[ByDesign]

This is a relatively new Optra Magnum, just crossed 12k on the odo. I have provided a detailed new car report when I took delivery of the car. This problems driving me nuts, and well, I'm hoping the Optra gurus on here can help (Poitive?).

Relevant facts

• Engine oil change (some high grade synthetic oil) was done at 5k km as per schedule
• The service adviser convinced my father to add some 'engine oil additive' at the 10k service (they keep bugging us for these add-on things like teflon coating etc.), which he said would add longevity to the engine life. Yeah right. But my old man agreed anyway. It cost Rs 670.

Ok, so this engine problems been happening almost every day, at the same place! This does sound weird so I'm going to try and structure this post carefully.



My driver drives my father to work and back in the Optra. I do not drive it. The driver's been driving for us for over 7 years and we haven't really found his driving skills lacking in any serious way. He even drove our accent CRDi for its entire life of 1.35 lac kms with us with no problems.

This morning I decided to drive the Optra to my dads office to see the problem for myself. I reset the trip meter just to see after how many kms of initial driving the problem would occur. Engine temps and all sounds, feelings were perfectly normal. The car was flying in 2nd gear till 60 to 70 kmph no problems. I instructed the driver to start the car and let her idle for a few minutes before I got in to drive.

Now we turned on to Mother Teresa Crescent road, and my dad said this was where the problem usually began. And sure enough, it was as if the car was dragging a great weight all of a sudden! On that very road as my dad predicted. Trip meter said 8.5 kms just for the record. So basically, the symptoms are as follows:

• All of a sudden car feels really heavy and sluggish
• Engine temps normal
• Cars at 70 kmph in 4th gear but can not hold that speed, decelerates quickly to 40 kmph even though accelerator is pressed
• Car can't hold even 40 kmph in 4th gear so I down shift to 3rd.
• Car feels really heavy, tacho doesn't really register any revs on my pressing the accelerator
• Car keeps decelerating (it feels like someone is pressing the brakes), ONLY the front wheels feel like they are braking
• Reach 10 kmph in 2nd gear
• I stop the car and let it idle, car is idling just fine at around 800 to 900 rpm. Very silent purr, no issues!
• Slot it into 1st and let it pull out, still feels horrendously weighted. Hardly moving forward
• The same continued for about 3 to 4 kms and then it started off again fine without any deceleration!

A week ago, on constant reports of this problem by my father and the driver, I called chevvy (Triumph motors service center, who services the car) and told them about the problem. So obviously after the whole apology game, we took the car over and they took the whole damn day to scan it for sensor problems, test drove it, etc etc. Couldn't find any issues. Last resort move they tell us that there was some composite on the brake pads so they cleaned it. From the symptoms and the manner in which the problem occurs, doesn't seem like a brake problem at all. Seems more like an electronics issue (?).

So we took the car back, free of charge obviously, and the problem happened again the very next day! That's when I said I would drive and see it for myself. The above first hand report is from my drive to office this morning.

Some other interesting points are:

• It only happens on the morning drive. The car stays parked in office from 9 am till around 7 pm, and it NEVER happened once on the drive back home.
• The car has been to Meerut recently (after the engine oil additive service), in the morning, and no problems whatsoever!
• It always happens near the same place in Delhi (mother teresa crescent area, gyara moorti, etc.) and lasts for about 2 to 3 km where the entire car decelerates massively like someones pulling it back.

Would anyone please try to tell me what this sounds like! I'll answer any questions! Could this be that defective fuel pump story that's so notorious with Optra Magnums? Mine I think has the blue sticker!

[mayankk]

It seems to be an intermittent limp mode being enforced by the brain of the car.
Get your car connected to a scanner, see what error codes are stored.
have them cleared, and then see.


Any lamps lighting on the console?

EDIT:Response:
Do try and get the errors cleared, IN PERSON.
I have an OBD2 scanner, but i apparently know zilch on how to use it cos some SW i tried gave me a power output of 32000BHP....so i am not to be trusted. I think Chevy guys may oblige you for that.


Re-edit: this one is why I thought of limp mode:
Car feels really heavy, tacho doesn't really register any revs on my pressing the accelerator

[ByDesign]

Originally Posted by mayankk

It seems to be an intermittent limp mode being enforced by the brain of the car.
Get your car connected to a scanner, see what error codes are stored.
have them cleared, and then see.


Any lamps lighting on the console?

+1 for the quick response.

It was scanned (or so the service guy said), and he said there were no error codes. Nothing on the console either. The problem just comes and goes without a trace.

[ssingri]

Please check if the problem is with the brakes, one way to do it is to coast in neutral and see if it rolls smoothly or de-accelerates quickly.
Also check if the wheels/discs are very hot.

[ByDesign]

Originally Posted by mayankk

EDIT:Response:
Do try and get the errors cleared, IN PERSON.
I have an OBD2 scanner, but i apparently know zilch on how to use it cos some SW i tried gave me a power output of 32000BHP....so i am not to be trusted. I think Chevy guys may oblige you for that.


Re-edit: this one is why I thought of limp mode:
Car feels really heavy, tacho doesn't really register any revs on my pressing the accelerator

Will ask to scan in person then. Thanks again.

Originally Posted by ssingri

Please check if the problem is with the brakes, one way to do it is to coast in neutral and see if it rolls smoothly or de-accelerates quickly.
Also check if the wheels/discs are very hot.

Doubt its a brake problem. As the symptoms indicate, it only happens in the morning on the first drive. Never any other time.

[mayankk]

Originally Posted by ByDesign

Will ask to scan in person then. Thanks again.



Doubt its a brake problem. As the symptoms indicate, it only happens in the morning on the first drive. Never any other time.

oho, I didnt see the only in the morning bit.
let me tell you what was happening with me about 2 weeks back.
First drive in the morning, when i started the car, it revved to about 1100, then the error lamp came on on the console, revs stuck at 1100, and car was in limp mode.
I used to leave it started for about 5 minutes, and then at the next start, the car was okay.
when i took it out sometime later, while driving sometimes the light came on, and the car went again in limp mode.
restart, maintain the revs high, problem gone.
i initially thought this was due to the cold, some problem with the temp sensor, thats why the car went to that mode.

anything familiar here?


If it does, then try this:
what I traced it to was a dirty TB.
opened it up, asked someone to maintain it at 2000 rpm, and sprayed TB cleaner into the TB.
clogging removed, TB was free, and problem gone.

[ByDesign]

Originally Posted by mayankk

oho, I didnt see the only in the morning bit.
let me tell you what was happening with me about 2 weeks back.
First drive in the morning, when i started the car, it revved to about 1100, then the error lamp came on on the console, revs stuck at 1100, and car was in limp mode.
I used to leave it started for about 5 minutes, and then at the next start, the car was okay.
when i took it out sometime later, while driving sometimes the light came on, and the car went again in limp mode.
restart, maintain the revs high, problem gone.
i initially thought this was due to the cold, some problem with the temp sensor, thats why the car went to that mode.

anything familiar here?


If it does, then try this:
what I traced it to was a dirty TB.
opened it up, asked someone to maintain it at 2000 rpm, and sprayed TB cleaner into the TB.
clogging removed, TB was free, and problem gone.

There are a few differences as far as I can tell. In my case, no warning signals, odd sounds, or even idling. Everything is normal except for the deceleration at that time and place. Plus which car did this happen to you with? Do you also drive the same car? I am not sure where the throttle body is located in a 2.0 Liter common rail diesel engine, but I will keep this in mind to tell the mechanic.

[BuRnT RuBbEr]

you should do that morning drive with the diagnostics connected and logging all the data. mayankk could lend his obd.

get the errors cleared in person as mayankk suggested.

alternatively, you could leave the car with service overnight and run the tests on the first morning drive there.

just thinking, could it be a handbrake problem? maybe you park overnight with the handbrakes active and in the morning, they remain stuck, heat up by the time you hit 8 kms and the problem starts?

what additive was added?

[RevvMusic]

I too had faced a very similar problem in my Palio S10 last month. My Go-To Mechanic at the A.S.S analyzed it for an hour and found the culprit to be faulty wiring and loose connection in the cables that lead to the spark plugs.

One of the spark plug cables had somehow developed a loose connection and after the engine temperature increased to a certain value after driving for sometime, the current values in that wire started to fluctuate resulting in the car suddenly becoming heavy, followed by deceleration.

I'd suggest that you get the wiring of the spark plugs checked for optimum current and voltage levels and see if the problem gets rectified.

[mayankk]

Originally Posted by ByDesign

There are a few differences as far as I can tell. In my case, no warning signals, odd sounds, or even idling. Everything is normal except for the deceleration at that time and place. Plus which car did this happen to you with? Do you also drive the same car? I am not sure where the throttle body is located in a 2.0 Liter common rail diesel engine, but I will keep this in mind to tell the mechanic.

Say, didnt I spot you in CP once?

anyway, this is with a petrol fiesta.

As for the TB, look for the hose coming out of the airbox, and where it connects to the engine block.
if located, open the clamp on the hose(easy job, not much to mess up there), if you see a butterfly valve, that is presumably it.

Or, head to the chanakya petrol pump, or pallika, and tell them to clean it.

[honeybee]

@ByDesign, it sure looks like a weird problem.

Have you tried taking the car on a different route? And if you are facing this problem every day without fail, why not take the workshop guys with you on the same route and show them the problem firsthand?

Also it might be a good idea to try a competent independent mechanic who can offer advice on what could be wrong.

[CDM]

Did they also add any fuel additive?

A friend had a similar, though not identical, problem with his Scorpio when the service center guys added some fuel additive. In his case, his Scorpio would behave erratically and become sluggish suddenly. Draining the diesel tank solved the problem.

CDM

[Blow Horn Ok]

Does the gears shift normal while the car is in problem? As you said the engine idles normally and there are no signs or wired noises, i doubt it to be transmission issue. Get it checked. When the car is is limp mode, does the engine rev normally (say 3-4k RPM)??

[honeybee]

Originally Posted by Blow Horn Ok

When the car is is limp mode, does the engine rev normally (say 3-4k RPM)??

Originally Posted by ByDesign

... So basically, the symptoms are as follows:

• All of a sudden car feels really heavy and sluggish
• Engine temps normal
• Cars at 70 kmph in 4th gear but can not hold that speed, decelerates quickly to 40 kmph even though accelerator is pressed
• Car can't hold even 40 kmph in 4th gear so I down shift to 3rd.
• Car feels really heavy, tacho doesn't really register any revs on my pressing the accelerator
• Car keeps decelerating (it feels like someone is pressing the brakes), ONLY the front wheels feel like they are braking
• Reach 10 kmph in 2nd gear
• I stop the car and let it idle, car is idling just fine at around 800 to 900 rpm. Very silent purr, no issues!
• Slot it into 1st and let it pull out, still feels horrendously weighted. Hardly moving forward
• The same continued for about 3 to 4 kms and then it started off again fine without any deceleration!

The RPMs are obviously not climbing up when the problem occurs!

[keyur]

Originally Posted by ByDesign

• All of a sudden car feels really heavy and sluggish
• Engine temps normal
• Cars at 70 kmph in 4th gear but can not hold that speed, decelerates quickly to 40 kmph even though accelerator is pressed
• Car can't hold even 40 kmph in 4th gear so I down shift to 3rd.
• Car feels really heavy, tacho doesn't really register any revs on my pressing the accelerator
• Car keeps decelerating (it feels like someone is pressing the brakes), ONLY the front wheels feel like they are braking
• Reach 10 kmph in 2nd gear
• I stop the car and let it idle, car is idling just fine at around 800 to 900 rpm. Very silent purr, no issues!
• Slot it into 1st and let it pull out, still feels horrendously weighted. Hardly moving forward
• The same continued for about 3 to 4 kms and then it started off again fine without any deceleration!

• It only happens on the morning drive. The car stays parked in office from 9 am till around 7 pm, and it NEVER happened once on the drive back home.
• The car has been to Meerut recently (after the engine oil additive service), in the morning, and no problems whatsoever!
• It always happens near the same place in Delhi (mother teresa crescent area, gyara moorti, etc.) and lasts for about 2 to 3 km where the entire car decelerates massively like someones pulling it back.

Would anyone please try to tell me what this sounds like! I'll answer any questions! Could this be that defective fuel pump story that's so notorious with Optra Magnums? Mine I think has the blue sticker!

The entire issue seems pretty weird, but there are a few things I would like to ask you :

1. Firstly, why would you do 60-70 in 2nd gear? See this post by me. At 2nd gear, 70 kmph means nearly 4000 rpm. You should not do that in 2nd gear. Check the chart - try shifting as per the chart and see if this happens.

2. 40kmph in 4th gear = 1000 rpm. That is definitely going to make the drive very laggy. At this speed, you will need to downshift to second to have any pickup. (see the chart in the post I mentioned again)

Optra has tall gear ratios, so you need to ensure that you drive in the correct gear. And then, till 2000 rpm you are going to be hitting the turbo lag region. From what I hear, you seem to be permanently in the lag region.

Still, the way you mention it, there seems to be something that is being miscalculated by the ECU or there could be a leak in EGR pipes or the air hose.

Try one simple thing. Switch of the vehicle, open the hood, disconnect the positive terminal of the battery and let it sit for about 15 mins. Then reconnect the battery and see what happens.