5SFE Spark Plug Tube Nuts

[ihgrad]

I have a 1996 Camry I bought used about two years ago. 6-12 months after purchasing, there was an enormous amount of oil leaking from the valve cover gasket. So, I replaced it, even though it didn't look deteriorated. 6 Months later, Oil was leaking again from the valve cover gasket. This time, when I went to remove the cover, I noticed the tube nuts were loose- like I could remove them with my fingers. I thought that was odd, but went ahead and replaced the gasket again. This time, I was EXTRA careful to torque them to the 17ft-lbs specified. I recently (6 months later) noticed oil leaking again while I was changing my oil. It seemed to be leaking from the valve cover gasket again, leaking down the fire-wall side of the engine. So, I had a hunch and check the tube nuts and they were LOOSE AGAIN! Has anyone run into this problem before? It is looking as if I need to tighten these nuts every month or two to keep the oil from leaking, which I don't have a problem doing if I must to keep the car running right. I figure maybe the incessant vibration that is inherent in the 5SFE causes the plug nuts to loosen over time. But maybe there is something more going on here....Any Thoughts?

[Mike Gerber]

If you have been using the same aftermarket brand of gasket, I would try another brand. Maybe a Toyota OEM gasket. When you torque the 30MM tube nuts, do it in an alternating patern; plug 1, plug 3, plug 2 and then plug 4 in 3 even passes. First 6 ft lbs, then 12 ft lbs and then 17 ft lbs. You might also try a different torque wrench. The one you are using might be out of calibration. This can effect low torque readings the most.

Mike

[Brian R.]

It may be that the tubes are working loose and are pulling out of the heads when the nuts are tight. Make sure they are secure.

[jdmccright]

I just had to re-tighten my (ahem) nuts last weekend..have to do it every so often. I've always had the thought that the gaskets and tube o-rings soften and deform over time. But now reading this, I think I'll put a paint mark on the tubes and nuts to see if there is any backing off of either one over time. Could be the result of all that inherent engine vibration? The mind ponders....

[RIP]

[ihgrad]

Originally Posted by Brian R.

It may be that the tubes are working loose and are pulling out of the heads when the nuts are tight. Make sure they are secure.

How are the tubes secured to the heads? Are they threaded? If so, are you saying they are threaded opposite, because otherwise they would be tightening at the same time, wouldn't they? I will check the tubes though in a week when I check my, uh, nuts again....In the meantime, I've got to figure out where this puddle of fluid came from (see other post).

[Brian R.]

Yes they are threaded with an adhesive on the threads and tightened to 30 ft-lbs.

[Mike Gerber]

Remember, the spark plug tubes are tightened to 30 foot lbs with the cam cover off. Then the cam cover is reinstalled and tightened to it's torque spec.

Mike

[Brian R.]

Tightening the tube nuts is one of those times it is advantageous to have a torque wrench which is metered in in-lbs so that the easy torque you are applying (6, 12, and 17 ft-lbs or 72, 144, and 204 in-lbs) is accurately measured.