[chrisat31]

Hi all
I took my 156 veloce 2.0l JTS for an MOT this morning which it passed, but the garage said that they had to push it off their ramp as it would not build up enough revs following the emission test. I also noticed that the temp gauge was reading about 110 degrees, this despite the temp is usually at a rock solid 90 degrees since new thermostat fitted last month. The engine management light is also on now. The MOT garage plugged in their computer and it flagged up throttle response issues which I've never had before this morning.
The only other factor that could have any bearing is that I gave the car a dose of Redex petrol system cleaner last week and was wondering if perhaps the revving at 2500rpm could have dislodged a bit of carbon.
Any suggestions would be greatly received as up until this MOT the car has been running sweetly.
I've parked the car to let it cool down a bit and will see what happens later.
Thanks

 

[David C]

Check your cooling fans work.
(both low speed and high speed)

 

[Nikolai]

It might help if you can check the fault codes and see if they're specific to a particular cylinder or if they are general engine ones.

 

[chrisat31]

It might help if you can check the fault codes and see if they're specific to a particular cylinder or if they are general engine ones.

Thanks I'll try the codes and report back

 

[chrisat31]

I've just read the codes and it says P1671 but the codes in my book only go up to P0999. I looked at P0671 in case i misread it but that is for glow plug & I don't think a petrol engine has one.
Now that the car has cooled down it seems to be ticking over fairly smoothly again but am worried in case it happens again while on the road. Thought I might take it for a run but will wait for my son to get home from work so that he can follow me in case i breakdown.
Any other suggestions gratefully received.

 

[David C]

I've just read the codes and it says P1671 but the codes in my book only go up to P0999.

A quick Google on that code is pointing to Fuel rail pressure regulator.

And also found :.

 

[chrisat31]

A quick Google on that code is pointing to Fuel rail pressure regulator.

And also found :.

Thanks, I've just read the link you sent, hope its not the injectors. Do you think the emissions test could have dislodged something or finally finished off a dodgy coil pack? My code reader cleared the code and I'll see if it returns during test drive later.

 

[David C]

The emissions test doesn't do anything that you wouldn't have done by driving it. The only difference is holding 3000rpm with no load on the engine (which means less fuel, not more). Big difference though is the car isn't moving. So will suffer if the fans don't work...

 

[chrisat31]

The emissions test doesn't do anything that you wouldn't have done by driving it. The only difference is holding 3000rpm with no load on the engine (which means less fuel, not more). Big difference though is the car isn't moving. So will suffer if the fans don't work...

I'll check the fans, it'll be kinder on my pocket than injectors. Must admit that most of my driving in this car has been on rural roads at reasonable speeds with no traffic jams so the fans not working properly wouldn't have flagged up as an issue.

 

[chrisat31]

I just took the car for a run to get to temperature and it ran fine, left it running after i got back and the temp rose to about 95-100 but the fan didn't kick in although i heard various relays clicking. I tried with A/C on & off which made no difference so it appears there is a problem on the fan system/circuit somewhere which is quite a relief after fears that it was injector issues.
I can't believe that the idiot doing the emissions test just revved it without checking that the temp wasn't going off the scale.
Anyway, any of you good people got any suggestions where I should start looking for the fan problem, my reader doesn't show any faults. Thanks

 

[David C]

Usual cause of the low speed fan not running is the resistor on the fan housing failed (located just below top hose).
That resistor is in the circuit to lower the voltage and give the lower speed.
As a quick "fix", you can try unplugging the two wires from the resistor and connect the two wires together.

When the ECU calls for the low speed fan, it will actually run at full speed. So will make more noise, but at least it won't overheat!!

 

[chrisat31]

Usual cause of the low speed fan not running is the resistor on the fan housing failed (located just below top hose).
That resistor is in the circuit to lower the voltage and give the lower speed.
As a quick "fix", you can try unplugging the two wires from the resistor and connect the two wires together.

When the ECU calls for the low speed fan, it will actually run at full speed. So will make more noise, but at least it won't overheat!!

Thanks I've just checked the fuses in the engine bay, (should have done that 1st - doh) and fuse no.7, 30 amps which according to my handbook is engine cooling radiator fan 2nd speed is blown. I'll pick one up and see what tomorrow brings.
This is my 1st Alfa, luckily I've just retired and got time on my hands as it seems that owning an Alfa is more of a lifestyle choice rather than just having a car. Good fun though! Cheers