1.2 compression problem

[Cathal]

I have a 2007 Fabia combi, Mark 1.  Engine is 1.2 petrol.

It is running rough and going into safe mode constantly.

Mechanic tested compression and it is 8,12,10 respectively for the 3 cylinders.

Mechanic tells me I need to have top off engine, and replace valves. And he wants to replace the timing belt at the same time.

He says it will be about €700euros. Thats probably the minimum.

 

Can anybody confirm, or suggest if this is the correct course of action.

I bought the car a year ago for 3000 euros. So 700 is a lot to spend on it. I would like to be sure it will result in a good performing engine...

 

Looking at Wikipedia, I think this is the engine in question, but it could easily be the 6v one, I don't know how to tell the difference.

1.2 HTP 12V 2003–2007 I3 AZQ/BME 1198 cc 47 kW (64 PS; 63 hp) at 5400 rpm 112 N·m (83 lb·ft) at 3000 rpm

 

[felicia16v]

Usual problem for these engines is the valve guides wearing which causes the valves not to seat properly and lose compression. Timing CHAIN is well worth replacing as to remove the cylinder head you need to remove the chain anyway.

[Breezy_Pete]

The giveaway to differentiate the 12-valve from the 6 valve is that the 12-valve has an engine cover with a little plaque in the middle pronouncing "1.2 12V"  Here's a pic of a Seat one, Skoda version has a grey background and a Skoda Logo!

 

 

 

6-valve one should be cheaper to repair as there are half as many valves to deal with, for a start.

700 Euros sounds like a lot, TBH

[felicia16v]

Chain kit is over £100 before you buy headgasket and new head bolts.

Valve guides fitting is a specialist job and the guides are £40/50 then new Stem seals.

I would think €700/£540 was an ok price tbf.

[KenONeill]

Has the mechanic done a wet compression test to confirm that the issue is valve(s) not seating rather than piston rings or bore wear?

[sepulchrave]

Has the mechanic done a wet compression test to confirm that the issue is valve(s) not seating rather than piston rings or bore wear?

 

It won't be Ken, these 3 cylinder engines are legendary for eating the exhaust valves, bore wear is incredibly uncommon these days on any engine I know of due the excellent tolerances in modern engines and the absence of bore wash due to lean burning for emissions and economy.

[Torbo]

I did the head job on mine Fabia 1,2 engine for som days ago. I renew one valve, changed six valvesteams (weak things), -seal and grinded the seats. I also redused the valvelengd for m 0 to 0,2 mm depend on grinding deapth. 

 

I also changed the timing chain, guidelines and tighten part. 

+ sealring to crank shaft and all the gaskets. 

+ one coil and i bought a lifter to be safe, but i don't have to change.

 

I bought the parts from Autoparts in Berlin to the half price from Norway.

 

Now the engine had 15 bar in compression and very nice running... Just like 4 cylinders...

 

Some special: I also grinded off 0.05 mm from the upper camshaft bearing to get 0,3 mm clearing. It was 0,08 mm. to get better oil pressure...

 

Good to be inside the garage now:

 

[sepulchrave]

Good work Torbo, nice to see your attention to detail, did you fit cast iron valve guides?

[Cathal]

Chain kit is over £100 before you buy headgasket and new head bolts.

Valve guides fitting is a specialist job and the guides are £40/50 then new Stem seals.

I would think €700/£540 was an ok price tbf.

Thanks.

The place I brought it too is a real general workshop. As you mention a specialist job, I may have to go to another more specialised workshop. I don't want to fork out 700 and get an inexpert job....

[Cathal]

The giveaway to differentiate the 12-valve from the 6 valve is that the 12-valve has an engine cover with a little plaque in the middle pronouncing "1.2 12V"  Here's a pic of a Seat one, Skoda version has a grey background and a Skoda Logo!

 

 

 

6-valve one should be cheaper to repair as there are half as many valves to deal with, for a start.

700 Euros sounds like a lot, TBH

thanks, Mine is a 6V so.

[Cathal]

I did the head job on mine Fabia 1,2 engine for som days ago. I renew one valve, changed six valvesteams (weak things), -seal and grinded the seats. I also redused the valvelengd for m 0 to 0,2 mm depend on grinding deapth. 

 

I also changed the timing chain, guidelines and tighten part. 

+ sealring to crank shaft and all the gaskets. 

+ one coil and i bought a lifter to be safe, but i don't have to change.

 

I bought the parts from Autoparts in Berlin to the half price from Norway.

 

Now the engine had 15 bar in compression and very nice running... Just like 4 cylinders...

 

Some special: I also grinded off 0.05 mm from the upper camshaft bearing to get 0,3 mm clearing. It was 0,08 mm. to get better oil pressure...

 

Good to be inside the garage now:

 

wow.

I wish you were my neighbour!

Do you think a general mechanic is up to this job, or should I pay a bit more and go to the really expert renowned engine man locally.

I'm afraid that a general mechanic won't be up to this job...

[sepulchrave]

wow.

I wish you were my neighbour!

Do you think a general mechanic is up to this job, or should I pay a bit more and go to the really expert renowned engine man locally.

I'm afraid that a general mechanic won't be up to this job...

 

A general mechanic won't do the head work, it'll be sent out after it's been removed.

[Cathal]

thanks to all who posted.

Most helpful.

Great to have this community...

[Torbo]

Glad you like things. I an old mechanic, and before we do everything. Now I´m not sure?. Yonger are good with newer cars, like data in car an electric. her I´m not good..

Some pictures to illustrate the job: 

Da kom jeg litt videre med Skodaen.

Klargjorde timingen av kamkjedet. Så da måtte jeg lage låsepinner for veiva og kamakslingen.

 

Slipte topplokket på en tykk glassplate med sandblåsesand, olje og whitespirit. Jeg hadde en planslipt stålplate til den slags før, men den ble borte i en flytteprosess. Det ser om som glassplata fungerte bra.

 

Jeg var litt bekymret for lagrene til kamakslingen, men her slipte jeg ned topplokket 0,05 mm på toppen som utgjør den ene halvdelen av opplagningen.

Målte underveis, slik at jeg ikke fikk for trange lagre. Havnet på 0,03 mm klaring- Utgangspunktet var 0,08 mm.

 

Sjekket også ut timingen med låsepinnene, og planla hvordan jeg skulle lage stopper for strammemekanismen, slik at kjeden ikke kan hoppe over.

Et avstandsrør under strammestemplet på mellom 10 og 12 mm vil gjøre susen - sikre mot tilbakeslag før oljetrykket kommer etter start.

Sylindrene var fine, uten sliptekant, striper eller annet. Så dette bør bli bra, og en morsom motor å få i gang.

 

[Torbo]

There is many good suggestions in the forum here. I am not a good advicer in your country...

Edited 7 February, 2016 by Torbo

[sepulchrave]

Yes of course, you need liquid nitrogen to fit cast iron guides properly.

[Torbo]

Good work Torbo, nice to see your attention to detail, did you fit cast iron valve guides?

Thanks! I am best with old things, but I was lucky this time.

 

 

Here is my hobbies : http://forum.pvklubben.no/viewtopic.php?f=28&t=1062&start=645

what I like...... don't read it if you don't like Volvos

Edited 7 February, 2016 by Torbo

[Torbo]

Yes of course, you need liquid nitrogen to fit cast iron guides properly.

Thats interesting! Can you tell me more about it? I can understand that, but how much press pass do you need? 0.06 mm? Or more?

I have only used bronze in aluminum heads, and cast iron in cast iron head. 

If I understand you right cast iron works good (better) in aluminium heads to...? 

 

Im learning..

 

I used this to delete fault codes on airbag and engine code

It worked.. Good menu. 

- good christmas present! 

 

first time I have use instrument like this...

Edited 8 February, 2016 by Torbo

[Torbo]

wow.

I wish you were my neighbour!

Do you think a general mechanic is up to this job, or should I pay a bit more and go to the really expert renowned engine man locally.

I'm afraid that a general mechanic won't be up to this job...

Come and wisit me! May be you must take some wood with you if you like it worm inside? I have been waiting 50 year to get a 70 m2 garage. Lathe and so on...

[KenONeill]

It won't be Ken, these 3 cylinder engines are legendary for eating the exhaust valves, bore wear is incredibly uncommon these days on any engine I know of due the excellent tolerances in modern engines and the absence of bore wash due to lean burning for emissions and economy.

Well, I'll give you that bore wear is (and should be) rare, but I still want convincing about broken or stuck rings.

[sepulchrave]

Well, I'll give you that bore wear is (and should be) rare, but I still want convincing about broken or stuck rings.

 

Broken rings are also very rare because it's so difficult to over-rev a modern engine since they all have rev limiters, about the only way to break them is to downshift far too early and that's as likely to burst the engine as break a ring.

Stuck rings are really only a phenomenon on engines which have been stood a very long time where the rings actually rust and stick in the grooves or on engines which have been burning a lot of oil for a long time and are driven far too gently.

[felicia16v]

Be honest though when did you see enough bore wear to create a miss fire.

If it was then it's new engine time anyway as the alloy blocks have a special coating on the liners so they can't be honed etc.

If you took the cam out you can usually wiggle the valve side to side with the spring still fitted they go that bad!

[Torbo]

I have read much about this engines her, and it seems to be a head problem, and not often problem with the rings. Like 

sepulchrave says there is over rev limiters on new engines and therefore nearly no problem with piston rings and piston. 

 

 

 

The prize you get is ok I think? But it is best to check more garages. May be Wino can tell you more about that?