Ibiza 2003 1.4 16V Engine stalls due to low RPM

[hkslls1]

Hi Guys. Today I checked my CAR (Ibiza 2003 62k mi 1.4 petrol 16v)with Torque Pro have following observations.
- Car as cold idle at 1000rpm
- Car after five minute drive and coolant Temp 75c idle at 675 to 700 rpm.
- Coolant temp does not go more than 78c while driving.

Problem is car running fine (For Five minutes) when cold but struggle a lot when it is hot and when I need quick acceleration. It takes ages to go and some times stalls.
Can some one help me out why this is happening.
Regards

 

[RMJ]

If your coolant temp won't go over 78, that says to me that your thermostat is stuck open. Wether that would cause it to stall or not, I don't know. I'd suggest start by testing your thermostat and see if it's opening.

 

[RUM4MO]

Next plan should be to clean and run basic functions on TBA and clean the MAP sensor as it will be oily - ever considered that the engine temperature sensor might be faulty, I think that it is due sensor, one for engine ECU and one for temp gauge, though it could just be a thermostat issue with the engine temperature.

Air filter okay?

 

[hkslls1]

Thanks a lot for response. May I know what is TBA? Regards

 

[RUM4MO]

Thanks a lot for response. May I know what is TBA? Regards

TBA is Throttle Body Assembly.

 

[hkslls1]

Thanks for reply. On sunday I took few more measurement which are here under.
- When cold
IAT - 5c
ECT - 10c
- When hot
IAT - 41c
ECT - 80c

IAT -32c
ECT - 75c

It looks IAT and ECT are quite far. I read from various sorces, ECT has to be 3c above IAT. Is it true? I also observe that when temp on scanner was 70c, dashboard was 75c. look dashboard needle goes fater than temperature on scanner.
When temperature of car goes up while driving, the gap between IAT and ECT goes high. Why this happens? TBA is also has back carbon near contact point otherwise looks quite clean. Can I clean it in-situ using carb cleaner? or I need to remove and clean. Then I think it need VAG.com for alignment which I do not have.
Please provide your opinion.

 

[RUM4MO]

I've never checked the inlet temperature, though maybe the "hot" inlet temperature is hot due to the cool air pipe thermostat not working. Though I can't say that that would cause the problems you are seeing, so maybe what your are reading is roughly okay.

If the car is being driven along a road there is nothing wrong with the engine coolant temperature rising while the inlet air temperature is remaining constant.

If the TBA looks okay maybe that is not your problem, though it would be helpful if you could run "basic functions" on it - and if you could do that, you would be4 as well to clean it up properly.

 

[hkslls1]

Hi RUM4MO, Thanks for response. Today I used torque pro and logged data details are as follows while idle.
-Inlet pressure varies 3.6 to 4.2psi at 700rpm
-short term fuel trims -13.6 to +27.5
-IAT 15 to 38 degree centigrade
- O2 at bank 1 voltage changes from .99v to 1.0
- O2 at bank 2 voltage changes from .5v to .55v
- Surprisingly no fault code registered on ECM
Apart from this car burned about 2 litre oil while running 1650miles. I was not aware of it. I came to know today when oil warning started flashing. I added around 2litre today. No much smoke coming out from tail except water. From engine also no visible oil leak. In fact engine is very clean in look.
Car still hesitate a lot when hot.
Please provide your suggestion.
Kind Regards

 

[RUM4MO]

First, a small thing, you should be seeing O2 Sensor 1 and O2 Sensor 2, ie pre and post cat - bank 1 and bank 2 are the first and second banks of a V engine!

A few reasons as to why that car is burning a lot of oil:- oil/air separator is faulty and not limiting air being drawn through it under high vacuum conditions - I had a version of this with no other running issues other than heavy pinking at about 1800>2200RPM during any weather conditions or engine temperatures - but only under heavy load conditions. That item does cost a bit though, I have not opened up the old one to check what had gone wrong though it does have a built in flap(?) motor, so that pushes the price up to roughly £90 I think! A simpler reason is that you have been over filling the engine on a regular basic, but nothing you have posted has suggested that. Next is that the engine bores are heavily worn, that used to be a problem with the earlier "A" version of this engine, but your one will be a "B" - BBY or BBZ so surely that reason should be discounted.

I hope it is the oil/air separator as it was with mine, though your one must be properly stuffed if it is causing the engine to falter and die as well as drink oil.

Edit:- the beauty of the Polo 9N is that VW fitted an oil level indicator/warning system so you get a warning well before a flashing oil pressure light!

I'm guessing that you know that checking oil level with this engine is close to being a "black art" ? What I do is, after stopping with a fully warmed up engine, wait 10 minutes only > remove/wip clean and refit dipstick > wait 5 or 10 minutes > remove and read oil level.

 

[hkslls1]

Thanks RUM4MO for this wonderful advise. I took car to Diagnostic Garage and said Engine oil is being drawn into Intake Manifold and they have shown me heavy coating of oil/black stuff beyond throttle's butterfly. They suggested following.
1) Cleaning or replacing Oil Separator (Main Culprit)
2) Cleaning of Manifold/Replacing
3) Cleaning/replacing TBA
4) Changing Oil
5) Cleaning/replacing Plugs
6) Cleaning/Replacing EGR
7) Review of O2 sensors

I think its all done by faulty oil separator. This car is 11 year old and doing all above will cost me lot.
It is possible I drive as it is by adding oil to it. Are these above jobs possible with DIY? just doing only cleaning for all.

Please advise.

Best Regards

 

[RUM4MO]

1) Replacing the oil separator, a bit difficult to reach the securing bolts as it is low down at "rear" of engine, certainly not impossible, just a bit difficult as you end up working by feel.
2) I never got round to doing that, should be relatively easy as the inlet manifold is plastic and you should be able to re-use the seals - or buy new seals.
3) Cleaning TBA again easy if you have VCDS to get the ECU to relearn the end limit values, don't try to manipulate the flap as you might distort the linkage etc, it should not need replaced yet!
4) Maybe if its old and due to be replaced on miles/months.
5) Again if they have been in for 30K+/36+months.
6) EGRs in general get a bad name, in my limited experience, ie of this model of engine, the EGR valve will still be clean and probably still okay, it is normally only its pipe port area on the TBA or manifold that gets choked and needs cleaning. Again, VCDS will let you let the engine ECU find its end limits.
7) If your O2 sensors are regularly causing associated fault codes to get logged then yes replace which ever one that is logging fault codes, S1 B1, the one in the manu-cat seems to be the one that goes fault and lets you know when it has.

Good luck! (spend wisely)

 

[hkslls1]

Hi RUM4MO,

Thanks for quick reply,
If I do not do any thing and keep adding oil, what would be consequence of it? Will it completely coke the engine?

Regards

 

[hkslls1]

Hi RUM4MO,
Another one. To remove manifold, Do I need to remove fuel lines and injectors?

Kind Regards

 

[RUM4MO]

In answer to both your questions, I'd think that it will be unwise just to leave it alone as it will coke up everything and start failing MOTs I'd imagine due to cat efficiency reducing.

As these engine are indirect injection, I'd guess that the injectors are in the inlet manifold, which, on reflection, might be why I left that idea alone.

If you throw cash at a new oil separator, if it is the same as mine was, you will reduce this oil usage a lot. I have not opened up the oil separator yet to work out what went wrong with it because I'd doubt if it could be forced open and sealed back up easily.

Maybe you need to get the air cleaner off and have a look, just in case the injectors are mounted in the cylinder head beside the inlet manifold.