there 2 metal pipes next to each other left one has a rubber hose going to a sensor, the right one has nothing on it

the squeak has changed to sorter and more it now goes chufee chufee chufee chufee. engine management light came on an it went limp on the a12 i pulled over unplugged the egr and plugged it back in, it came out of limp but light still on, am just about to take laptop out and plug it in

hmm seems signal was lost, hope it was just nut plugged in right to start with. does this look right?

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notorious said:

for the boost sensor it is slightly to the left and below the EGR sticking out with a black plastic loom with a yellow clip. Single Torx 30 bolt, pull out spray carb cleaner, don't stick anything into the sensor, just carb cleaner maybe soft brush if it is really dirty, return and tighten the bolt well. My screw fell out from engine vibrations because I only hand tightened it so I had to put a different one in.

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i still cant find it

i cleaned this i think its A MAP sensor?
was minging looked like solid plastic instead of a cadge with a little thing inside, it started to rain so i forgot to take an after photo.

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thats it Dave

that's my boost sensor? i thought it was supposed to have a tube on it going to turbo?
sounds like i have a bird in it at about 1800 revs now and it pulls back at every cherp

If the "squeek" you hear is what I think you hear then it may be the same noise I have on my manual gearbox Croma.

I can create the noise in lower gears (well I can hear it in 2nd and sometimes 3rd gear above road and engine noise). I gently accellerate up hill or under load towing and as I lift off and declutch then there is a "squeek squeek" a bit like a cuckoo cuckoo noise.

I think it may be a waste gate mechanism squeek as is I play with the throttle and loading I can get a fluttering squeek.

My logic here is that at lower vehicle speed ambient noise is much lower. Then requesting a modest power demand the turbo is puffing fairly hard and when you lift the pressure has to be released. You hear this mechanical noise as opposed to the typical "puff / hiss" of a waste gate on full power release.

With your auto box you probably can't play to much in exciting the effect.

dave said:

that's my boost sensor? i thought it was supposed to have a tube on it going to turbo?
sounds like i have a bird in it at about 1800 revs now and it pulls back at every cherp

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I think your talking about the boost solenoid valve. If the pipes to it are leaking it can make your turbo overboost (and looking at croma2 txt your boost is higher than the desired level throughout the rev range). It may be worth giving them a quick look over to see if they are perishing.

ive found my boost solenoid, but pipes going to it look fine, i pulled the fat one off and it is sucking,

I gave jip0 a lift to a meet on friday and he says my noise sounded like the turbo isnt spooling up properly.

The TMC guy was at stanford today, i took him for a spin and he also says its not just my waste gate and advised i get some one to have a look/listen to the turbo

dont take my word for it

im rubbish with engines im still learning

jip0 said:

dont take my word for it

im rubbish with engines im still learning

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you and the tmc dude
i need some friendly ex fiat tech to offer to have a look :idea:

Its not only the noise Dave, you can feel the car hesitating almost like a petrol engine with a bad spark plug or lead, its like little misfires. I think its either an air leak or boost control solenoid itself. It definately shouldn't be like that and I would expect any good Fiat techs on here will have seen it before, this is a very good engine used in Vauxhall and Alfa, normally very reliable. I don't think its serious, hopefully not the turbo itself although even if it is they can be rebuilt now quite cheaply. Let me know if you find the cause.

this boost control solenoid looks like it will be the same as other cars? thats the sort of thing i can go get from my mates scrappy if i know where to look,

I would get a Fiat tech to check the car over Dave before spending more money on parts you might not need. Someone in Fiat will surely have come across this before. I'm heading over to our local dealer now and will ask them.

i dont pay for small bits at my mates scrappy i just have to keep his computer and internet working
be cheaper than going to see techs i trust because they all an hours drive away. my local dealers are rubbish

i had to go up the yard anyway found a message on my answerphone from last thursday saying internet is broke. it wasnt was just school holidays last week.

Anyway i looked at loads of cars all the boost control solenoids looked different to the croma and stilo ones. vectra and saab had double ones

Not sure how much help I could be Dave, as Croma's were a rarity around my way, though the engine is familiar (the GM version of the Fiat Diesel, also used in the GM-chassis'd Alfa's).

Is the squeak the same noise you get when you switch-off? I'm trying to remember if they used the single "throttle body" shut-off valve, or the 4 individual flow shutter valves used to operate the engine as an 8v at low rpm.
Another possibilty is engine/gearbox mountings being under tension.

I wouldn't worry too much about your MAP sensor readings- a bit of a difference is normal due to atmospheric conditions/different engine load in different gears/etc. The best test for a Boost sensor problem is to compare it's readings to the atmospheric pressure readings with the engine not running. If the MAP sensor reads 2-300 mbar over (ie, 1300mbar boost where atmospheric pressure is 1000mbar), you know its faulty.

EGR valve opening readings can be inaccurate as they only show what the ECU is aiming for. There's no feedback from the EGR to tell it if it is achieving those figures. The best test is to compare EGR opening to airflow meter readings, and is easiest at idle.

Oh, the missing DPF pipe is probably nothing to worry about. When DPF's first came out, they ran with two differential pressure sensors (pre and post) to determine clogging, but they were prone to issues and were later altered by reverting to just one and only comparing the "pre" sensor to atmosphere.

ive not noticed a noise when switch-off
when the noise comes it pulls back aswell

dave said:

ive not noticed a noise when switch-off
when the noise comes it pulls back aswell

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Strange, most JTD's I know make a little 'chirp' as they stop when switched off, and a misfire-like issue can recreate this 'chirp' as the engine rocks about.

Going to be hard to guess at without experiencing it. Have you tried blanking the EGR to see if it stops the 'misfire' symptom? Can you get a 'snapshot' of the parameter data when it does it?