Hello yet again, right after thinking l had sorted the misfire on my 2005 1.4 16v looks like the gremlins have struck again, after sorting the bad brake vacuum pipe leaks on Friday last, the car seemed to be running fine over the weekend, until l got to where l was going to this morning, that is, on reversing into a parking place the misfire started again.

After clearing the code and EML all seemed fine and it drove home fine, so tonight took it for a good blast, maybe 25miles, speeds ranged from standstill to 80 and again it ran well, pulled up and went in a shop, came out, car started fine and then as l was parking up l noticed that the idle speed was at around 700 revs and just as l turned the ignition off it misfired and on restarting it was still misfiring.

What should be the correct idle speed be when the engine settles after the auto choke cuts of and it has warmed, as l have noticed on several occasions that the idle speed seems lower than it should, at a guess 850ish would seem about right, is this correct?

BBZ engine code?

I'm looking at a document here that quotes 580-780 rpm as idle speed range at operating temp for that code.

 

Would snapshot it for you but I'm on a tablet I can't really work.

BBZ engine code?

I'm looking at a document here that quotes 580-780 rpm as idle speed range at operating temp for that code.

 

Would snapshot it for you but I'm on a tablet I can't really work.

Yep it's a BBZ, and its ticking over at its lowest closer to the 580 which seems a little low, but if that's the official figures then l can't argue with them, oh well think l will start with a pressure test on number 3 and see what gets thrown up, shame really as for a small car it runs and drives nice, but coming on this forum has been a real eye opener, still can't help but think theres some thing going on with the electrical system, maybe I'm just trying to kid myself, that its not the burnt valve syndrome that these engines suffer with.

What was the code you cleared?

 

SN

Back on a proper computer, here's the snapshot:

 

 

The electrical control unit in the cabin monitors the system voltage, and can, if it thinks it necessary, demand a higher idling speed by chatting to the engine ECU. So it may be worth checking battery voltage before and after start-up, to see if there are any irregularities with the charging system that might be causing variable idle speeds.  Check also that your battery light comes on with ignition.

Ok now for the bad news, conducted a compression test on all cylinders today, although the engine was still pretty warm the reading were as followed, number 4 225, number 3 150, number 2 220 and number 1 225, so this lead me to pressure test number 3 cylinder that revealed pretty grim results that the exhaust valve/valves were leaking like a good one, as you could hear the escaping pressure coming out the exhaust pipe and at best achieved a reading of 80% in the read zone, so not good at all.

Although the engine was pretty hot when carrying out the test, it revealed what l needed to know, so l have now ordered a head set, head bolts and a couple of exhaust valves, just hope the head set has the torque settings as l do not know what they are as I've not worked on one of these engines, but it looks like its going to be fun.

Torque settings will probably come with the bolts, but 30Nm then 90° turn, then another 90° turn according to here. If you scroll back and forth from that page, you should find a few useful bits of info after dodging the donate pop-ups.

 

Good luck with the refurb, and try to take some pictures if you can, always interesting to see the insides of engines.

What was the code you cleared?

Sorry but did not clock the code at the time, as it was my mate who was in control of the reader (snap on) just told us it was a misfire on number 3, no other codes were detected although we system checked the steering angle sensor, as there were some hints on here, that this sensor may cause running issues, but that checked out ok.

Torque settings will probably come with the bolts, but 30Nm then 90° turn, then another 90° turn according to here. If you scroll back and forth from that page, you should find a few useful bits of info after dodging the donate pop-ups.

 

Good luck with the refurb, and try to take some pictures if you can, always interesting to see the insides of engines.

Thanks for your input once again, will see what l can do in the way of photos, but me and modern technology don't always get on, lol.

Right done a engine shake down during the week, head off job and low and behold had a burnt exhaust valve which was not seating in the valve seat very well.

I had already ordered two exhaust valves, expecting the worst, so replaced both the valves on number three and reground them in, whilst I was at it, I decided to remove all the exhaust valves and regrind them in and replaced all the exhaust valve stem seals that came with the head set, also made a blanking plate for the EGR.

Thanks to Wino, for letting me know the head bolt torque setting which came in handy, as the head bolt set did not have the settings printed on the box and after rebuilding the engine up and fitting new cam belts I proceeded to fire it up, which it did first turn of the key, although the hydraulic lifters rattled for a short period of time, within maybe thirty seconds, they filled with oil and it ran as smooth as you like.

Saturday morning refitted the o/s/f muck shield and wheel, new oil filter and oil, then a test run up the road and every thing checked out fine, in fact it seemed like a different car, pulled well, seemed tighter and the idle speed was settled and ran well for the rest of the day.

Seeing that this engine was new to me, once I got into it, it was pretty straight forward, as for those dam EGR valves, personally not only myself but other mechanics I have spoken to seem to think that these EGR valves cause no end of trouble and from what I can gather on these 1.4 16v BBZ engines the EGR recycled gases are ported into cylinder three.

So for now its happy days once again and hopefully now all the running issues have been sorted (for now) lets just hope my confidence returns as this little Skoda has taken me to hell and back.

Well done, however the EGR is ported into the plenum below the throttle body so all cylinders use it equally, since you've blanked it now you're likely to see a noticeable drop in fuel economy and therefore an increase in emissions because the primary function of the EGR valve in a petrol engine like yours is to reduce pumping losses during part throttle running, specifically in lean cruise conditions. The EGR valve will not have caused the burnt valve since EGR lowers combustion chamber temperatures, you should seriously reconsider the deletion in light of this information.

Well done for sorting it fella. As soon as I saw that compression number for pot 3, I thought "he's gonna like how it goes when that's fixed".

 

I think you'll get a fault light from the EGR blank? The engine ECU uses MAP sensor info to monitor whether the requested amount is being fed in, I expect. (Can't think just now how else it could 'know').

Well done for sorting it fella. As soon as I saw that compression number for pot 3, I thought "he's gonna like how it goes when that's fixed".

 

I think you'll get a fault light from the EGR blank? The engine ECU uses MAP sensor info to monitor whether the requested amount is being fed in, I expect. (Can't think just now how else it could 'know').

As yet have not experienced no fault lights coming up, however I will get the EGR system read and doing further reading its possible that the EGR may have failed due to the leaks that were discovered in the vacuum system.

When the head was removed I noticed that the inlet port on number three was marked with raised lettering (P3) which lead me to believe that what Bob, a mechanic of 45 years experience, seemed to think from his investigation into this engine, that the best part of the exhaust gases, mainly entered into number three cylinder, but of course this may not be the case, this then raises the question, why is the head marked P3 on that inlet port?

After you've driven it a few times, I think you'll get 16785, and possibly 16787 as well:

 

 

There are a bunch of other possible codes starting 17809, but they all seem to be detailed electrical stuff rather than flow related:

 

 

I've got no idea on the P3 mark etc., but I'd have to agree that where the EGR metal pipe ends, there's no way it could flow into any one cylinder.  If you have a look at Avante's thread about his pot 1 misfire, he's got some decent pictures of the EGR feed-in point.

Last Monday a lady driving a 1.4 16v pulled up next to me in a car park and I had a brief chat with her and asked if she had experienced any running issues with hers, she told me she had owned the vehicle from new and had never had any issues with the engine and it had covered 109k, the only problem she had with it, was the gearbox at around 70k.

 This as you can imagine left me feeling a little baffled as to why mine was in such a unhealthy state, with only 45k on the clock and full Skoda service history up to 36k then change of ownership and as the current M.O.T check confirms the mileage as correct.

 Thanks once again to Wino for the fault codes on the EGR system, they may well come in useful, as of Monday I will remove the blanking plate as I need to find out if the EGR  has failed or at least try to find out the state of play with it, as I'm now so far down the road, with the repairs with this little monster, I need to make sure that every thing has been checked so there is no recurrence happening for the time I own the vehicle.

Last Monday a lady driving a 1.4 16v pulled up next to me in a car park and I had a brief chat with her and asked if she had experienced any running issues with hers, she told me she had owned the vehicle from new and had never had any issues with the engine and it had covered 109k, the only problem she had with it, was the gearbox at around 70k.

 This as you can imagine left me feeling a little baffled as to why mine was in such a unhealthy state, with only 45k on the clock and full Skoda service history up to 36k then change of ownership and as the current M.O.T check confirms the mileage as correct.

 Thanks once again to Wino for the fault codes on the EGR system, they may well come in useful, as of Monday I will remove the blanking plate as I need to find out if the EGR  has failed or at least try to find out the state of play with it, as I'm now so far down the road, with the repairs with this little monster, I need to make sure that every thing has been checked so there is no recurrence happening for the time I own the vehicle.

 

You've answered your own question.

 

Low mileage use as a shopping cart ruins these engines, they never get thrashed or go on longer trips and they just choke up, the steel cylinder liners don't get run in properly and excess blowby and oil consumption result, mine was exactly the same. It took a year of ruthless spanking to get the oil consumption back down to where it should be.

 

Peak power is at 6100 RPM, you need to get it buzzing between 4 and 6k often, up and down the gears to work the rings hard, ONLY run it on super-plus unleaded and check the engine breather box is clear since this gets gunked up badly, particularly during the winter months.

You've answered your own question.

 

Low mileage use as a shopping cart ruins these engines, they never get thrashed or go on longer trips and they just choke up, the steel cylinder liners don't get run in properly and excess blowby and oil consumption result, mine was exactly the same. It took a year of ruthless spanking to get the oil consumption back down to where it should be.

 

Peak power is at 6100 RPM, you need to get it buzzing between 4 and 6k often, up and down the gears to work the rings hard, ONLY run it on super-plus unleaded and check the engine breather box is clear since this gets gunked up badly, particularly during the winter months.

 I had been thinking along the same lines as to the shopping trolly use, short trips on choke, engine never reaching temperature, cooling down, then another short trip and repeat over and over. I remember a number of years ago removing the head from a Ford Orion, with the 1.6 CVH engine that had only covered 8k and was just about running, the vehicle had been used to deliver Chinese food, so short trips, stop and start, still to this day I've never seen a cylinder head that was so gummed up.

As predicted after doing around 30-40 miles the EML came back on, so this morning jumped in the motor to go to the workshop to remove the EGR blanking plate I had put on, started the motor and low and behold had another warning light, no power steering.

Having no choice, I had to get over to the workshop, so flexing my muscles I pulled out of the parking space, no sooner had I got a few yards up the road, the power steering kicked back in again and managed to complete my journey to the workshop, where I removed the blanking plate.

On my return I was lucky to see a parking space right in front of my house and as I drove into it, the power steering went off for a moment then came back on again, so I guess there's now a issue with the steering angle sensor, although I did pop out and about, the power steering behaved its self.

Such a shame that this little motor has become a money pit, its almost like there's a jinx on it, even on the day I took it home, my Audi that I used in the morning, ended up with a puncture! Think the writing was already on the wall LOL.

Is the earth strap from the battery to chassis (front LH suspension top) 100%, it's worth removing, clean up the surfaces, apply a smear of grease and re-connect, worth a try.

 

DB.

Is the earth strap from the battery to chassis (front LH suspension top) 100%, it's worth removing, clean up the surfaces, apply a smear of grease and re-connect, worth a try.

 

DB.

During all the fixing work that I have carried out I did go over all the ground/earth leads, just a quick undo and a good re-tighten, but maybe I missed the one behind the battery on the turret, so will check it again, will also check the PAS fuse just to make sure its making good contact in the fuse holder.

Also check that the battery light comes on with ignition.