Oil temperature sender - Early 1.6 TD (JX)

[nicola.gemo]

Hello.
I am about to fit a VDO oil temperature gauge to my Westfalia (reason is that I got some issues with boost pressure and I would like to monitor the oil temperature.. plus I like old style gauges ). My engine is an early (1984) 1.6 TD JX. Now, I got a little bit of a problem with the sender.

I am told that normally you can fit a sender in the oil pan just by replacing the oil drain plug with the proper sender. However, the drain plug in my oil pan is actually a valve; here it is: http://www.vwbusshop.de/epages/GuenzlCl ... ID=7891214" onclick="window.open(this.href);return false;
Since the sealing is done by the conical head and not by the thread, I think I can't simply put a sender there. Is that correct?

Alternatively, I thought about a VDO Dipstick Oil Temperature Sender, but I see they are made for Aircooled engines, not diesel. So, not sure this can fit (anybody tried this out?).
Another option I considered is a sandwich plate on the oil filter (this would give more than one port). However, the JX engine has an oil cooler for water circulation just under the filter, which doesn't leave much space to move the filter around; I am concerned that an additional plate could cause troubles when changing the oil filter.
Of course, I could drill a hole in the oil sump and weld a nut to screw in a sender, but if possible I'd prefer a more direct and simple install.

Now then, anybody fitted an oil temperature sender to this kind of engine? Any suggestions where to fit it?

Thanks folks

[muttleypup]

Not sure if this would work, but can you fit a simple t-piece where the current oil pressure switch is? this will give you the extra 'port' that you need for a temperature switch without moving the filter, at minimal cost/work.

something like this https://www.vwheritage.com/shop/V240850 ... AtdG8P8HAQ" onclick="window.open(this.href);return false;

[quattrodave]

Not sure what thread sizes you've got but how about this 'T' piece screwed into the oil pressure sender on top of the filter housing ?
https://www.vwheritage.com/shop/V240850 ... Gwod84oKSQ" onclick="window.open(this.href);return false;

[quattrodave]

Ha Ha great minds think alike !

[muttleypup]

Ha Ha great minds think alike !

not sure mine is a great mind but it is a simple one!

[nicola.gemo]

Thanks to both of you for the helpful replies.

I do not have an oil pressure switch at the oil filter. In fact, I only had an oil pressure switch in the engine head (no buzzer for oil pressure). Couples of years ago I substituted this switch with an oil pressure sender, this one:
http://vw-t3-bus-shop.de/en/vdo-oil-pre ... ng-flasher" onclick="window.open(this.href);return false;

Do you know if the thread of the t-piece is the same of the oil pressure sender/switch? Would it be the case, I could fit the t-piece in the engine head and get two ports there!

My only concern is about oil flow: the temperature sender would not be in the oil stream, but rather in a hole where oil would not directly flow. Do you think it will anyway get the correct temperature reading?

[muttleypup]

You probably have a point regarding the sensor not being in the oil flow. The sump seems the obvious place in this case. To avoid drilling, which would mean dropping the sump and also creating another point for oil to leak! what about removing the existing drain plug and replace with a threaded reducing bush? (M16 outer thread i think to match the sump and then internal to match whatever the temp sender is). This could be welded in place if sealing on the sump is an issue and then the sender screwed into this, which will seal the same as anywhere else you locate it.

This sort of thing http://www.ebay.co.uk/itm/M12x1-5-Femal ... SwJcZWcxCT" onclick="window.open(this.href);return false;

That's the best my simple mind can come up with

[marlinowner]

According to ekta there is an M10x1 sealing plug on top of the oil filter housing, maybe that could be replaced with the oil temp sender. I wouldn't be too keen on fitting it via a tee piece for the same reasons as above.

[nicola.gemo]

what about removing the existing drain plug and replace with a threaded reducing bush?

Yeah, this is a actually good option. I think the sealing in my drain plug is done via the conical shape of its head, rather than the thread. However, probably not a big deal moving the sealing to the thread. As you said, I could even weld in the adapter, if needed.

[nicola.gemo]

According to ekta there is an M10x1 sealing plug on top of the oil filter housing

Thanks for the info.
I am not sure I have this sealing (I found several differences in my JX compared to late models, the oil pressure buzzer for instance). I will check it out because if there is one, than I think it could be straight forward to put a sender there!

[nicola.gemo]

Just an update, if anybody else has a similar problem.

I found out there are two kind of oil filter fitting the JX engine: W940/25 e W 1130/1. On my engine I have the former. The latter is shorter (and has a little larger diameter); so with this filter a sandwich plate can be fitted and still have room to accomodate the filter. This I am told is the solution when adding an oil cooler via a sandwich plate.

Which brings me to another question: has anybody installed an oil cooler in a standard JX engine? Does it help?

[RogerT]

Going back to the idea of a T piece and locating your temp sender on it, vs doing difficult things to your drain plug. My question would be... Are you looking for an accurate absolute reading of the oil temp, or are you looking to know when the oil temp is going up and down?

If you are looking for an accurate reading of the oil temp, how will you know when you've achieved this?

If you are looking for an indication of how the oil temp goes up and down, my bet is that the t piece will work fine, and it will be so much easier than doing stuff to your drain plug. The sender might be out of the flow a little, but the distances are just a couple of cm at most, and it shouldnt have any affect on the temp it measures - any effect it does have will be constant, and so your measurements will not necessarily be absolute but will be correct relative to each other. In addition, your pressure reading will not be adversely affected, as it is a fluid, so pressures will be constant?

Happy to be contradicted, as always. I'm here to learn too!

[nicola.gemo]

Going back to the idea of a T piece and locating your temp sender on it, vs doing difficult things to your drain plug. My question would be... Are you looking for an accurate absolute reading of the oil temp, or are you looking to know when the oil temp is going up and down?

If you are looking for an accurate reading of the oil temp, how will you know when you've achieved this?

If you are looking for an indication of how the oil temp goes up and down, my bet is that the t piece will work fine, and it will be so much easier than doing stuff to your drain plug. The sender might be out of the flow a little, but the distances are just a couple of cm at most, and it shouldnt have any affect on the temp it measures - any effect it does have will be constant, and so your measurements will not necessarily be absolute but will be correct relative to each other. In addition, your pressure reading will not be adversely affected, as it is a fluid, so pressures will be constant?

Happy to be contradicted, as always. I'm here to learn too!

Yes, a T-piece could do the job fine. It would probably be a little less responsive to temperature changes, but one could live that.

Regarding the temperature/pressure relation, not sure I got what you mean.. However,generally speaking, oil is a liquid, but its properties are affected by the temperature. I think the point is viscosity: the hotter the oil the lower its viscosity, the lower the viscosity the lower the pressure the pump can achieve (at constant rev). Infact, with a cold engine you can expect oil pressure up to 4- 4.5 bar at idle, but when the oil reaches 80 C you should read around 1.1 bar at 2000 rpm (that is for the JX). So, if when pushing your engine you see the oil pressure dropping, it might means the oil is getting too hot..

[RogerT]

Hmmm, beyond my level of competance I think...

[MGP]

The easiest way to fit the temperature sensor would be to go to your local hydraulic specialist, ask them to make you a new turbo oil feed hose with a fitting in it to take the sensor, ask them to make it in the ptfe pipe with the stainless over braid so that the hose is earthed.

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