2.7tdv6 engine

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I have no idea, but would hazard a guess its to do with power draw.
I know you can do compression test on modern trucks using just the diag computer, again I am assuming along the same lines as oscilloscope.
It is probably along the lines of it is seeing if they all have the same power draw.

yes.

From the starter motor I presume if that is the case, sounds a pretty unreliable method to me.

why? Was a main function on Bosch test equip.

I agree, too many possible variables to rely on load variation to compute compression pressures, I guess it would show no compression though.

As above.


I've never heard of it either, as I say, it might be OK as an all or nothing test for a broken crank, but I don't see it being possible to compute actual pressures from current variation, too many things could affect the readings from a weak battery to dodgy connections.

As above.

I think it is more of a comparitive test between cylinders, ie they are all pretty much the same so the problem is elsewhere.


With the diag laptop you can shut down individual cylinders whilst the truck is running, again I would assume for comparison purposes, ie shut down one cylinder and the others have to up their game to keep the thing running, the computer works out how much extra effort they are taking.

You can do some proper clever stuff these days, and we only really scratch the surface.

Yes.

J
 
Here u go , also made sure it was from a reliable source as in a professional mechanical as indeed I was also taken back



assume doing an actual compression test would be more accurate , was just saying because the engine wasn’t starting if it may be an easier and cheaper way to at least give an indication if the crank has snapped and OP was taking to a garage where they would have the equipment

Was just an idea and of course know I don’t have anywhere the knowledge u guys have , been spending a lot of time trying to understand oscilloscopes and thought it may be an easier test
 
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Here u go , also made sure it was from a reliable source as in a professional mechanical as indeed I was also taken back



assume doing an actual compression test would be more accurate , was just saying because the engine wasn’t starting if it may be an easier and cheaper way to at least give an indication if the crank has snapped and OP was taking to a garage where they would have the equipment

Was just an idea and of course know I don’t have anywhere the knowledge u guys have , been spending a lot of time trying to understand oscilloscopes and thought it may be an easier test


What engine was that on Gary?
I ask as it only appears to have 5 peaks.

Edit should have watched the video first!
 
What engine was that on Gary?
I ask as it only appears to have 5 peaks.

Edit should have watched the video first!


Hi mate

u know , I don’t think he mentioned it, think he was just doing a comparative test between the cyls

here’s another one , 4 x cyl engine

 
This one shows how to get the Psi

@lynall , are we going to have a play at work, lol



Bound to have the laptop on some truck this week, will see what options there are.
Sadly it is a Texa, and they are pretty wnak, ie ebs fault check sensor/wiring then replace ecu, and whilst that is acutally true it doens not pinpoint it accurately enough so you spend ages chasing your arse which takes time and time is money, the genuine Daf computer called Davie will tell you eaxctly which sensor, which wire number and what is wrong wth that wire ie o/c or s/c. sensor pulse wheel runout/missing/damaged teeth.
It is as vague as that on pretty much everything, after treatment faults can be fun and very time consuming to try and fix, I can gaurantee we waste thousands each year on parts from not having the correct diag kit.
 
Hi mate

u know , I don’t think he mentioned it, think he was just doing a comparative test between the cyls

here’s another one , 4 x cyl engine




He is a bit wrong there, he said engines have their no1 cyl timing belt end, and I think its some of the french cars which have it the other way around?
 
Bound to have the laptop on some truck this week, will see what options there are.
Sadly it is a Texa, and they are pretty wnak, ie ebs fault check sensor/wiring then replace ecu, and whilst that is acutally true it doens not pinpoint it accurately enough so you spend ages chasing your arse which takes time and time is money, the genuine Daf computer called Davie will tell you eaxctly which sensor, which wire number and what is wrong wth that wire ie o/c or s/c. sensor pulse wheel runout/missing/damaged teeth.
It is as vague as that on pretty much everything, after treatment faults can be fun and very time consuming to try and fix, I can gaurantee we waste thousands each year on parts from not having the correct diag kit.

hi mate

blimey sounds like boiler and heating systems , always found having decent equipment helped tremendously with faults where they were able to detail more within the system

suppose like the gap iid

My way of thinking , can easily test the High and low canbus , with a multimeter to see if it has the correct ohms , however if it doesn’t have the correct ohms the multimeter I’ve seen the breaker boxes or indeed the oscilloscope

that’s why I’ve been spending a lot of time and a half decent one with using ur laptop can be bought for around £120
That’s a 8 x channel one made by Hantek so don’t have to spend £1,000s which I assume in ur shop the diagnostics have price tags that are eye watering

Saw a good video the other day using an oscilloscope of fault finding a height sensor on a Range Rover

plus also thought it would be an interesting subject
 
He is a bit wrong there, he said engines have their no1 cyl timing belt end, and I think its some of the french cars which have it the other way around?

that’s the thing , with ur expertise u would know mate and thks for the heads up as every day is a school day

also see in the video it shows that they can tell ref timing belts , enclosed a screen shot of the comments

Know I wouldn’t ever get to ur level , but hopefully may get a better understanding of using an oscilloscope and how it can help with fault finding

444F0213-986B-4171-B927-FEB95CCB6F68.png
 
that’s the thing , with ur expertise u would know mate and thks for the heads up as every day is a school day

also see in the video it shows that they can tell ref timing belts , enclosed a screen shot of the comments

Know I wouldn’t ever get to ur level , but hopefully may get a better understanding of using an oscilloscope and how it can help with fault finding

View attachment 209347

Im no expert, trucks are way easier than cars, cars a nightmare, you wont find many hgv mechs doing private work at the weekends, mention working on a car, and the majority of them will start walking backwards!
 
Im no expert, trucks are way easier than cars, cars a nightmare, you wont find many hgv mechs doing private work at the weekends, mention working on a car, and the majority of them will start walking backwards!

Plse don’t count urself short my friend , know ur extremely knowledgeable and some things u have said in replies have gone well over my head

At least u have more room in a HGV vs a D3 , lol
 
hi mate

blimey sounds like boiler and heating systems , always found having decent equipment helped tremendously with faults where they were able to detail more within the system

suppose like the gap iid

My way of thinking , can easily test the High and low canbus , with a multimeter to see if it has the correct ohms , however if it doesn’t have the correct ohms the multimeter I’ve seen the breaker boxes or indeed the oscilloscope

that’s why I’ve been spending a lot of time and a half decent one with using ur laptop can be bought for around £120
That’s a 8 x channel one made by Hantek so don’t have to spend £1,000s which I assume in ur shop the diagnostics have price tags that are eye watering

Saw a good video the other day using an oscilloscope of fault finding a height sensor on a Range Rover

plus also thought it would be an interesting subject


I check can hi/lo all the time, dead simple dont use ohms, simply use volts.
For example nox sensors on scr system, code reader says nox heating circuit dead, most nox ecus will normally have 4 wires, 1 power, 1 earth and 2 can, so to check get multimeter check power and earth (make sure use the earth wire in the plug and not the chassis/battery) so long as voltage is battery voltage that side is good, then measure can hi/lo again using the same earth wire, actual voltage not that important so long as close to each other it will do ie 2.4 and 2.3 volts is good enough.
If all volts check out the nox sensor and its ecu (1 unit) are toast.
But you have to be cute becasue if the fault says out of range/parameters it could mean what it is seeing is indeed correct and there is an issue with the adblue injector not injecting adblue or injececting to much/leaking and messing up what the nox sensor is seeing.
 
Plse don’t count urself short my friend , know ur extremely knowledgeable and some things u have said in replies have gone well over my head

At least u have more room in a HGV vs a D3 , lol

They are getting real bad for access, old euro 5 engine manifold gaskets set of 6, battery gun 30/45 minutes done, euro 6 engine 8 hours!
 
They are getting real bad for access, old euro 5 engine manifold gaskets set of 6, battery gun 30/45 minutes done, euro 6 engine 8 hours!

bloody hell, that sounds a right amount of fun, not

also worse I assume because the parts are a lot heavier
 
I check can hi/lo all the time, dead simple dont use ohms, simply use volts.
For example nox sensors on scr system, code reader says nox heating circuit dead, most nox ecus will normally have 4 wires, 1 power, 1 earth and 2 can, so to check get multimeter check power and earth (make sure use the earth wire in the plug and not the chassis/battery) so long as voltage is battery voltage that side is good, then measure can hi/lo again using the same earth wire, actual voltage not that important so long as close to each other it will do ie 2.4 and 2.3 volts is good enough.
If all volts check out the nox sensor and its ecu (1 unit) are toast.
But you have to be cute becasue if the fault says out of range/parameters it could mean what it is seeing is indeed correct and there is an issue with the adblue injector not injecting adblue or injececting to much/leaking and messing up what the nox sensor is seeing.

thks mate , alas I’m at a considerable lower skill level , So assume is that like testing both sides of the sensor

apologises as most of that went over my head, lol
 
thks mate , alas I’m at a considerable lower skill level , So assume is that like testing both sides of the sensor

apologises as most of that went over my head, lol


Nah it really is dead simple, if I physically showed you it would take 2 mins, then you would know as much as me!
 
bloody hell, that sounds a right amount of fun, not

also worse I assume because the parts are a lot heavier

Only hubs and calipers, rest is on trolley of one sort or another.
They actually have trolley for the calliepr sand hubs, but they take to long to use.
 
Nah it really is dead simple, if I physically showed you it would take 2 mins, then you would know as much as me!

funny enough have always understood things easier when showed instead of nodding off in the classroom, lol
 
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