HELP - Temperature light flashing! first time for a year

[iandavidcassidy 0]

I noticed on a drive today that my fan was on longer then before ie. at water temp 100-110it used to be on for 2 min. Today it just stayed on for ages until i restarted my car.

 

Now - on the drive back i hit traffic after the M1 and the fan comes on and the temp warning light flashes. water was at 110 and oil at 118.

 

I pulled over and checked coolant level - fine. Engine bay was also stone cold. i would have thought for the fans to come on the engine would be hot to the touch but the air blowing around was just cool.

 

What could this be as i am so worried about the engine blowing up! Is it a sensor fault or something else>? If the engine is obviously cold can i carry on driving and ignore?

 

please help out a novice

 

cheers

[iandavidcassidy 0]

anyone pls! :D

[dr_mat 0]

Was the engine stone cold? Odd that the gauges read so high yet the bay is cold. I'd suspect the thermostat being stuck closed if you get hot air from the blower though (for example), but the radiator is cold.

But the odd thing is your fans came on - usually they're hooked to the temp sensor in the rad..

[Richie_FSOB 0]

i would say it was the thermostat stuck.

If you do happen to get the problem again, if it is the thermostat, some engine pipes will be red hot, and some still cold. Easy test

[iandavidcassidy 0]

the blower was working as we were on the motorway and i turned it on. the engine when i pulled up was not stone cold, but normal to better than normal as the fans were on so long. It was cold to touch on top and norm it is quite warm to touch,?

 

could it be a sensor making the fan stay on, would this send a water temp light error?

[iandavidcassidy 0]

thermostat stuck? can i unstick it? were is it. i am very bad at this type of stuff. but in 1 year of going around london sitting in endless traffic - my c has never overheated or done this before

[iandavidcassidy 0]

thermostat stuck? can i unstick it? were is it. i am very bad at this type of stuff. but in 1 year of going around london sitting in endless traffic - my c has never overheated or done this before

[potatonet 0]

ure thermo is under the aluminum cover for your AC compressor under your AC compressor under the car. after that there is a black plastic cover. if I were you and were going to try to unstick it I would just buy a new one because its a bitch to get to. anyway, which sensor are you talking about, there is a red light by the water temp that states that you are out of coolant, if that one is blinking you should check the expansion tank, or buy a new one for 20 pounds. if the car isnt overheating dont change the thermo just get a tank.

[iandavidcassidy 0]

the problen is that the coolant light came on but the was loads of coolant in there.

 

The other problem is that the fans seemed to be on longer that normal but when i checked the engine bay the engine seemed really cool yet the temp gauge was reading 100-120.

 

maybe a faulty sensor? help anyone else?

[golddust 0]

There is a black wire on the drivers side near the airbox that connects up to a small sensor on one of the bolts on the head/rocker cover. When that wire is earthed the fan comes on, even when engine is off. Check that it's connected properly. Mine wasnt and washing the car made a connection when that wire got wet so fan came on during washing, very confusing at first. That might explain fan being on for ages.

 

As for cooling, mine had and still has lots of grief around this topic. I must say your quoted oil/water temps seem very high. Mine were like that until everything went horribly wrong. My engine was overheating though and yours sounds like its fine. One head gasket and more later and my temps are 90 for water and 110 for oil, in traffic on M1.

 

Changing the expansion tank and cap proved to be worthwhile for me. German & Swedish (GFS) charged about £20 for the pair and that solved my cooling problems.

[iandavidcassidy 0]

gr8 - thanks for scaring me!

 

Do you really think my head gasket is on the way out. I started this thread thinking just the temp sensor was faulty.

 

I regularly get water temp of 110 and oil 118. always have done for a year and nothings ever gone wrong.

 

Does anyone else have a idea why the fan still stays on constantly and the water temp reads 120 when i can feel that the engine is cool?

[Henny 0]

Knackered temp senders... ;)

[golddust 0]

gr8 - thanks for scaring me!

 

Not trying to scare you! If your car isn't actually overheating it's fine! I was saying that I had similar problems AFTER my head gasket failed. Then found problems with a loose wire on the supply to the fan that comes from the temp sender on the rocker cover and a faulty expansion tank. SO, I'm suggesting you check that wire and maybe replace the expansion tank, which as I said costs about £20.

[kerrinmay 0]

My coolant temp is normally about 10 - 15 degrees less than my oil. Does this sound ok? It's just that the guy at my garage keeps saying about how the coolant should warm up before the oil does so I'm not too sure. My oil has only ever gone up to about 112 degrees max and normally it's a bit less than that.

[golddust 0]

kerrinmay, sounds normal to me. Dunno about which should get hotter first but the coolant is water based so it can't get too hot!

[iandavidcassidy 0]

cheers for you help guys!! I shall get some temp sensors then

 

henny - which ones will i need and where are they to replace ( ie . could a complete novice do it . me!)

[iandavidcassidy 0]

oh henny. and would Knackered temp senders cause the coolant light to come on - as this happened but there tank was full when i checked.

 

Maybe all the sensor went at the same time?

[golddust 0]

The coolant level sensor is part of the expansion tank, so must be replaced as a whole unit. GFS charge £14.50 plus VAT.

 

Dunno about the temp sensors... Check the GFS website, or Euro Car parts.

[Henny 0]

iandavidcassidy, which engine do you have?

[iandavidcassidy 0]

oh it;s a vr6

[Henny 0]

dunno where they are then, I've never worked on a VR before... :|

[Roger Blassberg 0]

Temp sensors on a VR are;

 

-coolant level; on the expansion tank. This controls the flashing warnig light.

-temp sensors to ECU (blue), to overrun pump/fan (yellow), and to aircon if you have it (black); on thermostat housing. Fixed by circlips and seals.

-radiator fans (brass hexagon screw plug); on radiator core, between top and bottom hose connections.

 

Best wishes

 

RB

[iandavidcassidy 0]

cheers roger. it was driving from london to St.Albans that my car did this! Can i change them myself? and is there an easy way to find the faultly ones?

[Roger Blassberg 0]

Your temperatures didn't sound that high, but it's always better to safe than sorry.

If the warning light flashes but the coolant is up to the Max line, the tank sensor is faulty and needs to be sorted out. Golddust says that the sensor is integral with the tank - I don't know for sure.

The blue two-terminal sensor will not affect the running temperature - it is purely to report to the ecu for fueling.

The yellow (middle) four-terminal sensor on the thermostat housing may be the culprit. It may have been substituted in the past by a black sensor, but it will still have four terminals. It is reasonably easy to get at, and cheap to buy. Looking at the engine from the front, it is to the right of the inlet manifold fitted into the thermostat housing near to where the bottom hose goes in. It is held in place by a 'C' clip which you gently ease out. Don't go at it like a bull at a gate because these housings are brittle and easily cracked.Prepare to lose your coolant. Replace the sensor and the rubber 'O'ring. Top up with G12+ coolant which is compatible with all other types. Do NOT mix G11 with G12, use only G12+.

If you have a/c there will be a third sensor (black), but again this will not give the problems you describe.

The fan thermoswitch is on the right side of the radiator, below the top hose connection. It is a brass hexagon plug, about 28mm, maybe more. Again, you will lose coolant when removing this. It controls the two speed fans during normal running. I forget the temperatures at which the fans cut in and out; the sensor is again fairly cheap and worth replacing anyway if you have any doubts about it.

Have you checked that both fans are turning? One is driven by an electric motor, the other is driven by a small belt from the first one.

If you in St. Albans again, let me know if you need further assistance - no guaranteed cures, mind you. Incidentally, I get most of my parts from Murray McDonald in Hatfield, opposite the Galleria.

 

Best wishes

 

RB

[iandavidcassidy 0]

cheers for your help! and everyone else