old land rover running on two cylinders?

[warch]

So what you might say?

Can't figure this one out,its a 60's petrol 2286cc. It was running absolutely fine beforehand incidentally.
I determined this out by pulling the plug leads off the plugs it affects cylinders 3 and 4.The two plugs do spark.

I've tested and discounted the spark plugs, plug leads, coil, condenser, points and distributor cap. The valve gear is intact and working as it should. Its fueled by a single carb so I can't see that fuelling would be a problem.

Has anyone got any suggestions or had this happen before, because for the life of me I can't work out what would cause this.

[stevensdrs]

I would do a compression test on cylinders 3&4.

[stevieturbo]

How was it being driven leading up to this occurrence ?

[warch]

It was driving perfectly. It is well worn but it isn't throwing oil out of the exhaust/ crankcase pressure doesn't look any worse than before.

I am anticipating an engine rebuild/replacement so yeah a compression test would confirm that this would be necessary, just wondered if there was any other possible/likely cause I'd overlooked.

[Steve_D]

Have you checked all the valves are opening...broken cam shaft?

Steve

[AtticusFinch]

Sounds more like a HG failure bettween 2 & 3

[Incorrigible]

I think you know the answer; compression test followed by inevitable strip down

Happy to be be wrong of course

[stevieturbo]

warch said:

It was driving perfectly. It is well worn but it isn't throwing oil out of the exhaust/ crankcase pressure doesn't look any worse than before.

I am anticipating an engine rebuild/replacement so yeah a compression test would confirm that this would be necessary, just wondered if there was any other possible/likely cause I'd overlooked.

I asked [b]how[/] was it being driven, not if it was driving ok.

ie were you tootling about at 30mph, or were you foot the the floor for ages etc ?

But a compression test would be a good start. The fact it's two cylinders could be as simple as HG blown between them

[warch]

stevieturbo said:

I asked [b]how[/] was it being driven, not if it was driving ok.

ie were you tootling about at 30mph, or were you foot the the floor for ages etc ?

But a compression test would be a good start. The fact it's two cylinders could be as simple as HG blown between them

Thats a good point, it was being driven quite carefully i.e. warmed up then driven at 45-50ish for about a six mile round trip. It's been off the road for a while though.

I hadn't thought of the head gasket packing in, it's a very good thought actually, I remember having an old mini packing in like that due to HG failure. Plus its only a three hour job last time I did it and I'd need to do that for a full rebuild.

[warch]

DP The valve train is fine all valves opening and closing as they should (was thinking broken valve train but I've never heard of this happening)

[stevieturbo]

It would be unusual for a HG to blow during light driving. But anything is possible.

Compression test

[warch]

Compression test it is, just spoken to someone on a Land Rover forum with an identical problem and he had confirmed HG failure. Seemed an unusual amount of vapour at the exhaust too (it doesn't normally produce more than a puff when warm). Thanks for all your advice everyone, I feel alot happier now I know how to proceed, having spent ages laboriously checking and swapping ignition components to no avail.

[MattYorke]

I agree it's likely HG failure, however the other cause of this I've seen is forgetting you've stuffed a rag down the inlet when you took the carb off to rebuild it and then put it back together with rag still in situ.

Edited by MattYorke on Monday 13th February 16:14

[warch]

MattYorke said:

I agree it's likely HG failure, however the other cause of this I've seen is forgetting you've stuffed a rag down the inlet when you took the carb off to rebuild it and then put it back together with rag still in situ.

Edited by MattYorke on Monday 13th February 16:14

I've had no end of experience in failing to remove/replace various parts down the years, my usual is leaving the rotor arm off, strongly followed by forgetting to put the sump plug back in before refilling with oil...

[anonymous-user]

Other than the shear weight of the iron LR cylinder head at full arms reach over the front wings, a HG change is easy on the 2.25. No cam belt/chain to worry about etc, and if you're feeling strong leave all the intake/exhaust manifolding / carbs on the head and just yank the whole lot of as a chunk (watch ya back though ;-)

[warch]

Max_Torque said:

Other than the shear weight of the iron LR cylinder head at full arms reach over the front wings, a HG change is easy on the 2.25. No cam belt/chain to worry about etc, and if you're feeling strong leave all the intake/exhaust manifolding / carbs on the head and just yank the whole lot of as a chunk (watch ya back though ;-)

Thats what I love about Land Rovers the sheer lack of mechanical complexity. The head is unbelievably heavy, I remember moving the damn thing about whilst I'll was lapping in the the valves. I usually stand in the engine bay for lifting the head and out.