Temp gauge question

[niveketak]

Having just ordered an electric temp gauge from Huke Basart, I decided I might as well remove the old one. Gauge was fun as I decided to unscrew the 2 tiny screws while the dash was still in place, I didn't fancy messing with the spaghetti behind the dash. Eventually that came out OK and am really looking forward to fitting the new one as my shoulder will have recovered by the time it gets here and the screws fit nicely down my bloody finger nails.

I then removed the sensor, no difficulty as the previous owner had cut the tube to the gauge.

Now I had assumed the temp sensor went into the water jacket but if it does I am in trouble as oil came out of the hole. It is probably a silly question but is it supposed to be measuring oil temp?

BTW dropped a screw on the garage floor but amazingly found it in a puddle of hydraulic oil from the clutch slave cylinder which had decided to throw up on the floor and empty the reservoir. I had noticed small spots of what I though was oil on the rubber floor mat on the garage floor but did think it looked a bit clear for engine or transmission oil. Just need Simon to answer the phone now, think its a bit hectic there as usual.

[Alf ista]

Are you sure the sensor was put in the proper place? The gauge does measure water temp. The temp sensor is in the top of the block just behind the valve cover. The oil pressure sensor is on the right hand side of the block just in front of the oil filter.

[Derek UK]

...top of the HEAD.... at the back.

Should be no oil in there.

[niveketak]

Oh dear, it is definitely the water temp sensor at the back of the head next to the valve cover with the tube to the gauge. There is no oil in the rad nor any water apparent in the oil so am mystified by this. The temp gauge didn't work at all as someone had fiddled with the outer mesh on the tube and I suppose it has emptied itself into the water jacket. Will have to do a proper flush when the new gauge and sensor arrives and then see whether there is any overheating. Car starts and runs perfectly and even passed the emissions check for the French MOT with flying colours he was very impressed at the emissions or lack of them.

[Ron Kwas]

nikeketak;

The mesh around capillary tube connecting sensing bulb (SB) and gauge is there to protect the tube...if only it is damaged, gauge would still function...but if tube itself is damaged, ether contained within will be allowed to leak to atmosphere and gauge would stop working (only in the unlikely event that solder joint at bottom of SB were to allow a leak would this be into the cooling jacket, and then it would not look like oil...ether has a very low boiling temp and would evaporate away. Note: This is refillable by specialists with proper technique and equipment, or convertible to electric by an outfit in Holland! * I have no first-hand experience with either, only know they exist!)...your oil source must be something other than temp gauge, and I have to question you associating the oil in coolant and non-functionig temp-gauge issues...I just don't see how they can be directly related...

I expect (hope for your sake) that a bit of oil got into your cooling system, and collected at the sensing bulb high spot, and that is what you saw when removing SB...remove all of it as well as you can by blotting in the sensor hole with a paper towel. If engine is otherwise running well, I'd keep an eye on coolant for oil, but wouldn't worry more about it unless you see it again...

Install new temp gauge, routing capillary lines carefully, with no sharp bends and vibration loops. Apply gasket sealer on threads of nut at SB, and anti-seize between sealing surface of nut and bulb so that nut is always able to turn with respect to bulb...uniting them with gasket sealer will cause bulb and cap. line to turn when nut is next loosened, weakening cap. line, and that is the last thing you want on that expensive replacement assembly.

Cheers!

[niveketak]

Thanks Ron, the tube and mesh had been cut for some reason by the previous French owner, not really a surprise when you look at some of the other bizarre things he has done.

I wasn't associating the lack of a working temp gauge with the oil I was associating the oil contamination I found when I removed the sensor with a lack of oil contamination in the general cooling system or visa versa. It would seem logical that if there is oil in the head then it should be contaminating the rest of the cooling system.

I do not know the history of the engine other than it has done only 27000 kilometres from new so don't know if maybe the head gasket has gone at some point and the oil has got into the cooling system and then as you said reached the highest spot in the cooling system. Until I get the new sensor and gauge I won't know how much oil there is. I can pump it out as I have a very small pump (which is not a euphemism for anything!).

I am replacing it with an electrical one from Huke Basart in Holland as I said in the original post

[JP 1800]

The most probable source of the oil would be from the rocker cover gasket. A small leak would allow the oil to pool into the crevice between the bulb and nut giving the appearance of oil in the head. I would not worry about it. I find the easiest way to remove and install the bulb is to first remove the rocker cover, so you can change the gasket then if needed.

[Ron Kwas]

n;

Ok on the electrical replacement...I request you take lots of pix and notes...I expect this to be of interest to many, and would like to add your info (with permission and attribution) to SwEm site. Thanks!

Cheers

[niveketak]

Thanks JP hadn't thought of that and now I have looked there is a bit of a weep at the back of the rocker cover so that does make sense.

Ron I will take pictures where I can, as I said I chose to leave the dash binnacle in situ so have to lay on my back across the seats with my head in the passenger foot well to do it so pictures could be fun and if they are any use please feel free to use them.

[arcturus]

I have the same problem of needing to replace temp' gauge. No way I could do it with panel in situ. good luck. BTW did you have to send in the old gauge first?