Skoda Felicia cold start problem

[vyex]

Hi everyone...

I registred to this forum because i have a problem and i can't find a solution so i decided to describe it...

At winter time (temperature around 0 °C) when i start my car cold, it runs roughly and doesn't increase RPM to approx 1200 to warm up the engine, instead it just runs on normal RPM when engine is warm (around 750). But at summer time (normal temperatures at around 20-30 °C) car starts completley normal (wheen cold started increases rpm to 1200, when warmed up, decreases to approx 750).

I've been having this problem for a longer period of time now (around 1,5 year) and here is a list of thing i have checked and changed so far:

-head gasket, and completley renewed head (valve seals, and all that..)

-coolant temperature sensor

-engine oil, and filter

-spark plugs

-fuel filter

-intake, and exhaust manifolds gaskets

-valve clearances have been adjusted (0.20 - 0.25)

-air filter

-the whole car has been hooked up to diagnostics, and throttle body has been adapted, and there were no errors there.

The coolant temperature sensor has been replaced recently (after throttle body adaptation), so i wonder should i do another adaptation after replacing temp sensor?

I'm all out of ideas right now so please help (lambda probe?, maf (thrust) sensor?)

Edited 24 January, 2013 by vyex

[adurer]

How about an OBD reading when cold starting?

That is the purpose of OBD socket: to hook in and gather data for diagnose.

Why would anyone throw parts at car before having some EVIDENCE... beats me.

[vyex]

The parts weren't thrown...oil, and filter and sparks were changed because of the mileage at which they were suppose to be changed at...gaskets were changed because thermostat blew up and coolant burned the head gasket...throttle body was readapted because there was idling issue (that was later on solved by replacing intake manifold gasket), and temperature sensor was the only thing i replaced without EVIDENCE of knowing that this is the issue (beside checking with he ohmmeter and finding that one part of sensor which sends value to dashboard is working,and the other which should send to ECU isn't showing anything- so i assumed that that part has failed), but after replacing it with new one, problem still persists, so i asked should i do another tba adaptation after replacing it?

Someone had simmilar or same problem....?

I know why there is OBD socket, thank you...and why would anyone reply to the topic if one hasn't got any productive answer or solution regarding the topic he is replying to...beats me.

[RainbowFire]

How about an OBD reading when cold starting?

That is the purpose of OBD socket: to hook in and gather data for diagnose.

Why would anyone throw parts at car before having some EVIDENCE... beats me.

-the whole car has been hooked up to diagnostics, and throttle body has been adapted, and there were no errors there.

Personally I'd take it that they used the OBD port when they ran the diagnostics.

Have you checked the wiring between the temperature sensor and the ECU? (For continuity and resistance)

[vyex]

Not really...what is the easyest way of doing that?

[TeflonTom]

Do you have access to vagcom? It might be worth resetting the basic settings in channel 0.

[vyex]

Listen man, if you don't have nothing smart or usefull to reply in this topic, please don't...i came here to get help, and so that this topic can help others with same issue, not addituede from a guy who thinks he knows everything...and please don't reply anymore, cause in forums...there's no need for people like you...

And i'm really sorry for my looking for answer to my problem came such a big fuzz for someone...i just wanted to hear other people if they experienced this kind of issue, and what they did to repair it...

@TeflonTom...i don't have access to VagCom, yet...but i'll have to arrange a sevice and take it to someone who has obviously...

[TeflonTom]

Ok, it is a very common problem for the coolant temperature sensor to fail, it does have 2 totally separate sensors in the same unit, one feeds the dash, the other feeds the ecu, it is also possible for the guage to be reading correctly but the signal to the ecu being way off.. I know you say you have changed it but dont assume it works correctly, I bought one from gsf that didn't work, then they replaced it, and that didn't work properly either, then i tried one from a local motor factors and i wasnt happy with that. in the end I just shelled out the £35 for a proper genuine skoda one and that cured it.

The symptom you describe with the cold start in winter suggests that the sensor does kind of work in summer but it goes out of range in winter, again this is fairly common for temp sensors to be out of range (ie having the wrong resistance) at extremes of temperature especially with cheap factored parts

in case you were wondering, I should have pointed out that the idle speed and a few other bits and pieces and dependant on the coolant sensor, if the ecu thinks the signal is out of range it will substitute this signal for a 'known' setting for a warm engine instead, this is why I suggest vag com, you can look at group 1 in measuring blocks to see what temp the ecu thinks it is.

http://www.briskoda.net/forums/topic/144738-common-issues-and-solutions-with-feliciafavorit-based-vehicles/#entry1811908

have a look at this link, it gives a bit more detail on the sensors... Legend.

[adurer]

@vyex

For somebody registered yesterday to this forum and not helped anyone, you sure have a lot of nerve judging me.

Didn't you like my initial response? Well, here's TeflonTom telling you the same thing: hook VagCom interface into OBD socket and do that damn relevant data gathering. All the rest are simple hypothesis without it.

Because you like useful replies and fast (aye aye sir) here's a free advice: if you'll go to that shop and use their interface, I suggest you repair the car in there, otherwise you'll look stupid or cocky. I haven't yet decided which one is true.

[vyex]

Ok, so my sensor is new but it doesn't mean it's sending correct data...got it, i'll tak it to diagnostics and then we'll see...that fact you said could actually be true, cause with the old original sensor a fan started when dial was at nearly 100 °C, and with this new one, fan starts when dial reaches 110 °C (on the dash), so it seems that this sensor is not reading correctly...but i'll see that after diagnostics..thanks.

@adurer...You see the topic title?-you assume that the person knows about his car's on board computer and that he knows he can see everything through diagnnostics?-you can assume that he or she maybe can't afford diagnostical exam at the moment, and so asks about his problem on forum?-what is forum for?-so everyone who comes with a guestion, you can answer him or her to go to diagnosstics and that will perhaps resolve their issue?-so what is the point of forum in your opinion?-to tell people that they have obd sockets and to go and check their car at someone who has VagCom...and you think that you are being helpfull with that?

TeflonTom atleast wasn't stupid nor cocky to me as a newly registred member and decided to explain some things to me, that i didn't know...and what did you do?-told me my car has an OBD socket (wooow), and that i throw'd parts at my car, with extra dose of sarcasm-that shows how helpfull of a person you are to newly registred members...if i wouldn't know any way of usefull helping to somebody...i wouldn't even reply on their topic...nah, i'm done with you now for sure

[Laurie Harper]

Adurer - you're correct in one sense. Teflon Tom did indeed give the same advice as you. The difference was that he gave it in a friendly and helpful spirit and did not try to be clever at the expense of another. You may not realise it, but your tone is very arrogant.

[RainbowFire]

Anyone else feeling a "massterful" wind blowing through?

[RainbowFire]

There are forum members with similar engine problems that have a VAG-COM (30 USD, not an arm and a leg) and told their findings after using it as instructed. They finally solved the issue without whining like vywx.

VAG-COM for 30 dollars? Really? Where from?

None of the official products are priced that low.....

http://store.ross-tech.com/shop/cat/VCDS.html

(VCDS-Lite is free, so if you paid 30 dollars for that.......... :| )

[Laurie Harper]

Adurer. "Double measure British brotherhood"? Eh? Now who's being paranoid? You have "zero tolerance for stupidity", do you? I take it that's "double measure Polish modesty"

[daverapid]

adurer, I've seen [and liked] some of your very useful replies in other threads and you obviously have a lot of experience with repairing cars. I also don't doubt that you're a nice guy in the "real world" face to face. But on this thread you do come across as being rather rude.

I hope you take that in the helpful way that I mean it.

[robk1]

^ Thank you Dave, very fairly & concisely put. Sometimes there's just a need for a bit of balanced & reflective capacity amongst what's bouncing backwards & forwards

[daverapid]

If the new coolant temperature sensor that was fitted isn't a genuine one I would recommend fitting a genuine one as suggested by Teflon Tom.

If that doesn't cure the fault we can then blame him!

[TeflonTom]

Yer totally my fault... Hey dave I bet a fiver that there's no fault codes stored on that car either.

[RainbowFire]

Tom, when you say you paid £35 for an OEM sensor to replace the looky-likey - how much was the looky-likey?

[devonutopia]

I have cleaned this thread up and ANY talk about non Ross-Tech / Cloned VCDS will be removed immediately and warning points issued as it is NOT allowed to be discussed!

[TeflonTom]

Tom, when you say you paid £35 for an OEM sensor to replace the looky-likey - how much was the looky-likey?

I can't remember now, they are roughy £10-15 iirc.

[adakt]

I have also exactly. The same problem.

[uma1998]

glow plugs are only there to start them on felicia i had a polo deisel with same engine and ecu that never came on after it was started cold

[adurer]

unter bazza faerkt asdfgh, abba hubba boney m. danyta welle disxelic?