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Yesterday the car suffered a significant loss of power. Started up cold and immediately when pulling away it just wouldn't pull. Not like limp mode but there was a definite loss of power. It initially sounded like it had dropped a cylinder, quite a gruff noise but that cleared.

Anyway this lasted a few miles and things seem to be getting back to normal but I'm convinced it's still not pulling as strong as before. Never got any lights on the dash.

At the moment the top end feels ok but the low down torque seems to have gone away a little. I checked for charge air leaks and there is nothing and as its pulling ok at the top end this can't be the issue.

My suspicion is that it's related to the turbo.

Any ideas. Filled the car up with Tesco 99 the day before, possibly bad fuel but again it only seems to be low down in the rev range where its suffering.

Only done 3000 miles
 

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Yesterday the car suffered a significant loss of power. Started up cold and immediately when pulling away it just wouldn't pull. Not like limp mode but there was a definite loss of power. It initially sounded like it had dropped a cylinder, quite a gruff noise but that cleared.

Anyway this lasted a few miles and things seem to be getting back to normal but I'm convinced it's still not pulling as strong as before. Never got any lights on the dash.

At the moment the top end feels ok but the low down torque seems to have gone away a little. I checked for charge air leaks and there is nothing and as its pulling ok at the top end this can't be the issue.

My suspicion is that it's related to the turbo.

Any ideas. Filled the car up with Tesco 99 the day before, possibly bad fuel but again it only seems to be low down in the rev range where its suffering.

Only done 3000 miles
It might just be poor fuel. So long as there aren't any warnings displayed, I suggest you let the tank go down to 1/4 full and then fill up with fuel from another filling station and hope for the best.

If you know someone with MES (MultiECUScan), it might be worthwhile to see if any DTC errors have been logged.

Andy
 

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Discussion Starter #5
I've been to Mangoletsi today to get the wheels which should have come with my car fitted, only 3 months late but that's another story.

Anyway I mentioned to them about the loss of power but they couldn't care less. Service guy said if it isn't doing it now and no warning lights then no point investigating.

I'm a maintenance technician and spend most of my time dealing with train drivelines (Cummins and Voith to those interested!) and if a fault isn't present at the time of investigation I can't usually get away with "No point wasting my time on it".

I'll see how it goes and if it keeps happening then I'll take it somewhere other than Mangoletsi.

Does anyone know how the vanes in the turbo are controlled on these engines, I.e electrically actuated or vacuum?
 

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Does anyone know how the vanes in the turbo are controlled on these engines, I.e electrically actuated or vacuum?
Vacuum, I believe, at least as far as the Quadrifoglio is concerned.

Andy
 

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I also think it is a vacuum actuator on the Alfa's,interesting thing to learn is that they don't need a wastegate, so no popping etc but there are electrical systems available on a whole myriad of manufacturers and engines.
 

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Not likely to be a leak in the vacuum line then. If it was electrically actuated I'd suspect that was playing up.

Also it had the Fuel firmware update yesterday so am I right in thinking they will have flashed the ECU which would have reset the adaptations? Throttle response seems different, needs a heavier foot to get it going.
 

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Not likely to be a leak in the vacuum line then. If it was electrically actuated I'd suspect that was playing up.

Also it had the Fuel firmware update yesterday so am I right in thinking they will have flashed the ECU which would have reset the adaptations? Throttle response seems different, needs a heavier foot to get it going.
There are many ECUs in the Giulia. My post :

https://www.alfaowner.com/Forum/alfa-giulia/1187339-giulia-quadrifoglio-lastesrt-ecu-software-versions.html#post17535479

covers the Quadrifoglio.

My guess is the fuel firmware recall updates either the instrument panel or the BCM or both.

It is possible that while updating those ECUs, they've updated all others at the same time which could mean you experience some change.

By 'adaptations' I guess your meaning things that the car has learnt over time rather than remapping that's been done?

With my Quadrifoglio, few of the settings I'd made were lost, so not all data is overwritten.

Andy
 

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Not likely to be a leak in the vacuum line then. If it was electrically actuated I'd suspect that was playing up.

Also it had the Fuel firmware update yesterday so am I right in thinking they will have flashed the ECU which would have reset the adaptations? Throttle response seems different, needs a heavier foot to get it going.
Mine is a 2.0 but 200hp early 2017 version. I had the fuel update recently and that had no impact on the ECU or the throttle maps. The fuel update is on a different module (BCM?), not the ECM. So there should be no question of adaptation unless they updated the ECM for a separate issue or because a new ECM update was available when they plugged the car into Witech 2. They should be able to confirm if the ECM was updated.

The turbo (Honeywell) waste gate is electrically actuated and controlled by the Powertrain Control Module. The actuator (Item 1 - first picture) has an electric motor and position sensor, with engine off the wastegate (Item 2 - picture 1) is placed in the open position and when the engine is started the PCM should close the wastegate. Thinking about this, if the wastegate fails to close when engine is started, it could explain why you feel lack of power at low revs until the cylinder is exhausting enough gas to spin the turbine and run the turbo within its operating envelope. As the waste gate is in its failsafe position i.e. OPEN, maybe it does not trigger a CEL or error code (am guessing here). I think you could use either MultiECUscan to actuate the wastegate or get the dealer to do some diagnosis. Do you feel this loss of power all the time at low revs or it this intermittent? Maybe the wastegate failed to open just that once or twice? It maybe worth asking to speak to the chief Alfa Tech in your chosen garage, every dealer will have one.

The dump solenoid is also electricially actuated by the PCM. Blue item labelled 1 on the turbo charge air pipe to the intercooler. Don't think the dump valve would be the issue as it would only matter in cut-off conditions within the turbo operating envelope.

I work in the power industry as a mech engineer. We are seeing more and more new technicians with zero motivation to to 'think' and find solutions unless the solution is written in the instructions. So I am not surprised with the automotive industry. There are still some good mechanics fortunately IF you can get past the service desk. This is where you need to push and show that you have mechanical knowledge. When I do this I usually get a better response.
 

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Discussion Starter #11
Metalgod that's great info cheers.

My suspicion is that the Wastegate is sticking as this would cause the symptoms I'm having. Now that I know its electronically actuated that makes it more likely that this would be the cause or at least that the mechanical portion of the actuator might be sticking. Any electronic issue would likely throw a code.

I should just get it looked at under warranty but being that I'm a tech by trade I can't help myself tinkering.

Cheers
 

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It is quite easy to see if the actuating arm linkage from actuator to the mechanical waste gate is moving. With the engine running get someone to switch off the ignition, you should see the arm move the wastegate open. Then get someone to start the engine and observe if the arm moves in the opposite direction. If it remains in one position it is obviously stuck. I like to do some initial diagnosis myself that way the workshop can't bullsh1t you, while you also gain more knowledge about the car in the process.
 

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Discussion Starter #13
Sorry I misread your message Metalgod. Actually it's not the Watergate actuator I'm thinking of it's the vane control.

I think at high rpm the actuator is not energised as the turbine is already at optimum speed but at low rpm the vanes geometry is altered to reduce lag.
 

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I work in the power industry as a mech engineer. We are seeing more and more new technicians with zero motivation to to 'think' and find solutions unless the solution is written in the instructions. So I am not surprised with the automotive industry. There are still some good mechanics fortunately IF you can get past the service desk. This is where you need to push and show that you have mechanical knowledge. When I do this I usually get a better response.
All spot on.

In part, it's the car manufacturer telling the technician to follow the diagnostic procedure and only replace/adjust what it tells him. That's particularly true of warranty issues as the dealer won't be paid for changing something other than the part identified by the diagnostics. Also the dealer tries to avoid spending money training his staff properly.

It does help to speak to the technician direct if you can. Middlepersons should always be avoided. Some AR workshops in UK do have well trained and skilled staff, but a minority in my experience.

I particularly trust LC Motors in Newport/Cwmbran. They only let their Master Technician work on Quadrifoglios and he is a genuine expert. I will happily drive 50 miles to them rather than the nearest AR Workshop.

However, as my car's free servicing is used up, I'll be using my trusted independent NJS at Pershore for all work except any warranty issues.

Andy
 

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Are you describing Variable Geometry Vane Turbo? The 2.0 is fitted with a twin scroll turbo and the inlet vane geometry is not altered with rpm. On the Giulia, the cylinder exhaust is sent directly to the turbo inlet in what is called 'pressure pulse' design with the direct connect between the cylinders' exhaust and the turbine impeller. There is no traditional exhaust collector manifold as such. I still think you may have a sticky wastegate actuator. Although, if the wastegate was permanently stuck open through it will constantly leak boost and you will feel loss of power further up in the range as well. It is a bit difficult without repeatability.
 

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Discussion Starter #16
So this turbo is not Variable geometry then? I'm trying to google the info but can't seem to get any decent info.

Like you said if the Wastegate was sticking then this would probably cause an issue throughout the rev range not just low rpm. I stand to be corrected though as a fully open wastegate might not be optimum for low speed performance.
 

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Correct the turbo is not variable geometry where the vanes move with rpm.
If it was running rough it could be a misfire. There have been some cases though rare where this has not triggered a CEL. If so it could still be bad fuel.

https://www.giuliaforums.com/threads/2017-giulia-ti-misfiring.22322/
Ok so that's my theory out of the window. So this being a twin scroll design then it could be back to the Wastegate control.

Read that thread on the US site and symptoms sound different to mine as in more severe. However the issues they have had regarding injector weap/leak doesn't sound good!

We get that on the Cummins Diesel engines from time to time and can cause quite a few issues.
 

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Ok so, looks like sod's law is at play and I tempted fate by posting about my thoughts on switching my car, how good the 2.0 early engine etc. on other threads!

This morning when I was already pushed for time dropping my son off to school, the engine started very lumpy from cold first thing, very similar symptoms to the OP. Switched off a couple of times and it was still quite lumpy. I had no choice but to carry on with the 1 mile drive and it was stumbling and bucking to the point my son asked me why is it so bumpy? Very much like a cylinder misfiring. It wasn't particularly cold this morning compared to previous days.

So I stopped outside school after drop off and plugged in my BT OBD reader and scanned using Torque Pro app. It confirmed Cylinder 4 misfire. Error code : P0304 - Cylinder 4 misfire detected. No CEL, only Start/Stop unavailable and stayed so. All DNA modes were available throughout. I even tried switching modes to see if the misfire would settle down but it didn't. After driving for a couple of miles and may be with engine coming up a little in temperature it seemed to start running OK. Start/stop unavailable warning remained. Power appeared to be back on all DNA modes. I drove the rest 15miles hard in both N and D partly in manual shift mode to see if that would clear the injectors in case that was an issue. I reached work without further issue. Car restarted fine after stopping.

Code P0304 may mean that one or more of the following has happened:
Faulty spark plug or wire Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer


My symptoms sound exactly like what @Cutterbuck experienced (See Post #14) with the exception that I did NOT get a CEL.
https://www.alfaowner.com/Forum/alfa-giulia/1120322-first-glitch-at-14-000k-miles.html

Some points to note -
1. 3rd service completed recently a week/200 miles ago. New oil and filter. I have asked dealer what oil they used. Car has covered nearly 28k miles.
2. Tank has Shell 95 RON fuel. I tend to alternate between 95 RON and V Power occasionally and predominantly use Shell as it is on the way to work with the odd occasion using Tesco 99RON. The last time I filled Tesco fuel was more than a month ago so I don't think fuel is the problem.

@Twiss002009, I now think the issue could be either a faulty or blocked injector, spark plug (not due to be changed for another year at least) or harness. Cylinder 4 is closer to the cabin - see attached.

I know some early multi air engines on the Giulietta and Mito had the MA unit going faulty or their associated oil filter blocking. I am not sure if the Giulia has a MA unit like those cars and I can't seem to find any info. I do know that the lubrication system also supplies the MultiAir module intake valve actuators with oil it uses to control intake valve opening and also an additional filter screen in the oil supply channel to the cylinder head (seen in picture 2), which ensures that the oil directed to the cylinder head components, in particular the MA module (I am guessing this is the item circled in yellow in Picture 3), is cleaned more thoroughly. The additional MA filter seems to be located by Cylinder 1 assuming I have the orientation correct in my head.

I am hoping @MacGeek can confirm if the MA unit in the Giulia is different and does not suffer the same issues as the early MA units. If it happens again I will get it booked in for investigation. I might try swapping the cylinder connectors to see if the misfire moves to a different cylinder. I think it is likely a plug, injector or harness issue given the engine seems to be running fine after the initial misfire.
 

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