Slight engine trouble, advice please

Soldato
Joined
25 Dec 2008
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5,976
Location
Sheffield/Norwich
Car is a 2002 VW Golf 2.8L V6 4mo 24V (engine code BDE).

I was driving back home yesterday and had a sudden loss of power and it wouldn't let me rev over ~2,200rpm, so clearly in limp home mode. It threw an engine malfunction light and code P0322, Ignition/Distributor Engine Speed Input Circuit No Signal.
It did something similar once before a few days ago where it lost power and power steering and flashed up a check oil warning so obviously I cut the power pronto. Oil level and all fluids fine, started up again and went home no further problems (no limp mode) but again had P0322 logged.

So this evening I've been dismantling the car to access the engine speed sensor to do a crude test mentioned in my Bentley - checking the resistance between two of the (three) pins to/from the engine speed sensor. This is meant to be between 480-1000Ω. This returned around 800Ω. Then I thought maybe I should warm the car up since it seems that's when problems normally arise with these sensors, got it up to temperature but couldn't get it to reproduce the error :( and then got another reading, of between around 960-1200Ω (though if I had to guess I reckon the accurate reading would be lower rather than higher since due to engine heat I was having to use two long screwdrivers).

I've also located the actual sensor and it's a pig to get at. It's bolted in with a 6mm hex between the oil cooler/exchange and a brace holding something that looks important (don't know what it is, sorry) and the sump. Even with the car on stands and the front off I can barely get an allen key in, let alone undo (or tighten it up if I got it off, to 10Nm).

So a couple of issues really - am I likely to be barking up the wrong tree by going after the engine speed sensor - is there something I'm overlooking, or do my test results make it unlikely to be that? The other issue here is I can't find the right part anywhere and I don't have a part number (just a hundred sensors on eBay for every model under the sun except mine - including the one for the Automatic version of my car (though really I wouldn't have expected there to be a difference!)

So currently I've got a car in pieces and don't know where to go from here :(

Any advice/help appreciated; cheers.

Obligatory pic:
 
Will do, thanks. Yeah - tight is an understatement! Sometimes I wonder if that engine bay was meant to take a V6 :p
 
Intermittent failures of crank position sensors when they get hot is a common problem across many different makes of cars. The fact that it didn't show the fault after you dismantled part of the car to gain access does not mean the sensor is ok. For starters it's probably not getting anything like as hot as it would with the engine under load, bumpers in place etc.

The resistance of VR sensors (or any non-superconducting material!) will always increase as they get hotter as well.
 
if its like other vw engines with distributors there will be a crank/speed/hall sensor on the block and one in the dizzy too. ive had the one in the dizzy go bad when hot before . took some bloomin diagnosing that one did
 
Intermittent failures of crank position sensors when they get hot is a common problem across many different makes of cars. The fact that it didn't show the fault after you dismantled part of the car to gain access does not mean the sensor is ok. For starters it's probably not getting anything like as hot as it would with the engine under load, bumpers in place etc.

The resistance of VR sensors (or any non-superconducting material!) will always increase as they get hotter as well.

Yeah good point. I did it properly though, got the coolant up to 110°C before the radiator fan kicked in and kept it there for 5-10 mins with liberal revving :p

Cheers bud, I'm on my iPad. Sorry, tablet device.

np :)

if its like other vw engines with distributors there will be a crank/speed/hall sensor on the block and one in the dizzy too. ive had the one in the dizzy go bad when hot before . took some bloomin diagnosing that one did

No distributer :p

OK, really looks like I need to change the sensor then, main issue is access. This thing is buried, I struggle to even reach it with a finger let alone replace it.
 
So I thought to myself, this would be a lot easier if I just manned up.

So I used the right tools, and manned up, and 45mins later got the old sensor out (well I left it in a bit to stop crud getting in).
Just gotta go to the shop tomorrow to buy a new one and hopefully job's a good'un! Still got to attempt to get a torque wrench on the thing though, that's going to be a PITA and probably not that accurate since it's going through a 90° socket adapter thing :(
 
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