Spark plug extender failure
Discussion
I've recently moved away from using the spark plug extenders (Beru ZL302) due to a miss fire issue and thought I'd share a few of photos.
When I first bought the car it suffered from some shunting and part of the cure was to replace the spark plug extenders with new ones. I changed them around July 2019, buying 10 from the last batch of 120 apparently. They took a while to turn up but I thought it was worth the wait. They looked genuine when compared to my old ones and at £7 through a recognised distributor I thought a good buy. The shunting lessened and I made sure they stayed well away from the manifolds.
Roll on this year and 1200 miles later and the miss fire comes back. Checked the extenders and... they are all cracked!
They all cracked in the same way and not at a seam. Two were slightly melted as seen in the photo.
I checked the plugs too and 3 weren't too clever, not completely fouled but wouldn't have helped matters either. A quick brush and back in they went.
So with angled HT leads now fitted to the spark plugs directly, well away from the manifolds, no more shunting.
Long may it stay that way and definitely no more extenders!
When I first bought the car it suffered from some shunting and part of the cure was to replace the spark plug extenders with new ones. I changed them around July 2019, buying 10 from the last batch of 120 apparently. They took a while to turn up but I thought it was worth the wait. They looked genuine when compared to my old ones and at £7 through a recognised distributor I thought a good buy. The shunting lessened and I made sure they stayed well away from the manifolds.
Roll on this year and 1200 miles later and the miss fire comes back. Checked the extenders and... they are all cracked!
They all cracked in the same way and not at a seam. Two were slightly melted as seen in the photo.I checked the plugs too and 3 weren't too clever, not completely fouled but wouldn't have helped matters either. A quick brush and back in they went.
So with angled HT leads now fitted to the spark plugs directly, well away from the manifolds, no more shunting.
Long may it stay that way and definitely no more extenders!The angled leads seem to be the best solution, I fitted some a year ago and they seem to be holding up.
If I do get a failure I’m going to buy the stuff to make them myself so repairs are easy and cheaper.
Even Mr retro leads on eBay has started putting the Tvr tax on his listed leads for the Chimaera and I bet they are the same as his £35 set for the Range Rover.
If I do get a failure I’m going to buy the stuff to make them myself so repairs are easy and cheaper.
Even Mr retro leads on eBay has started putting the Tvr tax on his listed leads for the Chimaera and I bet they are the same as his £35 set for the Range Rover.
I had a new set of Beru extenders fitted at a service by my TVR guru.
He felt the 15 year old original ones looked tatty, so did a bit of preventative maintenance.
6 failures in the next six months spoiled a sprint day, a track day and a trip to London (when 2 failed).
It was fine on the A1, just felt to be lacking in power, but the problem became obvious when we had lovely pops and bangs in north London traffic on the way to Ali Pally. Let the car cool, and then tested with an infrared thermometer (which by then I was keeping in the car).
It seems that even the great and good got caught by a duff batch of Chinese copies - mine came from an unimpeachable source.
I binned the extenders.
I now have ceramic capped leads, which for me have been marvelous, but let's not start a discussion running on the merits of different alternatives.
He felt the 15 year old original ones looked tatty, so did a bit of preventative maintenance.
6 failures in the next six months spoiled a sprint day, a track day and a trip to London (when 2 failed).
It was fine on the A1, just felt to be lacking in power, but the problem became obvious when we had lovely pops and bangs in north London traffic on the way to Ali Pally. Let the car cool, and then tested with an infrared thermometer (which by then I was keeping in the car).
It seems that even the great and good got caught by a duff batch of Chinese copies - mine came from an unimpeachable source.
I binned the extenders.
I now have ceramic capped leads, which for me have been marvelous, but let's not start a discussion running on the merits of different alternatives.
first off all: remove those extenders...and never refit-others...neither NOS nor replacements
buy a set of leads with angled ends and buy a set of heat sleeves for them:
https://www.ebay.co.uk/itm/8Pcs-2500-Spark-Plug-Wi...
buy a set of leads with angled ends and buy a set of heat sleeves for them:
https://www.ebay.co.uk/itm/8Pcs-2500-Spark-Plug-Wi...
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