Skoda Fabia 1.4 MPI Rough Idle!

[MinkyMike]

Okay, so, Head Gasket is done, The header tank is keeping its coolant on max, lovely and pink! (nice new coolant tank I ordered febi)

No mayonnaise in the oil filler cap, No pressure the next day in the coolant tank, and also no bubbles when its running, so fingers crossed it stays this way!

Tappets sound lovely  as well.

 

Onto the next issue, It's still seems to be rough idling(as before), some hesitation now and again when accelerating, like its misfiring I'd say, I've plugged it backing VAG COM Shareware and the misfire fault as gone though?

 

Also I did fit new spark plugs.

 

Anyway I've just ordered a new coil pack on carparts4less, HASS, for £43 pound including delivery! (at least I can rule it out then), I didn't want to go the 2nd hand route just incase I got a dud

 

Because I Love Throwing money at this car!! lol

 

Hopefully this solves it, if not, I might be looking at replacing Fuel Injectors, but this seems an expensive option.

 

I'll update when it arrives..

 

Just to add to this post, It had a new battery about 6 months ago, and I had been occasionally putting in that red injector cleaner in the fuel, not often but now and again when I was feeling flush, yeah not often

 

 

also the hoses from the rocker cover are really soft, collapsible and perished, anyone know where I can find this, cant seem to find them on eurocarparts.

 

Edited 20 December, 2020 by MinkyMike

[MinkyMike]

On 03/03/2018 at 20:16, TMB said:

The large breather hose that goes to the rocker cover is 047103493F There is one on ebay...

 

https://www.ebay.co.uk/itm/VAICO-Cylinder-Head-Breather-V109767/162578373670?epid=650611181&hash=item25da6d1c26:g:JSkAAOSwg8taM1m9

 

It's not listing a part number for the small hose but I used 5mm vacuum tube which you can also get on ebay.

Ah, Found in another thread cheers TMB!

[MinkyMike]

well, its not the coil pack.

[TMB]

3 hours ago, MinkyMike said:

well, its not the coil pack.

 

They do have a bit of a rough idle by default but shouldn't misfire. I wonder if it's a faulty injector.

[MinkyMike]

Maybe it's just a rough idle like yours then ? The misfire fault code as gone.. , I've put some stp injector cleaner in and a full tank, see how it goes, still waiting for them breather pipes, but it was Lithuania so god knows when that will come, maybe it's just me lol maybe it's ok. It drives and pulls fine.

[TMB]

7 hours ago, MinkyMike said:

Maybe it's just a rough idle like yours then ? The misfire fault code as gone.. , I've put some stp injector cleaner in and a full tank, see how it goes, still waiting for them breather pipes, but it was Lithuania so god knows when that will come, maybe it's just me lol maybe it's ok. It drives and pulls fine.

 

Might be. Mine has a slightly rough idle but never feels like it's hesitating or misfiring.

[maccy]

    Slightly off this topic but, this morning I thought as the car has not been run for over a week and it was covered in snow,I thought I would start up and warm up the engine as well as putting some charge back in the battery as I need to do a food shop.Started first time but after a few seconds the coolant hi-temp light came on and then started beeping,first thing I thought of was coolant level.I checked it and it was dead on the “min” level on the header tank.I let it run for 5 mins and it was still on.So I put just enough coolant in to take the level to half way.Still flashing on dash.Stopped the engine and restarted, light had gone off.

    So my question for the team is:  has anyone any idea at what level in the header tank does the “Low coolant level” light come on ?

   

[Xsr]

On 29/12/2020 at 15:47, maccy said:

has anyone any idea at what level in the header tank does the “Low coolant level” light come on ?

   

It measures the resistance on the sensor prongs inside the tank. These prongs are easily contaminated and give false readings. Especially when left stationary for a while. Weather conditions can also affect the sensitivity of the sensor (cold most noticeably) this has to do with the anti-freeze properties of the coolant. If it freezes and the coolant is not up to standard. It could damage the prongs. A new coolant bottle is required in that case. Same goes with contaminants (though you could try to rinse it out with a bit of brake cleaner as a dirty cheap solution to see if it fixes it.) If the problem returns its most likely due to contaminants like oil. And you should get your waterpump system / headgasket checked.

 

On 23/12/2020 at 12:22, MinkyMike said:

Maybe it's just a rough idle like yours then ? The misfire fault code as gone.. , I've put some stp injector cleaner in and a full tank, see how it goes, still waiting for them breather pipes, but it was Lithuania so god knows when that will come, maybe it's just me lol maybe it's ok. It drives and pulls fine.

 

I've had a lumpy idle problem with my fabia. A simple 'tune up' got rid of it (Cleaning the throttle body and air pressure sensor, and dump a bottle of wynns injector cleaner in the gas tank. followed by an italian tune up.) This was after i made sure i had no exhaust or vacuum leaks. (also a quick way to get a lumpy idle on a fabia) To be fair though the air pressure sensor was the only thing that was noticeably dirty so if i had to attribute it to 1 specific component it would be that. The wynns injector cleaner i use once a year. But to be fair. I've only noticed a significance difference the first time i used it. beyond that point it has just been a part of the yearly maintenance schedule and it has always responded fine. My AQW engine is lumpy by default. But you get a feel for it eventually what is normal and what not. I call them "hickups"  It shouldn't be continues.

[Alexandru]

hi guys. it's been a while since I wrote here the last time. I had an issue with a vacuum hose on mine. I had a poor idle and the engine was dying sometimes. I was looking under the hood one morning and heard an air leak, the hose was cut in the middle. I replaced it with a cheap, universal 8mm iirc, fuel hose and works just fine. I don't have a picture at hand right now, it's the one which is in the left side of the throttle body and gets to the head breather, the narrow, not the wide one. If I'll get the chance later I'll take a picture of it and will share it with you.

[MinkyMike]

Ah, yes mine are very brittle and are collapsing when squeezed, I ordered both breathers and the big one arrived yesterday just waiting for clic r type pliars to arrive so I can swap them.

[Alexandru]

fingers crossed !

[MinkyMike]

Well I've just changed them both, When taking the big one off the rocker cover, the metal hole was rammed full of black soot, like coal, so that's done, see if it makes a difference, not started it yet.

 

also... I've just noticed the coolant as gone from max to min, over a week ! no cream in the oil cap, but upon running my fingers across the bottom of the radiator I have a leak, at the bottom left if your looking from the front of the car,

where the metal fins meet the plastic, its not a lot but if defiantly explains where that little bit went, oh well, there's another job I've got to do, I'm gonna save my coolant this time because that was expensive! - is it an easy job ?

just undo the hoses and it pulls right out? , it really is never ending, I've never had a car with this many problems lol :/ the £'s are well adding up.

 

I'm fully committed now . Bah!

[Breezy_Pete]

Check that the leak isn't coming from the thermoswitch first. Seems very common and results in wetness below it. It's just above the bottom hose fitting. Tightening a little generally fixes it.

[MinkyMike]

19 minutes ago, Wino said:

Check that the leak isn't coming from the thermoswitch first. Seems very common and results in wetness below it. It's just above the bottom hose fitting. Tightening a little generally fixes it.

do you mean the radiator fan switch? - I think I had a leak there before, its on the other side, where the electrical cable plugs in, it's dry as a bone that side now..

 

there is nothing down that side I don't think, it feels as if the fins are rusted 

 

I'm guessing the head gasket had been gone for a couple of years judging by the state of the water in the system, maybe this contributed to letting the radiator erode?

Edited 9 January, 2021 by MinkyMike

[Breezy_Pete]

Yes, the fan switch.  Shame it wasn't that, it would've been a free fix.

I clearly read too fast the bit where you described the location. 

Edited 9 January, 2021 by Wino

[TMB]

You don't have much luck with this car Mike.

 

Thankfully, radiators can be had for cheap money these days. Unfortunately, the bumper, crash bar and slam panel has to come off to do the job.

 

These videos may help with the general idea...

 

 

 

Edited 9 January, 2021 by TMB

[TMB]

Superfluous post.

Edited 9 January, 2021 by TMB

[Westbury63]

On 20/12/2020 at 13:25, MinkyMike said:

Because I Love Throwing money at this car!! lol

We all love that.

 

Just a thought, temperature sensor. Had to replace 2 or 3 in my Mk1 Octi over 12yrs. The temp sensor sends infor the the ECU, and given they are £5 a pop, worth a punt?

 

My Octi has a slightly lumpy old at 3.5 yrs old, and was still there 12 yrs later. Character.

[TMB]

Yeah, definitely worth changing the temp sensor if it's old. Dead easy job. Strongly advise getting a genuine one.

 

Part number 06A 919 501 A

Edited 9 January, 2021 by TMB

[Xsr]

On 22/12/2020 at 23:04, TMB said:

 

They do have a bit of a rough idle by default but shouldn't misfire. I wonder if it's a faulty injector.

 

Two easy ways to test it (without having to disassemble anything)

One is to put a clamp meter in ohms on the injector leads and check for any abnormal readings.

Two is to use an oscilloscope and back probe the injector/injector rail and check the current draw of each injection pulse and check if any of them are not contributing as much as they should. (An obstructed injector will usually appear to have a lower curve than a good injector)

 

Doing both at the same time and cross referencing that data also makes it able for you to pin point which injector it actually is by moving around the ohm clamp.

 

Given that you can also do this with a noid light or power probe, they can easily throw you off.

 

If this is not your cup of tea, there is yet another way (disassembly)

Get yourself a EM276 injector tester (The chinesium kind that are cheap and widely available) pull the injectors and test them with that. 

Edited 9 January, 2021 by Xsr

[TMB]

^ Great info!

 

I'd honestly never heard of a 'noid light' but I've never needed to touch an injector so far. You learn something every day

[J.R.]

A clamp meter in ohms???????????????

 

Do you mean probing using the test leads on the resistance range?

 

If so then why a clamp meter?

[Xsr]

59 minutes ago, J.R. said:

A clamp meter in ohms???????????????

 

Do you mean probing using the test leads on the resistance range?

 

If so then why a clamp meter?

 

I had to read it a couple times before i understood what you meant. My use of words might be off.

What i mean to measure is amperage, or better said the resistance that causes the amperage to change.

Its driven by a solenoid. Any issues tend to show up as resistance which you can be measure that way. 

Same trick can be used on spark plugs leads to do a quick and dirty relative compression test.

Is it accurate? No. Does it work? It can provide you with indicative information as in 1 of the 4 injectors has a significant different reading than the others. So yes. Its quick and dirty. Could also be that 3 of the 4 are messed up and you are looking at a the one working injector. Or its all over the place and none of it says anything while one of em is messed up. Back probing with an oscilloscope and measuring current would then be a better option. But not everyone has one laying around.

Edited 9 January, 2021 by Xsr

[J.R.]

I had not seen your location and realised you were using a second language, like so many of your compatriots your English is so good I had not realised.

 

You can only measure voltage with an oscilloscope unless you start mucking around with shunt resistors. Not sure if a current probe would work on a DC solenoid, I have never tried one and sold my O scope several years ago which I immediately regretted.

 

I do agree that the scope trace will likely identify an anomolous injector.

[Xsr]

1 hour ago, J.R. said:

I had not seen your location and realised you were using a second language, like so many of your compatriots your English is so good I had not realised.

 

You can only measure voltage with an oscilloscope unless you start mucking around with shunt resistors. Not sure if a current probe would work on a DC solenoid, I have never tried one and sold my O scope several years ago which I immediately regretted.

 

I do agree that the scope trace will likely identify an anomolous injector.

 

That's ok. I'll take that as a compliment haha.

 

There's more than one way to skin a cat. And the usage of an amp/current clamp is one of 'em (not quite sure what the correct terminology is, we call it an 'amperetang' which literally translates to amperage pliers)

Edited 9 January, 2021 by Xsr