Technical Uno head gasket change -- slight mishap

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Technical Uno head gasket change -- slight mishap

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Oct 17, 2005
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124
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Location
Belfast, County Antrim
Okay, so around the end of last month I discovered that my head gasket was on its way out. Bummer, of course, but I set about planning a potential fixing session. Finally managed to get the tools and parts required together and organise a friend with a garage and a spacious driveway to help me out, and set about installing a new gasket set and timing belt with the Haynes and Porter manuals to guide us, along with some choice FF threads (y)

Well the process became a 2-weekender when I decided it really was best to get the head skimmed but hey, no big deal. Got all that done and went back to my friend's place to finish the job last weekend. Unfortunately while cleaning the old gasket/carbon off the top of the engine block the previous weekend, we had got some residue into the head bolt holes, which I'd initially missed on the guides as being something to avoid.

So, I went out and bought some pipe cleaners (of the tobacco-pipe cleaning variety), so that we could clean out the holes as best we could, which we did. Only here comes the "mishap" -- I wasn't concentrating as I was about to clean the second hole -- and it turned out not to be a bolt hole.... I realised this just as I dropped the pipe cleaner in, expecting it to rest a couple of inches down.... only to find it had dropped down through the engine block and out of sight. So now it appears I have a pipe cleaner in my sump. :bang:

The next unfortunate bit is that I can't seem to remove the sump to fish out the pipe cleaner, as the bolts start rounding off whenever I try to undo them. I was going to try and get a local mechanic to come around and do the job for me with his own decent tools (he apparently does various engine jobs at people's home addresses), but he's not got a free slot for a good few weeks. He actually said though that I could just leave it in there and not worry about it...! :confused:

Sooooo.... what does anyone else think? I wouldn't really have any detailed knowledge of the internals of an engine, but my initial thoughts were that this was a piece of steel wire (about 3 inches long) that will need to come out, otherwise it might get caught in the crankshaft mechanism, or block up the oil circulation system or something...? Or will it just sit harmlessly in the bottom of the sump/in a filter somewhere?
 
Interesting story!

You were obviously cleaning one of the four oil passageways at the front of the engine block...

I'd say this is a very minor setback but I would try to get it out...

My first thought is to fish down there with a magnet (powerful neodymium type) tied to a piece of wire, through the same hole you discovered. The pipe-cleaner should be made of ferrous wire so it should be attracted to the magnet.

You could also remove the sump drain plug and fish around from there with your magnet.

Otherwise it really shouldn't be difficult to take the sump off with the engine in the car; just a number of 10mm bolts. It might be a good time to buy a 1/4"-drive deep socket (10mm of course) that will fit the bolts really well. It can take a bit of wrangling before the sump actually comes off, due to the need to manoeuvre it around the oil pump. You didn't say which engine you have (FIRE?)

-Alex
 
Cheers Alex,

Yep, tis a FIRE engine -- unfortunately I can't seem to remove the sump myself as the flywheel housing cover needs to come off first, and all the bolts on it seem to be rounding off... The exhaust pipe also gets right in the way, which doesn't really help. :(

Tried fishing around inside the sump drain hole with fingers, but couldn't feel the wire. Also have a magnet and some string but the magnet was too large to fit down the oil hole from the top of the engine block (the hole in question was the top-left circular port as you look at the engine block from the front of the car).... and to avoid being massively behind we bit the bullet on the day and replaced the new gasket and head etc. anyway, so the sump is the only way in now :rolleyes:

Didn't try sticking the magnet inside the sump drain hole, but I don't think it will have enough purchase to pull it out; we tested on clean pipe cleaners and the magnet's a bit on the weak side on them; it'll only pick up if there's no additional resistance. I can certainly give it a go this weekend though; the other bit I've not tried yet is actually shining a torch inside the sump drain hole, on the offchance that the pipe cleaner is actually in sight.

If these don't work though, any idea whether having such a thing in the sump would affect the engine? Am I just being paranoid with the whole crankshaft damage/oil circulation blockage idea?
 
Well...
The oil pump pickup does have a perforated screen on it, so the pipe cleaner probably wouldn't get in and you'd possibly get away with it... but 'probably' and 'possibly' are not generally words to be used in connection with engine work ;)

However to lighten things up a bit, I should mention the Uno engine I was working on once, ummm... oh that's right, it's the engine in my Turbo :rolleyes: and suspecting a sump leak, I decided to fit a new gasket (by the way, it wasn't the gasket - oil tends to run down from other leaks and collect at the edge of the sump. And also by the way, the FIRE doesn't use a sump gasket - it has silicone sealant only). Anyway, so I removed the sump - and found several valve collets in the bottom! These are the little hard wedges that hold the valve spring caps on... someone obviously dropped them during some kind of head work...

A bit of furry wire should be a lot less harmful than valve collets (which just sat there harmlessly anyway), though if it does get into the oil pump in time, you could be in trouble.

I wonder if you have a strong enough magnet... mine are the neodymium type about 1cm in diameter and are extremely strong. You would probably be able to move one around under the sump (stuck to the steel) and the pipe cleaner would appear at the drain hole!

-Alex
 
Hmm, well I shall see what I can do about a stronger magnet -- and try going in via the sump drain hole -- but if it can't be removed then I guess it'll stay there for a while until I can find a cheap enough garage to remove the sump! seems a bummer to have to call someone in for so small a job, but hey.

Had another mechanic say much the same about leaving it in there... does seem to mean that I can "probably" run the car ok for the time being; the month and a half (so far) without a car to get me to gigs is driving me crazy.... (n)
 
Just thinking about the magnet-on-a-string approach...perhaps an extendable pen magnet would be better? They usually have pretty strong magnets and you can fish far more effectively than with a piece of string
 
Well, in the end we had no magnets that would fit through the sump hole -- tried using a pretty strong one and dragging it from the sides down towards the hole but heard no movement. Also tried shining a torch in, got a reasonable view but no sign of the pipe cleaner -- my guess is that it's sitting on the bottom of the sump, further than finger distance away from the hole.

Aaaanyway, we decided to bite the bullet and give the car a go in the end. Filled her up with coolant and cheap oil, and........ She runs! Which is a start (pun not intended, but acknowledged :))...

After giving the car a decent run down the road and back, she was starting to idle ok -- or at least not conk out for a goodly while. We noticed however that when left idling for a while, the engine wouldn't settle down to a continuous level of revs. It would cycle from slow (normal) idle to fast idle and back, in the space of maybe 15 seconds.

Taking a look in the engine bay brought our attention to a spark shooting from the end of No. 4 HT lead to the engine block, just before each climb to the higher revs, so once every 10 seconds or so. So I turned off the engine and took out the lead and spark plug... the plug looks to be in fine condition, but the lead seems to have a tiny hole in the side of the rubber, where the spark had been shooting out. Don't know whether this hole was the initial cause (i.e. just crappy old rubber insulation) or the consequence of something else...

So I bought new leads and fitted the whole set, but noticed that now there were two sparks that I could hear, but not see -- this time at the two middle plugs. If the sparks had been external again I would have been able to see them, but I couldn't. The idling obviously still isn't great either (she's often wanting to stall even within 30 minutes of startup, when stopping at lights etc). I'll take a look at the connections and make sure there's no moisture in the leads and so on. Except it's fewkin baltic outside, so I might leave it a while....!

I guess the poor idling might also be attributed to the accelerator cable not being properly calibrated when put back... we set it so that max pedal pressure created max aperture opening in the throttle body, but perhaps the minimum (unpressed) accelerator level is closing off the intake too much?

Final bit I've noticed is that there is steam out of the exhaust after startup again.... I'm hoping this won't last, and that it's just old water from the gasket breach being used up and/or moisture settling in the exhaust. I'll be keeping a close eye on coolant levels and getting extremely paranoid at any sounds I hear while driving... This whole head gasket change thing is high pressure stuff! (sorry :eek:)

Another oil (and filter) change are next on the list when I get time this week.
 
Interesting story! Good to hear the cars running I can't help you on the idle issue unfortuantely. The steam out the exhaust is probably just condensation. It pretty cold and wet out at the mo so probably the condensation that forms inside the exhaust. I was planning on doing some car work today but the weather is just cold and damp and couldn't be bothered to crawl around on the floor. The joy of winter.
 
Hi Tony,
About the accelerator cable setting - the throttle should be resting on a stop screw with the engine idling. It has a long 8mm hexagonal head at an awkward angle. So as long as the cable is loose enough to allow the screw to have an effect, it's OK. This is assuming it's a carburettor. If you have fuel injection there are other issues with a special switch on the throttle that HAS to click 'closed' with the engine idling.

The original problem with the HT lead, I've seen before - but the ongoing problems with the new HT leads really shouldn't be happening... Have you also checked the condition of the distributor cap, since I just wonder whether a worn-down brush in there would cause the HT voltage to rise above normal levels (as it builds up to jump the gap) and then of course the leads have to withstand the higher-than-normal voltages as well.

Another HT-lead problem is when sparks jump between adjacent leads on the distributor cap...

Otherwise it sounds like you're getting on great, and like thepottleflump says, no need to worry unduly about exhaust steam... and also, no need to worry about coolant level for the first week as there's bound to be some air-locks that will be filled.

It's getting into summer here, of course, which means burning sunshine, 24 degrees, interspersed with very heavy rain (seems to be in bigger drops than usual) and 18 degrees, high winds, and cold nights (5 degrees). Hamilton weather, in other words. I've spent several days tidying my garage. Might post up a photo once I've finished :eek:

-Alex
 
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Ok then, I guess perhaps I can afford to be a little less paranoid about steam etc :eek:

Interesting point about the throttle Alex; mine's an injector model, and I hadn't heard about any switch to be clicked closed.... I'll have a rummage through my Haynes manual. Certainly whenever I was setting it up, there was a rotating disc across the circular vertical air intake tube (inside the throttle body), which was rotated by pulling the accelerator cable, and spring-loaded to return to its position. I set up the cable so that when the pedal was fully depressed, the disc was sitting vertical, i.e. opening the tube. When the pedal was released, the disc would return to somewhere near horizontal, i.e. closing the tube. Didn't see any additional switches involved though, so I'll look into it.

Now to see if I can get to sleep and ignore the freezing temperatures and howling winds battering Belfast at the minute...! :(
 
tonyfurnell said:
Didn't see any additional switches involved though, so I'll look into it.

The switch is black, and we can call it "the idle plunger". You have to have enough slack in the throttle cable to engage it. This is actually very important, as it halvens the amount of "idling" fuel. Fiddle around the back / left (facing the engine from front) of the injection unit / carburettor to find it.

M.
 
Problem solved!

Well, at the very least, problem understood :)

With decent weather back today I finally had a go at cleaning the spark plugs and HT leads. Idling now mostly sorted. Also checked that the spring-loaded switch at the bottom of the accelerator mechanism (left-hand-side, bottom of the throttle body as you look at the engine from the front) is engaging fine -- I assume this is what Morty et al are referring to.

The one thing that's been worrying me even more recently has been the evidence of a "whistle", sort of like the sound of an old kettle boiling, at mid-high revs. I'd heard this sound before doing the head gasket change and attributed it to the knackered gasket.

BUT I finally discovered what it is today, and it's nowhere near as bad as I thought (i.e. that the head gasket change had gone wrong :eek:).... as well as the occasional whistle, there has been a constant hiss coming from somewhere in the engine, quite a loud one at that. I also thought that this was gasket-related, but it turns out that I've a rubber pipe/nozzle that has broken off the back of the throttle body. It runs to what the Haynes manual only describes as some kind of carbon filter/scrubber/something (book isn't nearby) -- I think it's related to vapour being picked up from the fuel tank.

So with this nozzle off, the engine is sucking air through the little hole every time the engine is on -- and the higher the revs, the more it tries to suck in. Hence both hiss and whistle -- and also a kind of "knocking" noise every so often, which stops when I've my finger over the hole. This is the noise that I thought was the sound of unseen sparks from the HT leads (y). Add to this the fact that the coolant and oil levels have been static so far, and I'm starting to think that I've won through..... :cool:

(fingers crossed!)
 
...yes indeed!
That of course counts as a 'vacuum leak' and would have been affecting the idling...

Sometimes you can get a small piece of brass tubing (maybe from a model shop or even another old carburettor) and drill out the hole to epoxy the brass tube in... it will have to be quite a good repair whatever you do, as a repeat of the same leak will be confusing and annoying... good luck! ;)

-Alex
 
A happy ending!

Yes, it seems that the head gasket was definitely not the only thing wrong with the engine before fixing it -- now fixed both gasket and vacuum leak and she ran beautifully, first time!

I got hold of the replacement plastic nozzle from my local Fiat dealers (£10, but hey what do you expect :rolleyes:), fitted it and bob's your uncle, the car is idling and accelerating again like a dream! Well, like a dream with a 1 litre engine anyway ;)

New oil and filter also added as of Saturday, so all of the old gunk should be well and truly out of the system. Fuel economy should be back down to normal again too, which'll be nice.

So thanks for all the moral support guys, she's all good now -- well until the next bit, which'll be a service on brakes... and maybe some new tyres needed, before the MOT in January! :(
 
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