Low compression on No. 5 cylinder and rough idle

[Puffwagon]

As a husband and father to 3 young children I empathize with your situation.  

Although there are a myriad of reasons that we could speculate upon, nothing is decided until your mechanic gives their diagnosis and offers various solutions. 

I do think that it is important to come to a conclusion about how the cylinder failed. Although forum members contributing to this thread aren't there with you to properly diagnose, I'm sure we can offer ideas as to how it may have failed. Your mechanic will know what to do. 

It is good news that there is no scoring of the bore. This will at least save some money if and when the engine is out for the block to be honed if indeed the issue lies with a broken piston or rings. 

You have a great car by the sound of it and take care of it well. From what you have said it isn't your fault that it is broken.

My 2 cents in what could have happened to cause it? A failed or partially blocked injector had leaned the cylinder out and detonated. 5 years worth of detonation in one cylinder will break the piston eventually. Obviously this is just my opinion based on what you have told us. Your mechanic should know to check for all possible causes. 

You'll be ok and you'll have it sorted soon.

Edited 27/02/16 08:20 AM by Puffwagon
Remove useless info.

[Vipir]

16 minutes ago, k31th said:

Judging by these symptoms, you cracked a timing chain guide and/or the timing chain has skipped a tooth. Leaving something like this happen for a long time will eventually cause valves to open at the wrong time which can cause detonation or cylinder pressure issues (or oil starvation which can cause almost any desctructive event in an engine)
From what you've said here, it doesn't look like anything you did in particular caused it, other than not getting it diagnosed successfully sooner (within warranty period, ideally) which you cannot be blamed for not getting done.. it's just something that you'll have to live with.

That's correct. If all of the bores are OK then you can re-use the engine and it's just rings (and gaskets, seals etc for reconditioning) and labour. It's about as cheap as any repair is going to be.

Any engine failure would be very unlikely to endanger you, so there's that...

FG F6 short engine is about $2200 from Ford spare parts. Might be cheaper again for a FG XR6T short engine.

You made the right choice.

I'll have to Google what a short engine is, and why would a Turbo be potentially cheaper than a straight F6?

Would the timing chain problem manifest itself in any other way or at any other time?

[Vipir]

6 minutes ago, Puffwagon said:

As a husband and father to 3 young children I empathize with your situation.  

Although there are a myriad of reasons that we could speculate upon, nothing is decided until your mechanic gives their diagnosis and offers various solutions. 

I do think that it is important to come to a conclusion about how the cylinder failed. Although forum members contributing to this thread aren't there with you to properly diagnose, I'm sure we can offer ideas as to how it may have failed. Your mechanic will know what to do. 

It is good news that there is no scoring of the bore. This will at least save some money if and when the engine is out for the block to be honed if indeed the issue lies with a broken piston or rings. 

You have a great car by the sound of it and take care of it well. From what you have said it isn't your fault that it is broken.

My 2 cents in what could have happened to cause it? A failed or partially blocked injector had leaned the cylinder out and detonated. 5 years worth of detonation in one cylinder will break the piston eventually. Obviously this is just my opinion based on what you have told us. Your mechanic should know to check for all possible causes. 

Also worth noting is that a failed thrust bearing will make noise when the clutch it depressed and a failed spigot bush will make noise when the clutch is released. Neither will influence the quality of the idle. 

You'll be ok and you'll have it sorted soon. 

Does it help that when I depressed the clutch there was no difference to the noise? And you could hear the awful noise in the exhaust.

I love my car. It is the most precious thing in my life (after the kids, natch) and I never tire of looking at him. Yes, he is a family car and a runaround, and yes, perhaps he is not treated with the reverence due his engineering, but he just lifts my heart when I feel a bit low. And sitting in him in the drive makes me smile. He's all mine. No-one owns him but me outright. 

And when I park in the supermarket carpark I find a bay where there are no other cars. When I come out, he is surrounded by nice cars: Falcons, ok looking Commodores, Subarus...he attracts good looking cars.

I am collating everyone's responses and suggestions and will be taking them to my beleaguered mechanic who is the loveliest person and is so patient with me.

I don't think I stress about my children's coughs and colds like I stress about this car and his efficient running.

This is my baby:

[Puffwagon]

If the mechanic had said rings then it has obviously passed the leak down test. If the timing chain has skipped enough to cause massive engine shaking then it is likely to fail a leak down test in every cylinder. 

[Vipir]

3 hours ago, FiftyOne said:

I think you can still buy fg short blocks direct from ford? Might be the quickest fix (plus the money there on) to get going again?

It will be an option to investigate, for sure.

Thank you.

[Puffwagon]

4 minutes ago, Vipir said:

Does it help that when I depressed the clutch there was no difference to the noise? And you could hear the awful noise in the exhaust.

I love my car. It is the most precious thing in my life (after the kids, natch) and I never tire of looking at him. Yes, he is a family car and a runaround, and yes, perhaps he is not treated with the reverence due his engineering, but he just lifts my heart when I feel a bit low. And sitting in him in the drive makes me smile. He's all mine. No-one owns him but me outright. 

And when I park in the supermarket carpark I find a bay where there are no other cars. When I come out, he is surrounded by nice cars: Falcons, ok looking Commodores, Subarus...he attracts good looking cars.

I am collating everyone's responses and suggestions and will be taking them to my beleaguered mechanic who is the loveliest person and is so patient with me.

I don't think I stress about my children's coughs and colds like I stress about this car and his efficient running.

This is my baby:

Lol I edited the clutch part out of my comment because it has nothing to do with your engine failing.

[Vipir]

Well, I guess we will know where we stand at the end of the week. 

If you are interested in the outcome, I will post the results when we know. That could be of use for anyone else who has a similar problem.

One good thing to come out of all this, (I always try to look for the silver lining), is that while my boy is garaged at the mechanic's, he is off the road not getting extra kms added to his odo, he is having a well-earned rest, my 4 brand new tyres (put on 2 weeks ago at no small impact to my savings) are not losing tread, AND my insurance is going to rebate me some money for the time he is not at home.

It's not much but it's all I have to hang on to at the moment.

Thank you for your input and support. 

I'll keep you updated.

[k31th]

14 minutes ago, Vipir said:

I'll have to Google what a short engine is, and why would a Turbo be potentially cheaper than a straight F6?

Would the timing chain problem manifest itself in any other way or at any other time?

A "short" engine is a bare engine (no accessories or manifolds or wiring) without the head and sump. Essentially the "block" containing crank and pistons - the "working" part of the engine. A "long" engine is a bare engine including the head and sump.

An F6 motor has slightly better internal components than an XR6T motor, hence an XR6T motor is slightly weaker and is also made of slightly cheaper components, hence the overall package should have a price difference from one to the other.

Timing chain problems manifest themselves suddenly and then reasonably consistently then onwards. Timing chain guide problems can be extremely sporadic.

[JETURBO]

Looks like you're in VIC

take it to Pitlane Performance in Frankston and let Mick take care of it,he's by far the most respected and responsible workshop/tuner that specialise in the Turbo falcon and will only diagnose and replace what's needed.

this sounds like it needs a workshop that knows the falcon inside out  

Pitlane is also a forum sponsor 

[k31th]

^^ this is good advice.