help finding the right compression tester fitting

[MrShorty]

Figured out the other day that my number 6 cylinder is weak/dead. It's getting spark and fuel, so I decided to do a compression test on the engine. Trouble is, my tester doesn't want to thread into the spark plug holes. I think it's just a case of the 14 mm adaptor I have is too short (the distance from the o-ring to the end of the adaptor is ~1/2". The spark plug is 11/16"). As usual, the parts stores in this county are almost useless when it comes to getting tools. The guy at Carquest said he might be able to get something, but he's not sure. I expect I could get it in Salt Lake, but I'd rather call ahead and find it, which means I need to know as best I can what I'm looking for, and what would be a available. A google search hasn't yielded much (I found one on a parts site in the UK that looked to be 6" long, but it didn't really say what it was). Any help finding the correct adaptor would be appreciated.

 

[MrShorty]

Talked to the gentleman at Carquest. His supplier told him that such fittings have to be custom made. I guess it's possible, but I wouldn't expect that to be true. I know I have seen on here that people have performed their own compression test. What have you used to attach the gauge to the cylinder?

 

[MrShorty]

Figured out what I needed. For future reference, you need a 14 mm long reach fitting (unless you try to use the rubber tip and hold it in place by hand). Nobody in this county could sell me just the fitting, and after gas and such to get to SLC where I could get just the fitting, I decided it was cheaper/easier to by a new compression gauge set that included the correct fitting. My advice to anyone thinking of getting a compression gauge is to get a set with all the adaptors you will need.

Now, the results of the compression test. Cylinder:
1. 130
2. 60
3. 155
4. 160
5. 145
6. 40
6 with oil. 120

I didn't go around and put oil into each cylinder, but this indicates that, at least for #6, my piston rings aren't sealing like they should. I don't detect any coolant in my oil, so I don't think there are any head problems, and I haven't done enough to check the valves. What comes next? Upper engine rebuild (I'm not sure it makes sense to open the engine up to only replace two piston rings)? My inclination at this point, is to put the plugs back in and take it to a shop and have them tackle the job. Any suggestions before that leap? Any thing else I should check before I take it in? When/If I take it in, any things to have them check out while they are taking the engine apart? I know the costs of such repairs are market specific, but any estimates of cost?

Thanks in advance for any help.

 

[Brian1]

You did what I would have done, gone out and got a new compression checker set. Wow, those 2 cylinders are really bad. Did you do the test with all the spark plugs removed? When you get a quote on a rebuild, also go to a junk yard and see what they want for a 4.0 out of another Explorer. It may be cheaper to swap in a "new" used engine. If you do make sure the yard has a warranty on the engine. good luck.

 

[MrShorty]

I performed the test per the instructions in the Haynes manual (didn't find it in Chiltons): all plugs removed, fuel pump and coil disabled, throttle open, engine warm (and I thought #3 was bad with the engine cold). You're right, those two are pretty bad. I'm surprised the engine runs as well as it does. (Maybe I should just unplug those two fuel injectors and run a 2.6 L V4 , Nah, get it fixed right) Thanks for the input.

 

[MrShorty]

She goes under the knife today

I dropped my Explorer off at the shop today. They are going to install a rebuilt long block and hopefully have it done by the end of the day Monday or Tuesday. I almost feel like I just took a family member in for minor surgery.