3rd cylinder problem (with pics)

[icebergsar]

so i was driving along in front of my brother a few nights ago, all of a sudden car starts stuttering, my brother said a little puff of smoke came out the exhaust. almost sounded like it was runnin on 3 cylinders. so ive taken the head off and this is what i found! any idea what the problem is????? thanks in advance!!

 

[tom172cup]

Its expensive is about all i know

 

[Dan519]

Well it's been rich on one cylinder, but that could be for a number of reasons. I wouldn't have taken it apart without doing some diagnostics first. Now you can't test compression. It could have been an injector, coil or plug lead at fault.

 

[icebergsar]

compression was (starting at gearbox side) 75,80,100,150! i put new leads on and new plugs, i disconnected each injector induvidually and it made no difference to running sound! :/

 

[icebergsar]

also no engine management light was on? surely a dodgey injector would have turned this on??

 

[krisbutler02]

it was rattling its head off sounded like the dephaser was knackered. maybe dropped a valve? bring it to me i will take a look

 

[JackJack]

it was rattling its head off sounded like the dephaser was knackered. maybe dropped a valve? bring it to me i will take a look

All the valves are there.

 

[krisbutler02]

doesn't mean one isn't bent slightly and stuck in guide !!!!!!!!!

 

[James105]

Not really a "dropped" valve if it's still there, but never mind. To be fair, taking it apart has been done far to quickly, a leak down test could have been carried out to check/ identify the compression loss.

With the head off, check the valves are seating ok. Put the head upside down and fill the chambers with petrol. Monitor if the petrol level drops in a certain chamber. Would help identify a valve seating problem

 

[JackJack]

doesn't mean one isn't bent slightly and stuck in guide !!!!!!!!!

I know but you didn't mention that !!!!!!!!!!!!!!!!!!!!!!

As Danny said should of had diagnostics first.

 

[krisbutler02]

OK James so if it hadn't dropped in the 1st place how would it get bent :sleepy:

 

[DannyR]

FLOL, was probably only a coil pack or similar.

 

[JackJack]

OK James so if it hadn't dropped in the 1st place how would it get bent :sleepy:

Contact with the piston from a tensioner failure is one way.

As DannyR said it's probably something simple.

 

[krisbutler02]

No Tensioner failure here darling.

 

[JackJack]

No Tensioner failure here darling.

I didn't say there was it was just an example of how a valve can get bent.

 

[krisbutler02]

OK goodnight :cheers:

 

[icebergsar]

FLOL, was probably only a coil pack or similar.

FLOL, as said no eml on, coil pack - all were arcing when i removed the leads! any decent suggestions would be appriciated!

 

[DannyR]

EML doesn't come on for coil pack as far as I'm aware, mine never has.

But yes it's something silly causing it to over fuel, didn't warrant engine apart!

 

[James105]

FLOL, as said no eml on, coil pack - all were arcing when i removed the leads! any decent suggestions would be appriciated!

Gave a decent suggestion above for checking your valve seating, might show something maybe.

Kris i'm offering him some potential advice, no need to be a jackass! Valve could have bent from valve bounce/ over rev as an example or timing slip.

 

[Dan519]

can you get closer pictures of the chambers on each cylinder, and of the pistons in the bores please

 

[icebergsar]

and if its just a case of over fueling in 1 cylinder why are 3 down on compression???

 

[James105]

and if its just a case of over fueling in 1 cylinder why are 3 down on compression???

Very hard to know why now its apart tbh. A leak down test would have almost certainly highlighted where the cylinders were loosing compression.

 

[JackJack]

and if its just a case of over fuelling in 1 cylinder why are 3 down on compression???

Was the compression test carried out correctly?

 

[James105]

Was the compression test carried out correctly?

Test carried out wet and dry?

 

[icebergsar]

wasnt me that did it! had it in a garage to do that! they were the results! not gonna pay garage prices for them to take it apart, when im more than capable my self! as they said that was there next stage! pretty trusted garage! anyway its apart and i need to find out what the problem is! so advice would be good! thanks

 

[DannyR]

Did you plug it into a decent diagnostics machine?

 

[icebergsar]

yep no fault codes

 

[DannyR]

Decent? What kind?

 

[icebergsar]

no idea! very reccomended garage, surely they would have a good one?

 

[DannyR]

Well they AA use ones that bring up naff all, and the cheap OBD2 readers don't either.

Ideally Snap On, CLIP, or a few others.

 

[JackJack]

Bosch KTS

 

[Martin_172]

i dont understand why you took it apart and will now need to spend £500 odd quid to put it back together without fully ruling out everything else first!

are the valves all opening and closing ok and try the petrol in the head to make sure all valves are sealing properly.

 

[James105]

So how I'm seeing it is it could well be 2 separate issues:
1) Loss of spark or over fuelling on the one cylinder. Which could be a multitude of potential reasons causing it.

2) Loss of compression on a number of cylinders which could be:
-Blowby on the piston rings which is going to be hard to test with the engine apart and unable to perform a leak down test, also without the compression test being carried out both wet and dry. What condition are the bores in? Any scoring or honing marks still visible?
-Inlet or exhaust valves not seating correctly. You can carry out the petrol in head chambers to check the seating is ok. If they are not seating ok, any witness marks on the top of the pistons or on the valves to indicate they have touched?
-Head gasket. Any sign of failure on the gasket itself when you pulled it apart? Again unfortunately a leak down test might have been able to rule this out as well. Was it using any water? (From what I understand head gasket failures on RS's are very rare)

What colour smoke was seen coming out the exhaust blue or black?

 

[Dave..]

My car dropped down onto three cylinders, plugged it in, replaced spark plugs and injector 3, job done. Don't remember taking the head off though?

 

[icebergsar]

i took it apart, as the belts needed replacing anyway, im turboing the car also, so this was just a good reason to do it all at once, pistons,conrods, head gasket, bolts, and all belts.
so as i said it was a good reason to take it apart and do it all properly. theres no marks on the pistons or valves. i shall carry out the petrol test on the head tomo. all honing marks are still visable no scoring marks wat so ever.

 

[Dan519]

if you're doing that, just refresh the head fully anyway

 

[The Fatty]

bit off topic, but can someone explain why the inlet and outlet valves are differnt colors? when i took the head off my car, they were the same color on both sides :s

 

[icebergsar]

if you're doing that, just refresh the head fully anyway

yeah im going to, im just trying to find a trustworthy place to get it all done! as i used a company around here on my 106 gti head, they did a good job but charged me wayyyyyyyy more than wat they quoted and took bloody ages! any suggestions, im in the south west btw

 

[Luke.]

PM me I know a place to get your cylinder head done..