I cleaned my boost sensor last weekend, as described here...

http://www.vectra-c.com/forum/showthread.php?t=88845

It's a doddle of a job. I cleaned it using carb cleaner and an old toothbrush. It took just a few minutes, and it's transformed the car. Mine was muckier than the one shown in the guide - it was a shapeless blob of black goo. The sensor itself is inside the little cage and is actually yellow after cleaning.

Whatever this thing does, it certainly does it better now.

The engine suddenly has "zing", especially at low revs. It makes the car feel lighter and smaller, if that makes sense.

It did take a few turns of the engine to start afterwards, so nothing to panic about. Fine ever since.

I used a torx bit and mole grips to slacken/tighten the bolt, due to the nearby hose preventing access with a screwdriver. It will just spin with the fingers after a first half-turn.

This will certainly be an annual maintenance job from now on.

Presumably the muck results from the EGR.

Thanks Doofer

Added to my list :- )

I took mine out and cleaned it this afternoon.

The sensor itself was easy enough to remove (and full of black gunk) and clean but I had to take the EGR off as it was obstructing the bolt.

I'll post again if I notice any difference but it was in a real mess so it couldn't do any harm.

It's the 8v.

The gap between the sensor and the EGR is just a bit too tight to get the torx bit and driver in.

Easy enough with the EGR out though.

Thanks Doofer
I cleaned my boost sensor last evening, simple job (8v) A stubby 30 torx just had enough purchase at an angle with a 10mm spanner to remove it.
It looked like a large mascara brush dipped in iron filings!
It makes a huge difference; no hesitation and as smooth as it should be with a mapped 160BHP.
Have we (or stealers who should know better) been putting innocent EGR valves to the sword? Why, oh why is it in dirty air?
CJLAR

Glad it worked for you - cleaning mine made a subtle but very noticeable difference. The shape of mine was unrecognisable - just a featureless blob of goo.

These sensors have been used for years on most cars. They've worked fine until emissions regulations required that the EGR valve is needed. It doesn't seem that anyone thought much about the repercussions of chucking a load of sooty, sticky exhaust gases back through the system, all over the sensor that was only ever intended to sit in fresh air.

Still, it's a doddle to clean so this is now part of my annual service regime (and really should be done by dealers too, but they don't bother).

Yes do this or else: -


Friday night giving it laldy down the A1 when I am approaching a caravan in the middle lane. A look in the mirror tells me that if I boot it I can pull into the outside lane and pass the caravan without causing any inconvenience to the Beemer some distance away.

Boots it, auto box kicks down, engine warning light comes on, engine goes into limp home mode. Pull over into inside lane uber quick before I get a Beemer in the boot.

Pull into Ferry bridge services and call RAC. Fault has been caused by the sensor registering overboost. Guy from the RAC reckons it has happened when the box kicked down - prognosis is that the sudden increased airflow shifted the accumulated crap in the sensor hence suddenly registering over boost.

So stuck for an hour at Ferry bridge at 10pm because I didn't do as doofer said.

Make sure you tighten the T30 torx bolt well. I didn't and the next time I checked it wasn't there anymore. The engine vibrations had worked it out all the way out! The sensor will still hold as it has a gasket but you can easily lose the screw. I put a similar screw in but its a bit to long so I will need to cut it down but it's working for now.

ferrybridge Radlet6, but that is only a few miles from civilisation! I was in an impropmtu convoy of 3, 0.033% of total UK, Cromas just outside Knaresborough the other day. I'm sure that we could've sorted you out between us,

Three together? that's one for the book of rare occurances. Closest I can get to that was when I found someone had parked one right next to mine in Asda's car park.

And let me tell you Ferrybridge services at 10pm on a Friday night is far from civilised.

I think Harrogate and Knaresborough must be a Croma hotspot - I see quite a few around here (compared to everywhere else in the country).

I have cleaed my sensor, as well, but at the end I tide the screw too much so I broke the nut inside :bang:! Now I need to repair it. The screw is free to rotate, however it is keeping the sensor on position. Otherwise, the sensor was very dirty and really it make a differents in terms of smooth running.

Cleaned my boost sensor today on my 1.9 16v auto . As described by others, it was completely clogged up after 6 years and 40k miles. What a difference it made to both fuel consumption and performance. I measured it over a short route I do regularly and managed 38.4 mpg whereas I'd normally be luckly yo get 33 - 35 subject to traffic. It easily managed to hold 80mph in 5th up one of the steepest dual carriageway hills I know (the A9 as you leave Inverness) whereas normally it would have to drop to 4th. Thanks for all the advice.

Hi, anyone cleaned booster sensor in 1.9 manual 8v Multijet?
Mine seems to have torx 40 screws, but that's not a problem. Access to screw attaching sensor to the wall of engine is really awkward, even trying to remove egr valve not easy,because of four screws holding that in place, two are very difficult to access. I have come up with an idea, that I will cut short torx screwdriver bit from 25mm to about 18/2015 so it would fit between screw I need to remove and body of EGR valve, and then turn that bit using combination spanner size 1/4".
Now, is there any less hassle involving process to do that on 8v Multijet engines?
Advice much appreciated, thanks.

On my 16v diesel I always used a short torx bit, designed to be slotted into a 1/4" hex driver. Just pop the bit in, hold it in with your finger then turn it using a 1/4" open ended spanner.

Just be careful not to over-tighten when refitting it, as you can get a lot of torque with a spanner.

Doofer said:

On my 16v diesel I always used a short torx bit, designed to be slotted into a 1/4" hex driver. Just pop the bit in, hold it in with your finger then turn it using a 1/4" open ended spanner.

Just be careful not to over-tighten when refitting it, as you can get a lot of torque with a spanner.

Click to expand...

Cheers Doofer, so you're saying that I would be able to buy torx bits shorter than 25mm or is that the one you call short?

I used a standard T30 1/4" hex bit intended for use with a magnetic screwdriver in a cranked ratchet holder. This has a closed end and a magnet to hold the bit, but is a tight fit. A standard 1/4" ratchet ring spanner or plain ring spanner takes up less space but you can drop the bit. A good trick is to use a couple of small "O" rings on the bit, one each side of the spanner. I also applied a very thin smear of petroleum jelly (Vaseline) on the sensor "O" ring to help it slide into place.
no problem starting, I'll do an update on the fuel consumption.
This appears to be a dual sensor. The visible yellow part looks like a thermistor for measuring temperature. The pressure element is inside the body of the sensor. The build-up of soot and tar will slow the response of both.

Call that a dirty one!!!? First time I did mine it sheared off some carbon build up as I levered it gently out of its hole.
When I cleaned it the response from the engine was so good I was doing 50 before I knew it , whoa there !!!

Paulski said:

Cheers Doofer, so you're saying that I would be able to buy torx bits shorter than 25mm or is that the one you call short?

Click to expand...

Hi G8RPI here,
The T30 bit I used (shown in photos) is 25.2mm long. My Croma is a 2006 16V manual and I had no problem. It sounds like the 8V is a bit tighter on space. The bits are hardened so you would have to grind them down, rather than sawing, if you want to shorten one.
Anyone got a 8V photo to post?