Help buying compression tester

[xveganxcowboyx]

I'm just about to go out and pick up a compression tester. I've used the regular screw in type before, but there is a press in style that is $12 cheaper. Has anyone used one of these? Is it accurate? Does it hold up to repeated uses?

 

[slider85]

i bought the screw in type, and I have no experience with the other kind. mine worked great and gave accurate readings. cheaper isn't always better. or if you don't want to spend the money you may be able to get it done for free at a repair shop.

 

[steve]

It's a bit of a pain trying to hold it in while you turn the key.
Spend the extra $12.

Steve

 

[xveganxcowboyx]

It's a bit of a pain trying to hold it in while you turn the key.
Spend the extra $12.

Steve

Ah, that's a good point. I guess I'll go spend the extra $. It's tough to make myself spend any extra when I have no job currently. Ah well....


Thanks!

 

[Old Mitsu Tech]

All pros use the screw in type. Depending on what you want to spend, one from a parts house should fit the bill.

 

[xveganxcowboyx]

I got the carquest screw in type. It semms to work. Of course I almost wish i hadn't bought it so I wouldn't have seen the 100 across the board compression.

 

[oldman]

I got the carquest screw in type. It semms to work. Of course I almost wish i hadn't bought it so I wouldn't have seen the 100 across the board compression.

Are they all about 100? When ever you get same low numbers across the board, you always want to double check the tester and procedure first before you jump into conclusions.

1. How much and what brand was the tester? pick up a more expensive one from Autozone to double check and return it afterwards.

2. Make sure the car is fully warmed up.

3. Make sure throttle is fully applied during cranking.

4. Make sure the battery is fully charged, wouldn't hurt to jump your battery with a running car while cranking.

5. Perform a wet test after the dry test.

http://www.dsmgrrrl.com/FAQs/compression.htm

 

[steve]

Also make sure that the seal isn't leaking at the head and if it's has a valve stem pressure relief on the side that it isn't leaking too.

Steve

 

[xveganxcowboyx]

It's hard to check everything, because I'm doing all this myself, but here's exactly what i went through.

Drove the car until it was at 100% operating temp.

Took out the plugs, pulled mpi1 fuse, and main plug wire.

Inserted the compression tester into the driver's side cylinder and cranked for 8-10 seconds with the throttle fully open, checked it, released the pressure and repeated. I got 98-100

It took a little while before I got to the second cylinder, because I was dumb enough to use the extention and had trouble getting it out. The engine was somewhat colder, but i repeated and the other cylinders were 100, 110-115, and 108.

I then added a bit of oil to each cylinder and checked them twice getting (from drivers side over) 200-225 (I think I put a little too much oil in to begin with - 200 is probably more accurate) 150, 170, 150.


With that kind of difference after a wet test I was thinking the rings have got to be fried. What's strange is all my plugs look fine and I don't think I'm smoking at all when driving.

I did get quite a bit of smoke coming from the manifold/turbo area after driving it. I assume it's just leaking some, but I had much less smoke out the tail pipe. I didn't spill any oil.

 

[Dark_Horse]

I second getting another compression tester to double check the results. Test it again and take it back. If you get the same results, you should do a leakdown test. Instructions are here: http://www.dsmgrrrl.com/FAQs/leakdown.htm

I found it's just about the same price (assuming you have an air compressor) to buy the leakdown tester as it is to have a shop do it for you.

 

[oldman]

I did get quite a bit of smoke coming from the manifold/turbo area after driving it. I assume it's just leaking some, but I had much less smoke out the tail pipe. I didn't spill any oil.

That's probably just oil burning off from the wet test. I do agree that the rings are in question, you should see no more than 30psi difference between dry and wet. Now combine this result with your other problems you PMed me about and see what you come up with. I deleted the PM so I don't remember the details.

 

[xveganxcowboyx]

That's the hard part. Too many problems and dealing with turbo issues is still pretty new to me. If anyone can offer an explanation for my extensive list of problems please feel free

Here is the link to my other thread with detailed info on what was going on. LINK


As for a leakdown test and other work for this... Money is a concern for me right now, but I can afford a little for this. I do have a compressor and might pick up a tester, but parts tend to be hard to get as I'm in a very small town. A friend of mine is coming to visit and we'll have a day free in which he's offered to help me pull the heard and put new rings in, but I don't know if it's a great idea to just do rings and a head gasket. Not sure I could afford a leak down tester and parts to do the rings.