Silicon rocker cover gaskets - Never again

[UKPhilTR7]

Hi guys,

I just wanted to let you know about my less than positive experience of Silicon Rocker Cover gaskets. In the latter part of past year, I ordered a silicon gasket from over the pond (none of the suppliers in the UK). I had heard that they were good for reusing and created good seals, so after a few emails, I ordered one.

I fitted it, using gasket seal on one side and then hoped that all would be fine. Looking back at it, the cork one that I took off was fine and I should not of messed with it. However, I did, and you live and learn.

After a few weeks I noticed that oil was on the floor under the engine and that there was a little drip from the front of the gasket (by the chain), on the battery side. So at the time I was unable to do anything about it, to I put a tissue to stop the oil drip, as much as I could.

Today, I decided to look at the leak and try to fix it. I took the rocker off and noticed the gap in the corner. So I took the whole thing off and cleared everything down as the gasket seal that I used had half gone. While cleaning it (not hard at all) one of the screw holes broke. I decided to try and use it. So I put more gasket seal on the rocker cover to fit the silicon gasket to. I put the silicon gasket on and noticed that it was not fitting around the corners of the cover (by the chain). The area where I had issues before. It was about 1 cm too big, so it would just fit into all the corners at all.

So I decided to throw it away and order a new cork Rocker cover gasket from the UK. I will never go for a silicon one again and waste my time.

Only my experience and I am sure other people have had far better experiences than what I have, but thought I would share my experience.

[john 215]

Hi Phil,

A case of 'If its not broke don't fix it ' OR ' Fix it till breaks '

Sure your experience will be handy to others,

Cheers John

[UKPhilTR7]

I totally agree John.

I was thinking that when the gasket broke and then would not fit

[John_C]

I have the silicone gasket on mine and it's the first gasket I've ever had that actually seals the oil in. I can't understand why yours didn't fit Phil because mine is perfect. I'm sure Joe would like to know what went wrong too.

[UKPhilTR7]

It may be a case of horses for courses lol.
Not too sure what went wrong as it was a meant to be a good replacement. However, it just didn't fit.

Where did you get yours from?

[FI Spyder]

When I got my car I took the valve cover off because a) it was leaking a little b) I wanted to repaint it because half the original silver paint was gone. I put a new cork gasket on, it was a little big but I've since read if you dry it out it will shrink a little. I sprayed some red tacky gasket seal on the side that would face the cover (always done on the "weak" side only) also so it is held in place as you turn it upside down to put it on. Also would easy (relatively) to take off as the lower (head side) is bare cork to metal. Tighten the screws, not too much as you don't want to distort the metal. Don't foget the rubber doughnuts at the screw heads. It has never leaked oil since (9 years ago now). A $5 or whatever a pop it's a pretty good deal. Never use a costly high tech solution to a simple inexpensive one.

[John_C]

I think Joe (Alexander Racing Enterprises) is the only person having the silicone gaskets produced so we must have got them from the same place. Mine was perfect and I expect it to be on the car a very long time. I had the previous cork one on there for over seven years but I never managed to get it to seal 100%. The silicone gasket sealed easily and immediately. One of those fit and forget solutions for me so I can't understand why yours didn't work. Was it from Joe at ARE or someone else?

[DNK]

I think there are 2 makers out there.
Joe and something Innovations (or something like that)

[UKPhilTR7]

It sure is a shame that mine didn't work as I brought it with such high hopes. Not here to point fingers, just to let everyone know my experience.

[John_C]

Gasket Innovations is one of Joe's ventures at ARE. I can't understand why my gasket is absolutely perfect and yours isn't. This does suggest yours came from elsewhere and perhaps made for a Stag rather than the slightly larger TR7 rocker cover.

[REPLIC8]

The trouble with the cork gaskets is the aftermarket ones available are too wide (about 8mm) and therefore they don't fit the groove in the rocker cover. I fitted a NOS cork one on my car which is about 5-6mm wide and it sealed perfectly and hasn't leaked at all.

[UKPhilTR7]

I have since contacted the company and they are sending me a replacement to try. I am more than happy to do this, as the one that I had may of been a "bad one". So that will be arriving in the post hopefully very soon and I can fit it.

I must admit that when I contacted the company they were very helpful and apologetic. They were sorry to hear about the issue and offered to send me another one when I provided my postal address. I cannot speak highly of the guys and in the end I felt really bad that I had to send the original email to them.

So now I have one cork gasket in the UK, two cork ones on their way and the slilcon one on its way too. So 4 gaskets for one engine. I am trying to convince my wife that we should get another tr7 to use the gaskets up. At the moment she is not falling for it lol.

[UKPhilTR7]

Well last night I fitted the new silicon gasket that i was sent as a replacement. I followed the instructions to the word and used very high temperature gasket maker to stick it to the rocker cover. I put the curved edge to the cover. I left the gasket and the gasket maker to stick to the cover for an hour and then fixed it to the head and left it for 24 hours. I literally did everything to the letter.

I started the car and let her run for a bit and guess what, the leak is still there. After all that it didn't work. The silicon gasket was perfect on the outline of the cover.

As you can see from the pictures below the leak is coming from the corner of the front part, on the battery side.

I did run my finger around the edge of the rocker cover to see if there were any other leaks and there was nothing. In the entire outline the rocker cover and the head match. However, on this corner, there is a few mm overhang by the cover. So this appears to be more the rocker cover and not the gasket at this stage. Due to the cover not fitting the head flush on this corner, the silicon gasket is not in full contact, thus creating the leak.

The two bolts at the front and the four nuts securing the rocker cover fitted sweet and were all inline.

I think I have the following options:

1. Loosen the rocker cover and try to push the silicon gasket in slightly in the corner to try and create a better fit.
2. Try to fill the gap in the corner with gasket maker
3. Loosen the cover fixings and try to push it into a better fit on the corner. This may throw the other sides out though.
4. Take the silicon gasket off and go back to cork, in the hope that it may fill the gap in the corner more
5. Purchase a new rocker cover and hope the alignment is better.
6. Take the rocker off, grease the offending corner and hope that this creates a good enough seal to stop the leak

Has anyone come across this very slight gap in the corner of the rocker cover, thus creating the leak and if so how did you get it to stop leaking?

[john 215]

Hi Phil,

To be honest can't say I have ever looked but can do over the weekend, my first thought was that the cover had become distorted in some way but difficult to see how it become for want of a better word ' spread ' in that area but appears to be the case. Does the top edge ie. opposite fit any better ? Did you check to see if any distortion present before fitting, glass is a ideal surface for that, but not the better halfs glass top coffee table !

Can certainly see why it would leak, cannot be much contact area left, what with the chain whipping oil around not a surprise it does.


Cheers John

[UKPhilTR7]

I am thinking that I need to take it off again and possibly fit the cork one. Why does such a simple job have to take so long with our cars???

I am wondering if the cork one will give me the better coverage once it is squashed down. I would of thought the silicon one would be better for that though.

When the cover is off I can check to see if it is warped in any way. Not using the other half's glass table though