VDO gauges advice needed

[aki]

good morning everybody!

I got my hands on three second hand VDO gauges: pyrometer (900C), oil pressure (100 PSI)and turbo (vacuum and boost 30 InHg to 15 PSI).

I did some research on the part numbers and think I got the VDO part numbers right:

pyro: 310.015.009
oil pressure: 350.010.003
turbo: 150.361

now, my problem is that here in sydney olympic instruments has apparently closed down and I dont know where I can get the sender units for those gauges. I wanted to go there in person to get the matching senders as it is very easy to get it wrong. I tried REPCO and supercheap auto, however, the contradictory information I got made me very suspicious.
now, is there a good shop in the sydney area where I can go?

from my own research I BELIEVE that the parts I need to connect the three gauges are:

1.) pyro
320.714 thermocoupler
240.039 loom (1m)
320.059 weld boss
what is actually a "weld boss"? do I really need it? the loom, again do I really need it? I want to put the thermocoupler into the EGR blanking plate. is there anything else I need to consider?

2.) oil pressure
360.086 (10-180 ohm)
I think there are some senders which give the pressure and the idiot light, too. or is that only true for temperature sensors?

3.) turbo
where can I get a T piece to connect a pressure hose to the waste gate acc.?
I would need some pipe, an olive and a nut, too, however, I dont know where to get 'em.

soo, have a nice sunday guys!

[rick130]

you can download the VDO catalogue from the VDO/Siemens Australia site. it lists all the senders, adapters, etc to go with all their guages.

I used to use Tru-Speed instruments in Sydney (Silverwater ??) for mods and repairs, but don't know if they are still in business.
I think Airco Instruments are also a major wholesaler. Maybe Google is your friend here.

As for a T piece (I'm assuming a 2/300tdi) what most of us do is drill and braze the fitting to the existing T piece.

[Bush65]

good morning everybody!

I got my hands on three second hand VDO gauges: pyrometer (900C), oil pressure (100 PSI)and turbo (vacuum and boost 30 InHg to 15 PSI).

I did some research on the part numbers and think I got the VDO part numbers right:

pyro: 310.015.009
oil pressure: 350.010.003
turbo: 150.361

now, my problem is that here in sydney olympic instruments has apparently closed down and I dont know where I can get the sender units for those gauges. I wanted to go there in person to get the matching senders as it is very easy to get it wrong. I tried REPCO and supercheap auto, however, the contradictory information I got made me very suspicious.
now, is there a good shop in the sydney area where I can go?

from my own research I BELIEVE that the parts I need to connect the three gauges are:

1.) pyro
320.714 thermocoupler
240.039 loom (1m)
320.059 weld boss
what is actually a "weld boss"? do I really need it? the loom, again do I really need it? I want to put the thermocoupler into the EGR blanking plate. is there anything else I need to consider?

2.) oil pressure
360.086 (10-180 ohm)
I think there are some senders which give the pressure and the idiot light, too. or is that only true for temperature sensors?

3.) turbo
where can I get a T piece to connect a pressure hose to the waste gate acc.?
I would need some pipe, an olive and a nut, too, however, I dont know where to get 'em.

soo, have a nice sunday guys!

Weld boss, will be a part that you weld to the exhaust manifold/pipe, with an internal thread to suit the fitting for the thermocouple.

In your case you would weld it to the egr blanking plate. The plate is not thick enough to gain enough threads for the fitting if you only tapped it. Most people weld a suitably sized pipe socket to the plate, which does the same as the weld boss.

Not sure if you need the loom. Thermocouples usually have a long enough tail and joining more wiring could affect the calibration - a thermocouple takes advantage of the phenomenon that a voltage, proportional to temperature, is induced at the join of 2 dissimilar metals, and joining wiring to the tail introduces another 2 joints between potentially different metals. I would think the loom is to supply power, but may do a little more.

What else to consider? Size of thermocouple. I guess most of us use 6mm diameter thermocouples, but 3mm diameter thermocouples respond more quickly to temperature changes.

As temps are rising as you climb a hill, the temp reading from a 6mm thermocouple will be reading less than the actual temp because of the time lag. The reading from a 3mm thermocouple will be more realistic.

But 6mm thermocouples are more durable. You wouldn't want fragments of a thermocouple passing through the turbine. And the sensible way to drive a hill is to keep an eye on how quickly the temps are rising and unless you are close to the top, grab a lower gear before the temps get too high (allowing for the lag of 6mm thermocouples).

You will probably need some fittings to plumb in the sensor for the oil pressure gauge, and you need to be careful with thread sizes. Some are bsp (parallel or tapered), npt and metric. Some sizes can be close but not the same with respect to diameter and thread pitch.

I tap a 1/8" bsp thread into the inlet manifold for the boost guage. If you measure boost pressure at the compressor outlet, it will be less than at the manifold, because of pressure drop across the piping and intercooler.

There is a plug at the rear of the inlet manifold that can be used (I'm assuming you have a 300Tdi). Not sure if it is 1/4" bsp or 12mm metric.

Use nylon tubing and suitable compression fittings instead of piping. The best fittings for nylon tubing have a metal tube that fits inside the nylon tubing, so the tubing doesn't collapse as the olive is crimped to it.

[rick130]

John, I just drilled and tapped my blanking plate, can't recall if it's 1/8 BSPF or 1/8 NPTF, but either way, they are a very fine thread and it works OK.
The VDO thermocouple is 1/8 NPTF, so IMO you could tap the blanking plate and not worry about the weld boss.
Mines been there for three or four years and probably 100,000km.

[discowhite]

I got my hands on three second hand VDO gauges: pyrometer (900C), oil pressure (100 PSI)and turbo (vacuum and boost 30 InHg to 15 PSI).

so the boost gauge is 15psi max?? if it is its abit short of the 16-17psi standard of a td5 and 300tdi?

cheers phil

[Bush65]

John, I just drilled and tapped my blanking plate, can't recall if it's 1/8 BSPF or 1/8 NPTF, but either way, they are a very fine thread and it works OK.
The VDO thermocouple is 1/8 NPTF, so IMO you could tap the blanking plate and not worry about the weld boss.
Mines been there for three or four years and probably 100,000km.

Thanks Rick. I was thinking about a response to the question. I didn't check how thick the plate was and relied on memory

[aki]

so the boost gauge is 15psi max?? if it is its abit short of the 16-17psi standard of a td5 and 300tdi?

cheers phil

hi Phil,
yep, you are right, and apart from that I wont need the vacuum, too. however, the three gauges came altogether.

btw, this afternoon I calibrated the gauge. I never looked into a turbo gauge before and it was quite interesting. my "calibration" seems to have worked, my gauge now compares to two tyre pressure gauges. when I first got it it did not indicated 0 but 20 InHg. right now my turbo gauge is going to 15 psi max, however, I can imagine that I can change its range, too.

all the best, cheers, axel

[loanrangie]

Autobarn can order VDO parts in, the VDO/ Siemens head office is about 10 mins from home and i drive past everyday.

[EchiDna]

http://www.sso.siemensvdo.com.au/fil...Commercial.pdf

this is the current catalogue (9mb in size for those on dialup)...

[Dougal]

The sender for the Pyro is a just a K type thermocouple, an industrial instrumentation place will have them for the best price.
My VDO Pyro (same description as yours) came with a 6mm probe which I found too slow to react. Do a hard acceleration run, back off and the needle keeps climbing from heat soak.

I replaced it with a 3mm K type probe and am much happier with the response time.