Check Engine light when boosting

[Fez]

Guys, appreciate your advice on this.

I'm running a stock setup on my glanza. All factory stuff except for the magnecor leads.
My turbo started spitting oil through the blow off valve and is about to be replaced.
I had the check engine light come up all of a sudden today on my routine drive to work.
I immediately stopped to car to look for any obvious signs that may have led to that and didn't find any. So I setoff again, this time being very gentle on the throttle, and no check engine. Later got a scan done through the diagnostic port and was told that the error was corresponding to the knock sensor. The check engine only comes on when you get a bit aggressive on the throttle.

I'm planning to put in the new turbo this week, any advice on how to treat this issue?Could the sick turbo be the cause for the engine check light to lit up?


THanks

 

[SupaStu]

Unless the sensor is faulty, someone here will be able to give you more advice soon chap

 

[Fez]

Unless the sensor is faulty, someone here will be able to give you more advise soon chap

Thanks mate Hope its not the sensor too. Most certainly, the knowledge base here is tremendous, looking forward to the expert opinions

 

[AdamB]

If the error you got was for the knock sensor and under heavy throttle loads, it generally means that the knock sensor is doing its job, by retarding ignition timing to stop the engine from detting. It could put the car in limp mode unless the ignition is switched off and back on again.
Chances are if the turbo is spitting oil into the intake, it will be pre-igniting the mixture which is causing the detonation, so the knock sensor is doing its job by saving the engine.

I would advise to stay off boost, drive carefully until you get a new turbo on there thats in good condition.

 

[Fez]

If the error you got was for the knock sensor and under heavy throttle loads, it generally means that the knock sensor is doing its job, by retarding ignition timing to stop the engine from detting. It could put the car in limp mode unless the ignition is switched off and back on again.
Chances are if the turbo is spitting oil into the intake, it will be pre-igniting the mixture which is causing the detonation, so the knock sensor is doing its job by saving the engine.

I would advise to stay off boost, drive carefully until you get a new turbo on there thats in good condition.

Hey Adam,

Thanks for the reply. Super explanation for a newbie
And assuming this error is because of the turbo issue, once I get in the new turbo in, should I reset the ECU? It is the stock ECU.
Of course will give the sensor and wiring a through check up too.

 

[AdamB]

You can reset the ecu yes, will do no harm. Just disconnect the battery terminals for half hour or so.
While your at it you could check the wiring, but chances are the wiring will be good if the check light is only coming on under a loaded throttle

 

[Fez]

Noted. Thanks!! Will update you guys how it went. Appreciate the advice, repped

 

[Fez]

want to update you on the check engine situ I had a couple days back.
The new turbo went in today, and all went well
However, I took the car for a spin after and went on boost and there came the check light again.
The mechanic said that he checked the knock sensor and the wires and that there was nothing wrong there. And also, the check engine only comes when boosting.

So went home slowly, removed the battery terminals and went for a drive half an hour later, still the same.

Now I pulled the bat out and also pulled out the ecu fuse. thought of leaving her to simmer overnight.

your thoughts on this?

 

[AdamB]

Was the intercooler cleaned out when the new turbo went on? There is likely to be still oil in the intercooler and piping.

 

[Texx]

If the error you got was for the knock sensor and under heavy throttle loads, it generally means that the knock sensor is doing its job, by retarding ignition timing to stop the engine from detting.

No, code 51 is a knock sensor signal circuit malfunction. There's a number of reason this code would flag, either the knock sensor is faulty, the sensor has come loose and losing it's body ground, there's a wiring issue between the knock sensor and the ECU or the ECU is faulty.

I would suggest either your knock sensor has come loose and requires tightening back up or you have either a break in the wiring or loose connection that goes open circuit as the engine moves on its mounts. Check the sensor is secure, it doesn't need to be ultra tight (45Nm), so just nipped up enough to hold it tightly in position. Check the wiring connector fits securely into the sensor and that there's no sign of any damage or wear to the wiring in the engine bay. If the problem still persists you'll need to get hold of a digital multimeter and start checking some resistance values.

 

[Fez]

Was the intercooler cleaned out when the new turbo went on? There is likely to be still oil in the intercooler and piping.

This I will have to re-check.. is there a way to, say flush the intercooler or summin? I made sure that all the pipes etc were cleaned well, just didn't think of the intercooler :$

 

[Fez]

No, code 51 is a knock sensor signal circuit malfunction. There's a number of reason this code would flag, either the knock sensor is faulty, the sensor has come loose and losing it's body ground, there's a wiring issue between the knock sensor and the ECU or the ECU is faulty.

I would suggest either your knock sensor has come loose and requires tightening back up or you have either a break in the wiring or loose connection that goes open circuit as the engine moves on its mounts. Check the sensor is secure, it doesn't need to be ultra tight (45Nm), so just nipped up enough to hold it tightly in position. Check the wiring connector fits securely into the sensor and that there's no sign of any damage or wear to the wiring in the engine bay. If the problem still persists you'll need to get hold of a digital multimeter and start checking some resistance values.

thanks for the explanation texx. I will re-check the sensor for snug fit and also the wiring. will report back after. appreciate the help

 

[Fez]

Hey guys, Hope everyones having a good weekend

An update on the situation that I had ;


went over to a garage in the afternoon to check out the ECL issue. We jacked the car up, and refitted the knock sensor. Actually one of the wire connections had come loose close to the collar. the wire itself was quite well insulated and was in decent nick. Left the battery terminals off for about half an hour, and no more error codes

To make sure everything was working as it should,went out for a drive. The car was not boosting as she used to. i.e only the first of the three boost lights on the dash lit up and my boost meter showed between, 2.8-3 psi. and I should be running around 8 -8.5 psi right? (its an auto gauge btw)

Your thoughts on this?

 

[Fez]

Guys, finally got everything sorted. ECL initially was because of a loose connection on the knock sensor itself. Took it out and fitted it back in.
Boost issue was sorted after removing all the hoses and refitting, there was also an issue with the boost solenoid, it was stuck in the low boost setting.

Once again thanks for the advice and support, TGGT rocks!!

 

[Mikey4410]

superb glad u got it sorted.i have a high low boost solenoid if you want it.works well. £5.00

 

[Fez]

Thanks mikey. So relieved it was nothing more serious. Thanks for the offer too. My solenoid is fine, its the connector which seems to be knackered.
Anyways will check on it and hit you up if I do require the solenoid. Cheers

 

[Mikey4410]

no probs.....