No compression on driver side cylinders 1,3,5

[thehangerman]

My 1994 ZX300 none turbo wont start , checked compression , very strange , on passenger side head was 90 PSI on all the three of them , but on driver side 0 no compression on all the three , what went wrong , Help

[nissanfreak12]

Check the timing belt, sounds like it slipped one one of the cam gears. When was the last time it was replaced? Last time the tensioner was replaced along with the bearings?

[thehangerman]

Thank you nissanfreak12 for your reply , looks like this is a good possibility , will start tearing it down , do you think that i will have bent valves and is 90psi on the passenger side head enough to get it running later.

[nissanfreak12]

Its hard to say on the bent valve issue, depends on how bad the belt slipped. That really the only explanation other than the head gasket just breaking apart in all three cylinders, which is unlikely. If it was only a tooth or two, you may be ok, anything more, very high chance you did.

90psi is low, but I am also guessing you checked it with the engine cold. Personally, I would take the belt cover off, check the components, count the timing belt cogs as per the FSM, that will tell you if your off. Don't rely on the marks on the back plate. If they are off, readjust so everything is correct, turn by hand to make sure nothing hits, and try and start the car. If its starts, replace the timing belt, bearings, tensioner, water pump, and so on. You can run the car for a short time without the coolant lines connected and the covers off, 5 min max. Don't rev it too high or drive it. This will give you an idea if all is ok without spending a ton of time putting it back together.

[thehangerman]

Thanks for the advise
I took the timing covers off ,of course the whole nine yards ,yes the car is out of timing , strange enough the belt is not broken and is in good condition but loose and guess what , the tension er is seized , ( the part of the tensioner holding the pulley ) is seized around it's pivot and the hydraulic piston could not push the pulley in order to keep tension on the belt ,the built has jumped on the passenger side ( pistons 1,3,5) 3 dents ( this head has 90 psi on compression test ) but on the other head it jumped 5 teeth and of course had a zero compression , but you wont believe this , NO BENT VALVES , ALL OF THE PRESS AND RELEASE BACK EASY AND I TRIED AIR PRESSURE ON THEM.
we live and learn.
all the best to you and our friends in the forum.

[nissanfreak12]

Good to hear, make sure you get a 120k kit, don't go cheap. Only so many times you can have luck like that.