Heat and efficiency ...

[Mudlark]

Just got back from Croatia last Sunday; 4220 trouble free Kms compared to last years excitement. Official MPG was 28.03 which is about 3mpg better than I have ever got before and Im wondering why.

Im also wondering why on the guage the van is also running hotter than it used to; there may be reasons for that which i will go into....but on the way down we went over Gottard in the Alps and the temp guage went all the way up to 100%; full fan and the red flashing coolant light going. I stopped and checked the obvious and all was well; I have done 3500 Kms since with most of the driving in the hotter climes being done with the guage on 80% and the low fan running. On a number of occasions we got up to 100% on the guage with fan and flashing lights.

Did a similar trip last year and I have never had the fan running on full or the guage at 100% so something has changed.

So I have an over 10% improvement in MPG and a van that is running hot. Its not losing coolant; topped up at Gottard and never needed any more the whole trip. I have a leaky rocker cover gasket so there is a fair bit of oil up the back of the van, I got through two liters of regular little top ups along the way; but im not doing a Clive and blowing smoke out the back.

I am though down on power but dont think thats connected; was discussing that with folk at Syncropendence; seems to be a turbo boost problem that is mostly evident in 4th on hills and my guess at the moment is a sticky/stuck EGR valve.

The following were replaced just before the trip:

Exhaust Silencer, K&N Filter, Water Coolant Temp Sensor, Oil Cooler water pump (AFN Engine).

Mechanic replenished and bled the coolant; used VW pink additive and Im hoping he knows how to mix it and in what ratio. I have not had to break into the coolant system for a long time, but what was in there was not pink and i have been guilty of just topping her up with water Im afraid.

So the following scenarios occur to me:

The MPG could just be the new air filter and silencer ? If so what a bonus!

The extra heat could be:

Too much coolant additive?
Thought that the coolant temp sensor may be the wrong one (AFN engine/JX Van) but while that might change the needle position on the clock if they ( AFN/JX sensors) are different but it would not trigger the high speed fan as thats done from the radiator.
Discounted the oil cooler water pump unless some how its working in reverse and taking heat from the oil side into the coolant side, but i cant see how.

Anyhow; just looking for any insights the wizzards out there might have.

Have decided to start by draining the coolant and refilling with a known proper mix and seeing what temp sensor was fitted.

As the sensor feeds into the ECU I would expect i would need to fit the original AFN one and not the JX; but does anyone know if they are different?

[Aidan]

usually sensor for the guage and sensor for the ecu are seperate things
guage could be erroneous reading caused by earthing of the signal wire which needs continuity checking but if really that hot I'd replace the water pump and do a complete system flush and reverse flush the rad

[syncrosimon]

I have just changed my coolant, and before the change the temp would go up when flat out, about two needles width past the red light. After the coolant change it just stays rock steady. I was using G12+ and think that as I was topping up with neat coolant that the persistent leak caused a gradually increase in the strength of the coolant till there was not enough water to take the heat away.
Years ago on the DG Syncro I had an electrical short from the battery box lid(too tall battery). When it shorted out the temp went up very fast, and the red light blinked....till the short went away.

Sounds a great trip, any photo's??

[keeno]

Do you have an intercooler? An afn engine will pull one Bar of boost (14.7 psi) under full load. One Bar of boost will cause a rise in intake temp by around 90 degrees celcius. A one degree intake temp rise causes a one degree rise in exhaust temp. It is linear. If you are not getting rid of that extra heat, the rest of the engine will have to absorb it, ultimately via the cooling system. A lack of intercooler will show itself mostly only on long runs when the heatsoak is most prevalent. Also, mpg will suffer greatly on a 1z of afn motor to the tune of about 10 % due to the loss of thermal efficiency caused by the reduction in charge density through heat expanded air.

28 mpg on a run for an AFN motor is really poor, even heavily loaded. You definitely have some efficiency issues there. If I absolutely nailed my Doka with a 1Z around town, I would get that kind of MPG. On a run, 33-35 genuine, sat nav verified MPG was the norm. Even higher if I took is easy. Are you MTDI or ECU controlled?

[Mudlark]

Keeno; yes there is a charge cooler. Its ECU tdi. The conversion was done by Bernd Jeagar many moons ago. The last owner went all round the americas in this van and said that in his experience 25mpg was typical. The van is about 3600 Kg when loaded for a trip; lots of heavy bits like winch, bullbar etc and it was running the airco for most of the trip.

I have always thought the van should be capable of better MPG but never delved too far; to be honest i was chuffed with 28MPG as opposed to the 25 i have been getting; but I would love to get 30+ !

So I guess you think I am on the right track for starters with the coolant and sensor?

As an aside; would a sticking EGR valve on the turbo cause any heat issues? Most of the problems at the high temperature end were on long climbs, the Bremmer pass in Austria was a lot of fun; these climbs had me dropping down to third fairly quickly, I could get the speed in third back up to 80kph@3000rpm which I could hold; but if i moved up to fourth the thing would just die; there seemed to be no boost at all. All the time i was watching the temp guage rising which is hardly surprising given the outside temp; but my usual experience would be that i can move up to fourth at 80kph; hear the turbo spin up and accelerate up to 90-100kph+ without difficulty.

Remember though that my temp guage has always been a smidge above the LED without fail. Since the work it is now at about 60% without fail. The temp comes up a lot quicker than it used to but i put that down to the water pump on the oil cooler which is now working.

Aiden; looking on ETKA i could only see one coolant temp sensor on the AFN ?? But it has a four wire connector so could be doing both? The JX sensor quotes 0-125 degrees C; not quoted on the AFN but imagine it would be the same range but perhaps a different resistance; depends whether it has to work in line with whatever the dash pods are calibrated to ? Easy fix is to swap them out and see if it makes a difference.

Simon: Over 1200 pictures all in all ; I have plotted the whole route in .kmz format to load in Google earth so will put something up for those interested when i get a bit of time. We had some great drives cross country.

[..lee..]

cant help much as my afn conversion is sat on the garage floor gathering dust. egr valves are evil in my opinion, just had a horrible experiance with my delica`s egr and i`ve now bypassed it, it runs much smoother and better mpg " although is still terrible on fuel "

can you rig up a boost guage to check boost in 4th. you will loose power if egr is playing up too.

lee.

[keeno]

A sticky EGR will cause mucho problems, both with heat and lack of boost! The best thing you can every do on a diesel is blank off the EGR at the inlet manifold side. Exhaust gas recirculation is, in my humble opinion, a complete waste of time. All it does is clog your inlet manifold with carbon, cause a massive amount of heat into the inlet manifold (engine) and reduce efficiency. When the pen-pushers in Greensville thought this one up, they did not factor in the inefficiency a semi-clogged inlet manifold and heat spike would cause. Bin it! You do not need it for emissions test etc.

Every diesel I have owned I have blocked off the EGR where it enters the inlet manifold. A simple plate made from 1.5 mm aluminium is all that you need. It takes a few minutes to make and install. You will notice the difference on MPG and heat immediately!

You could bin you catalytic converter as well, as you don't need this for the emissions test either. Removing the cat will increase response and net a slight gain in MPG. It also reduces back pressure, therefore engine temps. I gained 5 bhp on the rolling road with my 1Z by removing the cat. A 6% increase in efficiency on an otherwise stock engine...

Ah, the laws of physics...

[HarryMann]

28 mpg on a run for an AFN motor is really poor, even heavily loaded.

I don't think so, not a big 16" Westy Syncro with all the trimmings, All Terrain tyres etc... I was even thinking of asking Mark if he'd 'fotgotten' a fuel fillup in his numbers

SyncroAnd101: Expedition Camper (Syncros) over approx. 5,000 miles from GBto Southern Morocco and back, off-road, sand, snow, rocky roads part way, part high altitide (Atlas Mountains)

1.9 mTdi, off-road tyres, high-top, fully loaded, roof rack etc. + 2 people == 30.93 mpg.

That I believe was cruising somewhat slower than Mark would be, and Jake has said that the figures are not 100% recorded and thus verifiable, but it gives a guide, and the other two on that trip were not a busting way away from that (+/- a bit I believe). All mTdi's not ECU controlled. All intercooled.All heavily loaded.

So I'd say 30mpg for such a beast is as good as it gets over long distances, in fact very good. I'd accept that modern econo road-tyres would improve things to the extent it could be measured (an mpg or two)

[keeno]

Ah, MTDi. Yes, they will be less efficient than the ECU controlled AFN stock system. Not sure on this manual pump business as it kind of defeats the object for me. The wiring involved (for ECU) is not as daunting as most people think. Nigel Allen did my ECU wiring on my 1Z with immobiliser and he has done many other T25s including PD motors with their even more complicated wiring. The cost of wiring for full ECU is less than the cost of an MTDi pump, so it was a no-brainer for me!

[HarryMann]

The wiring involved (for ECU) is not as daunting as most people think.

Yes, but I think the reason a lot of Syncros are done that way, is so when used as expedition vehicles they don't have to take a spare ECU (though ironically, a spare pump is not uknown )

I'll ask Doug what his long distance mpg figures come out like, as that's a lightish Syncro Doka with ECU/PD, plenty of intercooling and high gearing. I think he's talked of 30-35 mpg, depending on usage.

[syncroand101]

Just as a comparison, I have done Cornwall and back and North Wales and back in the last month - fairly well loaded, not to the hilt, all with Mud Terrains and roofrack+kayak etc, Did the fill, then refill at destination noting mileage, things have got better with the longer 3rd and 4th. Was about 34 mpg, driving about 65mph most times.

With chargecooler and oil cooler. Boost is about 0.5 (JX turbo). Temp hardly budges most times, unless on a long steep climb..

[HarryMann]

Good result (Mark's looking )
Keep the figures going Jake? We need some proper long term 'continuous' recordings... that give a true overall picture without gaps.. to compare to the TD ones we have plotted

Odo Litres
Odo Litres(Brim)
Odo Litres(Brim)
Odo Litres
Odo Litres(Brim)
etc..

Been begging for some good long-term records for years

Please please anyone who's done it like this...

[keeno]

My 1Z TDI Figures. These are all local driving, no motorway. Only very occasional dual carriageway driving. The trip mileage is the 'corrected' mileage from sat nav as my Doka is a 14 incher with 16 wheels with 205-80-16 Muds. I no longer have this truck, so these are the old figures still saved on my I-phone app. Boring, but thorough...

19 April 2010. 39,327 miles (167.6 mile trip) 30.7 mpg £1.209/L 24.81 Liters used £30 spent

7 April 2010 39,176 miles (193.1 mile trip) 34.8 mpg £1.189/l 25.23 litres used £30

16 March 2010 39,002 miles (203.1 trip) 35.34 mpg £1.149/l 26.13 liters used £30.02

9 March 2010 38,819 miles (168.7 mile trip) 29.13 mpg £1.139/l 26.34 liters used £30

27 Feb 2010 38,667 miles (144.3 mile trip) 24.46 mpg £1.119/l 26.82 liters used £30.01

15 Feb 2020 38,537 miles (204.24 mile trip) 34.94 mpg £1.129/l 26.57 liters used £30.00

27 Jan 2010 38,353 miles (168.7 mile trip) 29.1 mpg £1.139/l 26.35 liters used £30.01

[Mudlark]

Thanks for the input ....

I have started using Road Trip for the iphone since May and am plotting every fill. I brimmed the tank on the way back through Luxembourg as Diesel there was 86p per liter. I have 28.03 Mpg overall since May. For the Croatia trip standalone I have 28.44 up to Luxembourg, i need to brim again here at home to get the final verdict.

There does not seem a lot you cannot do on an iphone or Android these days. Since upgrading to the latest Apple software i can multitask Memory map, Tom Tom, and a couple of other useful apps and switch between them at will; record my fill-ups, take (not good quality) pictures through the screen and text, surf, email and phone; all from one device. It has de-cluttered my dash a little and proved its worth since I took it on. I switched roaming off while abroad so lost some functionality but used wi-fi where i could find it when needed. I grant you it is a small screen though.

In Luxembourg there were very long queues at every filling point and more HGV's than I could count all waiting to get at the fuel pumps. When I got to the pumps and looked at the price the penny dropped; I was only sorry my tank was still just under half full. Duty in luxembourg seems to be very low all round as in the service station shop they were selling rolling tobacco by the keg along with other 'duty free' items. You start to understand what British HGV drivers are up against with this fuel pricing. Anyway I digress.

I will let you know how we get on.

[..lee..]

i`ve found pretty big differances in fuel consumption in relation to speed trying to hold a constant 70 /75 i`m down to 20mpg but if i run at 65 and let her slow on the hills i`m up to 25 ish. ( 2.1 petrol mind )

i recon pushing the extra air makes a big differance.

lee.