Ford Focus II (2004 - 2007) - 2004 1.6 Zetec Spark Plug blown out of engine

Honest John Back Room » Technical matters
View Threaded
Thu 31 Jan 2008 09:55
2004 1.6 Zetec Spark Plug blown out of engine - Sparkydogg
Has anyone ever seen an issue where a spark plug blows out of your engine?

The issue happened to me this weekend, starting the car outside my house I heard a loud thud and then lots of coughing and spluttering. To my amazement when I opened the bonnet I found spark plug #3 (plus plastic casing) lying beside the engine block with a lot of brown fluid everywhere.

First assumptions were my head gasket has gone, but the garage looking at it told me the spark plug has literally blown up and ejected itself from the engine.

After replacing all 4 spark plugs, they say the engine is working fine.

Anyone heard of this?

Cheers...
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:01
2004 1.6 Zetec Spark Plug blown out of engine - Carse
Sparky,

I can only assume the spark plug was loose in the first place or it would have stripped the tread from the head when it ejected. If the plug was loose (un screwed) the compression from the block would have ejected the plug.

To answer you question accurately I have never heard of a similar case.

Carse
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:06
2004 1.6 Zetec Spark Plug blown out of engine - cheddar
Sure it was not just the central core of the plug, i.e. the threaded part was still in the head?

Not about the brown fluid, sounds like head gasket unless the engine had ingested water which had blown the plug out hydraulically though again it would surely have stripped the thread in the head.
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:05
2004 1.6 Zetec Spark Plug blown out of engine - Peter D
You said "brown fluid everywhere". What was this fluid. It sounds like NO3 filled or injested the brown fluid from somewhere and hydualically forced the plug out at start up. Was the whole plug blown out as this would have ripped the threads out. Regards Peter
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:07
2004 1.6 Zetec Spark Plug blown out of engine - cheddar
Snap!
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:13
2004 1.6 Zetec Spark Plug blown out of engine - Sparkydogg
Thanks for your replies guys. One thing i should mention, these spark plugs aren't screw fit, they seem to a bottle stop style plastic fit (i.e. ribbed plastic). Pity i can't upload a picture.

I've never seen this fitting before, probably a cost saving from the manufacturer. The brown fluid had no oil consistency, more like rusty water or rusty coolant. But again i've no idea why water or coolant would be anywhere near the the spark plug casing.

Do spark plugs get cooled by the engine coolant in Focus' ?
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:15
2004 1.6 Zetec Spark Plug blown out of engine - Sparkydogg
Just realised my mistake. The car was registered March 2005. Still inside the Manufacturers Warranty.
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:18
2004 1.6 Zetec Spark Plug blown out of engine - cheddar
Sounds like it was the core of the plug, not the whole plug, the plug is defo screw fit, the head around the plug is cooled by the coolant being circulated through it though it shouldnot be brown and rusty unless coolant has been drained and replaced with plain water, and if it is in the cylinder it indcates a head gasket probelm.

Had you driven through water just prior the switching it off, before the plug issue?
Reply | Report as offensive | Link
Thu 31 Jan 2008 10:19
2004 1.6 Zetec Spark Plug blown out of engine - normd2
yes, this happened to me once many years ago in a Simca 1100 Special, it left quite a dent in the bonnet - pretty sure the plug was not loose as the plug hole now had a smooth bore all the way down. It was an alloy head I believe and had certainly subjected the poor thing to quite a bit of stress as I used to thrash it everywhere - ah the joys of youth!
Reply | Report as offensive | Link
Thu 31 Jan 2008 11:50
2004 1.6 Zetec Spark Plug blown out of engine - Peter D
Sopmehting is quite wrong here. Was there and signs of water in the cylinder. This is a standard type plug TR5A-10 type steel and ceramic core. Was there any water missing from the header tank. You say the car in still under warrantee, I suggest you get this logged with Ford. Regards Peter
Reply | Report as offensive | Link
Thu 31 Jan 2008 13:01
2004 1.6 Zetec Spark Plug blown out of engine - Screwloose
Sparkydogg

Your base problem is leaking core plugs in the well of the head. This has filled at least one of the plug recesses with water - which has been there so long that it has rusted the plug casing away and allowed it's ceramic section to escape.

Removing the rest of it would have been fun! It says something for Ford's HT leads when they can work submerged in 2" of water for months on end.

I think that your Focus is too late for the leaking washer jet problem [that was more a Fiesta issue anyway] so unscrewing what's left of those core plugs will be a nightmare.
Reply | Report as offensive | Link
Thu 31 Jan 2008 18:42
2004 1.6 Zetec Spark Plug blown out of engine - sunbeamer
Although not a spark plug problem, my uncle who regularly looks under the bonnet of his 05 plate 1.6 zetec focus was horrified to discover coolant everywhere. It was at the time still under warranty, and the Ford dealer initially diagnosed a core plug, but then decided a new cylinder was required. The car was off the road for 4 weeks due the part being on back order and staff shortages! It had covered 44k miles, mostly motorway.
Reply | Report as offensive | Link
Thu 31 Jan 2008 19:08
2004 1.6 Zetec Spark Plug blown out of engine - cheddar
Screwloose, I was thinking that "lots of brown water" would be more than would collect in the plug well?

Also if it a matter of the plug being corroded as you suggest, it could be water from an external source, jet washing etc?
Reply | Report as offensive | Link
Thu 31 Jan 2008 19:26
2004 1.6 Zetec Spark Plug blown out of engine - Screwloose
sunbeamer

Not at all surprised to hear that the dealers fitted a new head; once those taper-threaded plugs have rusted, they're the devil's own job to extract. I always recommend that the head be sent to the head-shop, machined-out and brass BSP ones fitted instead.

cheddar

The worst ones have about a litre of water in the well - and they still don't miss a beat. It might be jet-washing; it was alleged to be leaky washer-jets - but all the ones that I've seen have been corroded core-plugs.
Reply | Report as offensive | Link
Mon 11 Feb 2008 21:53
2004 1.6 Zetec Spark Plug blown out of engine - trevoryz426
washer jets have been reworked with a rubber seal if your washers havent got a seal between the jet and the bonnet then they will leak onto the spark plug area fill with water and then turn a rusty colour . the water will coroded the spak plug thus causing the spark plug to self eject
Reply | Report as offensive | Link
Tue 12 Feb 2008 12:20
2004 1.6 Zetec Spark Plug blown out of engine - Glaikit Wee Scunner {P}
Non screw-in spark plugs and diesel engines without valves (HJ in Sunday Telegraph).
What a surreal world we live in.
Reply | Report as offensive | Link
Tue 12 Feb 2008 13:28
2004 1.6 Zetec Spark Plug blown out of engine - Screwloose
GWS

These are just ordinary spark plugs; it's the build-up of water in the well that rusts the top of them away until the ceramic section escapes.
Reply | Report as offensive | Link
Tue 12 Feb 2008 13:39
2004 1.6 Zetec Spark Plug blown out of engine - Glaikit Wee Scunner {P}
Screwloose, thanks for the clarification. It was the OP's assertion that the plug was not screwed in that threw me!
Reply | Report as offensive | Link
Sat 23 Feb 2008 16:13
2004 1.6 Zetec Spark Plug blown out of engine - pete. t
washer jets have been reworked with a rubber seal if your washers havent got a
seal between the jet and the bonnet then they will leak onto the spark plug
area fill with water and then turn a rusty colour . the water will coroded
the spak plug thus causing the spark plug to self eject


Hi mate, do you know from what model year on thewashers have been reworked.
Cheers Pete

Edited by Dynamic Dave on 23/02/2008 at 21:07

Reply | Report as offensive | Link
Sat 23 Feb 2008 17:04
2004 1.6 Zetec Spark Plug blown out of engine - bazza
I had a 2005 Mk 2 new shape Focus 1.6 petrol and had the leaking washer jet problem. Rain water seeps through and fills all 4 plug wells with water up to an inch or so deep. I managed to suck it out with a straw but not pleasant, followed by lots of kitchen roll. I tried all sorts of sealant to stop the rain water but the best solution was an engine cover made out of an old rubber car mat! Note that the nearside washer jet leaks water onto some electrical connectors next to the battery, so worth covering that as well.
I was not impressed!
Cheers Baz
Reply | Report as offensive | Link
Mon 25 Feb 2008 21:06
2004 1.6 Zetec Spark Plug blown out of engine - Fullchat
After this thread I went and had a look at my 2005 1.6 Zetec. Sure enough there was some water in the area around the spark plug covers. Pulled out the plug covers and it was indeed very damp in there. Plugs out and copper greased. All water sucked out.
Now I have a question. If its the washer jets and the water leaks into the plug area it would have to be about 7mm deep to ingress the plug chambers as there is a ridge where the plug cap fits in. Thats a lot of water to come off the bonnet through the washer jets holes, gasket or no gasket. And I would have thought a reasonable amount of water round the plugs would evaporate with engine heat. Just some thoughts.
My warranty is up in a week so I really have to bottom this soon.
My thoughts at this stage are leaky jets and core plugs as we haven't had rain for a good week. Are core plugs a common problem?

Edited by Fullchat on 25/02/2008 at 21:09

Reply | Report as offensive | Link
Mon 25 Feb 2008 21:14
2004 1.6 Zetec Spark Plug blown out of engine - Fullchat
Bazza. Have hand crafted a beautiful piece of rubber mat, even fits round the oil filler cap. But
how did you fasten yours down?
Reply | Report as offensive | Link
Sat 1 Mar 2008 16:36
2004 1.6 Zetec Spark Plug blown out of engine - Fullchat
Given it a week and rechecked this am. New water round the plugs, non on top. Looks like the core plugs. Booked in with Ford dealer.
Reply | Report as offensive | Link
Sat 1 Mar 2008 17:14
2004 1.6 Zetec Spark Plug blown out of engine - bazza
FC
Sorry just saw this, have been away. My patented rubber cover was held down with 4 large zip ties at each corner, fastened loosely to avoid pulling on anything and easy to remove to inspect the wells. I tried to make sure that it was positioned so that any rain water run-off didnt run off onto anything electrical.
When I first discovered the problem, the water was indeed rusty and my first thoughts were core plugs or something similar. But it seemed like rain water rather than coolant. After cleaning it all up, the problem came back within a couple of weeks, after heavy rain and I found water seeping through the jet washers. I reduced this with silicone sealant but couldnt stop it completely. In my case, it was confirmed as the problem as I found wet drips on the cover the morning after heavy rain. Also the plugs were completely dry after fitting the cover, over a year or so.
Did you completely remove all the water? It's a right pain and doesn't (suprisingly) evaporate with engine heat - there's a suprising amount of water in those wells!
Please let us know how you get on and the final outcome.
Reply | Report as offensive | Link
Sat 1 Mar 2008 19:11
2004 1.6 Zetec Spark Plug blown out of engine - Fullchat
Will do.
Reply | Report as offensive | Link
Sat 22 Mar 2008 20:06
2004 1.6 Zetec Spark Plug blown out of engine - pete. t
Just recently had the same issue on my 2005 MKII; took it to dealership as it is still under warranty and revised washer jets have been fitted along with rubber seals, interestingly enough these revised ones finds the rubbers have a small recess into which the jets sit, but on looking at a '57 plate the other day and it's jets were just mounted on rubbers which are formed to the same shape as the jet, so looks like there's two types of designs out there!!
Cheers Pete
Reply | Report as offensive | Link
Mon 24 Mar 2008 19:10
2004 1.6 Zetec Spark Plug blown out of engine - Fullchat
Update

Washer jets changed a couple of weeks ago. Checked today - snuff dry. I really was surprised how all that water managed to get down into that area!
Reply | Report as offensive | Link
Wed 3 Dec 2008 13:58
2004 1.6 Zetec Spark Plug blown out of engine - frenchie
Hiya, just admitted my 05 Focus 1.4LX into the garage. It was backfiring and losing power then the engine warning light came on. I am not one to know where to look for problems under the bonnet so I took it to Ford.
Ford tell me that the backfiring is due to the coil pack that needs changing and i have a coolant leak (leaking onto the spark plugs) and my washer jets are faulty and leaking onto the spark plugs.
We discuss the pros and cons of changing spark plugs. He doesnt want to change them because if they snap them trying to get them out then they'll need to change the cylinder head for circa £2000!

Any thoughts?
Reply | Report as offensive | Link
Wed 3 Dec 2008 14:20
2004 1.6 Zetec Spark Plug blown out of engine - Screwloose

Only one. Take it away from the boys and let a proper mechanic look at it.

Reply | Report as offensive | Link
Wed 3 Dec 2008 14:26
2004 1.6 Zetec Spark Plug blown out of engine - frenchie
Yeah fair one. The focus is starting to annoy me! I had the power steering go in September due to a couple of faulty washers on the high pressure pipe to the power steering motor. Its starting to get expensive!
Reply | Report as offensive | Link
Wed 3 Dec 2008 14:59
2004 1.6 Zetec Spark Plug blown out of engine - Screwloose

They clearly have liitle clue and even less interest. It's either coolant [core plug leak] or rainwater [washer jet hole leak.] Two seconds with an antifreeze tester answers that one - if they had a brain...

Drain the chamber, start it up and add a squirt of penetrant. If the coil pack is duff, change it and/or the leads. If still a problem; carefully remove the plugs now the engine is hot - it's not rocket science.

Even if one breaks - and it's rarer on these than the Fiesta ones; every experienced mechanic faces that problem twice a week - hammer in TX55 bit, undo shell.

At the very worst, if the core plugs won't unscrew; head off and down to the head-shop for machining. Around £125 for a full head overhaul. That's not something that dealers ever want to consider - £2000 for a head? Silly money.
Reply | Report as offensive | Link
Fri 5 Dec 2008 11:32
2004 1.6 Zetec Spark Plug blown out of engine - frenchie
Cheers fella. £125 or there abouts wont be half as painful. Have had new type washer jets installed now at a cost of £1.91 each. The guy at the Ford franchise agrees it would have been easier to do a recall!
Reply | Report as offensive | Link
Wed 2 Jun 2010 13:11
2004 1.6 Zetec Spark Plug blown out of engine - pmach

The problem of rusty water in the spark plugs' well persists even in 2010. Wife's car had orange engine warning light come on. She called AA who diagnosed a spark problem on cylinder 4. He said he was 80% sure it was a coil pack problem. Ok to drive to dealer to discuss. Garage quoted £70 for futher diagnostics then £100 for new coil pack. I used to mess with cars when they had points & coils etc. Bought a clone coil pack for £40, dead simple to fit. Problem still there. Stupid me. Had a look at the spark plugs. Up to their waists in rusty water. Why? What to do? Checked on your website -and there is the full answer. Just brilliant. Thanks. -pmach

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide

From economical vans to those that have the largest payloads, we have a shortlist for everyone - click to find out which will suit your needs.

Undecided on which van to buy? Our Top 10 shortlists can help...