Club 80-90 Forums

Then when on the motorway it's possible to switch it on and adjust the potentiometer to raise the reported temperature to the ECU.

Exactly what I meant when I said about running open-loop cold... edited my post to take out the 'how about an in-line adjustable pot' bit even Great idea to fiddle tune or debug a recalcitrant installation

Regardless of the Tdi ecu frigging fuelling about, why would running or allowing engines to run so cold ever be a good idea, has always been one of the first lessons of i.c. engines not to run cold, for economy as well as lubrication and condensation reasons.

85 ~92 usually considered OK for economy and oil and engine life. Oil temps should be about 200 ~220 (approx 100C +/- 5) for a performance engine, bit lower for a roadie

The water thermostat opening temp (as marked) is not the temp engines will necessarily end up stabilising at of course.

Had a little drive in it today down a local fast bypass, temps do seem to stay in the 88-90 region so all good there. Also the 'rich' smell from the exhaust has totally gone, so that has to be a good sign.
On another related topic, as i mentioned earlier i fitted a new coolant temp sender as well part no 078919501B (new version drops the B) and found it sends the dash gauge off the scale (the sender is 4 pin and does the T3 dash gauge and gives a reading to the ecu, which i can read on the scangauge). I got an exchange today, and instead of sending it off the scale, it moved the needle 3/4 of the way across at cold, so not ideal! Put the old sender back in, this is much better but still not quite in sync (90 degrees being clear to the right of led) Now i could leave it like this, but i like things to be as they should.. i phoned Andy, who kindly answered the phone His engine is running at 90 degrees and his gauge needle sits on the led
Turns out he has a slightly different sender from a golf (mines passat) of a slightly earlier vintage with a yellow band on it. etka gave me a part number to search and i found one, part no 357919501A. I've ordered this sender (1/6th the price of mine at £4!) I'm hoping this sender may be more closely matched to the T3 gauge

if you dont have any luck , my mate makes these :

https://www.spiyda.com/magento/index.ph ... izard.html" onclick="window.open(this.href);return false;

we use them in our 16v mini conversions , as we have this problem all the time ( ie using the temp sender from the donor car does not match a mini one )

this just fixes it all.

Matt

or you can just use a resistor in parallel if the gauge is underreading, and a resistor in series if it's over reading...

i was chatting to Andy about this, and i did mention a resistor of some kind to bring the gauge down, are these senders linear in their resistances? or would that make no difference?
hopefully this sender will work though.

nice little bit of kit your mate does Matt

Hi Lloyd,

good point.

The plot of temperature against resistance is logarithmic - asymptotically reaching a lower limit of resistance as the heat increases. The gauges are intended to portray linearly wrt temperature. This means if you correct an over-reading scale by adding a resistor in series, the mid-temperature value won't be half way on the scale. Matt's friend's thing will do that correctly no doubt, but since there are no temp markings on the vw gauge it never bothered me!

If there were temperature markings then this would be bad as it would only be correct for a given value. This is why I only used my resistor in parallel thing once the engine had got up to temperature but was reading low - otherwise it's mess with the timing advance etc when cold.

Ewen

cheers for that, your describing roughly what i thought would happen. To be honest, in a week it wont bother me If this other sender does the same i'll move on and just have to get used to it. Will just have to make a mental note of the new 'normal position' or ignore it and use scangauge.
Might well get a water temp and oil temp gauge (just sold mine ) and fit them in the dash tidy it looks like i'm getting

A little over or a litle under the LED its only an uncalibrated gauge - don't spend a lot of time nor money on it... VW never intended that LED to be anything more than a LED and put it fairly central, I'm sure, without much implication on needle position. Just nice if it's central like most gauges at normal opconds

But I like this...

if you dont have any luck , my mate makes these :

https://www.spiyda.com/magento/index.ph ... izard.html

we use them in our 16v mini conversions , as we have this problem all the time ( ie using the temp sender from the donor car does not match a mini one )

this just fixes it all.

Looks a good bit of kit, there's some clever people & clever stuff about, nodoubtaboutit

Got some fuel consumption figures in l/100km over the last couple of years here Harry if they help your Wiki. This is for High Top Westy with a 1Z engine in it. Standard wheels/tyres and original DY gearbox from 1.6NA. Usual cruising speed about 90 to 100kph and 99% of driving is loaded for camping with two adults and a child and bike on back. There's a gap from July last year to June this year where the first engine died and had to be replaced and by coincidince the speedo cable snapped at the same time. I didn't get round to fixing the speedo until the MOT in early June so the data best looked at in two chunks as I have no idea of milage between these dates and probably missed recording a fill up. Lloyd - the figures from Oct last year are those from the engine out of that Blue Golf you sold me. Been reading about your adventures with your new engine - well done for sorting everything. The swap I did from a ready converted installation was a cinch in comparison.

Seems the average consumption is in the mid 30's in mpg so I was quite happy with that. Have nothing to check on engine temps but the readings from a couple of weeks ago were from driving in daytime temps of over 30 degrees and the consumption seemed nice and low those days. My temp gauge usually sits well to the left of the led but does climb sometimes on the motorways and big hills so I'm tempted to get the higher opening temp stat to see if I can get the engine temp up a bit.


25 Jul 2010 411071 614 39.99 11.9462540716612 part fill Purley
8 Aug 2010 411549 478 44.33 9.27405857740586 brim Aberystwyth
23 Aug 2010 412022 473 42.77 9.04228329809725 brim Sevenoaks
30 Aug 2010 412520 498 40.00 8.03212851405623 part fill Minehead
5 Sep 2010 413072 552 45.21 8.19021739130435 brim Mottingham
19 Sep 2010 413556 484 36.87 7.61776859504132 part fill Ipswich
7 Nov 2010 414004 448 40.44 9.02678571428571 part fill Mottingham
10 Apr 2011 414403 399 29.01 7.27067669172932 part fill Biggleswade
22 Apr 2011 414751 348 40 11.4942528735632 part fill Colney Hatch
25 Apr 2011 415197 446 45.07 10.1053811659193 part fill Totton
30 Apr 2011 415614 417 44.65 10.7074340527578 part fill Stafford
4 May 2011 416204 590 53.02 8.9864406779661 brim Stoke
19 Jun 2011 25 part fill Ashsted
23 Jun 2011 417103 54.29 8.81979977753059 brim Dieppe
29 Jun 2011 417726 623 52.34 8.40128410914928 brim Caen
2 Jul 2011 418243 517 43.8 8.47195357833656 brim jumieges
2 Jul 2011 418517 274 24.01 8.76277372262774 brim Calais
30 Oct 2011 -418517 19.22 -0.00459240604324317 part fill Enfield
1 Apr 2012 0 29.54 0
10 Jun 2012 419361 20.43 0 part fill Tottenham
16 Jun 2012 419585 224 56.19 34.2053571428571 brim Boulogne
20 Jun 2012 420187 602 51.87 8.61627906976744 brim Epinal
27 Jun 2012 420830 643 54.34 8.45101088646967 brim Capellen
28 Jun 2012 421331 501 41.05 8.1936127744511 brim Ardres
15 Jul 2012 421933 602 52.35 8.69601328903654 brim Maidstone
18 Aug 2012 422633 700 12.58 part fill Maidstone
18 Aug 2012 422703 70 47.37 7.78571428571428 brim Ardres
26 Aug 2012 423279 576 43.78 7.60069444444444 brim Hoogblokland
26 Aug 2012 423604 325 29.25 9 brim Calais

pirate-pete wrote: Lloyd - the figures from Oct last year are those from the engine out of that Blue Golf you sold me. Been reading about your adventures with your new engine - well done for sorting everything. The swap I did from a ready converted installation was a cinch in comparison.

Glad to hear it's running well. Could have been a lot less painful for me if i had kept that golf a little longer
Your gauge position seems similar to jeds, i suppose really its hard to tell if you are running that cool or the coolant sender is not matched to the gauge, i would guess you are running cool. Good figures there too, but you being 2WD probably helps that a lot too. The part number for the correct stat is 044121113 £17 from a VW dealer, you can get it cheaper for a copy part, but not worth it really. Takes no time at all to fit as well.

Thanks Lloyd. Just checked the stat from the box of spares I saved from the old engine and that has the same part no as you quoted. These are 87 deg stats.

Rather than fit another of these I was thinking of finding a 92 deg one as I often used to step up to these in cars to get better heater output. The temp gauge shows the same position on the gauge with the old engine as it does now so it is possible that the gauge is mismatched slightly to the TDI engine temp sender. On the other hand, I don't often hear my radiator fan kick in so am thinking engine is running on the cool side. I drove for a while last year with a faulty radiator switch so used to manually switch fan if in traffic jams and the temp gauge started climbing. Because of this I reckon I would be able to hear the fan on the high setting should the 92 deg stat be too high.

Also have the temp sender from the first engine and it is the same as the one with the yellow band you have just ordered. Part 357 919 501A marked 140 max and 40-94 which I first thought would be its range. If so 40 degree would be where the needle starts to move and 94 degree when on max. Would have thought 94 degree a bit too low for a max reading though. I'll be interested in hearing where your gauge ends up when you get it before I decide whether to swap to a higher temp stat.

There is a bit of reading here
http://forums.tdiclub.com/showthread.ph ... +high+temp" onclick="window.open(this.href);return false;
On thermostats if it's of interest?

I changed my stat today, scan gauge was saying 75 degrees with the old one - now I sit at 88. The other thing with the engine at 88 degrees, the vw gauge now sits over the led, where as with the old stat it was about half way between cold and the LED. I will be interested in seeing if there is any difference in fuel consumption now.

Fuel consumption wise I have ran 2 tanks with new engine (AFN) both tanks have returned 6.8L/100km.

My averages have been between 10-12LHK up to now, but my van is very heavy, undergeared to a certain extent and is normally packed to the gills for camping. My LED and needle line up at about 83, but as said I run at 90 now. Be interesting to hear what differences if any you find, I'll be taking my van away for the next two weekends, so should be able to report back then

Mines a 2wd westy, the fuel consumption measured at the moment were over a holiday, so 4 up (2 adults 2 under 5s) all the camping stuff and 4 bikes.

I am also on the original JX gearbox, I am in communication with Aidan about getting this sorted out.