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(2004 cooper s 160k miles) so I was driving home from work yesterday and about halfway home, I started to feel a misfire. Made it home on 3 cylinders and once I got home and opened the hood, the spark plug flew out of the cylinder head (didn’t hit me thankfully). I inspect power plants for a living and have access to nice borescopes, used the
scope to inspect the threading on the head and found two cracks...(see attached) the answer seems obvious but it looks like I’m in the market for a new head. Would I have any luck with a time-sert or heli coil? Any input is much appreciated!
I think it is time for a new head, as it is showing casting break down. Make sure to use premium fuel in it.
Using heli coils or other fixes like it, might only be a stop gap for a new head. Mini had problems in the gen 1s with head castings, although, they will never tell you that!
This is a very unusual type of failure!
Keep us posted on what you do!
So I decided to buy a new head... it should get here next weekend. The head does not come with a cam seal, do most gasket sets include this?
thanks in advance.
So I decided to buy a new head... it should get here next weekend. The head does not come with a cam seal, do most gasket sets include this?
thanks in advance.
Just for others out there. The cracks can be fixed , the two seats replaced, and the threads fixed with inserts. Just a thought if you can not find another head. Most head shops can do this.
(2004 cooper s 160k miles) so I was driving home from work yesterday and about halfway home, I started to feel a misfire. Made it home on 3 cylinders and once I got home and opened the hood, the spark plug flew out of the cylinder head (didn’t hit me thankfully). I inspect power plants for a living and have access to nice borescopes, used the
scope to inspect the threading on the head and found two cracks...(see attached) the answer seems obvious but it looks like I’m in the market for a new head. Would I have any luck with a time-sert or heli coil? Any input is much appreciated!
Congratulations for your new head.
I am very curious and jealous that your access of a - evidently professional borescope. I cannot help but to wonder what is this GE borescope? I am aware GE is into aviation, locomotive powertrain, power plant, and healthcare. What is this borescope? I hope not from one for detecting colon cancer.
Those foto sure look like from the metallic colon .
Just for others out there. The cracks can be fixed , the two seats replaced, and the threads fixed with inserts. Just a thought if you can not find another head. Most head shops can do this.
Seriously? Fix the spark plug thread with insert. The OP didn't say the spark plug was loose. How about the crack on the cylinder head, and I am not on cracks? Just ignore the leaking vap?
It looks like the combustion was higher than the aluminum casting could handle. It looks like metal is deposited on the exhaust valves. Wrong heat range plugs, low octane fuel, too much timing advance, etc.
I had an aluminum headed D gas engine and very high combustion temps did similar damage (v8 small block Chevy) (in the sixties!) old fart here!
I would not consider fixing it on my car! I would hate to have to do a repair again, sooner than later! You can do many things to repair heads, but these Mini heads are not hard to find!
The Borescope is called an XLGO from GE. Yes they are very expensive, I borrowed this one from work. No it was not used for a colonoscopy lol, used for industrial inspections. It is a huge step up from the rigid/Milwaukee brands you can find a home depot.
It looks like the combustion was higher than the aluminum casting could handle. It looks like metal is deposited on the exhaust valves. Wrong heat range plugs, low octane fuel, too much timing advance, etc.
I had an aluminum headed D gas engine and very high combustion temps did similar damage (v8 small block Chevy) (in the sixties!) old fart here!
I would not consider fixing it on my car! I would hate to have to do a repair again, sooner than later! You can do many things to repair heads, but these Mini heads are not hard to find!
I bought the car last April for a pretty good deal. it had BOSCH Platinum 4 plugs in it and there is no telling what fuel the previous owner used, i always use 93 octane. After I replaced the head, I put colder range NGK plugs in it torqued to spec. Hopefully the issue is fixed, I've put 130 miles on with the new head and it runs great so far. As far as too much timing advance, how can i check that? Thank you for the info.
These cracks can be fixed by a competent machine shop with aluminum experience.
But there in lies the rub, they must be well versed in this kind of repair, esp when it comes to the heat used and taking care to match the repair metal to the head metal. (The repair metal has to be as close of a metallurgical match as possible for the repair to last)
The reason it's not don't often is because of the expense -vs- finding simple replacement head.
The point is not about if it is feasible or possible. Anything is possible if the desire is compelling enough. If it were a Lotus 16 valve head for Mk I Escort or Lotus Elan for sure. The repair will require carefully welding the two cracks, clean out the spark plug thread, but more challenge have to machine the seat of the valve seats - followed with new valve seats. The cost will be prohibitive compare to finding a used head that is aplenty.
The Borescope is called an XLGO from GE. Yes they are very expensive, I borrowed this one from work. No it was not used for a colonoscopy lol, used for industrial inspections. It is a huge step up from the rigid/Milwaukee brands you can find a home depot.
It is always fun to find out what our Miniac's profession than just stay narrowly on topic. I figure the scope is likely for industrial inspection use, like oil and gas or metal fabrications. The resolution is too low for colonoscopy for sure. It has a 6mm diameter probe so at least won't be too hurtful with proper lubrication. For those curious here are the specs. It has MIL spec certification for what's worth. It packs a microphone and the most interesting feature is the articulating probe head controlled via a joystick.
I think the video sensor is not located at the probe head. The probe is likely consists of a fiberoptic bundle and a compact microphone.
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I figure the scope is likely for industrial inspection use, like oil and gas or metal fabrications. The resolution is too low for colonoscopy for sure. It has a 6mm diameter probe so at least won't be too hurtful with proper lubrication. 