote:

_KUNENA_BBCODE_HIDEIMG

the sensor im talking about is the green one which is responsible for sending the reading to the ecu and is responsible for fueling etc.

it has nothing to do with the reading on the dash/gauge-thats the grey sensor to the right on the same pipe no?

Sorry man, I know this is a little confusing. Bottom line, i cant remove this sensor without a bleed afterwards!

had a very quick look :P at mine and I can't see anything in mine that resembles the sensors in the picture, but they are likely to be in there somewhere....but yes i'd imagine that those sensors are in contact with the coolant so a bleed would likely be required (correction if I'm wrong).

hope its something simple I'd be ready to give up at this stage.

Ha it can get frustrating.Though In a weird kind of way I kind of enjoy doing this work on the car and trying to figure it all out.Ive certainly learned a huge amount. still, would like to get it sorted though. One day

p.s that picture is from a turbo model i believe. But the two coolant sensors are defo on your car, they are on mine anyway!!

Mister Two wrote:
Ha it can get frustrating.Though In a weird kind of way I kind of enjoy doing this work on the car and trying to figure it all out.Ive certainly learned a huge amount. still, would like to get it sorted though. One day

haha good stuff...you got the BGB and a multimeter? theres a chapter on how to test all these sensors are working as they should.

eringobragh wrote:

haha good stuff...you got the BGB and a multimeter? theres a chapter on how to test all these sensors are working as they should.[/quote]

Yea got the BGB. have a multimeter on its way to me from the UK as we speak. decided to buy one after 3 sensors replaced and still no fix


Thanks for your help mate.

eringobragh wrote:
haha good stuff...you got the BGB and a multimeter? theres a chapter on how to test all these sensors are working as they should.

Mister 2, that advice from eringobragh is the best you can get. No need in changing parts, test them first, then chage if needs be. For all you know the connection might just need a drop of boiling water and some WD40 to remove the issue.

Only testing the part will tell you that, and save you having to drain, refill and bleed the system IMO

Well, as I had the new part arrive I decided to give it a go and replace it anyway. Ive become a lot braver with working on my 2 and also cos I found it near impossible to get my multimeter leads anywhere near the sensor

It was no bother at all-all you need is a deep set 19mm socket and your good to go.Once the engine is cold you will only lose a dribble of coolant.

From what I learned on MR2OC, you will not have to bleed the coolant and that turned out to be the case-just needed a capfull to top up in the filler neck. Apparently it has something to do with the fact that once your working on any areas of the cooling system that are above the height of the radiator, you will not introduce an airlock-hence no need to bleed.

Just thought Id post my experience for anyone thinking of attempting it.