Technical No Turbo

[Badols]

Hey people!

I've been on the forum for while now, since owning a Croma makes this actually kind of a necessity! One problem after the other... But! I do love this car!

Now, I followed a guide posted by someone on cleaning the boost sensor. At the same time I cleaned the EGR, both were really due apparently!
The problem that has occurred now is that there is no more turbo boost, just a big "woosh" sound at around 2.2k rpm.

Could anybody give me a lead where to start looking? Could it be just a hose that's detached?

 

[s130]

Sounds like the turbo is blowing OK but the pressure/air is being leaked/vented else where.

Ensure all hoses and clips are secure and not broken.

As you had the EGR valve off and cleaned it you could have:

1) Valve stuck open
2) Gaskets not sealing correctly
3) Split/broken EGR feeder tube in inlet side of EGR

 

[Badols]

Thanks for the quick response!

I'll check this straight away! Let's say the EGR valve is stuck open, is there a way to, let's say, make it work properly again? Or is it for the bin then?

 

[Badols]

I think I solved the problem, the ring around the bottom hose of the EGR wasn't tightened completely... The hissing sound is back, but for the real proof I'll have to wait till I get to got the motorway again!

Thanks a lot!

By the way, any idea what could cause the power steering to shut down for a few seconds and then work perfect again? As well, but rarely, when starting the car it doesn't turn on, drive a bit and starts working then...

 

[tarquin1867]

Sounds like a bad connection on the main pump cable.
Several posts on this forum if you check back . Use the "thread tools" at the top of the front page . There is a lot of power going to the steering so a poor connection will show up as heavy steering

 

[Badols]

Well, as said, I went on the motorway, turbo kicks in at around 1.8k rpm, with whistling sound. BUT, it lacks a lot of power before that, like snailspeed till 1.8k rpm, full throttle or not, and then it burst away until you shift, then snails ahead till the turbo kicks in again... Could it be in that snail-mode or something? If so, can this be solved by unplugging the battery for an hour?

Thanks for the reply on the steering problem, I'll look into that today!

 

[BrianMcL]

Check the small vac out hose at the front of the engine as well as it can be prone to perish and split which has a big impact on power.

If it's burst or loose some insulating or self amalgamting tape should cure it, at least for fault finding purposes.

As with any power related problem with these cars the easiest way to test / eliminate the egr system is just to get a decent piece of metal (I've used pieces cut from an exhaust bandage and an aluminium mess tin in the past) and blank the egr off completely. If that cures the problem then great, if not you haven't wasted too much time or money and you've eliminated one common fault. Don't worry about the check engine light - it'll go off once you've been through a few stop start cycles once the blanking plate's been removed.

The power steering issue is almost definitely the wiring loom. An inconvenient but inexpensive part to replace.

 

[Badols]

Hey!

So I've been to a Fiat dealer in the end, it was in the limp home mode. They erased it and it got immediately back in it. They swapped the EGR valve with a new one, no more limp home mode... But, this wouldn't be a Croma if it would be fixed now. No no, it just keeps stuttering, a new EGR, a revised one, what ever... If I recall they told me they put a gasket with three holes in it, still stutters..

What's up with this car? Is it the boost sensor?

 

[Doofer]

I've just been looking at mine today. We've ordered a new car to replace ours, but have to wait another month before the new one arrives. I was hoping I'd find a split hose that a bit of tape would sort out, but I can't find anything.

With mine, it's very slow below 2000rpm. Above that it's not bad but still underpowered. Above 2000rpm you can hear the turbo, but recently the noise has turned into a hissing noise - if you drive past a wall with the windows down then it sounds like an aerosol can being sprayed.

FiatECUScan shows that the actual air pressure is 1000mBar (i.e. atmospheric pressure), whatever the desired pressure is.

So all the evidence suggests that the turbo is working, but there's a leak somewhere that's letting all the pressure out.

I took the filter box out today and had a look with the engine running. I was hoping I'd be able to hear something and home in on it, but I couldn't. The hissing doesn't happen just by revving it - it needs to be under load.

So I'm lucky in that it's going in a month so I'm not going to worry about it any more. It's definitely not right though, and there are air pipes all over the place when you start looking.

I thought I'd found it as I could feel a draught at the front. But then I found it was just the fan, which always blows if the air con is on, so switch this off to have any chance of finding it.

So you're not alone, and I know that mine is not the EGR valve or boost sensor (both checked). The 1000mBar figure means there is an air leak somewhere. If you have the ability then this would be worth checking on yours.

 

[Badols]

Thanks Doofer, but it has power all the time, when I floor it there's no stuttering.. when I cruise at not matter what speed, it it stutters/shocks. So the nor the speed or rpm is like influencing it, nor does the turbo, it shocks with and without turbo going.. when accelerating normal it shocks as well, except when I floor it.

I don't get it, it's a new EGR valve, normal gasket --> shocks, after that (and still) modified gasket --> Shocks!

Thing is, in the work shop the connected a second EGR-valve and put it somewhere around the motor, but left the not connected one on the motor, then there was no shocking.. So, what is giving a bad or wrong signal? The boost sensor?

 

[cromalee]

With mine, it's very slow below 2000rpm. Above that it's not bad but still underpowered. Above 2000rpm you can hear the turbo, but recently the noise has turned into a hissing noise - if you drive past a wall with the windows down then it sounds like an aerosol can being sprayed.

FiatECUScan shows that the actual air pressure is 1000mBar (i.e. atmospheric pressure), whatever the desired pressure is.

So all the evidence suggests that the turbo is working, but there's a leak somewhere that's letting all the pressure out.

On fes, look at the differential pressure in the dpf. See how it reacts to engine speed/ load. I had a similar noise from mine.

 

[Doofer]

Interesting. What was the cause in yours?

I think I'll leave mine alone now though. Provided it's not something that's going to develop into a breakdown that is - it seems to be running OK but it's very low on power - it needs 5th or sometimes even 4th on motorway hills. It only has to survive for a month.

 

[cromalee]

Interesting. What was the cause in yours?

.

The dpf was blocked. Like *solid*. Although fes reported "normal clogging", the fiat algorithm obviously was out of touch with reality.

The dpf problems started with an ignored "change oil" warning ( my wife, not me!!) followed by a failed egt sensor (reading open circuit) which i hacked by fitting a 400 ohm resistor. This allowed the car to function, but would not complete a full regen as the temp was not rising enough ( fixed resistor - next time I'll use a pot!)

The hissing sound was accompanied by lack of power. I eventually took the dpf off, to find that the ceramic waffles inside were blocked solid with a glass like residue. I removed the first part ( between inlet and temp sensor) but this wasnt too bad. The blue/black waffles in the main body were worse. I removed the first layer of this material to find that the rest was spotless. Cleaned it all up and popped it back on. I also flashed over the ecu with a home made dpf off file (fes now shows "No DPF" under version), left in my hacked temp sensor and reconnected the differential sensor.

Result? Blew a turbo hose off on first test drive!!!! Quick spin into halfords for a 5.25 euro jubilee clip and its been absolutely fabulous since Its got amazing mid range power, but a bit of a sod on diesel.

Weird thing is, that in the 8 months my wife drove it (18,000 miles), it had not a single issue. Missing the oil change really buggered things up.

 

[keithglos]

As I have mentioned before, they need both the oil service counter and the oil degredation couter reset at service.
Most garages are not even able to do this even iuf they knew about it.

Oil degredation means that after 20000 miles since previous reset you can't do a regen, as the oil is seen to be too bad to take the high temperature.
Keith

 

[Doofer]

Apologies for the unintentional thread hijack, Badols. I thought my info might be relevant to your issue.

Thanks for the help.

I'll leave mine well alone then - it doesn't sound like there's a simple fix.. It's being PXed in a month, so as long as the wheels go round then it's fine. It's just passed its MOT like that, and the fuel economy is also fine.

I still think there is a leak of the compressed air after the turbo, as it was reading 1000mBar, even when attempting to get 1500mBar. That said leak to me, i.e. atmospheric pressure all the time. 1000mBar = 1Bar = atmospheric pressure. There's that much pipework though, I didn't know where to start looking. I couldn't hear or feel anything obvious, but that doesn't mean much.

I did reset the oil change earlier this year, when it was changed. I did notice a puff of smoke and low MPG when coasting fairly recently when it seemed to be regenning OK.

Badols... have you tried blocking off the EGR valve, as a test? It's probably best if you have a look at some figures from the ECU while driving though.

 

[Badols]

Hey! Sorry Form the long silence!

No problem Doofer!

As for the problem.. It is still there.

I did do some tests. I took of the EGR completely -> No stuttering, but an awful hissing/whistling sound and dash light.

In the garage they put like a spacer between the magnet and the valve, I took it out, it got worse.

I'm not particularly looking for a way to block off the EGR completely, just figuring out what is actually causing the problem and solving that is.

Which sensors influence the EGR? Which sensor is causing it to malfunction?

Could it be the gaskets being placed wrong, so the valve doesn't close fast enough? Or does this not matter?

It's driving me fxcking nuts!!

 

[Doofer]

You will get a warning light when blocking off the EGR valve - it was suggested as a diagnosis, not a cure.

If it runs OK when it's blocked off then it's likely there's a problem with the EGR valve not closing properly. The lights are nothing to worry about, and will go out after a few runs with the blocking plate removed.