Hi!

A couple of days ago I bought a 1998 octavia.

Bought it from an older couple who took great care of it mechanically but neglected everything else. Was planning on using it over the winter so I wont even bother with the cosmetics.

Something I didnt notice when I testdrove it but that later on started bothering me was the performance of the engine. No cel lights, and everything else works perfectly.

I have read about coolant temp sensors, ignition coils, and lots of different things failing on these cars, but before I start replacing anything I would like to figure out what the problem is.

To guide those who are willing to give their input, I would describe the problem as a loss of torque? Especially going uphill it struggles to gain any speed no matter what gear or at what rpm the car is in. The idle is a little irratic(missfires slightly)? And in some cases it wont start on the first turnover. Second start it runs normaly. One thing I suspect could be the problem is something electrical? Maybe coilpack? Because after having washed it once, the car wouldn't start, after a few turnovers it did.

Any input would be very helpful, I have no Cel and I guess this makes it even more difficult figuring out what the hell is wrong with it ????

You need a diagnostic test. Is nothing more than a blind guess with out. You may not have a cell but there will be faults stored in the ECU.

Usually faults are..

Coil packs and leads

Coolant temp sensor

Air mass sensor

Pre cat lamba sensor

Perfect thanks! Was wondering about that, if it stored the fault codes. Will get it connected to a odb pc toworrow. Anything more you would recommend looking at?

Will get back tomorrow with fault codes!

So - I got it connected to a pc!

 

Found a stored fault! (00525 Lamda signal to low). Cleared it, and took the car for a 25km run, it didn't come back up.

Took it for another drive and looked at the live data, and the voltage of the lambda was changing between 0 - 0.9V very rapidly, i guess this means that it is ok?

 

Another thing that i noticed in the live data was the coolant temperature, it started from somewhere around 10'C (same as outside temp) and went all the way up to 80'C and stopped there,

it's supposed to hit somewhere around 90'C, right? Temp guage was showing 90'C but the computer thinks it's 80'C?

 

And then the intake temp sensor, was showing 23'C It was 8-10'C outside and I was driving on the highway doing 120km/h, can this be right? 

 

That's all I know for now, any input would be greatly appreciated! 

So, no answers yet but I'll keep on posting updates, maybe someone else has the same problems later on and my experience can be of help.

Got the coolanttempsensor home and it didn't fit, apparently there are two different models, they share the same connector but the "sensoring" part can be either completely flat or pointy. I ordered the pointy one and the tip of it hits a pipe or something in the thermostat housing. Will get it replaced further down the line. But I discovered something else, that I think might be the cause of the performance issues I am having.

Three times now I have experienced the same thing. Cruising on the highway I've experienced a judder? Not a missfire but something very similar to when you allmost run out of fuel. And this has led me to believe that it is a clogged fuelfilter, fuelpump problem. I suspect the filter as it looks to not have been changed since the car was new. Strange considering how well maintained the car is otherwise. Will get this replaced next week and get back with results.

And on to something unrelated. I experienced something very unusual with the car upon stopping, when I came to a complete halt the car wobbled. To me it felt like the engine was moving. I inspected the engine mounts, and they all seemed fine, not quite sure about the dogbone mount but I guess it's alright. A few days later it developed a squeak when braking, especially low speed. Very confused about what might be the cause I inspected the frontend. And found that the left front wishbone bushings were severly worn especially the rear one. With the wheel on i shook it back and forth and to my surprise there was lots of play in the bushing. So I guess the previous wobble when breaking and the squeak from the front end both relate to this front wishbone bushing. This to will be replaced with the filter. Will get back with results.

Not sure about the AEE engine code, but my 1.6 BFQ has a DBW throttle body and it had a lot of the symptoms which you've decribed (loss of power when pushing the accelerator pedal to the floor, erratic idling, non-linear acceleration from time to time ) until I've taken the throttle body out, cleaned it with carb cleaner, put it back in and did a throttle body alignment with VAG-COM. No problems after this. So, if you have an electronic throttle (DBW), it's worth to give it a good clean.

Edited 23 October, 20169 yr by n.chris

So the front wishbone bushings and fuelfilter has been replaced!

 

Not quite sure if the fuelfilter made any difference, but can say that replacing the wishbone helped (what felt like an engine wobble) and horrible frontend squeak during breaking.

Car now feels so much better!

 

 

Not sure about the AEE engine code, but my 1.6 BFQ has a DBW throttle body and it had a lot of the symptoms which you've decribed (loss of power when pushing the accelerator pedal to the floor, erratic idling, non-linear acceleration from time to time ) until I've taken the throttle body out, cleaned it with carb cleaner, put it back in and did a throttle body alignment with VAG-COM. No problems after this. So, if you have an electronic throttle (DBW), it's worth to give it a good clean.

 

Was planning on doing this, and searching for vaccum leaks too, Thank you! Will get back with results

New to thread. I think you have a thermostat problem. The (IMO useless) design of the gauge control system means that it reads 90C when the engine temp is between 60C and 105C. 80C is "a bit cool" which makes me think that the thermostat is opening too far (or maybe even stuck open; is the car slow to warm up?)

New to thread. I think you have a thermostat problem. The (IMO useless) design of the gauge control system means that it reads 90C when the engine temp is between 60C and 105C. 80C is "a bit cool" which makes me think that the thermostat is opening too far (or maybe even stuck open; is the car slow to warm up?)

Thank you for your input! It seems like this could also be the case. Car was not slow to warm up when the intake "heating" hoses were connected to the exhaust manifold. But I removed them for better performance

which I got, but as a consequence it is now slow to warm up. Could be a problem with the termostat. Will be replacing things as I go along. As for now the new fuel filter seems to have gotten rid of the 

judder I experienced during highway cruising, and maybe even gave a slight performance increase.

 

I am leaning towards getting the throttlebody cleaned and aligned as the symptoms described by n.chris are very similar to the symptoms I am having. And it should hopefully be a very cheap fix.

 

Thermostat will probably be replaced when I get the cambelt and waterpump replaced. Will get back with results!

Ah, the non-standard pre-heating setup makes it hard to carry out diagnosis of cold start, warm up and running temperature issues.