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Moisture in cylinder #3 - 850 - help?

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Silverghost

Yoda
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Hoping to find knowledge/help. Our 64 Mini started running rough yesterday. Did a quick check, found nothing out of order. Pulled the plugs and found #3 was wet...didn't smell like gas and wasn't oil. How should I proceed?? Compression check? How can I determine if head gasket went, cracked head, warped head, etc. I have the ability to do the repairs myself, I want to do it efficiently and cost effectively.

I look forward to your replies.

Thanks,
Peter
 
Peter,If water or coolant is getting in the combustion chamber you will probably see steam or water coming out the exhaust . May even have a sweet smell if it's coolant. Also check your dip stick for signs of water in the oil. good luck. May be a head gasket or a crack between the valves.
Bob
 
One source seemed to think head gasket....would like if that were the case. I will check the oil to see if any signs of misfortune <fingers crossed!>
 
Just because the wet plug didn't smell like gas doesn't mean you should write fuel off as a possibility. By all means do a compression check to screen out a possible head gasket, but if after putting in a fresh, dry plug the problem happens again, be sure to check the float valve in the carb.
 
Thanks for the input. A compression check and a new plug are definitely in order. What should the compression leevel be? I seem to recall having a compression gauge in my toolbox, otherwise I will go buy one. How do I check the float valve? Please keep your fingers and wrenches crossed the cause a simple fix!

Peter
 
The report is in:
Cylinder #1: 110 psi
Cylinder #2: 130 psi
Cylinder #3: 70 psi
Cylinder #4: 130

Is it possible to determine whether blown gasket or cracked head before I pull the head? Obviously a new set of head related gaskets in needed. Then a trip to the shop to have the head pressure checked? Any thoughts on a root cause here?

Thanks, Peter
 
Remember that you need to run the compression test while holding the throttle wide open to get a consistent reading. The values will be different for hot and cold engines. Generally the actual compression numbers aren't as important as how consistent they are from cylinder to cylinder. Your #3 is significantly lower than the others. The next check with the compression gauge is to put a teaspoon of oil through the spark plug hole of #3 and repeat your test. If the compression increases it indicates you probably have problems related to the rings. If it stays the same, the problem is likely in the valves or head gasket.

You may want to Google for information on leak-down testers. These go beyond the compression test in helping you identify where leakage may be occurring.
 
Ok, mystery solved....the jam nut for the intake valve on cylnder 3 decided to back itself completely off the stud and take a nap in the top of the head. Fortunately it didn't migrate anywhere else and really make a mess. There was a woodpencil diameter sized gap between the rocker arm and the end of the valve. No damage to anything <whew>. I now have a new appreciation for that bumper sticker "All the parts falling off this car are of the finest British workmanship"! Next project is to upgrade cooling system. Recommendations on radiator type, fan type, and/or electric fan, etc. All of the above?

I look forward to the feedback.
Peter
 
I'm glad you found the problem and that it was nothing major.

If you're replacing major cooling system parts you have a lot to choose from.

It seems the prevailing wisdom is to run the Super-2-Core radiator for efficiency. (I don't even know what radiator is in my car! ) There is a fair amount of discussion about which fan is better. The 6-blade tropical fan moves a lot of air but some people say it makes too much noise compared to the more common 11-blade fan.

I've heard mixed comments about adding an electric fan. I have no first-hand experience so I can't comment.

A component you didn't mention is the water pump. There is a high-flow water pump designed for the 1275 that can be adapted to the small bore engines. This pump has a cast iron impeller as opposed to the stamped steel one. I have never heard a bad comment about this pump from anyone who has used it.

If you have a clean radiator and everything seems to be otherwise in order you may want to consider replacing your summer coolant with a mix including Red Line Water Wetter. I run this in my car along with the tropical fan. I just finished a weekend of relatively long distance driving in 93 degree heat and the temperature gauge stayed pretty close to mid-scale all day.
 
Thanks Doug. The place that remedied the valve problem found that the water pump is chattering a bit....the noise became evident once the valve train stopped it's racket... A new pump is in the back waiting to go in. I am thinking since the rest has to come out to do the pump, why not do the job all at once. Just as in the cylinder problem, I want to be effective and efficient in time and dollars. Measure twice, cut once as the old addage goes.

Thanks again,
Peter
 
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