Bazookabob
Well-known member
Hello gang
I thought I should share my experience with the dreaded stuck glow plug and subsequent repair.
Firstly, I was in the process of removing the heads to take to a machine shop for re-build. Five glow plugs came out without any issue at all. In fact it seemed too easy. #5 though was a bit tight so I soaked it in wd-40 overnight. Went to remove it and it turned easily, or so I thought. It actually snapped without any effort at all. Since the heads were heading to the machine shop, I decided to let them extract it. They told me no problem.
It was a problem, a big problem as they ended up hammering it out from the bottom thus taking out the M8 threads. They tried to insert a heli-coil to repair but the damaged thread was too much and not enough meat left to hold the heli-coil. I forgot to mention that they did the valve job on the head before extracting the plug. The only options left were to replace the head with a used one or to take the head to another machine shop that said they could weld the hole and re-drill and tap it.
I chose to take it to the other machine shop and have it welded. They had it for a week before they could look at it and told me they couldn't fix it. It was going to be too difficult to align the new hole and they didn't want to be responsible.
Okay, I thought if I needed a replacement head, I'd take this one home and either fix it myself or destroy it completely.
The fix:
I heard about Time-Serts so I looked up the specs. M8 time sert would not work as the hole was too large. An M10 however would so I bought the M10 x 1 kit. Drilled out the hole for the insert with barely any material coming off the drill bit. Just the right size. Installed the time sert solidly. Meanwhile I found a M10 to M8 reducing bushing which I then threaded into the M10 time sert with some thread lock. Installed the glow plug and it set perfectly.
Total cost - less than $130.00 plus the new glow plug.
What the machine shops couldn't fix.
Reducer bushing test fit on glow plug.
M10 X 1.0 TIME-SERT KIT https://www.threadkits.com/time-sert/metric-series/kits/?p=2
Reducing bushing https://www.fittings.space/gsm26-m8x10-m10x10m
I thought I should share my experience with the dreaded stuck glow plug and subsequent repair.
Firstly, I was in the process of removing the heads to take to a machine shop for re-build. Five glow plugs came out without any issue at all. In fact it seemed too easy. #5 though was a bit tight so I soaked it in wd-40 overnight. Went to remove it and it turned easily, or so I thought. It actually snapped without any effort at all. Since the heads were heading to the machine shop, I decided to let them extract it. They told me no problem.
It was a problem, a big problem as they ended up hammering it out from the bottom thus taking out the M8 threads. They tried to insert a heli-coil to repair but the damaged thread was too much and not enough meat left to hold the heli-coil. I forgot to mention that they did the valve job on the head before extracting the plug. The only options left were to replace the head with a used one or to take the head to another machine shop that said they could weld the hole and re-drill and tap it.
I chose to take it to the other machine shop and have it welded. They had it for a week before they could look at it and told me they couldn't fix it. It was going to be too difficult to align the new hole and they didn't want to be responsible.
Okay, I thought if I needed a replacement head, I'd take this one home and either fix it myself or destroy it completely.
The fix:
I heard about Time-Serts so I looked up the specs. M8 time sert would not work as the hole was too large. An M10 however would so I bought the M10 x 1 kit. Drilled out the hole for the insert with barely any material coming off the drill bit. Just the right size. Installed the time sert solidly. Meanwhile I found a M10 to M8 reducing bushing which I then threaded into the M10 time sert with some thread lock. Installed the glow plug and it set perfectly.
Total cost - less than $130.00 plus the new glow plug.
What the machine shops couldn't fix.
Reducer bushing test fit on glow plug.
M10 X 1.0 TIME-SERT KIT https://www.threadkits.com/time-sert/metric-series/kits/?p=2
Reducing bushing https://www.fittings.space/gsm26-m8x10-m10x10m
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