1980 CJ-5 Valve Cover

[flyer92]

Greetings all! I've had my 1980 CJ5 for over 15 years, and have been struggling to keep my OEM steel valve cover from leaking the whole time. Unlike many 1980s with the AMC 258 i6 / 4.2l I6, my engine came with the earlier steel valve cover (curvy on both sides)....not the plastic one (straight on passenger side/curvy on driver side).

While I'm glad to have the steel valve cover instead of plastic, it has finally gotten leaky enough to the point that I have been looking for a good aftermarket cover. I have been thru several steel replacements, and every one is garbage, because the interior dimensions are slightly smaller than the OEM cover, resulting in engine components knocking against it. While there are plenty of decent aluminum covers out there, none have the same bolt pattern as the older steel covers, as these are designed to replace the plastic covers with one flat side. I have tried every sort of adhesive and gasket material to seal things up, but nothing works for very long. So...just curious if any of you experts know of an appropriate aluminum replacement, or perhaps an adapter that will allow me to use a straight-sided aluminum cover on my older bolt pattern. I'm at wit's end, so glad to consider anything at this point! Many thanks...

 

[Lumpy Grits]

I would first check to see that you have the correct PCV valve.
The PCV valve plays a major roll here.
Then, I would do a compression and leak down test of the engine looking for blow-by in the rings.
I have always had good results with Permatex non-harding.
https://www.permatex.com/products/g...nts/permatex-super-300-form-a-gasket-sealant/

LG

 

[flyer92]

Thanks, LG. Agree 100% on the PCV valve, and am using the correct one. Perhaps I need to do the compression/leak-down test as you mentioned, but I'm on my second engine now, and have had the same problem with both. I can't remember if I ever used the Permatex Super 300 you recommended, but I've had the most success with their Aviation Gasket Sealer. Maybe my next step is to try the Super 300 and see how it does. Just curious, though...do you recommend using it on both sides of the gasket, or just on the side facing the valve cover? I've heard pros/cons for either method, but I think I need to apply on both sides for this situation. Again...really appreciate your advice...many thanks!

 

[Lumpy Grits]

I used it on both sides, and let it sit for 24hr before start up.
Tighten the v'cover bolts to no more than 10 ft/lbs.
Use the sealer on the bolt threads, so they don't back out.
LG

 

[Posi]

50 inch lbs or 4 ft lbs

Re-torque them after a few miles.

 

[Lumpy Grits]

50 inch lbs or 4 ft lbs

Re-torque them after a few miles.

Good to know-May I ask your source?

My FSM(MR-252)on page B-126 shows 28 in/lbs for the OEM plastic.
LG

 

[Posi]

Good to know-May I ask your source?

My FSM(MR-252)on page B-126 shows 28 in/lbs for the OEM plastic.
LG

Plastic? We don't need no stinking plastic.....
All AMC metal valve covers is 50" lbs.

 

[Lumpy Grits]

The plastic v'cover and the 2-piece axles, are just 2 examples of how the 'bean-counters' were the ones run'n AMC.
LG

 

[Belizean]

The plastic v'cover and the 2-piece axles, are just 2 examples of how the 'bean-counters' were the ones run'n AMC.
LG

Mine came with plastic also. Don't ever drop that sucker either. Don't bother asking how I know this. I found a spare one just a few years ago and put it off to the side

 

[elwood blues]

Greetings all! I've had my 1980 CJ5 for over 15 years, and have been struggling to keep my OEM steel valve cover from leaking the whole time. Unlike many 1980s with the AMC 258 i6 / 4.2l I6, my engine came with the earlier steel valve cover (curvy on both sides)....not the plastic one (straight on passenger side/curvy on driver side).

While I'm glad to have the steel valve cover instead of plastic, it has finally gotten leaky enough to the point that I have been looking for a good aftermarket cover. I have been thru several steel replacements, and every one is garbage, because the interior dimensions are slightly smaller than the OEM cover, resulting in engine components knocking against it. While there are plenty of decent aluminum covers out there, none have the same bolt pattern as the older steel covers, as these are designed to replace the plastic covers with one flat side. I have tried every sort of adhesive and gasket material to seal things up, but nothing works for very long. So...just curious if any of you experts know of an appropriate aluminum replacement, or perhaps an adapter that will allow me to use a straight-sided aluminum cover on my older bolt pattern. I'm at wit's end, so glad to consider anything at this point! Many thanks...

Having a '78 I also have a the older style valve cover. I had bought one of the expensive newer aluminum valve covers and could not make them not leak either. I finally went to a junk yard, found an AMC 258 i6 / 4.2l and I bought just the valve cover, took it to a machine shop and paid them to chemically clean it down to hard metal. A little straightening with a dead blow hammer and a wood block, a couple coats of paint and it was better than new.

I don't know that anywhere makes the 1980 and older style, Clifford Performance used to. Here's a used one from eBay:

https://www.ebay.com/itm/1969-AMC-R...394380?hash=item23a47b394c:g:TAAAAOSwEg1a6ieU

 

[flyer92]

MR 252 only applies to 1984-1986 CJ7 /8's, which had the plastic valve cover on the I6 engine. Unfortunately, I don't have the manual for 1980 CJ's, but 50 in/lbs sounds about right.

Elwood...I did a similar thing with my steel cover as well, and also found a nice OEM spare a few years back, but that one is as unruly as my original cover. Thanks anyway for the tip on eBay...that one looks nice too. I think mine just needs a little more hammer time, but as you well know, it can be a long and laborious trial-and-error effort. One other thing that can help, is to grind off some of the bottom/vertical flange that typically causes the cover to bottom out on the head, particularly with the thinner (5/32") gasket. Just have to be careful not to grind too much off, as it will degrade the rigidity of the valve cover, and make things even worse. I've seen people do that with great success, but I think it should only be considered as a last resort. I also talked to Clifford last week, and they only made an aluminum replacement for the plastic valve covers, not steel. This was short-lived, though, because the Chinese companies replicated it pretty quick and sold at a much cheaper price. Since Clifford didn't want their quality products to get confused with the cheap Chinese , they just quit producing it years ago.

Again...thanks for the great discussion, and appreciate the help!