Did a compression check on my trooper

[mepr]

Alrighty, while doing the tune up i ran a compressions check and heres what i came up whith
#1, Dry: 102, Wet: 110
#2, Dry: 101, Wet: 145
#3, Dry: 68, Wet: 90
#4, Dry: 110, Wet: 160
Alrighty after that and the tune up it runs alot better but still has a miss, could it still be a valve problem? I know #3 needs some help but im hoping i can drive it untill i get some money. Does this seem ok for a motor whith 150,000miles?

[mlclark]

Does this seem ok for a motor whith 150,000miles?

No. Those numbers are way beyond bad. You have a burned exhaust valve on #3. You need to get it fixed.

Michael

[mepr]

well i know theres one low cylinder, but the other 3 sound near to normal dont they? Im going to try passing emmisions and if it does and im probly going to drive it while my luv is in the shop. Would this be a bad call?

[mlclark]

You probably won't pass emissions. Most likely, that one cylinder is putting out a good bit of unburned HC's because without the compression, it is not very efficient. You might make it, but it will probably depend on how stringent they are in your area.

As for fixing it, I would suggest getting it fixed ASAP. It would probably cost you under $200 to get it fixed. That is with you pulling the head and having someone going through it.

Running it like that makes it unbalanced. As I said, it runs great, but with a slight miss. One of my earlier engines did the same thing. Made two trips across the state at speed without a problem. What will happen is that the burned valve will continue to deteriorate until you are closer to 0 psi. This will cause it to run worse and worse. Damage is probably debatable, but...a burned valve is not a good thing.

BTW, how much oil did you add for the wet test? Jumps of 50psi is a bit much and could point towards rings. 101 is also a bit low. You should be closer to 145 or so. Remember, your gauge is not calibrated, so it is more important to compare numbers than actually pay attention to the numbers.

When you did the compression test, did you pull all the plugs? Did you do the test with the throttle wide open? Did you crank it for the same amount of times for each cylinder? I usually crank it for 8 revolutions. I found this is where the reading stabilizes.

Michael

[mepr]

well i dont know exactly how much oil was added (my dad was doing this). I did it with all the plugs out and whith the gas pedal pushed to the floor. I also cranked it for about 6seconds. Im just wondering if it will hold out for about a month of driving whith out any new damage while my luv is getting stuff done. then ill start looking at it harder (rebuild head work what ever needs to be done)

[mlclark]

It seems that you have already decided to keep driving it, but you keep asking if you should. I doubt anything said here will change your mind. If it was me, I would fix it. But go ahead and drive it. Worst thing that could happen is that more damage occurs.

Michael

[mepr]

that kinda what i was asking if it will do a bunch more damage. But i have my cash kinda worked around now so im probly just going to do a full rebuild on it so i dont have to worry about for some number of years.

[mlclark]

that kinda what i was asking if it will do a bunch more damage.

Will it do a bunch more damage? Probably not. But, there are things like running an unbalanced engine (what you have since it is not firing correctly). Rings will seat differently because of the lack of compression. As I said above, compression will continue until it is 0. During that time, it will run more and more poorly. Worst case, it drops that valve into the cylinder, but...that is probably not likely.

You asked for advice. Mine is fix it as soon as possible or find other wheels. A burned valve is considered a major mechanical failure.

Good Luck,
Michael

[mepr]

yeah i am going to do a full rebuild since i need to do the head. May as well do it all while its apart.