Spark Plug fell out?

[theorganist]

I was driving to work this morning in the Renault 14 when I heard a bang and then what sounded like the exhaust manifold blowing!!

 

Assuming it was the manifold I took it to the local exhaust place near my house and went of to work in my parents 206.

 

I have just had a bewildered man from the exhaust place on the phone telling me my exhaust is fine but one of my spark plugs has fallen out!

 

Has anyone else come across this before, wondering if it could be a worn thread or too much pressure or something?

 

Thanks,

Pete.

[M'coli]

My uncle had it happen in the 1980s on a Renault 12 estate, it just stripped the thread. He couldn't believe that Renault had used medium-length thread plugs on an alloy head.

[Alexg]

I was driving to work this morning in the Renault 14

 

the dream, lived

 

sorry I can't help with the plug problem, but commuting in the 14 is the coolest thing ever....

[ashmicro]

Sounds like a stripped thread to me too. Isn't that a Pugrot 1360 TU in those?

 

 

I had a plug blow out in my old Manta (CIH engine). Stripped thread in cylinder head.

[Station]

They can be easily repaired with a helicoil. This is thread that is screwed into a removed old thread (drilled out) and substitutes the old thread. Obviously the head has to come off due to the amount of swarf from drilling.

[Volksy]

If the head has to come off, that means the engine and box need to come out, as these have the lay-back-and-die engine where the head is pretty much recessed into the bulkhead

[theorganist]

Hi Thanks for your replies,

 

Isn't that a Pugrot 1360 TU in those?

Yes it is, mine is the 1218cc version.

 

the dream, lived Cool

 

sorry I can't help with the plug problem, but commuting in the 14 is the coolest thing ever....

Yes it has been fun (apart from this morning)!! I usually go by train but have been using the car as it had been sitting unused for several months.

 

The engine is quite awkward, even changing the spark plugs requires someone with double joints, three elbows and six foot arms from what I can gather!!

[simmo]

Worth trying a spark plug hole tap before going with a helicoil, (you can make your own out of an old plug)

If the engine is the same as a Pogo 104 they come out relatively easily.

Wet liners though a little extra care needed if the head has to off.

[CreepingJesus]

Sure sounds like it's blown the thread out.

(It's possible for the plug centre to get blown out, leaving the steel sleeve in your cylinder head. That can be a tricky fix too, 'cos you have to get the sleeve out without dropping swarf into the cylinder.)

Helicoil's probly the answer, and if you can't find a garage who can do it, bike shops always have Helicoil on hand (many bikes are notorious for seized exhaust manifold studs - destructive extraction necessitates a Helicoil), as will many engineering shops, especially the kind who specialise in plant/machinery maintenance.

Good luck with that, it would be a shame to spoil the ship for a ha'penny o' tar!

[Guest Leonard Hatred]

It's not a TU, because that was launched in the mid '80s.

It must be the chain cam 'suitcase' engine.

[ashmicro]

It's not a TU, because that was launched in the mid '80s.

It must be the chain cam 'suitcase' engine.

That's like a Samba then, XW/XY valise engine. 72 degrees back toward the bulkhead in that case. (pun intended)

[Guest Leonard Hatred]

Do they have a gearbox in the sump too?

[theorganist]

Hi,

 

It's not a TU, because that was launched in the mid '80s.

It must be the chain cam 'suitcase' engine.

It is a chain driven overhead camshaft. Iave to be honest not sure of the actual designation but yes it is the 'suitcase' engine. The parents 206 is a 1360cc I just assumed that it was from the same origins. It is the engine developed with Peugeot and used in the 104/Samba etc. I think Renault fell out with Peugeot and stopped using it, probably why they didn't use the same engine in the Renault 9 & 11 which were (for the smaller ones) OHV as far as I am aware.

 

Do they have a gearbox in the sump too?

The gearbox isn't in the sump but does share the same oil.

 

Helicoil's probly the answer, and if you can't find a garage who can do it

 

The garage that MOT'd the car say they can do it and don't seem to think that is that big a job.

 

Thanks everyone for all your advice.

[trigger]

Silly question but when the plug blew out didn't you notice that the car was running on three?.

 

Though i can't imagine that the R14 has the most refined engine so i doubt you could tell anyway.

[nigel bickle]

Awkward job-good luck.

 

Obviously helicoil is the preferred route, but short-termist bodgery will keep you mobile/solvent in the short/medium term.

 

I have several 60's Suzukis,and they often blow their centre plugs out. Sometimes overseas- when a'repair' isnt feasible.

 

I've wrapped the thread in a plastic bag -taking up the'slack'andmelting into thethreads, thats done over 1000miles successfully.

 

I've also smeared chemical metal on the plug thread before fitting - thats still in there-several years on.

 

Just a suggestion- if the bill looks excessive..

[CIH]

my old bluey blew out a couple of plugs after they hadn't been tightened properly

 

 

fortunatly it only needed a quick thread cleaning and was sound afterward

[warren t claim]

Aren't cars running on LPG more likely to blow out plugs or is that bollocks?

[Guest]

Don't worry me like that, the Laurel taxi has 8 of the sodding things due to some kind of weird emissions setup.

[warren t claim]

Don't worry me like that, the Laurel taxi has 8 of the sodding things due to some kind of weird emissions setup.

Maybe it's fitted with an Alfa Twin Spark engine and is some kind of prototype GrandeArna.

[Lankytim]

Aren't cars running on LPG more likely to blow out plugs or is that bollocks?

I have heard this too, but seen no evidence of it. I know LPG cars eat the plugs much quicker than a petrol powered lump and they need replacing every 10k or so.

[Albert Ross]

If they do give a stupid quote..... I could do it........... for a less than stupid quote.

[Rusty Pelican]

When i worked for a garage at 18 my old boss fitted new plugs in a Renault 12 , must have over torqued them somewhat as two blew out

CIH , That Bluey looks fantastic , need one in my life at some point

[meggersdog]

Pinto engined MkIII Cortinas used to do this alot.The HT lead would stop the plug from firing through the bonnet.Taper fit plugs either go loose or so tight you snap them when removing leaving just the thread in the head just like a MkIII Fiesta.

It might be worth checking to see if there is or isn't a washer at the top of the thread.It's so long since I've worked on a suitcase engine I can't remember what type of plug they use.If it is the taper fit (no washer) fit a new set,job done.

[theorganist]

Silly question but when the plug blew out didn't you notice that the car was running on three?.

It obviously lost compression but I have noticed that before on cars where the exhaust has come away from the manifold. To be honest I was in a hurry this morning as I had to be at work quickly so didn't even look under the bonnet, I just assumed it was the exhaust (obviously wrongly!).

 

If they do give a stupid quote..... I could do it........... for a less than stupid quote

Thanks for that I will bear that in mind.

 

Thanks Nigel and Meggersdog will do some investigation tomorrow.

[Father Ted]

I had a Mk 2 Fiesta that use to do that on number 3.

 

Same car had a spark plug doubling up as sump plug too.

 

10mm plugs - FTW!

[CIH]

When i worked for a garage at 18 my old boss fitted new plugs in a Renault 12 , must have over torqued them somewhat as two blew out

CIH , That Bluey looks fantastic , need one in my life at some point

Pandamonium's mate bought it but TBH I probably should have kept it. It got me through 2009-2010 winter without missing a beat.

[ashmicro]

Same car had a spark plug doubling up as sump plug too.

 

10mm plugs - FTW!

Haha! I haven't seen that in years, but WHAT a bodge! Autoshitetastic.

[theorganist]

Problem solved:

 

Found the old spark plug on the road where it fell out, the thread looked fine. Went to local small motor factors, bought spark plug, fitted it, no problem with the thread, car runs fine.

 

I reckon the plugs had been changed fairly recently (by the looks of it) and that one had not been screwed in properly and had gradually unwound itself.

[M'coli]

Result!

[Alexg]

Great result !