no compression

[starrebel]

I have a 1994 2.3 Quad 4. It won't start. Thers is zero compression in all 4 cylinders. Timing chain is fine (lined up) someone told me it could be oil pump. Does anyone know anything about this.

[xeroinfinity]

Welcome to AF !

If you dont hav any compression then its either the valves/giude seals or the rings are shot.

I highly doubt that all the rings just went bad at the same time.

Did you just replace the timing gears or chain, water pump ?

[starrebel]

Motor was rebuilt about 10,000 miles ago. chain was replaced and head was redone. chain is still lined up. The car was running the next day it wouuldnt start. It tried to fire a few times and then nothing. when I checked compression there was zero so I pulled off the timing chain cover and everything is good. water pump was also replaced. Someone told me it could be the oil pump that there is some kind of pressure switch in it that will not allow any compression.

[gmack221]

the only way I can think of that an oil pump could make you have no compression on all cylinders is if it had tons & tons of pressure & pushed the lifter sleeves out, which would keep your valves open all the time. I doubt this is the problem ... but anything is possible ...

If the valves are stuck open you have bent valves & probably a bad head now ... just doesn't make sense to me, the motor would have sounded like you put lego's into the intake, made a terriable noise then quit running.

lets start at the begining, are you positive your compression tester is good? are you positive the compression tester was properly seated to the head? have you tried putting a finger over the plug holes & having someone crank over the car to see if it has any compression?

try the finger thing first ... something doesn't seem right about having no compression on all 4 cylinders. If it blows your finger off you have compression. What happened just before it quit running? If you just went out one day to start it and it didn't fire it sounds like a spark issue ... If it were no compression it would have died on you while it was running. Explain what happened and we'll try to help you find the problem.

[xeroinfinity]

I figured the timming was off ,
bent the valves, leaving it compressionless

Wasnt sure if the Quad was a sohc or dohc.
Either way,
thiers many things that have to be set perfectly,
or their will be troubles.

[starrebel]

It was running a little rough for a couple of days (not anything real bad) my girlfriend was driving it, she shut it off when she got home from work and the next day it just wouldn't start. It fired a couple of times like it wanted to and then nothing. I checked the compression with my finger in the holes and got nothing. Didn't even bother with the tester. She had complained about a pinging sound a week or so earlier but when I drove it I couldn't hear anything. I have ckecked by putting my hand over the exaust and the the air intake and cannot feel any compression there either. It is definately a bizarre situation. I am going to tear into it this weekend and

[xeroinfinity]

Taking it apart is the only way to find out whats going on.

Good Luck !