Sluggish cold start --- 1.2 TSI CBZA

[Koreenium]

Normaly starting the engine sounds nice and crisp. RPM jumps to 1400-1500 and comes slowly down. If the catalytic converter needs to be warmed up, engine is going to idle around 1100-1200 rpm for 20-30 seconds and then comes down to 650-700 rpm unless the AC is running in which case it comes down to ~900 rpm. But recently I got a new problem. Cold starts when the car has been sitting for 4+ hours, no matter what the temperature outside is, I get really sluggish engine start. RPM jumps to 1300 and immediately drops to 1000 or less. And instead of nice crisp start it sounds muffled, sluggish. And I can feel that the engine idles rough. A lot of small and some bigger jolts shake the cabin every few seconds. I used VCDS and noticed that there are maybe few misfires every now and then on all 4 cylinders at any random time but they don't seem to correspond to the jolts I'm feeling. After the engine warms up all of these problems go away. Engine starts nicely, no jolts, no misfires. 

 

Video of sluggish cold start: 

 

When the car has run atleast few minutes or has been properly warmed up by driving around:

 

Things that I have done a while ago way before this started happening:
1) Changed spark plugs with Bosch Iridium FR6HI332. Old were decently clean and completely dry but warn out. Who ever changed the spark plugs prior used quite a lot of anti-seize on the threads. I just checked recently and the spark plug for the first cylinder had loosened itself and I retorqued them down to 25 Nm.

2) Changed faulty N80 EVAP purge valve/solenoid. No problems with it after that.

 

 

Other problems I noticed around when this sluggish cold start started happening and overall poor engine performance. Engine block breather valve under the turbos pressure tube/pipe started leaking because the rubber grommet had split. I replaced the grommet, I got the whole thing out, and the one way breather valve itself. After that I noticed that the oil seperator had started leaking instead of just seeping oil. Also noticed that the AC compressor is seeping oil and it has been doing it for a while. No major leak there.

 

What I have done after this problem started occuring:
1) Obviously replaced the split, leaking rubber grommet for the engine block breather valve.

2) Replaced engine oil but instead of regular 5W-30 I used 0W-40.

3) Cleaned the throttle body.

4) Used STP fuel system cleaning stuff. 

 

When cleaning the throttle body I also noticed that there is a lot of oil inside the inlet manifold.

 

Not sure how much is coming from the turbo. Turbo seems fairly dry and there is fairly light coating of oil all the way to the throttle body.

What I have read on some russian forum is that a leaking oil seperator and oil in the inlet manifold suggest there could be some sort of problem with the engines oil and oil vapor movement. Possibly a blockage somewhere? And some guy even suggested cleaning, replacing engines non return valve ( 03F103175A ) which I have not done yet.

 

 

Also overall engine performance before the turbo kick in around 1600-1800 rpm seems to be poorer compared to before. And for example when I'm driving around 40 km/h in 4th gear and I want to accelerate then the engine starts to struggle. It makes quite loud, vibrating, rumbling noise and fades away as the speed increases. 1000-1200 rpm at 40km/h and it's rumbling up to around 1400-1500 and then it runs smooth. I'm pretty sure it was not like that before or maybe that's my imagination? RPM seems to be lower aswell when driving at a constant speed compared to before but I did not really pay much attention to this before so I might be wrong.

 

Oh and only fault code I get is: "00819 fault code lower limit exceeded" but that seems to have something to do with the AC system.

 

 

Anyway I need your help. Hopefully you can give me suggestions as what to do next. I also have VCDS so I can use that to check any values if that helps.

[xman]

Misfires, so 90% certain that it's one or more plug lead failure. Very common even at low mileage on pre 2012 engines particularly no. 3 lead which rests on or very near the turbo heat shield without the protection of plastic trunking found on later engines. They should measure about 9k ohms each end to end with a multimeter.

 

Essential to replace these asap as a faulty lead frequently promotes coil pack failure due to over voltages in the pack.

 

All your performance issues may disappear once the leads are changed as its just down to a very weak spark on two cylinders (the "waste spark ignition" design means plugs fire in pairs on this engine)

 

Use a proper tool to remove the spark plug metal boots, dont pull by the leads as you will just break the fragile cores.

Edited 2 October, 2020 by xman

[Koreenium]

Thank you for the suggestions! I'll be replacing ignition leads and the ignition coil. 

I do have a special puller for removing the igniton leads.

 

So this may fix performance issues but would this also affect the cold start like that? Because once the engine is warm, it starts and runs smooth.

[xman]

8 minutes ago, Koreenium said:

 

So this may fix performance issues but would this also affect the cold start like that? Because once the engine is warm, it starts and runs smooth.

 

Think about it. A cold start and the engines runs a really rich mixture for a couple of minutes to heat up the catalytic convertor quickly. Weak sparks struggle to ignite rich mixtures cleanly.

 

[Koreenium]

I replaced the ingintion wires with Bosch wires and replaced the ignition coil with BERU. Now the engine runs ever so slightly smoother and has slightly better acceleration at 1200-1400rpm. But first cold start had exactly the same problem and engine does not run any smoother when cold. If I immediately turn engine off after first cold start and start again, it starts up just fine. I have to check if I still get random intermittent misifires.

[xman]

It may be worthwhile to disconnect your battery for 5 minutes to reset the ECU learnt parameters. Also have you checked your air filter is reasonably clean?

[Koreenium]

1 minute ago, xman said:

It may be worthwhile to disconnect your battery for 5 minutes to reset the ECU learnt parameters. Also have you checked your air filter is reasonably clean?

I had battery disconnected for half an hour perhaps.

 

Air filter is basically looking like brand new.

[Koreenium]

I'm going to check the gap on spark plugs and see if any of them are cracked, damaged.

[xman]

On 02/10/2020 at 17:31, Koreenium said:

 And for example when I'm driving around 40 km/h in 4th gear and I want to accelerate then the engine starts to struggle. It makes quite loud, vibrating, rumbling noise and fades away as the speed increases. 1000-1200 rpm at 40km/h and it's rumbling up to around 1400-1500 and then it runs smooth

You should really change down gear at 40km/h. From my experience with our 1.2tsi fabia 86ps, it is unreasonable to expect a smooth experience accelerating from 1000rpm in 4th gear unless very very gently. From my recollection it can be pretty rough if you try to accelerate hard like that and the engine vibrates and complains a lot until you get to 1300 rpm or above. It wont do your hydraulic? engine mounts any good either. In any case its best to keep the engine revs above 1400 rpm, as it is far more efficient in that region and use less fuel than slogging it. Will also reduce long term nasties such as carbon build up and possible fuel/oil dilution.

 

Have you checked whether the small pcv valve located in the back of the cam cover to the right is still intact? These often break off and hang down on the flexble rubber hose going to the air box. I wouldn't have thought this would make a difference to cold starts though.

 

Sometimes running issues are caused by a history of excessively slow gentle driving. Have you tried an "italian tune up"?  If you dont already know, this is just a phrase used by some to describe hard acceleration from say 1500- 4500 rpm several times (I recommend 3rd gear) developing max boost to clear out soot and debris from the engine. Only do this with a warmed up engine though and where it is safe and legal to do so!

 

Edited 7 October, 2020 by xman

[Koreenium]

27 minutes ago, xman said:

You should really change down gear at 40km/h. From my experience with our 1.2tsi fabia 86ps, it is unreasonable to expect a smooth experience accelerating from 1000rpm in 4th gear unless very very gently. From my recollection it can be pretty rough if you try to accelerate hard like that and the engine vibrates and complains a lot until you get to 1300 rpm or above.

Yes. I usually change down and try not going below 1400 rpm but for whatever reason I remember it being smoother even at 1200rpm back when I got it. Maybe I just remember wrong as I mostly listen to fairly loud music when driving around. So perhaps it diluted my perception on how the engine is supposed to sound and feel. But I usually drove around city in 4th gear at 40-50km/h and it definitely lacked power when accelerating but like I said, I remember acceleration being smoother and less struggle for the engine. It still sounds like it's struggling in 3rd and 4th gear when rpm is below 1400. maybe slightly better than before. Now I'm mostly in 3rd gear for anything below 45km/h because the engine really does not like it otherwise.

 

42 minutes ago, xman said:

Have you checked whether the small pcv valve located in the back of the cam cover to the right is still intact? These often break off and hang down on the flexble rubber hose going to the air box. I wouldn't have thought this would make a difference to cold starts though.

One of these things?

I actually changed it just recently, after I started getting performance issues I noticed that oil was leaking around from the hole where it plugs into cam cover. I found out that the rubber grommet was actually split. Luckily I got it out without anything falling into the engine. It helped alot with poor engine performance but did not fix it completely. And after fixing this I started getting a significant oil leak from the oil separator. Which I'm going to be hopefully fixing soon.

 

48 minutes ago, xman said:

Sometimes running issues are caused by a history of excessively slow gentle driving. Have you tried an "italian tune up"?  If you dont already know, this is just a phrase used by some to describe hard acceleration from say 1500- 4500 rpm several times (I recommend 3rd gear) developing max boost to clear out soot and debris from the engine. Only do this with a warmed up engine though and where it is safe and legal to do so!

I have been running it more agressively lately. Especially considered that I have to downshift far more often now. Fuel consumption has definitely gone up. Before I averaged around 6.5L/100km but now I'm more around 7.5L/100km. If my math is correct.

I was wondering if the rougher idling when engine was cold may have something to with soot build up on valves.

 

 

[Koreenium]

I went on a test drive and ofcourse my laptops battery was empty so I couldn't use VCDS but cold start was still sluggish. And no matter in which gear I am, even very gentle acceleration from 1400rpm, engine starts struggling but at 1500rpm becomes smooth. I also noticed that as soon as I step on the gas, there is faint gushing noise and as soon as I let go, it stops. Perhaps this is normal?

[xman]

45 minutes ago, Koreenium said:

I also noticed that as soon as I step on the gas, there is faint gushing noise and as soon as I let go, it stops. Perhaps this is normal?

 

Stepping on/off the gas will close/open waste gate (electric actuator) and increase/decrease airflow and exhaust flow but in my experience its inaudible 

 

Check your boost pipework/joints and intercooler carefully for air leaks. Also check exhaust joints and pipework from turbo onwards for holes/leaks including the flexi joint in the exhaust.

Edited 7 October, 2020 by xman

[Koreenium]

13 hours ago, xman said:

Stepping on/off the gas will close/open waste gate (electric actuator) and increase/decrease airflow and exhaust flow but in my experience its inaudible 

It's almost inaudible. I have to be driving on some smooth road to really hear it.

 

13 hours ago, xman said:

Check your boost pipework/joints and intercooler carefully for air leaks. Also check exhaust joints and pipework from turbo onwards for holes/leaks including the flexi joint in the exhaust.

Any tricks to find any possible air leaks? On a quick look I did not notice anything obvious. Might need to get a vape pen. 

 

 

I did some monitoring with VCDS and noticed that on a cold start I get misfires basically only on the 1st cylinder. Which also happens to be the one cylinder where the spark plug had loosened itself over time. I also had hard time getting the ignition wire onto the 1st spark plug as if something was in the way. New wires looked just fine so it may be that the spark plug is damaged or something. I'll be checking that once the engine cools down. I did also get 1 misfire on cylinder 3. And when monitoring the misfires I noticed that VCDS only gives me options to observe misfires on cylinder 1,3,4 and 6 so cylinder 3 is actually 2?

 

When monitoring misfires I can now definitely distinguish misfires from engine randomly jolting. So the jolts I feel are not misifres? What can they be?

[Koreenium]

21 hours ago, Koreenium said:

I also noticed that as soon as I step on the gas, there is faint gushing noise and as soon as I let go, it stops.

Actually gushing is not the right description. When I press accelerator, even slightly and I don't accelerate, I get this flapping noise that reminds me of flat tyre. And as soon as I let go, it completely stops. I also noticed that when I go over a wavy road, this noise comes and goes as long as the accelerator is pressed down slightly.

 

 

I removed spark plugs and tried looking inside the engine. I don't have a borescope so what I saw was limited but it looks like there is quite a bit of carbon buildup on the piston. All 4 cylinders were nice and dry. Spark plugs themselves look good.

 

 

I am planning to do vacuum test with a vape pen. What would be the ideal vacuum line to use for testing?

[xman]

On 02/10/2020 at 17:31, Koreenium said:

Who ever changed the spark plugs prior used quite a lot of anti-seize on the threads. I just checked recently and the spark plug for the first cylinder had loosened itself and I retorqued them down to 25 Nm.

 

10 hours ago, Koreenium said:

did some monitoring with VCDS and noticed that on a cold start I get misfires basically only on the 1st cylinder. Which also happens to be the one cylinder where the spark plug had loosened itself over time. I also had hard time getting the ignition wire onto the 1st spark plug as if something was in the way. New wires looked just fine so it may be that the spark plug is damaged or something. I'll be checking that once the engine cools down. I did also get 1 misfire on cylinder 3. And when monitoring the misfires I noticed that VCDS only gives me options to observe misfires on cylinder 1,3,4 and 6 so cylinder 3 is actually 2?

 

Just thinking out loud......

 

Antiseize or grease on spark plug threads is a bad thing on the EA111 engines. Grease interferes with electrical and thermal path to the head and if it is something like copperslip, electrolytically corrodes threads in the aluminum head. The fact the sparkplug came loose could mean thread is loose/damaged or.............

 

You say you had problems putting the connector back on the no.1 plug as if somethings in the way. There is very little clearance around the metal boot, so maybe the plug is not true in the head, due to someone crossthreading/damaging/recutting the soft thread in the cylinder head? Maybe thats why theres a lot of grease in there....

 

Due the waste spark ignition design on the 1.2tsi, if you haven't got the boot fully down and properly connected then, you will get misfires shown on both no.1 and no. 4 cylinders. (electrically they are in series connection)

 

 

10 hours ago, Koreenium said:

When monitoring misfires I can now definitely distinguish misfires from engine randomly jolting. So the jolts I feel are not misifres? What can they be?

 

This reminds me of my experience of a Polo decades ago. That in the end was due to a damaged/burnt  exhaust valve seat which I found with a compression test. Something small had lodged on the exhaust valve seat on its way out I think. That used to jolt (badly) whenever I tried to accelerate under load.

 

Hope this gives you some ideas on tracking this down.

 

Q. Does it burn/use oil?

 

Edited 8 October, 2020 by xman

[Koreenium]

19 hours ago, xman said:

Antiseize or grease on spark plug threads is a bad thing on the EA111 engines. Grease interferes with electrical and thermal path to the head and if it is something like copperslip, electrolytically corrodes threads in the aluminum head.

That's good to know. Every time I have taken the plugs out I have also been able to clean some of it off. Whoever did it, used some sort of grey antiseize.

 

19 hours ago, xman said:

The fact the sparkplug came loose could mean thread is loose/damaged or.............

This time when I removed the spark plugs they were all secured just fine. So perhaps it was because of antiseize?

 

19 hours ago, xman said:

You say you had problems putting the connector back on the no.1 plug as if somethings in the way. There is very little clearance around the metal boot, so maybe the plug is not true in the head, due to someone crossthreading/damaging/recutting the soft thread in the cylinder head?

I removed the spark plug and when I put it back in again, the ignition wire went on just fine. I did not look at the threads so I don't really know. I had no problems taking it out and putting it back in.

 

20 hours ago, xman said:

Due the waste spark ignition design on the 1.2tsi, if you haven't got the boot fully down and properly connected then, you will get misfires shown on both no.1 and no. 4 cylinders. (electrically they are in series connection)

That's good to know. Most of the misfires happened on number 1.

 

20 hours ago, xman said:

This reminds me of my experience of a Polo decades ago. That in the end was due to a damaged/burnt  exhaust valve seat which I found with a compression test. Something small had lodged on the exhaust valve seat on its way out I think. That used to jolt (badly) whenever I tried to accelerate under load.

 

Hope this gives you some ideas on tracking this down.

I can also do the compression test. What sort of numbers should I get?

 

20 hours ago, xman said:

Q. Does it burn/use oil?

Not much. I changed oil 2000km ago and it's basically at the same level as before. Ofcourse assuming there is no oil dilution.

[Koreenium]

On 08/10/2020 at 21:00, Koreenium said:

Actually gushing is not the right description. When I press accelerator, even slightly and I don't accelerate, I get this flapping noise that reminds me of flat tyre. And as soon as I let go, it completely stops. I also noticed that when I go over a wavy road, this noise comes and goes as long as the accelerator is pressed down slightly.

I was trying to record this but my phone is not capturing the sound. But I found this video on youtube where they have a very similar sound when pressing accelerator.

 

[Koreenium]

Well, I think this engine is slowly on it's way out. Just today I noticed that there was burnt oil slowly leaking out of the exhaust. It was completely dry few weeks to a month ago.

 

Not to mention that oil separator is leaking pretty noticeably and has even sprayed some oil out. I wanted to take it apart and reseal it but it's basically impossible without taking the subframe out etc.

[xman]

It might be as you say, the oil seperator not doing its job properly.

 

Check the pcv (positive crankcase valve) system is not blocked and causing over pressure in the crankcase.

 

I wonder if its worth trying to clean with some engine flush, although it may very well cause even more problems, so maybe not.

 

Could be piston ring wear, excessive blow by and crankcase pressure.

 

Wet/dry compression checks will reveal. No ideas about numbers. But check they are balanced. Clue might be cylinder 1, loose plug could be the problem cylinder?

 

Maybe see if you remove the oil filler cap, or alternatively the dipstick, you can feel/see air blowing out.

[Koreenium]

I cleaned the PCV pipes. They were not blocked but I noticed that there was quite a bit of oil in it. And one of the ends that connects to the check valve (non-return valve on the cylinder head) had fair amount of gunk in it but not blocked. And then I looked into the check valve and it had quite a bit of gunk and so did the bigger short pipe that connects the check valve to the turbo. I took the check valve off and noticed that it wasn't working as intended. You could blow air and brake cleaner through it in every direction. So I replaced it with a new one and my first impressions are that it made a noticeable difference. Now the engine is much more happy to rev and it feels pretty much like it used to before at lower rpm. Rumbling noise seems to go away near 1300-1400rpm instead of 1400-1500.

 

I took the dipstick out when the engine was running and I did not feel any air movement. Engine did not seem to have been affected by this at all. When I removed oil filler cap then It felt like quite a bit of air was getting blown out. Not sure. And it felt like the cap was held on with basically no vacuum? Not sure what to think of this.

 

Did not do compression test just yet.

[bigjohn]

5 hours ago, Koreenium said:

 

I took the dipstick out when the engine was running and I did not feel any air movement. Engine did not seem to have been affected by this at all. When I removed oil filler cap then It felt like quite a bit of air was getting blown out.

 

As Xman has mentioned crankcase can get a bit of pressurisation if something is wrong with crankcase ventilation be it something blocked or a faulty PCV. With excessive crankcase pressurisation gases will try to escape somewhere, be it inlet/exhaust valve oil seals which can increase oil consumption and this may show up at the exhaust tailpipe [EDIT - the oil in the inlet manifold might be a clue?] . Re check everything re crankcase ventilation.  Different engine but my old Octavia 1.416v suffered with a blocked oil pipe within the air filter housing as part of the breather setup that caused the oil level to be low after a few hundred miles, when I sorted it oil consumption went back to normal.

 

Also how many miles has the engine done? Gases being blown out could also be a bit of piston blow by?  When working with older cars in the past I've known crankcase pressurisation to push oil past all sorts of things be it oil valve seals , crank oil seals, gaskets (sump, rocker etc) and on an old Cortina the dipstick was ejected. 

 

Cylinder no 1 misfiring is strange - just in case is all well with the timing chain, no rattles etc?

Edited 18 October, 2020 by bigjohn

[Koreenium]

Replacing the check valve fixed my sluggish cold start. Now it starts normally again.

 

19 hours ago, bigjohn said:

As Xman has mentioned crankcase can get a bit of pressurisation if something is wrong with crankcase ventilation be it something blocked or a faulty PCV. With excessive crankcase pressurisation gases will try to escape somewhere, be it inlet/exhaust valve oil seals which can increase oil consumption and this may show up at the exhaust tailpipe [EDIT - the oil in the inlet manifold might be a clue?] . Re check everything re crankcase ventilation.  Different engine but my old Octavia 1.416v suffered with a blocked oil pipe within the air filter housing as part of the breather setup that caused the oil level to be low after a few hundred miles, when I sorted it oil consumption went back to normal.

I'll recheck the hoses. I'll use a soft plastic rod or something like that and see if there is any resistance in the way. 

There aren't that many parts to the PCV system is there? I know there is that one hose that comes from the air filter housing and connects to the PCV valve. Got the PCV valve just repalced aswell.

And then there is that 3 way hose where one end connects to the N80 purge valve (I also replaced this with a new one as I was getting an fault code refering to it, which has not come back after replacing it.) another end connects right below the throttle body, to the inlet manifold and the third end connects to the check valve which was broken and just got replaced. Anything else?

Perhaps there is a blockage inside the engine somewhere?

 

20 hours ago, bigjohn said:

Also how many miles has the engine done? Gases being blown out could also be a bit of piston blow by?  When working with older cars in the past I've known crankcase pressurisation to push oil past all sorts of things be it oil valve seals , crank oil seals, gaskets (sump, rocker etc) and on an old Cortina the dipstick was ejected. 

242 000km, so quite a lot. It could be that at this milage engine is just worn and this much blow by is normal. I'm going to put a rubber glove over the oil filler cap hole while the engine is running and see how much it inflates it. Perhaps what I felt was just an air movement and not really air being blown out.

 

20 hours ago, bigjohn said:

Cylinder no 1 misfiring is strange - just in case is all well with the timing chain, no rattles etc?

I did some more testing and now I got only 1 misfire on cylinder 1 but 3 misfires on cylinder ?4? (actually 2?) For whatever reason when checking misfres, cylinders are labled as 1,3,4,6. And when checking knock sensor, cylinders are labled like this: Cylinder 1: knock senor voltage cyl.1; Cylinder 2: knock senor voltage cyl.4; Cylinder 3: knock senor voltage cyl.3 and Cylinder 4: knock senor voltage cyl.6. So I assume that cylinder "4" misfires are actually for cylinder 2?

 

Interesting thing about misfires is that they generally happen only after cold start while idling and instantly stop when I start moving. I may get a single misfire randomly when driving but not more untill next cold start.

When I removed old plugs a while ago then cylinder 1 and 2 plugs had most amount of wear on the ground electrodes. Other two were in very good shape.

 

I can't really hear anything unusual and I can't hear any timing chain rattle as far as I can tell. Even my friend couldn't hear anything. 

I can't remember exactly from the top of my head but with VCDS I was able to see some timing chain related stuff and some angle after last timing chain replacement was 2.5 degrees and current timing chain stretch was 3.4 degrees. I can recheck these values.

[xman]

28 minutes ago, Koreenium said:

When I removed old plugs a while ago then cylinder 1 and 2 plugs had most amount of wear on the ground electrodes. Other two were in very good shape.

 

That's normal for this engine. The waste spark ignition system means plugs fire in pairs, 1+4 and 3+2, one plug in each pair has a positive current flow and the other has a negative current flow, so one will wear the ground electrode, while its partner wears the centre electrode. The plugs have an iridium alloy centre electrode (very tough) and a platinum alloy disc on the ground electrode (less tough and tends to fall off eventually, leaving a bare ground electrode.

 

On our engines, the worn ground electrodes were always on cylinder 1 (left side) and cylinder 3.

 

Are you sure your leads are correctly configured?

 

Edited 19 October, 2020 by xman

[Koreenium]

4 minutes ago, xman said:

On our engines, the worn ground electrodes were always on cylinder 1 (left side) and cylinder 3.

 

Are you sure your leads are correctly configured?

Maybe the worn electrode was on cylinder 3, can't remember.

 

Leads are correct.

 

One interesting thing I recently noticed when I was replacing ignition coil and ignition leads was that the two further away connections on the ignition coil had this greenish, white powdery type of corrosion but the two closer to the engine had none. They looked almost brand new. And two of the leads had clearly been moved around at some point because one with greenish powder on the inside the connection, was plugged into one of the clean connections on the bottom of the ignition coil and the other clean ignition lead was connected to the connection with greenish bowder. I think they were cylinder 1 and 3 cables that had been switched. But they were otherwise correctly configured.

[xman]

Just a simple point, its important never to overfill the engine oil, check when hot, the level on the dipstick should lie within the hatched zone on the dipstick. I tend to stay a bit under, say 75% as I notice most of our engines are not installed level but tend to drop at the gearbox end.

 

Overfilling oil can lead to churn and excessive oil mist and pressure that could overwhelm the oil seperator and finds its way though the pcv and into the intake, ultimately into the cat/exhaust.

 

Have you checked the battery voltage during a cold start, just in case its low?

Edited 19 October, 2020 by xman