Leaking Valve Covers (cam / rocker covers)

[The_Mantis]

Hi all newbie here👋

 

Had a 350z for 4 year now and been through 2 new sets of rocker covers.

 

Cheap Ebay specials at first, started leaking towards the rear of engine and into spark plug tubes.

 

Expensive Tarmac sportz ones were the exact same.

 

Both sides have leaked at one point or another. New seals included in the covers and correct gasket material/seal has been used. There is not damage to the head that I can see after cleaning off the old sealant. Problem looks like the cover warping as they are not flat at all once removed. 

 

Can anyone help or have a solution? Or what's peoples opinions on the aluminium covers?

[MONKEYSOCKS]

Are they genuine nissan or oe spec? 

Had nissan oem rocker covers fitted at tarmac in October and have no problems. 

 

I don't track the car though. If you do use it on track it might be worth looking at the aluminium ones as they are obviously more heat resistant and serviceable from what I've heard. 

[ZMANALEX]

Sold hundreds of these without any issues whatsoever.

 

VQ35DE and HR cam cover kits are in stock and good to go same/next day.

 

Just drop me a pm if I can help further.

 

 

[The_Mantis]

The expensive ones were OE spec. Which has warped beyond belief, and flooded the spark plugs. The cheap ebay specials held up better surprisingly but still leak into spark plug tubes after a few months and not many miles. I don't track day the car as I fear it might detonate, and I installed a catch tank with hoses connecting to the cam covers to relieve pressure. First time I replaced the covers I only used the gasket sealant in the corners and front radius as recommended online, but second time I applied gasket sealant to the whole head with a larger bead in the corners. I even used sealant on the spark plug tubes which didn't help.

 

It's almost as if the car is running hot to warp the plastic but temp gauge is good, and no running issues. Engine is healthy and survived the dyno making 266bhp after 100k miles (DE engine). Exhaust looks black like car is running rich which should if anything help with cooling. Its recently had a coolant change etc. 

 

I assume the aluminium covers will help, there is a pair on ebay for £130 new. or £399 from tarmac. It's just a lot more money on items I've already purchased twice of varying costs, so would much prefer on repairing/reinforcing the part used ones I have now if anyone has any advice or has had similar problems to me?

[ZMANALEX]

I don't quite get your story.

 

Are you saying that the face of the cover, which holds the rubber gasket in place is "warping"?

 

If that were the case, then you would have a severe external oil leak from that area.

 

Please post up, an image of the "warped" cover clearly showing the "warp" using a metal straight edge.

 

Just to be clear, are you saying that all spark plug apertures are filling with engine oil?

[The_Mantis]

Sorry, you're right the warp is the mating face of the cover that seals against the head. In-between the bolt holes have arched up and in general the rear of the cover have bowed upwards too. 

 

I am at work right now so will have to upload a photo later around 5pm.

 

And the O-ring seals within the cover are failing often, allowing oil to seep through to drown the spark plugs in oil. Sorry not sure what you mean by apertures.

[ZMANALEX]

So it looks like you have two issues:

 

1 being the "warping" of the covers between the bolt holes, causing an external oil leak and the other being the spark plug tube oil seal failures, causing oil to leak into the spark plug apertures.

 

The aperture is the area where the spark plug is located, where the oil is pooling.

[The_Mantis]

Correct yeah, might have to bite the bullet and buy the aluminium ones at this point as I'm on my second pair. Third if you count the pair the car came with when I bought it. 

 

I should point out that the external leaks have appeared on both LHS and RHS covers and in different places (one at the side and another at the rear). So I know there is no damage or warping of the heads, no need to have them skimmed etc.

 

I just want to know if anyone has had similar issues with regular failures of seals and what have people done to prevent the oil leaks without replacement parts.

[ZMANALEX]

I have sold hundreds of these covers and never had a warping issue, so I can not provide any informed input on that one.

 

I assume that you are using the correct torque sequence procedures?

 

Oil seals are a common failure, and replacing the seals or replacing the complete cover is the only option, I am afraid.

 

I would be looking very closely at the tubes, checking for any damage which may effect proper contact with the oil seals.

 

The tube failures are not a common issue and any damage is usually self inflicted.

 

The covers that I sell come with a 12 month parts warranty for mechanical failure or manufacturing defects.

 

I do not know what warranty came with the eBay covers that you bought, but it may be worth contacting your eBay seller.