Peugeot 205 GTi 1.9 fast road engine (need advice!)

[DamirGTI]

Hello Guy !

Please if you have some spare time can you look at this pictures and let me know is this valves, combustion chamber and piston crown color good ?!
The exhaust valves are gray , inlets are black/tan , and pistons are light coffee/tan color .
Does this indicate good or bad fuel mixture - rich or lean ?
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I've fix my engine yesterday (the coolant was leaking inside one cylinder...) and it‚ was one cylinder liner cracked (the cylinder No 4 on the timing belt side.. you can see that cylinder liner on the picture also the head gasket area from that cracked cylinder) which was causing water leaking inside the‚ combustion chamber ‚ ... The head gasket was fine , but this time I've tight all the head bolts like you have recommended me before !
Also I've found that my expansion bottle pressure cap was faulty - it was leaking , not holding the coolant system pressurized :(
Can i blame this broken exp. bottle cap for cracking the cylinder liner ? me thinks that coolant inside the engine/block was boiled out (when i was switching off hot engine ..) and create steam pocket around that liner which cause liner metal surface stress‚ - overheating and cracking - does this make any sense ?!
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Thanks in advance !!
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Kind regards !
Damir

Pictures :

[Guy Croft]

The piston crown and ex valve color indicates good mixture quality although the amount of deposition on the ex valve head (at the combustion or 'firing' side) after so few miles might be indicative of rather poor quality gasoline.

The back of the inlet valves indicates oil coming down the valve guides - worn out.

As for the cracked liner, well, maybe, but insofar as cause of crack are concerned all I will say is, no, engines don't like the integrity of any part of the cooling system being compromised!

GC

[DamirGTI]

Hi !

Great - thank you !

As for the petrol quality , well it could be that because here in my country petrol is really not so good - it still contains a bit too much of sulphur because our domestic refinery's are old (plants are not yet equipped to make low sulphur unleaded petrol , and petrol quality varies hardly from one to the other pump station) , and government mainly don't allow foreign petrol companies coming in our market - selling their petrol here and building their plants here . (of course every one of them in ministry has some sort of benefit for this bad petrol politics !)
I can count only one foreign petrol companie here which has pump stations in this country (but they are also selling our petrol from our plants , and they import just one amount of high RON petrol like 98 or 100 octane ..)

Also i was mixing Acetone and Xylene with 98RON petrol so maybe this caused carbon deposits inside the engine to let loose quicker ?!

Valve guides where new fitted , I've replace the guides when i was rebuilding this engine and I've made around 5000Km-s with this engine from the rebuilding this year .

Kind regards !
Damir

[Guy Croft]

Good report, well done.

But that carbon on the back of inlet valves - on all 4 I guess, and so evenly distributed it can only have come down the valve stems; oil pulled in under manifold vacuum. If none of the inlet valves were seating you could get carbon blown out of the cylinder, sure, but I have seen your work and don't imagine it's that. Do you have any other explanation?

Backs of inlet valves will always be more-or-less carbon-free and quite clean - on a well sorted engine.

GC

[DamirGTI]

Hello Guy !

Well i really not know why was this happened .(must admit this was a bit strange to me also when i was removing the inlet valves out !)

Can it be that I've bought some bad quality valve guides ?! however they where a bit pricey (not OE stuff but some aftermarket..) , they are not bronze material guides this ones are some sort of silver/gray metal valve guides , sorry but i don't know how to say for this type of metal in your language but I'm sure that you will know about which material I'm talking here ...
I didn't press the guides inside the cylinder head (or out..) - the guy at machine workshop was doing them and after that my mate made multi angle seats for me , then i was just relaping valves after cutting with grinding paste and fit the steam seals on valve guides at the end ..
Can it be because of the seam seals or engine oil quality ?!

Also I've adjusted valve clearances as best as i could - inlets 0.20-0.25mm , exhausts 0.30-035mm ...

Strange , everything was working fine - no exhaust fumes or what so ever the engine didn't consume oil not even a little bit ...
Toping up was not needed at any point except just a little bit on the beginning of the engine running in procedure ..(I've use straight 15W-40 mineral oil for running in this engine , then after around 800-1000km i switch to 10W-40 semi synthetic oil )

Thanks !
Damir

[DamirGTI]

Too bad i didn't make some more detail pictures during this engine dismantling job :( ,
But here's one more picture - closer look at the valves (in the middle)

On the picture -> from left to right :
First valve is the inlet and then second is exhaust valve both from the 2-nd cylinder (2-nd cylinder from the timing belt side of the engine!)
Third valve is the exhaust valve and fourth is again inlet valve from 3-rd cylinder (you can see also on the picture in the end right corner one bit of the inlet valve from the 4-th cylinder ..)

Kind regards !
Damir