How the heck are you supposed to get the plugs back into a turbo lump? Brute force? The plug packaging says they should be tightened to 28Nm but that's good for about half a turn (no I'm not sticking 'em in sideways!). I broke my normal ratchet and had to apply something well over 100Nm on the torque wrench to get all the old ones out, even after soaking in some WD40 overnight
2 of them went in easy as pie, but the other 2 (cylinders 2 and the impossible to reach 4) I've had to leave half out because I don't want to do some damage... Thankfully they're working ok but I just can't screw them in further without using an excessive amount of force. Removal of them shows they're not cross-threading either
Any ideas? Should I just force them the rest of the way?
Ewwwww, I hate it when spark plugs don't go in very well.
Sounds like the old ones were well stuck in due to the heat of the head on your turbo'd motah.
Maybe the threads are a bit 'sticky' on the dodgy ones. So you haven't managed to get the new plugs to meet the crush washer?
I wonder if you should get the old plugs, gob them up in some LM grease or engine oil and wind them back in to lubricate the thread, then try your new plugs, again with some gobbo on the thread to help ease them in ?
Cars in my care:
2021 Kia Spottage 1.6 Pez Turbo Dual Clutch Gearbox Trickery
2013 Renner Twingo - donkey work
I reckon it could be due to the amount of rust on the threads - from the state of the plugs I took out I reckon they could have been the factory-fitted ones! I've put the new ones in with a helping of copper grease, but i'm pondering other ways of cleaning the threads up a bit, maybe a slightly damp bit of kitchen roll (Bounty of course!) pushed against the threads with a screwdriver?
About a year back my engine management light started flickering. Diagnostic at Peugeot threw out some emission code that had everyone puzzled. As a last resort before I replaced the lambda sensor it was suggested that I try replacing the spark plugs. I had checked the plugs and they looked fine and had done less than 30k. I thought it was a waste of time but as it was the cheapest option I thought I may as well give it a try . I put in some Bosch Irridium plugs and haven’t had a problem since.
Bosch engine management, Bosch plugs maybe they like each other.
On the plug lead side. I just replaced the plug leads on the Golf. Although the leads can’t increase the voltage to the spark they certainly can lose some along the way thru high resistance. I checked the resistance of the old and the new set and there was a negligible improvement 5.8k ohms to 5.9k ohms. Even the ten year old set was well within the tolerance of 30k ohms. I had a old set of 8mm Taylor plug leads lying around that I had taken off the race car, they tested to 2k ohms. So there is a definite less resistance.
On a normally aspirated engine they say there is a spark intensity beyond which an improvement is going to give no further improvement in engine performance whereas with turbo/supercharged engine there will be a benefit at higher boost applications.
The resistance of a foot length of 1/4in copper wire is knocking about 0.0001ohm by my reckoning! Probably double that for stranded. OK there's obviously something gone on with the connectors in HT leads...
Actually scratch that, that can't be right. I ain't done the math, but kilo-ohm resistance would equate to the end pretty much being touchable as opposed to fry-your-heart kind of painful.