ST170 Engine Problem - Head gasket top end or something else

[wattsie_2004]

About 1/2 mile from home this evening my car suddenly lost power and begun to sound like a tractor! I managed to limp home and into the drive luckily so I made it home (just.)

The car is a Ford Focus ST170 (2005) and has done just under 80k. I've never had any engine trouble before and the car always starts first time, gets serviced regularly etc.

I recorded the sound in case someone more knowledgeable than me can give me some advice. The sound seems to be coming from the block (rather then the manifold or elsewhere) and it sounds horrendous.

Link to mp3 of the sound: https://docs.google.com/open?id=0B0Lrsmyomi4rTmxlR...

While I will need to find a mechanic on Saturday I was wondering if anyone could give me an idea of the problem (other that it's fked! ) I'd be grateful, thanks!

[lemonslap]

Sounds like the exaust manifold is missing! Have you had the timing belt replaced yet? Possible it's jumped a tooth and blown the inlet manifold off or damaged a valve?

can post up a video of it running with the bonnet open?

[Pumaracing]

It's just a blown exhaust. From the frequency probably just one of the manifold primary pipes but it should be very easy to spot.

[wattsie_2004]

Link to Youtube Vid

I haven't had the timing belt replaced yet, that was on my list of pending things to do in the new year.

Pumaracing said:

It's just a blown exhaust. From the frequency probably just one of the manifold primary pipes but it should be very easy to spot.

Would that result in the loss of power?

There was also a juddering which reminded me of public busses about a decade ago, which used to judder and shake a lot - though this could have been due to me under-accelerating for the last 100m or so.

Edited by wattsie_2004 on Thursday 13th December 12:15

[lemonslap]

After hearing the noise again, spark plug blown out? If it is one of the primary's as Puma pointed out, the manifold heat shield is a pig to remove due to the bolts corroding and it must be reinstalled or the fan wiring gets BBQ'd!

[Pumaracing]

Yep I guess it could be a plug blown out but whatever it is it'll be easy to spot. I'm sure the OP could manage that himself if he has a look.

[wattsie_2004]

Thanks for the suggestions.

I'll have a look tomorrow morning. By the time I get home from work it's pitch black outside and the lighting in the drive isn't great.

[stoocake]

If you can check it out in the daylight, run the engine and have someone hold a cloth over the end of the exhaust - it's cold enough lately you should be able to see if there's any exhaust gas escaping from the manifold.

[wattsie_2004]

Blown out spark plug. It's sitting lose in the block and would appear that it can't be screwed back in as the thread has been damaged (on the block rather than the plug)

Just tried - it takes 14 turns by hand to fully screw in one of the others. The blown one can be turned 25+ times and still pulls out.

Now I have the answer to the problem, I have to go about fixing it. What causes a blown plug though?

[stoocake]

Oh dear, hopefully it won't be too expensive to fix. It could have been cross threaded when they were last changed I guess, or over tightened - I'm assuming aluminium head?

Someone makes a tool that allows you to repair the spark plug threads without taking the head off - it screws in, expands and then you unscrew it where it cuts new threads and collects the swarf. Can't remember who makes it - I'll have a quick search.

ETA: Wonder if this is it: http://www.toolstop.co.uk/index.php?option=shop&am...

Edited by stoocake on Saturday 15th December 12:26

[Megaflow]

wattsie_2004 said:

Blown out spark plug. It's sitting lose in the block and would appear that it can't be screwed back in as the thread has been damaged (on the block rather than the plug)

Just tried - it takes 14 turns by hand to fully screw in one of the others. The blown one can be turned 25+ times and still pulls out.

Now I have the answer to the problem, I have to go about fixing it. What causes a blown plug though?

Stripped thread in the head. The head is going to have to come off, ignore anything which suggest doing it in situ as that is just storing problems for the future with swarf in the cylinder.

Edited by Megaflow on Saturday 15th December 15:59

[Pumaracing]

It should be possible to do a helicoil repair with the head in situ. Taking this off will be very expensive. Careful hoovering out of any swarf afterwards via a thin tube connected to a vacuum cleaner plus a bit of cranking with the plugs out will clean things up ok. I understand there are specialists who can come out and do this but don't have any contact numbers. It cropped up on here not long ago though I think.

[PaulKemp]

Second vote for insitu helicoil
If that doesn't work its head off anyway so worth a go first

[Evoluzione]

I read somewhere about filling the combustion chamber with shaving foam before doing the thread insert, don't know quite how they got it all in there though and I think you'd have to work pretty quick as it may start to break down and disappear.
Afterwards they simply turned the engine over with spark plugs out, injectors unplugged and it blew out.
Any residual swarf left in is of no consequence as it's very soft, apart from the part of the SS insert coil which breaks off, i'd make sure that bit comes out!

[PeterBurgess]

We have fitted about 20 inserts insitu over the years. We have been ok so far but always say to customer it is make or break. It is the case if it fails the head would have had to have been removed anyway, but wouldn't make one feel any better I suspect. We use lots of grease on the tap and only go in a turn or two before removing tap, cleaning and regreasing. As Evoluzione says the 'sweaty hands' time is snapping off the tang from the insert, usually one punches it through to the other side but this cannot be so with the combustion chamber in the way. We use long nosed pliers and a swift movement to snap the tang off. As Evoluzione points out any fine turnings will be soft and hopefully non dangerous on an ally head. I do not think we would carry out the op on a CI head in situ though.

We also use Wurth Sert spark plugs repair inserts which give a good repair if somewhat frustrating trying to fit them. We have to prepare the Serts first and use a tap from another system.

Peter

[wattsie_2004]

Have found someone in Hereford now, Phoenix Re-bore Ltd which were recommended by the garage I spoke to, as they (the original garage) said they would have to have the head off which would be expensive. They recommended Phoenix as somewhere that does the Helicoil fittings.

As they only work weekdays I won't know any more until tomorrow.

[Sardonicus]

Wurth Time-Sert's fitted hundreds over the years in-situ and never had any problems even with recessed plugs on twin cam cylinder heads more of a premium product than Helicoils IMO