Felicia 1.3 Cylinder Head Corrosion Around Coolant Ways

[RicardoM]

[areed]

Bought a set of wheels off ebay, here they are after a good clean:

 

The balance weights seem to be stuck inside the wheels, rather than clipped to the rims like my current wheels.  Two of them look to be missing some of the weights too, but the other two seem to be OK.  The tyres have plenty of tread, so I will put the good pair on the front of my car.

 

 

You are partially correct. It is all about the quality of combustion in the end. A weak spark means unburnt air/fuel mixture. That in turn makes the oxygen sensor report a rich mixture. The ECU then cuts fuel to injectors resulting in a lean mixture which is again hard to ignite by a weak spark. The engine does not develop enough power and runs hotter putting more stress on valves. That is shown consistent enough on all your spark plugs.

 

If you want to know a little bit more on lost science of reading the spark plugs, see http://www.4secondsflat.com/Spark_plug_reading.html

 

Very interesting! I'm impressed that so much can be told about the running of the engine just from looking at the tiny details on the spark plugs.  I suppose that with modern ECU's replacing manual adjustment on modern cars, such skills aren't as useful as they once were.  

 

Regarding my spark plugs, I suspect that at least part of the lean engine conditions were due to the faulty lambda heater wire.  I think this because, when I was doing the idle test after fixing it, I noticed that before the sensor got up to temperature it tended to read quite high.  I assume that the exhaust gasses go some way to keeping the sensor warmed up, but not far enough - particularly under low load - leading to erroneously high sensor readings and an overly lean operating condition.  

 

I am doing another long journey in a couple of weeks, with no use planned before then.  If the plugs don't look ideal after that, then I'll hit the shops and swap them for the ones listed earlier.  Feels like a bit of a waste to remove these ones given theyre virtually new, but if they're wrong then thats that :(

 

Other jobs planned in the coming weeks:  

• Change the wheels
• Clean residual mud from under the engine
• Replace the metal lower coolant pipe (got bent out of shape by the verge)
• Replace a rubber exhaust mount
• Replace the aux drive belt
• Work out why the radio has stopped making sound

This car has turned into quite a project/hobby!

[Breezy_Pete]

With the radio, try pulling it out far enough so you can give the connectors at the back a wiggle. Fair chance the speaker connector has a few solder joints that have succumbed to heat/vibration/age and need re-flowing to the PCB. Depending on the layout of the innards of the radio, this may or may not be a simple job.

[RicardoM]

Very interesting! I'm impressed that so much can be told about the running of the engine just from looking at the tiny details on the spark plugs.  I suppose that with modern ECU's replacing manual adjustment on modern cars, such skills aren't as useful as they once were. 

You know... life existed before computers too amazing, isn't it? For instance, you would be surprised how many information you could get from using a vacuum gauge too. Before car computers, the vacuum gauge hooked to the intake manifold was the 'OBD scanner' of today. I've learned to use both old and new methods in my engine diagnose process and I encourage you to do it too. I am not a big fan of modern car computers because many times the sensors themselves are the culprits for the engine malfunction. See your case. But I stop here because the old vs new debate would open a can of worms.

 

Regarding my spark plugs, I suspect that at least part of the lean engine conditions were due to the faulty lambda heater wire.  I think this because, when I was doing the idle test after fixing it, I noticed that before the sensor got up to temperature it tended to read quite high.  I assume that the exhaust gasses go some way to keeping the sensor warmed up, but not far enough - particularly under low load - leading to erroneously high sensor readings and an overly lean operating condition. 

Here is an example of normal operation of the oxygen sensor. It is a warm start idling diagnose session.

 

Try searching for 'open loop' and 'close loop' terms for a better understanding of ECU normal operation.

Edited 1 February, 2016 by RicardoM

[RicardoM]

I've made 2 spelling/grammar errors.

... how many much information you could get...

... searching for 'open loop' and 'closed loop' terms...

[KenONeill]

Bought a set of wheels off ebay, here they are after a good clean:

 

 

The balance weights seem to be stuck inside the wheels, rather than clipped to the rims like my current wheels.  Two of them look to be missing some of the weights too, but the other two seem to be OK.  The tyres have plenty of tread, so I will put the good pair on the front of my car.

 

This is the "modern way" over here. "Stick on" weights are usually retained better, particularly if the wheel is "kerbed", and can be fitted about equidistant between the wheel edges, so you need less weight, even if tyres weren't being made better (better balance, and a "light point" marked by a dot of paint to be mounted by the valve).

[felicia16v]

Also those particular wheels are quite close to the track rod end and clip on weights sometimes rub on them.

[areed]

With the radio, try pulling it out far enough so you can give the connectors at the back a wiggle. Fair chance the speaker connector has a few solder joints that have succumbed to heat/vibration/age and need re-flowing to the PCB. Depending on the layout of the innards of the radio, this may or may not be a simple job.

 

Tried this to no avail, but changing the radio back and forward between radio and aux seems to have fixed it for now at least.

 

You know... life existed before computers too   amazing, isn't it? For instance, you would be surprised how many information you could get from using a vacuum gauge too. Before car computers, the vacuum gauge hooked to the intake manifold was the 'OBD scanner' of today. I've learned to use both old and new methods in my engine diagnose process and I encourage you to do it too. I am not a big fan of modern car computers because many times the sensors themselves are the culprits for the engine malfunction. See your case. But I stop here because the old vs new debate would open a can of worms.

 

I'm keen to learn both old and new ways of dealing with car issues, by working on this car, so that one day I can own and maintain an older/classic car of some kind.  I always wanted to own an original mini, though since browsing these forums the Skoda Rapid has strangely caught my eye.  Sadly, those seem like hen's teeth these days though.

 

Here is an example of normal operation of the oxygen sensor. It is a warm start idling diagnose session.

 

Try searching for 'open loop' and 'close loop' terms for a better understanding of ECU normal operation.

 

That looks like how mine was behaving when I tested it after fixing the broken wire, once I have replaced the coolant pipe I will retest it to be sure.  

 

This is the "modern way" over here. "Stick on" weights are usually retained better, particularly if the wheel is "kerbed", and can be fitted about equidistant between the wheel edges, so you need less weight, even if tyres weren't being made better (better balance, and a "light point" marked by a dot of paint to be mounted by the valve).

 

Interesting, thanks for the info!  

 

Also those particular wheels are quite close to the track rod end and clip on weights sometimes rub on them.

 

On mine the weights are clipped to the outside of the wheel, so I don't think this would be a problem - although it does slightly interfere with the appearance of the wheels.

 

 

Update on the car:

 

Replaced the front wheels with the best of the ebay ones, neither of the tie rods appeared to be bent but I took some pictures just in case:

 

 

 

When the car hit the verge, some mud and grit got on to the auxiliary drive belt, causing several "lumps" on the belt like this:

 

 

Looked dodgy to me, so I replaced the belt today and cleaned all of the pulleys up too.  While I had the wheel and the belt off, I gave the timing chain cover a good clean (I think that the crankshaft end very slowly seeps oil, but it was impossible to tell with all the dirt around).  Didn't realise there was a nice Skoda logo on it until today:

 

 

Also replaced one of the exhaust mounts, because it was "slightly" worn out:

 

 

All in all, a successful day for car maintenance

[criiser]

Um,

 

Out of curiosity, how do you expose the timing chain cover that nice? Open/remove something in left wheel house? Rusted bolts?

 

Br, Christian

[areed]

Um,

 

Out of curiosity, how do you expose the timing chain cover that nice? Open/remove something in left wheel house? Rusted bolts?

 

Br, Christian

 

It probably looks a bit more open than it actually was because the camera was quite close to be honest.  I didn't do anything special to access it, I had the wheel off and the car was up on stands but that's all.  Also the auxiliary drive belt was removed prior to cleaning.

 

I think that some of these cars have covers in the wheel well, and a bottom tray covering the front of the engine.  They aren't there on mine though, either removed and discarded long ago or never fitted.

Edited 8 February, 2016 by areed

[RicardoM]

I think that some of these cars have covers in the wheel well, and a bottom tray covering the front of the engine.  They aren't there on mine though, either removed and discarded long ago or never fitted.

Not 'some' but all have a protection cover, aside of a front shield. See photos. Both have the purpose to avoid damaging parts of the engine. Sadly, you know exactly what I mean.

 

 

 

[areed]

Not 'some' but all have a protection cover, aside of a front shield. See photos. Both have the purpose to avoid damaging parts of the engine. Sadly, you know exactly what I mean.

 

 

 

 

Those are precisely what my car doesn't have, yeah.  If all cars were fitted with them, mine must have the mounting points for them.  Given previous experiences, would be worth my time seeing if I can find some to buy!

[criiser]

Yep.. And I would need to remove them to have an much easier installation of the AUX belt (Or whatever that belt running around there is called. Waterpump, generator, etc etc.)  

 

/C

[RicardoM]

areed

I've looked at the begining of this very long topic and I've realized you didn't mention what simptoms made you think the engine has a bad HG and how you tested for being 100% certain. I think many people might need that information to know when to act and what to do. In the end, how would you rate the HG job you did in terms of success? Anything you could have done different?

 

I have a suggestion to make if you will. Since your topic has got very long and is getting more and more off topic, can you consider creating new topics for each separate issue of your car? Don't get me wrong, I like how you take care of your car and how you document every step. But it will be easier for another member to find help for his car if the topics are organized by issues. You can't toss the entire history of repairs of a car in a single huge topic with a title referring specifically to cylinder head corrosion. Just my 2 cents.

[areed]

areed

I've looked at the begining of this very long topic and I've realized you didn't mention what simptoms made you think the engine has a bad HG and how you tested for being 100% certain. I think many people might need that information to know when to act and what to do. In the end, how would you rate the HG job you did in terms of success? Anything you could have done different?

 

The initial symptom I had was that the coolant level kept dropping.  I inspected the car several times, carefully, for any sign of a water leak but didn't find anything.  Water was being blown out of the expansion reservoir cap, but not enough to explain all of the losses.  This could either be due to a faulty cap, or due to the coolant system being over-pressurised.  A head gasket leak can cause this, but so can other things I believe so this wasn't conclusive either.

 

I did some reading and learned that a white emulsion, or "mayonnaise" in the oil filler cap was a sign of water in the oil - which can be due to head-gasket failure.  This stuff can also appear if you do short journeys though, so seeing it when I looked wasn't a conclusive diagnosis.  To decide for sure whether the head gasket was leaking, I wiped off this mayonnaise before I next made a long journey (about 80 miles, most at ~60mph).  When I checked the car at the other end, more mayonnaise had formed.  In addition, the coolant looked contaminated somehow.  It had a bit of a skin on it, and the colour seemed a bit more rusty/brown than it used to.  

 

At this point I had a choice: change the head gasket, or drive the car until it died then buy a different one.  I like doing things myself, and was keen to learn about maintaining my own car, so decided to have a go at changing the head gasket (plus scrapping the car seemed like a huge waste).  I've driven several hundred miles since the repair, and seen none of the above symptoms return, so I think I can say that the repair was a success.  Maybe it's still to early to say whether it will hold though, so perhaps ask me again in another 100k miles :p  

 

Anything I would have done differently?  If I had any choice, I wouldn't have done the entire job in a car park in December.  Beggars can't be choosers though, and it was 100% doable anyway without a garage or anything.  I tried not to skimp or cut corners while doing the job, so I'm happy with the repair that I did.  I maybe should have replaced the exhaust manifold nuts, or cleaned the engine more while I had good access to it, but these are minor things I feel.

 

I have a suggestion to make if you will. Since your topic has got very long and is getting more and more off topic, can you consider creating new topics for each separate issue of your car? Don't get me wrong, I like how you take care of your car and how you document every step. But it will be easier for another member to find help for his car if the topics are organized by issues. You can't toss the entire history of repairs of a car in a single huge topic with a title referring specifically to cylinder head corrosion. Just my 2 cents.

 

You are right, I should create separate topics to help keep the forum organised and useful both for myself and others. I've kept using this thread purely because I've been enjoying keeping it as a sort of journal of my adventures in car maintenance.  In future I will use new threads for each job

[RicardoM]

Congratulations for your decision of keeping the car and doing the repair yourself. You have learned a lot and if you watch the forum you will learn even more. Felicia is easy to work on and something tells me you will make good money one day repairing other people's cars. As an aside job or full time. See PM from me soon.

 

Very informative explanation about the symptoms and diagnose. We have a Felicia owner from Ecuador that has to do the same head gasket job very soon. Amazing how many head gaskets failed in the last months...

[nimbus]

Here is what I mean by 'too Chinese'. There are two types of thermostats inside: the ones with 'hooks', which are rubbish (see below why)

 

and the ones fixed with a circlip. These are good.

 

Here is a direct comparison.

 

The best buy is this one below. You can see clearly the thermostat, it has the o-ring, no need to buy the sensor so the price is minimal.

So if the thermostat is faulty, it means that you only change the metalic part (interior component) and not the plastic to ?

[RicardoM]

Yes, in theory. But with so many third party manufacturers today, the chances to match the thermostat with the case are almost null. Do yourself a favor and buy it new as a whole.

[nimbus]

okay thanks for your answer

[Anthony96]

How did u do a throttle  body conversion 

[Bernardor]

On 25/11/2015 at 21:48, RicardoM said:

Eso podría cambiar porque estoy en el proceso de escribir una guía para hacer el trabajo de la junta de culata de la A a la Z. Te he visto tomar muy buenas fotos, así que te animo a que tomes más fotos de todo el proceso (mecanizado incluido si es necesario). te lo permitirá). Nuestro otro colega del foro, fpga (Dean), hizo lo mismo pero no me importaría tener fotos más detalladas para una guía mejor ilustrada. Cuando esté listo, publicaré la guía en la sección de guías. Mientras tanto, puedes preguntarnos cualquier cosa que no te resulte clara y que no haya sido explicada en el tema de Dean. Échale un vistazo también a tu messenger personal.

Gracias por tus aportes ricardom.

Cuando podrás tener la guía de la que escribes ?