# Engine Shaking



## adubey (Oct 22, 2007)

I have a Nissan Altima 97 with 100K on it. I was driving to office when I started getting these jerks in the car and the CEL started blinking. It felt as if the car was about to stall. I have driven it home and I noticed that at higher speeds the jerks were gone but at lower speeds (<50 mph) the engine and the whole car would shake. Also I checked the exhaust. The smooth air pressure is gone and its now replaced with more powerful pop sound...

I havent yet checked the CEL codes as yet but anyone has idea why this would happen? FYI I saw there was some oil in Spark plugs and I intend to change the valve cover gasket and spark plugs gaskets for it.


----------



## repus (Apr 3, 2007)

my 96 altima did the same thing a while back. The spark plugs where covered with oil, I changed the Valve cover gasket and was fine after that.. I would start there..


----------



## jserrano (Oct 27, 2004)

Change the valve cover gaskets and replace the ignition wires because they are likely leaking spark to the engine block as well.


----------



## adubey (Oct 22, 2007)

I am getting the gaskets from eBay today. I will keep you posted once I install it. Thanks for the feedback. Please keep them coming in.


----------



## jsaxton1981 (Oct 24, 2007)

also it is time to change that timing chain too it sounds like.


----------



## KDragon (Oct 9, 2006)

Why would you suggest to change to chain?


----------



## adubey (Oct 22, 2007)

Is this a symptom of Timing chain too??? I thought timing chain should last longer..


----------



## jsaxton1981 (Oct 24, 2007)

I had a '93 that I had to replace the chain at 98k, the symptoms described above are similar to what I had on mine.


----------



## Altima SSS (Oct 10, 2007)

adubey said:


> Is this a symptom of Timing chain too??? I thought timing chain should last longer..


I'd check the ECU codes for sure. If you have oil inside the spark plug wells then that can't help. Get that fixed, and while replacing the valve cover gasket take a look at the timing chain and the chain sliders to see if anything looks broken.


----------



## adubey (Oct 22, 2007)

Just now checked the ECU codes - P0304 and P0325.


----------



## KDragon (Oct 9, 2006)

so do the gasget and plugs/wires/rotor/cap and let us know how its running. If that does not help try spraying carb cleaner around the intake runners and listen for a change in idle.


----------



## adubey (Oct 22, 2007)

Well heres the experience: Changed the valve cover gasket, spark plug gasket, spark plugs, spark plug cables, distributor cap. Drove it half a mile successfully.. some casualties - found PCV hose was broken hence got to replace it; while tightening bolts on valve cover noticed that one of the screws has broken threads in engine block.

The jerks and rough idle are gone now however still there are some vibrations.

Any suggestions on what to do for the thread? Would the thread repairing compound available in market work or should the block be re-threaded?


----------



## Altima SSS (Oct 10, 2007)

adubey said:


> .. some casualties - found PCV hose was broken hence got to replace it; while tightening bolts on valve cover noticed that one of the screws has broken threads in engine block.
> 
> The jerks and rough idle are gone now however still there are some vibrations.
> 
> Any suggestions on what to do for the thread? Would the thread repairing compound available in market work or should the block be re-threaded?


Was it the PCV hose on the valve cover that was damaged?

The vibrations you are now feeling might be normal, as the 4-cylinder will always have some.

For the damaged threads, the ideal fix is to have a heli-coil insert put in if possible. Is it one of the studs that screws into the head for the valve cover that is stripped out?


----------



## adubey (Oct 22, 2007)

Yes it was the PCV hose on the valve cover thats damaged and yes its the studs that screws into the head for the valve cover.. 

Can those vibrations be due to broken hose?


----------



## adubey (Oct 22, 2007)

What would be the problem if I let the valve cover defect remain..?


----------



## adubey (Oct 22, 2007)

Any suggestions anyone?


----------



## NissanTxUser (Apr 16, 2007)

1. Will this help?
HELICOIL

2. Just out of curiosity and FYI for myself - what type of spark plugs did you use.


----------



## adubey (Oct 22, 2007)

I used the Bosh Platinum ones.


----------



## KDragon (Oct 9, 2006)

adubey said:


> I used the Bosh Platinum ones.


Next time get NGK plugs there the OE plug and iv heard these KA's are kinda picky about the plugs you use. I'm running BKR5EGP's and there great :woowoo:


----------



## Altima SSS (Oct 10, 2007)

adubey said:


> Yes it was the PCV hose on the valve cover thats damaged and yes its the studs that screws into the head for the valve cover..
> 
> Can those vibrations be due to broken hose?


Yes it could ... because some fresh outside air could be sucked back through the intake tube after the mass air flow sensor ... and that could make the engine run worse.

Any leak in the closed PCV system (even a popped out dipstick or badly leaking valve cover gasket) can also cause the engine to run worse because this un-metered air (by the mass flow sensor) is added air that is being supplied by leaks instead of going through the air filter and mass air flow sensor.


----------



## adubey (Oct 22, 2007)

I have closed the tear in the pcv valve as didnt have much time to repair it. The car has smoothed out since then. 

I am planning to use some thread repairing compound for fixing the valve cover.


----------

