A note on leaking valve covers & cold start up noise
#17
04-11-2011, 07:39 PM
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I'd suggest being very careful when tightening the valve cover bolts and/or using washers to increase torque. The valve covers bolt holes are reinforced with brass to handle torque loads and displace torque. The OEM bolts are designed for minimal torque and will snap if you over torque them. If you're luck, the bolt will break off with enough length to get it out of the head. If you're unlucky, the bolt could break off inside the head. Have fun with that one.
The valve cover leaks on the VQ, like most any car, are common. I've never owned a car that doesn't eventually have weeping or leaking valve covers. It doesn't seem to matter if the valve covers are plastic or metal. They all seem to leak. Subarus and Porsches are notorious for this because of their boxer design. The leaks on the VQ valve covers usually come from the areas that require RTV sealant per the FSM. These areas are typically the lower corners of the valve cover and/or the front cam lobe crevices.
As for the tensioner and a stretching chain, this is the first I've ever heard of a such a thing on VQ motor. The timing chain should not be super tight. The tenisoner is designed to keep the right amount of tension on the chain. Too much tension and you'll wear out the tensioner or the chain itself. Hopefully the guy that "fixed" this VQ had the FSM because there is a very specific procedure to setting chain tension. Additionally, the last I heard, the tensioner was spring loaded and not adjustable. Tensioners on the VQ's, especially the VQ30s (95-01 Maximas), have a history of wearing out and getting noisy as the miles pile on. The VQ35 tensioner is beefier and tends to last longer. However, they can get noisy. The fix is simple, replace the $50 tensioner which is accessible through an opening in the timing chain cover. The common tensioner noise is a rolling metallic sound right at start up. It tends to last about 1 second until the chain is fully lubricrated. It's more of an annoyance than an real issue.
I can't really comment on the oil pump issue because I can't really follow what the exact issue is he's describing. The oil pump is a super simple device and they rarely fail unless you try to wind the VQ30/35DE past 7500rpms.
The valve cover leaks on the VQ, like most any car, are common. I've never owned a car that doesn't eventually have weeping or leaking valve covers. It doesn't seem to matter if the valve covers are plastic or metal. They all seem to leak. Subarus and Porsches are notorious for this because of their boxer design. The leaks on the VQ valve covers usually come from the areas that require RTV sealant per the FSM. These areas are typically the lower corners of the valve cover and/or the front cam lobe crevices.
As for the tensioner and a stretching chain, this is the first I've ever heard of a such a thing on VQ motor. The timing chain should not be super tight. The tenisoner is designed to keep the right amount of tension on the chain. Too much tension and you'll wear out the tensioner or the chain itself. Hopefully the guy that "fixed" this VQ had the FSM because there is a very specific procedure to setting chain tension. Additionally, the last I heard, the tensioner was spring loaded and not adjustable. Tensioners on the VQ's, especially the VQ30s (95-01 Maximas), have a history of wearing out and getting noisy as the miles pile on. The VQ35 tensioner is beefier and tends to last longer. However, they can get noisy. The fix is simple, replace the $50 tensioner which is accessible through an opening in the timing chain cover. The common tensioner noise is a rolling metallic sound right at start up. It tends to last about 1 second until the chain is fully lubricrated. It's more of an annoyance than an real issue.
I can't really comment on the oil pump issue because I can't really follow what the exact issue is he's describing. The oil pump is a super simple device and they rarely fail unless you try to wind the VQ30/35DE past 7500rpms.
The whole tensioner thing;
I NEVER said the tensioner is adjustable, it is indeed adjusted automatically by oil pressure. If you notice the oil passages from the engine the oil that actuates the tensioner comes from the same passage that my oil ring was damaged, meaning I had a bad sealing there and the pressure was taking a bit more time to charge it up.
The valve cover;
I did mention REALLY THIN WASHER. So the comment is ignored.
#18
04-11-2011, 10:11 PM
Ok when i did mine i brought 10 stainless steel thin washers that look like this.
Same thickness almost as the bolt head rim
I then cleaned the plenum:
Before
After
Then i cleaned the Throttle body
Before
After
I cleaned the surface where the gasket sits
And used RTV sealant to glue the corner of the gaskets in
I didnt need to buy a new cover or gasket, they both looked fine to me..
I installed a Oil catch can to monitor any new loss of oil
used RTV sealant on the fittings and thread tape also.
Upgraded the hoses too as ones that come with them are crap
Same thickness almost as the bolt head rim
I then cleaned the plenum:
Before
After
Then i cleaned the Throttle body
Before
After
I cleaned the surface where the gasket sits
And used RTV sealant to glue the corner of the gaskets in
I didnt need to buy a new cover or gasket, they both looked fine to me..
I installed a Oil catch can to monitor any new loss of oil
used RTV sealant on the fittings and thread tape also.
Upgraded the hoses too as ones that come with them are crap
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