Hi guys, since the CAM belt has been done the main engine fan is always on...when I start the car its on and when its warm its on, it never stops. Anyone have any ideas for this new problem.... Thanks in advance.

Edited October 24, 20169 yr by 182stevecup
Solved

Hi guys, since the CAM belt has been done the main engine fan is always on...when I start the car its on and when its warm its on, it never stops. Anyone have any ideas for this new problem.... Thanks in advance.

Viscous coupling might not be working. ill get one sent to you ;)

 

Alright maybe I'm jumping conclusions.

Is it an electrical issue then groover?

Edited October 22, 20169 yr by Alic

Yes, there are two temp sensors on the water pipe, IIRC the smaller one, single blade operates the fan, if its connected then the sensor is duff.

 

If its not that one its the other one lol

 

- - - Updated - - -

 

The viscous fan will always turn with the engine unless its buggered then it wont be on all the time lol

What did it do before? :confused:

Yes, there are two temp sensors on the water pipe, IIRC the smaller one, single blade operates the fan, if its connected then the sensor is duff.

 

If its not that one its the other one lol

 

- - - Updated - - -

 

The viscous fan will always turn with the engine unless its buggered then it wont be on all the time lol

 

Not sure I understand what you're saying. Is it supposed to always be on and Ive never noticed or is it a problem to be looking into. The noise it makes when on sounds like a car that's sitting in traffic and the fan comes on to cool. Quite loud, you can hear it from inside the car, something ive not noticed before.

 

- - - Updated - - -

 

Not sure I understand what you're saying. Is it supposed to always be on and Ive never noticed or is it a problem to be looking into. The noise it makes when on sounds like a car that's sitting in traffic and the fan comes on to cool. Quite loud, you can hear it from inside the car, something ive not noticed before.

 

Not sure mate but I'm sure it didn't sound like that.

Although I have read it has a variable speed but seems to be stuck on high...maybe that's what up.

Is the fan running when you turn the ignition on (but don't start the engine)?

Let's get some sense here. Are we talking about the viscous fan? The large white one bolted to the water pump or the black plastic one in front of the radiator which is the Auxiliary fan for the aircon?

 

The viscous turns constantly, it's filled with a sort of wax and spring thing that once it hits a set tempreture locks up and spins at engine speed and will roar. Below this temp it runs at lower speeds. They tend to fail on, roaring constantly. Get some card and use it to touch the fan, don't use your hand. The resistance of the cardboard should be sufficient to stop then fan rotation. If not it's probably locked up.

 

If it's the electric fan, this one comes on under certain circumstances dictated by the ECU. Aircon on in traffic, then fan will come on. Overheating, on. Etc. It will also fail on if the temp signal is lost. Often this is the larger plug on water pipe dirty or failed connection, the ECU will then failsafe and fan on. The smaller blade connection next to it is for the dash gauge.

The viscous turns constantly, it's filled with a sort of wax and spring thing that once it hits a set tempreture locks up and spins at engine speed and will roar. Below this temp it runs at lower speeds. They tend to fail on, roaring constantly. Get some card and use it to touch the fan, don't use your hand. The resistance of the cardboard should be sufficient to stop then fan rotation. If not it's probably locked up.

 

Spot on...ill try the card thing when I get 5 minutes today.

I'd have a stab in the dark and say from what I understood of your question that's your most likely culprit. New viscous couplings are not cheap though, £300+ from memory. So unless your flush I'd fit a known good one from a breaker. At least if it's on your not going to overheat.

I'd have a stab in the dark and say from what I understood of your question that's your most likely culprit. New viscous couplings are not cheap though, £300+ from memory. So unless your flush I'd fit a known good one from a breaker. At least if it's on your not going to overheat.

 

Thank you. Another problem hopefully sorted.

Because you say you can clearly hear it from inside the car, I would lean towards the problem being the electric fan myself.

Does the frequency change if you rev the engine?

Granted, you can hear the difference between an engaged viscous fan and a disengaged one, especially with increased RPM.

Does the fan sound more like a hair dryer for instance? (constant) as opposed to a roaring sound that varies with engine speed?

Have you checked the connectors for good clean contact yet?

Also there is a simple test for the sender by way of its resistance.

Let's get some sense here. Are we talking about the viscous fan? The large white one bolted to the water pump or the black plastic one in front of the radiator which is the Auxiliary fan for the aircon?

 

The viscous turns constantly, it's filled with a sort of wax and spring thing that once it hits a set tempreture locks up and spins at engine speed and will roar. Below this temp it runs at lower speeds. They tend to fail on, roaring constantly. Get some card and use it to touch the fan, don't use your hand. The resistance of the cardboard should be sufficient to stop then fan rotation. If not it's probably locked up.

 

If it's the electric fan, this one comes on under certain circumstances dictated by the ECU. Aircon on in traffic, then fan will come on. Overheating, on. Etc. It will also fail on if the temp signal is lost. Often this is the larger plug on water pipe dirty or failed connection, the ECU will then failsafe and fan on. The smaller blade connection next to it is for the dash gauge.

 

I tried the card thing and the fan did stop with a touch of pressure but the roaring sound continued!!! Maybe its supposed to sound like that!

I tried the card thing and the fan did stop with a touch of pressure but the roaring sound continued!!! Maybe its supposed to sound like that!

Do you mean as soon as you let go the roaring continued? Or when you stopped the fan there was still roaring?

Viscous fan Normally it just blows when cold, and then ramps up suddenly after about 5mins idling when the engine is warm. Does yours always stay at the same max speed?

Edited October 23, 20169 yr by Alic

I tried the card thing and the fan did stop with a touch of pressure but the roaring sound continued!!! Maybe its supposed to sound like that!

 

It sounds like your other fan is running then. Time to check some electrical connections as mentioned previously, mate.

It sounds like your other fan is running then. Time to check some electrical connections as mentioned previously, mate.

 

Cheers mate, after further investigation without taking anything apart and its seems to be coming from the front corner left (drivers side). Would that be where the fan in located...if so how much of a bugger is it to get to?

 

Together we will crack this. Ill have a go tomorrow.

Cheers mate, after further investigation without taking anything apart and its seems to be coming from the front corner left (drivers side). Would that be where the fan in located...if so how much of a bugger is it to get to?

 

Together we will crack this. Ill have a go tomorrow.

The electric fan is the other side of the radiator under the nose panel:

The pipe thing you see is the intake

https://z32.wikispaces.com/Coolant+Temp+Sensor

 

Have a look at this link, the yellow connector needs to be checked thoroughly for good connections.

Check for corrosion.

 

Might also be an idea to check for error codes as if its missing that connection it would throw up a code.

Edited October 23, 20169 yr by Alic

The Sub fan will be the culprit, its the electric fan in front of the ac condensor to cool the gas temp but its also used as an emergency fan if the ecu can not see an engine temp.It is controlled by the ecu temp switch located on the top water pipe next to the dash gauge sender which is (1 wire) only.Its the yellow plug with 2 wires,check its secure and the terminals are making a good connection.If it was the viscous locked in bits of cardboard will not stop it nor your fingers either !

The Sub fan will be the culprit, its the electric fan in front of the ac condensor to cool the gas temp but its also used as an emergency fan if the ecu can not see an engine temp.It is controlled by the ecu temp switch located on the top water pipe next to the dash gauge sender which is (1 wire) only.Its the yellow plug with 2 wires,check its secure and the terminals are making a good connection.If it was the viscous locked in bits of cardboard will not stop it nor your fingers either !

 

I'd take this advice. You've proven the viscous isn't locked out with the card test. The noise is coming from the nose cone, sounds like a dodgy ECU sensor as was the other suggestion.

Notice Jimmer also pointed out your CAS being wound right up. If the ECU temp sensor is poo your timing will be affected too. Maybe the timing was set on a gauge warm engine whilst the ECU was trying to advance it to warm up the block. As has been suggested by the guys you need to check that connection is clean and if it is resistance check that sensor.

Sounds like you could do with an expert like Jimmer to cast thier eye over the car and set it up correctly. I know your using someone local but an experienced hand in these cars wil save you a fortune longer term.

Sounds like the problem is with your ECU temperature reading, hopefully just a matter of making good the Yellow connector connection.

As a secondary concern, you will still need to ensure that your viscous fan is working correctly however.

When the engine is initially fired up from cold, it is so that the fan blades can indeed be stopped be a well gloved hand.

However, once the engine is up to full opperating temperature and the car is at a standstill, after about 30 seconds or so, depending on ambient, the fan will noticeably engage. Please do not try to stop its rotation at this point, however, once the car exceeds 30-35 mph, the fan should disengage and simply rotate under slight drag. The reason for this is down to the fact that the incoming air is sufficient to cool the radiator and thus relieving the fan of its duty. What will happen is the incoming air will rotate a thermal spring at the centre of the viscous coupling resulting in the closure of an internal valve, this will allow the fan to freewheel, saving horsepower.

Hopefully, if the viscous fan is working correctly, you will notice a diffence in roar depending on conditions as described as above.

HI guys, thank you so much for the info, well impressed. I know that I need a special specialist but the person I have been using for the CAM belt is a the go to man for Cosworths in Europe and I know its not the same car but when I called him this morning he had the same suggestions that you guys have outlined! He also said that they may have re- attached something that wasn't on before because it was faulty and disconnected. He is having a look, especially as I have just paid him nearly 600 for the CAM belt but I will definitely get it to Jimmer as and when these little issues are sorted and I trust the car to go more than 5 miles off my drive. I will tell my tech about the connectors and hopefully this will help. Electronics are not my forte. Thank you again.

Edited October 24, 20169 yr by 182stevecup

Well ill be, someone on my journal thread posted a picture of the two sensors on top of the water pipe in front of the engine. Removed them, cleaned a bit, re applied and then boom... the radiator (front corner) stopped, the engine temp went up slower instead within 30 seconds and settled properly, the motor ran perfectly and the issues are all resolved. Thank you again, I needed some good luck and great advise before I lost my mind. Cheers guys. Is it weird to say I love you?

Can I like this more than once? :lol:

 

Great news, pal :thumbup1:

The person I have been using for the CAM belt is a the go to man for Cosworths

 

Way way not the same, so far removed its like black and white

 

He also said that they may have re- attached something that wasn't on before because it was faulty and disconnected.

 

Rubbbish

 

paid him nearly 600 for the CAM belt

 

Jeeez !!! was it gold plated ?

.

 

I will tell my tech about the connectors and hopefully this will help.

 

The "tech " should of done it right first time if such an expert

 

 

 

Right going to stick my head out here, you guy is not a zed specialist and as such has made some basic errors, ( temp sensor connection issue is well known)

 

Unless he has ConZult diagnostic which I doubt it is unlikely he set the engine up correctly after the belt was changed such as timing, tps, idle control etc, and £600 for a non specialist that sent the car out with the temp sensor issue just about spells out he found it hard and charged you for too many hours or maybe not.

 

Bare in mind, a cambelt change is a while you wait job on a 300zx, seriously whilst you wait, no mystery just get it done and set up correctly and out 3.5 hours max.

 

Why would you spend more money than going to a dedicated 300zx specialist, get an incomplete job done and then still say he is pucker ??

 

 

I dare say he may well be a great Cosworth guy but the 300zx is way different.

 

Jeff