Intermittent temp gauge

[sejman]

I looked down at my instrument panel the other day and say my temp gauge sinking down to the bottom, only to return to the normal position (9 o'clock) a few seconds later (very gradually). I've seen the same behavior a few more times in the last couple of days.

I'm assuming that this is a bad connection to the coolant temp sensor - the gauge must be heavily damped, giving it that gradual up/down movement. There's no check-engine light or other sign of problems.

Any other ideas?

[earthworm]

Corrosion, at the engine connection is the most likely, if not, then it is time to test the sensor.

I still think the connectors are of good quality, but made on a low cost basis..

[Doug]

Hello All.

'02 9-3 2.2 Diesel TiD 63,000 miles.

Coolant gauge (sorry - gage!) suddenly went to zero today for the first time ever. Remainder of instruments work. No change to the temp gauge after trying "Night Panel".

With connector pulled off the sensor on the thermostat housing, idle speed rises a little and engine symbol comes on below the temp gauge. Push connector back on, back to normal except gauge still at zero.

Checked Ohms over the sensor - agrees with specification (I.e. 385 ohms 10 minutes after stopping engine).

I suppose the gauge is not a seperate item but part of the instrument cluster??

Any suggestions gratefully received!!

Best Regards - Doug

[hkayssi]

The car has 2 temp sensors. You tested the wrong one

[Doug]

I know the petrol versions have two sensors, but according to the Haynes Manual the diesel has one, mounted downward into the thermostat housing, right side front of block.


Anyone got any advice on the diesel situation?

Many Thanks - Doug

[earthworm]

In the good old days, the temperature gage was one piece, a capillary tube was used between the engine and the dash board. About $20-30 for a new one..

Today the quality of parts is better, but not perfect..
Dealers may check the gauge using a slave unit to determine exactly which part is malfunctioning....sometimes this can be in the connections/wiring.
A new cluster may run $500 or more at the dealer; there should be rebuilt ones available...one would think
I am not sure, probably the gage can be repaired in the cluster, by an electronics repair facility, I'd guess..or an advanced DIY..

[Doug]

Just had it serviced. The Tech II says its the sensor/sender thats faulty, even though the ohmeter check works.

Before I replace it myself, any advice on getting it out of the block? 64,000 mile diesel. Its easily accessible, on the thermostat housing on the right side front, but I worry about breaking it if its siezed in.

Many Thanks - Doug

[Doug]

Hi.

Diesel Coolant Gauge u/s.

Coolant sensor replaced by the local Saab Independent, as it also needed the turbo oil return pipe replaced, and I have no means of getting access underneath.

Anyway, gauge still doesn't work. Mechanic took advice from Saab on some other courses of action - no joy. He suggested a local car electrics specialist. Although the correct version (2.2 TiD) is listed in his manual on ECU connections, there is no pin listed for the temperature gauge output from the ECU (although there is an input pin from the sensor). So another dead end.

I'm letting a Saab main agent look at it on Monday.

If a new instrument cluster is needed, I will look at alternate sources to Saab obviously, but there are several versions of the cluster (turbo boost gauge or not, etc etc).

1) Anybody know whether there are different variants for the diesel or are they all the same? If not, how to identify?

2) How would the new cluster be told what the odometer reading is, is this memorised in the odometer/instrument cluster, or elsewhere, so the new odo displays the reading transmitted by another component?

Anyone changed their cluster and have any advice?

Many Thanks

Doug

[earthworm]

Originally Posted by Doug

Just had it serviced. The Tech II says its the sensor/sender thats faulty, even though the ohmmeter check works.Would this not then point to a wiring/connections problem, and the Tech may not detect this.. And, one could make a test device using a potentiometer or a rheostat or a simple resistor - this would prove that the wiring is good or not..

Before I replace it myself, any advice on getting it out of the block? 64,000 mile diesel. Its easily accessible, on the thermostat housing on the right side front, but I worry about breaking it if its seized in. Place a good snug wrench on the unit and give it a rap with a hammer or your hand..In some cases a special tool is available for this task from Snap-On or Mac tools..

Many Thanks - Doug

I have had the cluster out(checking the SRS light), this is rather easy to remove; maybe a good electronics man could fix this - a new cluster is far too expensive..

[Doug]

Update

Saab Dealer has traced the problem to the gauge. An outfit near Poole (UK) called Autotek claims to be able to repair the problem (with no charge if they can't).

With such a sealed unit, is this possible?

I'm about to take the cluster out and send it to them.

Cheers!

Doug

[earthworm]

Good luck, Doug

The professionals can "break into" sealed units quite often..
The odometer is a separate piece....helps a little.
The gage was roughly $20 30 years ago, 0.3 to 0.5 labor time..
Today, for a car owner to pay $500 or whatever for a new cluster plus 1.0 labor - this simply is not right...

[Doug]

Thanks Earthworm. $500 for a new cluster + labour huh? In the UK its 500 POUNDS + tax + labour so about twice the cost!

Anyway, for UK readers benefit - Autotek came back with a repair cost of £179, no vat, + post, which I declined as I have sourced (via ebay shops) second hand "guaranteed" units for £95 + vat + postage, and £125 + vat + postage.

Since I now have the removal/instal skills I'll take my chances!!

Regards - Doug

[earthworm]

Doug and Sejman, you two(I hope) have caught me at a time when the brain is fresh and uncluttered.

The temperature gauge info is fed thru the ICE unit - this does the "heavy damping" and if it malfunctions - God only knows what can happen. ..
The ICE(integrated central electronics) must be checked out. This is a $50 deal as compared to the cluster at $500....
And guessing is never the best way to do things...
The Haynes manual schematics are good...

[hkayssi]

Good luck and since you're in the UK and shopping ebay, check salvogroup and neobrothers123 as well as m5_saabcentre and thgparts. I dealt with them and they're fantastic and reliable