Major Problems

[ripspeedtimmy]

Hi People

Just thought id inform people of my latest problem, fitted a new set of spark plugs yesterday, tightened plugs to reccomended torque load, Re-Attached leads 1 by 1 in right order. Started car then all i heard is an almighty bang, sounded like a shotgun. Turned off engine and noticed a dink in my bonnet. Opened bonnet to see the HT lead half hanging out of my engine, the HT lead had so much force behind it that it nearly pierced the bonnet. Pulled the lead all the way out too see that it had cracked half way down the middle and i noticed that the plug was still in the lead, minus the threaded part, which was still in the head :S I managed to get the thread out of the head. no problems there and nothing fell into the cylinder so thats fine, i repaired the ht lead as best i could and the put the original plug back in, I started the car and all seems fine, i drove it home this morning and there is a very very slight misfire at low rev's, which i am hoping is due to the dodgy lead. I popped down to the motor factors that supplied the spark plug and explained the problem. They have told me that they will send along the plug to NGK for testing as they think it may be a faulty plug and send along any expenses that i have incurred due to the plug, e.g. quote on respraying bonnet and new HT lead, When i first told them they blamed it on a compression problem but i know that that is a load of rubbish because i put the old plug back in and tightened it to the same load as all the others, and there is no problem at all... Just thought i would let you all know

[bert.tsport]

Hi People

Just thought id inform people of my latest problem, fitted a new set of spark plugs yesterday, tightened plugs to reccomended torque load, Re-Attached leads 1 by 1 in right order. Started car then all i heard is an almighty bang, sounded like a shotgun. Turned off engine and noticed a dink in my bonnet. Opened bonnet to see the HT lead half hanging out of my engine, the HT lead had so much force behind it that it nearly pierced the bonnet. Pulled the lead all the way out too see that it had cracked half way down the middle and i noticed that the plug was still in the lead, minus the threaded part, which was still in the head :S I managed to get the thread out of the head. no problems there and nothing fell into the cylinder so thats fine, i repaired the ht lead as best i could and the put the original plug back in, I started the car and all seems fine, i drove it home this morning and there is a very very slight misfire at low rev's, which i am hoping is due to the dodgy lead. I popped down to the motor factors that supplied the spark plug and explained the problem. They have told me that they will send along the plug to NGK for testing as they think it may be a faulty plug and send along any expenses that i have incurred due to the plug, e.g. quote on respraying bonnet and new HT lead, When i first told them they blamed it on a compression problem but i know that that is a load of rubbish because i put the old plug back in and tightened it to the same load as all the others, and there is no problem at all... Just thought i would let you all know

its a good job someone was not leaning over the engine with the bonnet open when it went bang...

[ripspeedtimmy]

thats the thing, i was going to start it with the bonnet open, but my friend said to me close it because it was starting to rain, if it hadnt rained, it would have been a completely different outcome

[bert.tsport]

thats the thing, i was going to start it with the bonnet open, but my friend said to me close it because it was starting to rain, if it hadnt rained, it would have been a completely different outcome

death by ht lead, loss of teeth... if lucky, just brown pants... :D

[dvdmeister]

Yikes thats pretty freaky - all most as freaky as when my uncle was changing the springs on his car and the spring clamp he was using on the old spring he had just removed spontaneously broke - the spring basically punched a hole through the garage wall and ended up about 25 feet away half embedded in the grass - scariest thing ever!

[Black Knight]

If you overtighten a plug it can distort the body which releases some of the clamping load between it and the insulator. That can cause the insulator to come out of the body.

You stated that you tightened to the correct torque load though. Where did you get the torque spec from?

Just seen another thread you had running about a pinking problem. Were you putting brand new plugs back in to try and sort this?

A pinking problem may have some relevence to this somehow. Does seem to be a bit too coincidental

[ripspeedtimmy]

I was told the reccomended torque load by a trained toyota mechanic, a friend of mine hee hee. I changed the plugs because apparently they are meant to be changed every 13000 miles and i have not changed them in 21,000 miles :S If it remedies the Pinking problem its an Added bonus

[Black Knight]

2 Questions:

1. Did you put any lubricant on the threads (copper grease or the like)?

2. Having a look around the web it looks like Denso plugs are tightened to a higher torque than NGK plugs as standard. Denso plugs are the normal Toyota plug type so it's possible that your friend gave you the spec for a Denso plug that was too high for an NGK plug. Can you check with him?