What are my spark plugs trying to tell me?

[NonSyncro]

Just purchased a 1974 series 3 Land Rover. Had my first chance to have a poke around the engine today, but the spark plugs show quite heavy brown deposits on the electrodes.


Apologies for the poor photo

Planning on having the cylinder head off to change the valve stem seals since it lets off plenty of blue smoke on start up and intermittently while driving. Does this confirm my suspicions of valve stem oil seals, or are the spark plugs just getting a bit old?

NonSyncro

[Maximum Bobs]

http://www.verrill.com/moto/sellingguide/sparkplug...

Could very well be oil related, also if you're taking the head off I'd personally get hardened valve seats installed so you won't have problems in the future caused by unleaded petrol. That's of course if it hasn't already been done.

[stevieturbo]

Contamination is usually down to something in the fuel. Although Ive never seen a plug that bad !

How long have they been in there, or what was it running on ?

And all the v8's had hardened valve seats anyway, so unleaded use should not be a problem.

[NonSyncro]

stevieturbo said:

Contamination is usually down to something in the fuel. Although Ive never seen a plug that bad !

How long have they been in there, or what was it running on ?

And all the v8's had hardened valve seats anyway, so unleaded use should not be a problem.

Have no idea how long they've been in there, only had the landy 2 days now.

Should have said its a 2.25 petrol. Already got one RV8

Previous owner run it on unleaded with Castrol Valvemaster lead replacement additive.

[Maximum Bobs]

sorry didn't realise it was on all four plugs & just assumed it was one. Might be worth just putting a new set of plugs in & running it without the additive for a while to see if the build up comes back or not.

[powerstroke]

NonSyncro said:

Just purchased a 1974 series 3 Land Rover. Had my first chance to have a poke around the engine today, but the spark plugs show quite heavy brown deposits on the electrodes.


Apologies for the poor photo

Planning on having the cylinder head off to change the valve stem seals since it lets off plenty of blue smoke on start up and intermittently while driving. Does this confirm my suspicions of valve stem oil seals, or are the spark plugs just getting a bit old?

NonSyncro

Thats most likely from oil burning!!! causes this sort of ash/carbon build up on the plugs ,

Edited by powerstroke on Monday 24th October 08:56