Earlier this year, I made a mistake when changing injector cups and ended up blowing a head gasket. With that being said. I have the engine at the machine shop for a basic overhaul, new bearings, rings, head job. Hope to get it back this week or next. Then the project of putting it all back together to run again. All this after 288k. My mistake cost me a lot of down time. Would I do it again. Yes, I would know that I know exactly what I am doing with the cups. Trial and error got me this time, but not again.

Will let you know when she is back on the road again.

Ted

 

Ted, any chance on letting us know what the mistake with the cups was? Maybe we can all learn from your experince.

 

I mistakenly did not put the injectors in to keep pressure on the cups when I installed them and I believe that is why the cup did not seal. I had at least one cup that allowed water to enter the cylinder and hydro-lock the engine at speed.

 

Putting the injectors in place does not seal the cups. If the cups are installed correctly there is no requirement to install the injectors within a certain period of time. What you most likely did was not clean the bore out completely of old sealant. If there is a tiny bit of old sealant left where the bottom of the cup fits in the bore, the cup won't seat all the way. It can be very difficult to get all the old pieces out and very difficult to visually verify that the bores are clean. That would certainly cause the problem you had. Next time, there is an easy way to verify. After the injectors are installed, the tops of the solenoids should all be perfectly level. If you have one that sticks up 1/8", that's going to cause a problem for you. You can also pressurize the cooling system and spray soapy water into the bores and see if any of the cups are leaking.

 

I cleaned all of the bores out where nothing was left and they were nice and shiny. I had one bore that would not seal correctly and it had a very clean bore to work with. The only conclusion the guru's down here could come up with is the injectors should have been installed right after installing the cups. Another individual did same procedure and install injectors right after cups and is still driving his. So I am at a loss. If you say that it shouldn't matter, then something else is amiss. Those bores were so clean you probably could have eaten out of them. Either way that doesn't matter now. The machine shop will have everything installed and sealed so I should be good for many hundreds of thousands of miles more.

Ted

 

did you let the loctite cure for 24 hours? Did you use the correct loctite? Were the cups fully seated? Was the adhesive applied in the correct location on the cups? I did mine and had to wait on parts (valve cover gasket and UVCH) so mine sat without injectors in it for almost a week after I put the new cups in. I've put a few thousand miles on it since then and there is no more diesel in the coolant.
The other posts are correct, the injectors do not hold the cups down, and if you try to torque the injectors to get the cups to seat, you will mess up the copper crush washers.

 

I also did a cup job and left the injectors out for 24 hours and then pressure tested the coolant system with them out and haven't had any issues. If you had enough coolant leak into the engine that hydrolocked the engine while it was running then I doubt it came from a cup. That would have to be a substantial leak and sounds more like a cracked head or blown head gasket.

 

I also should mention that my injectors were installed days after the cups went in on my build. So I know for a fact it doesn't matter, and there is nothing in the design that would call for the injectors to be installed immediately after, either. If you had a leak, it was because one of the things mentioned by afmedic happened.

 

I've done my share of cups... and I never install the injector until after I have pressure tested the coolant system with air and looked for leaks. The immediate injector install theory doesn't "hold water" with me.

 

I left the cups for a week before installing the injectors as I had to wait until the next weekend to have enough time. It will all be okay now. I have the experts doing the work. I also pressure tested and it held pressure. So I do not have an answer for anyone. The only thing we could come up with was the fact that one individual installed injectors after cups and did not have a problem. I did not and did have a problem. Not an issue anymore as the machine shop will clean everything up and get it back to me soon.

Ted

 

At least you'll be back on the road. Good luck to you, and don't get discouraged from doing your own work again, things happen and this was probably something completely unavoidable.

 

Finally received some news from the machine shop. Block and heads are solid with no cracks. Crank is true and polished. New bearings and rings in lower end. The heads will be completely reworked and ready with new parts. Once all back together, I plan on breaking it in on my drive to and from work. About a 45 minute drive each way. Will drive to work and home, change oil, then drive for a week, change oil, then go for a normal oil change to round it out. That is the plans for now. But it will be a week or more before it is returned to me.

I appreciate all the comments and help. I am by no means a mechanic, just like to work on my own things and this is a heck of a lot cheaper than a new vehicle.

Ted