Temperature sensor problem (unsolvable)

[oldcrazyman]

G' Day mates, we got a strange problem with a TB42:
The problem is to start engine when it's hot or cold too. When cold with the temperature sensor plugged needed 7 or 8 quick contacts on the starter. If the engine doesn't starts it needs to unplug the temperature sensor.
When the engine running its engine revs are under 500 rpm. Then after a moment rises above 1000 rpm and then stabilized at 750rpm when engine hot.
Hot starting with temperature sensor connected is almost always ok but the engine rpm is much under the 500rpm, the engine growls and you have to play with the throttle to get to 750rpm.
When you are moving the engine is fine but after a sudden slowdowns, with heavy use of the brakes or scaling gear, the engine revs drop under 750rpm and if pushing throttle the car doesn't moves, it growls, and it tends to go off.
You have to play with throttle or change in N to have a response of the engine and come back at 750rpm needed to run the car.
The diagnostics checking says always error code 13 = engine temperature sensor circuit.
Replaced one by one the following parts:


- 3 temperature sensor

- 2 throttle sensor throttle body

- 2 airflow sensor

- inlet duct

- auxiliary air control (ACC)

- fast idle compensating device (FICD)

- Fuel pressure regulator

- wiring connectors (all)

- termometer

- ECU

the error 13 still there! (note: all the replaced parts come from another nissan Patrol same model working perfectly).
On the working Nissan has been replaced the components with (supposed) problems coming from the "broken car" and it still to run perfectly.
At the replacement of the ECU the diagnostics test gave code 55 = all ok. But the start was still difficult. Re-checked, after starting, the diagnostics test and reappeared error 13 ....
All the masses of the engine have been checked and are ok.
We worked on (with a friend) for a whole weekend and no solutions...!
A big big thanks to everybody can help us!

Nim & Gus

[oldcrazyman]

I found this guy with a similar issue but not solution for him too:
http://www.nissanpatrol.com.au/forums/showthread.php?2161-Coolant-Temperature-Sensor

[Col.T]

Hullo Gus.
You're a long way from Oz aren't you.
Sorry you've got no response so far and I'm not able to help as I have no experience with error codes except once and I got the dealer to fix it.
Makes sense that if the action you've taken is correct for the error code as read, then the trouble should be gone.
PERHAPS the code is not as you've read or for your model, that code means something different. Sounds silly I admit but your trouble persists.
Maybe worth spending time searching the web for that code on the chance that some other error could be indicated. Searches under 'engine error code 13' or similar, with or without car make and model pull up lots of results. I know some codes are supposed to be universal but I suspect 13 may not be.
Again sorry for nothing positive.
Good luck and welcome to the Ivory Coast,
Col

[oldcrazyman]

Hi Col.T,
thank for you opinion, I searched on Google but all the Nissan Cars, from 4x4 to berlina, the error code 13 is ECT sensor...

Probably, we r thinking, all the 3 sensors we changed were faulted, and for a strange case, the other Patrol starts with no problems (detail: the second Patrol can't move, cuz the frame is rotten, so we can't test it on moving).
We r searching a 4th sensor to try with, and may be we buy a new one on ebay...

[Col.T]

G'day again Gus.
Still I'm no use, sorry.
Seems to me though that if all the replaced parts worked perfectly on the other wagon then regardless of the code, the problem must be elsewhere. You replaced the temp. sensor three times? Maybe two were no good but if one was proven OK on the other car, how can that be the trouble?
I've not worked on a petrol engine for over 20 years and that was before on board diagnostics. Should you start looking for really dumb things now?????
Badly fitting connectors? Cracked/faulty/pinched wires? Poor insulation, bad earthing somewhere?
Hope someone else can join in but those problems seem a bit confusing.
Good luck
Col.

[Kelvinator]

Try swapping the wiring loom from the donor car. No other suggestions though, electrical gremlins are my bane.

[oldcrazyman]

Try swapping the wiring loom from the donor car. No other suggestions though, electrical gremlins are my bane.

Already done Kelvin, thanks (wiring connectors - all).
For u guys is it possible that all the 3 sensors we changed are all fault, but for a "mysterious" mechanical conjunction on the other patrol they work?

Just trying to understand if it's the case to buy a new sensor or to search an other solution...:icon_bonk:

[Kelvinator]

I would highly doubt it. I would suspect that there is either a part in the the engine temperature circuit that you are unaware of, that the computer talks to that you possibly wouldn't think of. Or that the code being thrown up is irrelevant, that something else is faulting out and showing up as a fault through the temp circuit. As in a temperature so high or so low somewhere or a reading that the ecu believes is so wrong it has to be a fault.

I have also once had a voltage/earth issue that threw up a fault code so wrong it stuffed me round for days trying to find out what was really going on.

Unfortunately I don't know the petrol patrols enough to help much further.

[kevin07]

in my short experience with these sensors that coolant temp sensor is a big one as per attachment from bigrig. DONT USE AFTER MARKET SENSORS USE GENUINE ONLY.

[oldcrazyman]

there is one thing sounds strange in the coolant circuit: the water in the radiator goes down (for a normally usage), but it doesn't takes the coolant liquid from the coolant tank...How this is possible? (The rubber tube from coolant tank to radiator is free and clean)
I noticed that few days ago. Water in radiator goes down, water in coolant tank doesn't...

[happygu]

Already done Kelvin, thanks (wiring connectors - all).
For u guys is it possible that all the 3 sensors we changed are all fault, but for a "mysterious" mechanical conjunction on the other patrol they work?

Just trying to understand if it's the case to buy a new sensor or to search an other solution...:icon_bonk:

Gus,

No - it would be extremely unlikely that the sensors are faulty if they work on the other car.

I would be tracing the wire back to the ECU from the sensor, and make sure that it is reading the same value as it is at the sensor with a multimeter.

If the cars are identical, you could also try swapping the main ECU

[kevin07]

have you checked the number 6 spark plug see what it looks like also how long has the o2 sensor been in there

[oldcrazyman]

@ happygu: yes we already swapped the ECU, and at the first test was code 55 (no error), after the engine start back to code 13... :-(

@ kevin07: sorry, i'm italian, and i didn't exactly understand what you mean. The 6 sparks are clean, just checked last week. Which exactly is the O2 sensor?

[kevin07]

its a sensor that is plugged into the exhaust should be able to see it looking down from passenger side

[NissanGQ4.2]

its a sensor that is plugged into the exhaust should be able to see it looking down from passenger side

And looks like this

48681

[oldcrazyman]

And looks like this

48681

OH yes got it! No, that we didn't change it, but do you think it could be the cause for all these problems?
Can I take it off just to do a try or It should stay there?

[NissanGQ4.2]

do you think it could be the cause for all these problems?


I would say so but I'm no mechanic, have a read of this: http://o2sensors.com.au/static/why-replace-oxygen-sensors


Can I take it off just to do a try or It should stay there?

I assume if you just disconnect it and its the cause of the problem then the problem will still be there, do you have one on the other vehicle you could swap over?

[oldcrazyman]

I would say so but I'm no mechanic, have a read of this: http://o2sensors.com.au/static/why-replace-oxygen-sensors

I assume if you just disconnect it and its the cause of the problem then the problem will still be there, do you have one on the other vehicle you could swap over?

Thanks man, the link is interesting and surely I'll take a look at the sensor. Anyway I did the test for that sensor (2000rpm for 10 second) and it's good: the check light on dashboard makes 7/8 lights in 1o second = good!
What about the fact that the radiator liquid goes down? any ideas?

thanks all mates

[kevin07]

if and when you take out the o2 sensor you will probably find that it has fins,these fins should all be open about 1/8 of an inch you will find that they have closed up. water one do you have any coming out the back. when ichecked my o2 sensor with a snap on reader all it said was running lean.

[oldcrazyman]

if and when you take out the o2 sensor you will probably find that it has fins,these fins should all be open about 1/8 of an inch you will find that they have closed up. water one do you have any coming out the back. when ichecked my o2 sensor with a snap on reader all it said was running lean.

Hey Kevin, sorry but your english it's lil bit tricky for my Us english, sorry but i don't understand very well...
I don't see what's the problem with the o2 sensor in the case described in the first post.
The o2 sensor is working perfectly as saying the checking test (2000 rpm more than 6 lights in 10 seconds).
The problem still about the coolant circuit (error 13) and the car continues to have performance's problems even after all the pieces we've changed.
That's why we are asking to you australian patrol guru guys ;-) We finished our shoots :-(

[kevin07]

what im saying is that my o2 sensor was good on computer but when I took it out it was no good all the fins were closed.

[kevin07]

the water thing have you done a compression test.

[kevin07]

next step on the water loss if there is no evidence of it leaking is take for a dye test and or listen to the exhaust for a small hissing noise and or popping

[oldcrazyman]

the water thing have you done a compression test.

ok i'll check the o2 sensor.
What about the water compression? Do you mean to press the big tube going from radiator to thermostat when engine hot?
If you are talking of that, yes i did it. It's pretty hard, I can't totally press it, but I can press ah half of its diameter, more or less...is it correct?

[kevin07]

if its not taking water from the overflow it may not be pressurising properly is there any signs of a leak if not it has to be going through the exhaust. that's why I want you to listen at the back of the exhaust for any sort of hissing or popping.but the compression test is on the cylinders. you need a compression tester to do it from where the spark plugs are.

[mudnut]

Also check that the radiator cap is sealing at the lip. Water will expands with heat and when it cools it drags air in instead of water from the tank.

[oldcrazyman]

Hi all,
I just finished to check all you guys said, nothing came out. The car still has the same problems exposed in the first post.
The engine start to show those problem only when it's getting hot, otherwise, when cold it's perfect!

@ kevin: i just took out the O2 sensor...sorry but mine has not fins...check the pic
48742

I'm loosing the hope....:(

[NissanGQ4.2]

Considering the O2 sensor has probable been in there since it was made it would be an ideal time 2 put a new one it anyway, regardless if it fixes the problem or not

[oldcrazyman]

Considering the O2 sensor has probable been in there since it was made it would be an ideal time 2 put a new one it anyway, regardless if it fixes the problem or not

Ok thanks, I will buy one from the site posted by Kevin.
Do you guys think it's better to buy even a new coolant temp sensor? We tried three of 'em, but all were old and extra used.
Maybe with a new one the problem could be fixed.

Today I tested much better my problem and I've seen that this temperature (photo) is the limit to a good performance. A lil bit hotter than that and the car does what I explained...:furious:

48748

[NissanGQ4.2]

Those temp gauges mean nothing, mine normally if I remember correctly sits about half way or a bit more.

[NissanGQ4.2]

Have you tested the water temperature sender that sends its info to the ECU ( not the gauge )? I f I remember correctly there's 2 for EFI's one for gauge and one for ECU, think its behind / around the alternator somewhere.

[kevin07]

Ok thanks, I will buy one from the site posted by Kevin.
Do you guys think it's better to buy even a new coolant temp sensor? We tried three of 'em, but all were old and extra used.
Maybe with a new one the problem could be fixed.

Today I tested much better my problem and I've seen that this temperature (photo) is the limit to a good performance. A lil bit hotter than that and the car does what I explained...:furious:

48748
100 pecent buy a new coolant temp sensor but only genuine Nissan I put a new non genuine and car was great when cold and was not driveable at full operating temp

[oldcrazyman]

Have you tested the water temperature sender that sends its info to the ECU ( not the gauge )? I f I remember correctly there's 2 for EFI's one for gauge and one for ECU, think its behind / around the alternator somewhere.

What are the sender exactly?
We changed what you see in the pic
48756

[oldcrazyman]

Hello guys, back with updates!
I brought the Patrol to an "electric specialist".
He checked with diagnostic, and he saw that one cable of the sensor does mass.
He excluded the wire and makes a "bridge" from the ECU to the sensor: NOTHING, same problem.

But we notice one thing: the sensor has two cables, one lightgreen/black and one orange (which is what it was doing mass). If you remove only the orange one, the engine starts at the first time, and going to notice a real improvement, excellent throttle response, seems to be ok.

The usual loss RPM problem occurs ONLY when engine is hot and ONLY if once stopped, with automatic transmission, switching from N to D. Only in this case the RPM fall down.

Now I'm turning with the orange cable disconnected to check also the fuel consumption.

Question: how can I know exactly what they do those two cables, means which is that signal they send to the ECU?

[kevin07]

change no 3 with genuine

[oldcrazyman]

change no 3 with genuine

What? sorry i didn't get it...

[kevin07]

What are the sender exactly?
We changed what you see in the pic
48756

you have one marked as number 3 change that with a genuine Nissan part.

[oldcrazyman]

ok Kevin i understand, but 3 is the number of original/genuine sensors we already tried!
We already changed 3 different original (genuine) Temp Sensors coming from others Patrol 4.2 efi. And all those sensors installed on my Patrol didn't fix the problem. On the others Patrol work good. That's why we don't think the problem is there. Otherwise we've fixed the issue months ago and I didn't post here...

[kevin07]

ok unfortunately that is a problem either your wiring is broken or theres another sensor that's not working and its a matter of elimination. how did you go with the o2.

[oldcrazyman]

Hi all, i'm finally come back from Italy where I bought a NEW temp sensor.
Plugged in its place the Patrol now DOES this:
- Still problem to get start
- When I'm driving at average speed, when I softly touch the gas, I hear the typical "pop" of the air in the filter
What does it means? Too much air or too poor air coming in?

What the Patrol DOESN'T no more (looking solved):
"When you are moving the engine is fine but after a sudden slowdowns, with heavy use of the brakes or scaling gear, the engine revs drop under 750rpm and if pushing throttle the car doesn't moves, it growls, and it tends to go off.
You have to play with throttle or change in N to have a response of the engine and come back at 750rpm needed to run the car"

Diagnostic checking Code: 55 = Nothing Wrong

[salzgq]

Hey did you end up finding the problem? I'm having the exact same issue with mine :/

[kbchez]

Fault 13 ecu water temp sensor. This sensor is just below the thermostate. From my memory.