Weird G60 problem

[Andy665 0]

Travelling home this evening and all hell broke loose with water and oil temperature guages.

 

Oil temp is normally no higher than 90-96 degrees but leapt up to as high as 130 but was rising and falling in 4-6 degree lumps by the second. At the same time the water temp, usually running at 90 degrees went upto just over 100 degrees.

 

The water temp warning light then came on, pulled over, switched off and popped the bonnet, nothing untoward under the bonnet, oil level fine, no steam,or smoke, expansion tank at normal level

 

Switched back on and oil temp settled at about 110 degrees and water temp at just below 100 degrees.

 

Totaly stumped - only things done to the car recently have been an oil change yesterday and the black water temp guage sender replaced last week.

 

Any ideas???????

[kongo127 0]

Well there is something wrong for sure mate, because you´re having oil and water temperatures issues.

 

Could it be the water pump termostat?

 

Did you noticed you radiator fan working on both speeds?

 

Keep posting!

[Andy665 0]

Is the water pump thermostat the blue sender?

 

The strange thing is that I'm not convinced the temp readings were correct, the engine bay certainly was no hotter than normal and levels were normal

 

Must admit I was not conscious of the radiator fan cutting in, I'll get a new switch tomorrow - radiator fan not cutting in would not unduly affect the oil temp though - would it?????

[kongo127 0]

The water termostat is mechanical and attached to the water pump.

 

Your problem is not related with the blue temperature sender, this one only tells the ECU the water temperature for timing / enrichment purposes.

 

The black sender, which is located next to the blue one is for cluster temperature readings. These senders are not interchangable.

 

It would be such a coincidence to get water sender and oil temperature sender defficient at the same time.

 

So i guess that there´s something going wrong.

 

Hot wire the radiator fan to see if it´s working properly.

 

Then turn the engine on and watch the radiator fan behaviour according to the water temperature seen on the cluster.

 

You may also touch the water hoses to figure which way the water is passing through, to understand what´s the state of the mechanical water pump termostat (open/clese).

 

Hope this helps!

[bcstudent 0]

My guess would be the voltage regulator on the back of the clocks.

[Andy665 0]

Going to start with the simple things first, current plan of action is:

 

1. Swap the instument cluster over and see what the readings are

 

2. Replace the oil temp sender

 

3. Replace water pump thermostat

 

4. Ask for further assistance

 

Gut feeling is that its electrical rather than mechanical, seems strange that both oil and water temp readings should both go crazy, even more so when there there was no deterioration in performance, fuel economy, no funny smells or loss of oil or water

[steveo29 0]

could well be a bad earth .....that causes the figure to shoot up n down quickly

 

or the voltage reg on the cluster

[Andy665 0]

Maybe a stupid question but I'll ask it anyway.

 

If it was the voltage regulator on the clocks wouldit not affect the other MFA functions and the other instruments - seems strange it was only affect the oil and water temp readings and the water temp warning light?

[steveo29 0]

have a look at the earth cable ....theres one on or near the rocker cover, i think thats related?

[Andy665 0]

I'll check that out.

 

Been out to the local VW site to order some parts and the water temp guage is now behaving itself, sitting at its usual 90-95 degrees. The oil temp guage showed a peak of 118 degrees but less than a mile later it was 98 degrees, totally convinced now that its electrical.

 

Going to swap over the oil temp sender from the other G60, is this the one closest to the block above the oil filter housing?

[Andy665 0]

Fingers crossed it's now sorted.

 

Fitted new OE water temp sender - now back to reading 90 - 95 degrees (that will teach me to buy cheap non OE parts)

 

Fitted new oil temp sender and now seems to be reading more realistically, peaked at 108 degrees when left ticking over for half an hour and fell back to 94 degrees after 10 minutes out driving.