Here's a weird one....

[Dominic]

Hi folks

Any ideas on this anyone?
I went to start the car this afternoon, (it was working perfectly well last night) and the starter wouldn't turn, though it drew current, as the warning lights in the speedo dimmed.
I assumed the starter had jammed, but it was turning freely when I tried a spanner on the end. I then tried the starting handle, but it was immoveable.
So, I put the car in 4th gear, handbrake off, and pushed it backwards for a few feet. The engine turned freely, and when I tried starting on the key, worked as normal.
Oil is up to the line on the dipstick. Engine is as smooth as silk, up to & including 70. Oil pressure showing the usual 75lbs on the dial, temperature guage needle sitting where it always does, a fraction below the middle line.
Does anyone have any idea as to what could have caused this?

Dom

[bmcecosse]

Hmmmm - water level ok ? Was thinking maybe water had leaked into one of the bores and was 'wedging' the engine. Otherwise - may be just a loose battery connection/bad earth ??

[Dominic]

Just checked the water - maybe a fraction low, but the car is on the camber of the road at the moment, so I'll have to check tomorrow. Some mayo inside the oil filler cap, but I've been doing quite a few short (4 mile) journeys on a cold engine recently. Hopefully it won't be the head gasket again, I only replaced it 1000 miles ago! The engine has only done 8000 miles since I bought it newly reconditioned from one of the major suppliers in spring 2007!

[linearaudio]

Hydraulic lock sounds the only feasible explanation as the engine turned going backwards. Sometimes that sort of thing only shows up when cold, expansion sealing it up when hot. See if it does it again, then start thinking about head gaskets!

[Dominic]

I must say that hydraulic lock occurred to me.... It used to happen regularly to my model aircraft diesel engines when I was a kid. Apparently it was easy to bend a con rod by forcing the engine over tdc when flooded.....
I wonder if there's any comeback against the supplier after 21 months? (g'tee for 12 months) When I replaced the head gasket recently, I'd say that the block had never been skimmed from the look of it, but in the description on the web page it states that this job is carried out.

[RogerRust]

Being an optimist by nature. I'd hope that it was just a loose battery connection!

[IslipMinor]

Yes, I would definitely check the electrics, but with good modern oils, mayo should not be present, unless the engine never gets up to a reasonable temperature.

Why did you need to change the head gasket on an almost new engine? It does sound as if this is the area to look at first. Has it been using water or oil recently?

[rayofleamington]

how many turns did you turn the starter motor? If the starter dog was jammed on the flywheel ring gear you amy need a few turns to free it.
Moving the engine (flywheel) with the car in 4th amy have been enough to push the starter dog away.

However, hydraulic lock is also a possibility...

[Dominic]

I had to change the head gasket, as the one fitted when the engine was rebuilt failed, with a 1/2" gap between cyls 1 & 2. (Noisy!) Replaced it, with the obligatory re-torquing after first run, then again at about 500 miles.
I have a feeling that a little water is going awol.
I tried starting 3 times on the starter, but it was free when I manually turned the squared off spindle. After that I tried starting handle, but didn't want to bend it!
Reversing in 4th gear, the engine turned immediately.
Electrics seem fine.
Off to work now, fingers crossed it'll start without problem!
If not... it's the micra instead!
Dom

[bmcecosse]

Well - the fact you turned the engine backwards and it came free does suggest there may have been some water trapped - and luckily the reverse turning expelled it. If it happens again - make sure you turn it backwards, although thinking about it - it could still 'wedge' that way too - it really depends where the pistons have ended up at the time and where the water has crept in. So perhaps the best advice is to turn it 'whichever way it willing to be turned by hand on the fan belt' - but do make sure the ignition is OFF !

[Kevin]

Was there any type of click when you tried it as it sounds more like a dodgy starter bendix to me and as Ray has said it can take quite a few turns to free it off and its often easier to put it in gear to free it off just as you did.
If you do take it out to give it a clean remember it should not be oiled or greased and should only be lubricated with graffite, pencil lead is fine for this.

[Dominic]

When I turned the key, if I remember rightly, it clicked as per normal, but sounded as if it were being forcibly stalled, and therefore unable to spin. It (the starter) was completely free when I turned the spindle by hand.
I have also noticed, especially when cold, there is a more pronounced "tappety" noise than usual, though the gaps are accurately set (just checked).
The car has started normally the last 3 times.
I'll try a pressure test next to see if there is any difference between pots. Will also see if there is any trace of water when spun over without spark plugs.
And I fondly thought that buying a new engine would prevent any problems from that area for a good few years........

[bmcecosse]

I hesitate to ask - where the 'new' engine came from !?

[rayofleamington]

And I fondly thought that buying a new engine would prevent any problems from that area for a good few years........

did the new engine come complete with flywheel and new ring gear? I've only had this kind of thing with very worn ring gear.

[Dominic]

The engine was bought from one of the main suppliers, who share a name with one of the Hollywood Film Studios!
I replaced the ring gear with a virtually new one, on the original flywheel, after having it trued up by my local engineering shop.
I phoned them (local engineers) this afternoon for their advice, they advised that the cylinder head should always be skimmed after a head gasket failure.

[MGFmad]

I don't know why the advice is given that following HGF, a head should be skimmed - surely this is only necessary if the head as bowed due to overheating, if the head surface is completely flat and true, whats the point os skiming a head, just to achieve what you already have.

[bmcecosse]

They are just making work for themselves! Only skim if the head is bowed (and even then - you need to consider it may 'un-bow' it's self later) - or if you want a better CR anyway.

[Dominic]

Good news (I think!) - I've just tested the compression, twice over to make sure! The pressures are:-

1) 152lbs
2) 150lbs
3) 152lbs
4) 158lbs

The water level seems stable, though I will be checking with a dipstick over the next few days. There was no sign of water in the cylinder when I spun the engine over without the plugs. (Isn't the button underneath the solenoid useful!)

I'm beginning to think that the starter may have been at fault all along. There is a fairly constant "jingling" that I originally put down to timing chain, but as that is new, and a duplex, it seems on the face of it, unlikely. This jingling is the same whatever engine speed. I read somewhere on one of these forums that if the business end of the starter is worn (not necessarily the teeth), it gives just that noise.

I've just bought a new old stock starter on ebay. from Mr Gostling as it turns out, so will fit that when it arrives.

I've had not so much as a hint of that original problem of the engine jamming in about 30 starts since the weekend. A case of wait & see I guess!

[MarkyB]

I bet that jingling is a broken bendix rebound spring.
Doesn't explain why it jammed (probably worn bendix on starter or ring gear)

[bmcecosse]

Fingers crossed for you!