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Old 10-12-2019, 06:09 PM
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Oil in pre-chamber w123

Pulling the injectors today I noticed 3 4 and 5 prechambers had oil in them. I've not noticed any smoky startups or anything like that. Anything to worry about?

Going to do a compression test and I was just curious if this is going to make it a wet test and cause inaccurate results??
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Old 10-12-2019, 06:09 PM
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And it's a 1985 turbo if that matters
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Old 10-12-2019, 07:27 PM
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Well didn't seem to make much of a difference. 300+ on four chlinders and 250 on one. Gonna have to live with that haha

I bought the ceramic grease for installation of injectors. Do you guys put it on the tip threads AND bevel mating surface?
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Old 10-13-2019, 12:21 AM
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Originally Posted by Tlaurin View Post
Well didn't seem to make much of a difference. 300+ on four chlinders and 250 on one. Gonna have to live with that haha

I bought the ceramic grease for installation of injectors. Do you guys put it on the tip threads AND bevel mating surface?
I just use regular never-sieeze type compound on the threads that go into the pre-chamber collar. Have never seen anyone use it on the heat shield nor the tip if the Injector.

The question is what is the compression on the rest of the Engine.

Could be the valve stem seals are shot.

If the fuel is not combusting well there won't be the same amount of pressure in the cylinder to expand the rings properly and that can cause the oil on the cylinders to be pushed up.
You may have a head gasket leak between the adjacent cylinders or you may have a head gasket issue allowing oil in.
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Old 10-13-2019, 05:55 AM
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300+ on four chlinders and 250 on one.

leak-down test will tell you what the problem is
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Old 10-13-2019, 11:48 AM
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I wonder how oil could get into the pre-chambers. Even if excessive oil in the cylinders, seems it would be hard to get into the pre-chambers since average flow is the other way. Sure it wasn't diesel fuel mixed with carbon? I don't think diesels have much problem with oil getting past the valve guides since they don't have a high intake manifold vacuum to suck oil in like gas engines do when idling. I've pulled the head off my failed 1985 engine ~10 yrs ago, also removing the camshaft assembly. I don't recall rubber valve stem seals, but then didn't look for them.
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Old 10-13-2019, 04:03 PM
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Quote:
Originally Posted by Tlaurin View Post
Pulling the injectors today I noticed 3 4 and 5 prechambers had oil in them. I've not noticed any smoky startups or anything like that. Anything to worry about?

Going to do a compression test and I was just curious if this is going to make it a wet test and cause inaccurate results??
Is it possible the injector wells were sitting in oil/diesel mix, when pulled this flowed into pre-chamber?
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Old 10-13-2019, 10:15 PM
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With the heat shield out and you shine al light down into the Pre-chamber it is hard to see because it is a dry flat black color.
If oil has been burning inside of the Pre-chamber the whole thing inside will have a shiny wet look and often build up but it wont look like Oil like you poured some oil on flag black paint. If Oil burned in it will be solid or have a slight gumminess to it.
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