I was driving my 1990 Nissan Maxima with 101k miles, and it gradually lost power. I checked for spark and Im getting no spark, and 0 compression in all 6 cylinders. I pulled the timing belt cover and the belt turns with the key.
The engine is turning over, but wont spark. It us turning over very fast. Much faster than it usually does.
I had a spare maxima, and swapped over the distibutor and ignition coil and still no spark..
any ideas guys?
2007-02-14 16:23:47 · 9 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
The belt did not jump a tooth..all alignment marks are ok.
2007-02-14 16:39:02 · update #1
Might be some problem with your cams.
2007-02-14 16:29:33 · answer #1 · answered by Brain of JFK 2 · 0⤊ 0⤋
It sounds like you have either bent or burned valves. This means that the valves no longer seal the compression in, and so the starter turns much faster. Unfortunately, the engine needs compression to run. A simple pressure test is needed - but not compression test. Remember - compression is formed by the piston rings and the valves, holding in the pressure created by moving the piston up..
Screw a sparkplug-sized fitting (sparkplug thread at one end, air hose fitting at the other - any good garage should have one, or can make one) into the sparkplug hole of cylinder #1. Set the engine at TDC so that both valves on that cylinder are closed (compression stroke). Attach compressed air to the fitting, and listen. Is most of the hissing sound coming from the air intake, or the exhaust pipe? Or the oil dipstick? This will tell you which valve (if any) isn't sealing correctly. If it's coming from the dipstick, you have either a) very bad piston rings, or b) a hole in the piston. Repeat for all the other cylinders.
This is a very useful test, as it shows not just how low your compression is, but where you are losing it.
If it is bent valves, your timing belt has stretched too much, or it has been over-revved. Either way, you should replace the belt and the head (a decent second-hand one should be OK.) Replacing the valves and repairing or replacing the valve seats is probably not worth the expense.
Good luck!
2007-02-14 18:38:31 · answer #2 · answered by Me 6 · 0⤊ 0⤋
First examine if that is an interference engine. next bypass again and examine all of your marks on correct useless center on the compression stroke.Line it up if that is not any longer actual. Use a compression gauge to study the compression through spinning the engine over a minimum of four or 5 situations. in case you discover you obtain a tendency valve you are able to most likely replace the valve or valves or placed a used head or finished engine in it. A rebuilt or new head isn't suggested at the same time as coping with an overhead cam engine,as i have had the bottom end bypass out because the right end grow to be to tight.you would destroy out with it no matter if it is a very low miles engine.(0-20k)miles.
2016-12-04 04:58:03 · answer #3 · answered by ? 4 · 0⤊ 0⤋
Is this an inline 6? There should be a shear pin in the cam shaft that makes the camshaft turn with the cam gear. If this is missing or has sheared off that would cause all of your symptoms. Take off the head cover and turn the engine over. Do the valves move up and down? if not this may be your problem.
Good luck.
2007-02-14 17:16:01 · answer #4 · answered by sk33t3r 3 · 1⤊ 0⤋
Timing belts often do not break but instead strip off their teeth and jump out of time. In an interference engine that can cause the pistons to hit the valves and bend them resulting in "no compression in all of the cylinders".. If this has happened ..not good.. look to see if your camshaft is turning at the same time as your crankshaft.
2007-02-14 16:52:51 · answer #5 · answered by the_buccaru 5 · 0⤊ 0⤋
Is the camshaft turning as well? I suspect belt is turning but missing teeth or tensioner went bad, would explain gradual power loss, as teeth lost, timing of cams would change, sounds like distributor is run off camshaft since no spark, take cap off and see if rotor turns as you turn over the engine, if it doesn't has to be belt, tensioner or possibly broken camshaft
2007-02-14 16:53:31 · answer #6 · answered by theM_A_N 1 · 0⤊ 0⤋
I wish I could help I think there are more than one belt that is involved with timing on those. Did it jump timing?
2007-02-14 16:34:43 · answer #7 · answered by john g 1 · 0⤊ 0⤋
your belt could have jumped and still be intact but i suspect theres more to the story
2007-02-14 16:31:09 · answer #8 · answered by Anonymous · 0⤊ 0⤋
swap the computer if this don't help then your s h it out of luck if not the crank positioning sensor is bad try that
2007-02-14 16:30:52 · answer #9 · answered by Stephen A 2 · 0⤊ 2⤋