Valve covers

Happy holidays all! I have a 2004 Tacoma with 198k miles and have continuously fought with these valve covers leaking. I have changed out gaskets and cam bore plugs more than once along with the grommets. It just seems that no matter what I do they continue to come loose and leak. Especially on the back corner right above the exhaust which leads to burning oil smells entering the cab when I come to a stop. I occasionally tighten the bolts that are accessible which helps some but I know this isnt the best thing since those bolts that are inaccessible are loose and not being tightened. The torque rating on these is very minimal so it just seems impossible to get this problem under control. I suppose it is also possible the covers are warped but just wondering if this is common or if anyone has any other suggestions.

 

Have you tried tightening them by hand and forgetting about the “torque spec”?
Obviously the spec on them isn’t “good enough”.

I’d go by feel and get them good and snug.
Start in the center and work your way out.
Then go over them once more to check.

 

I used a 1/4" drive + 10mm socket with my hand, but did not involve by whole arm as I "torqued" them down.

I also applied Toyota FIPG around the whole valve cover. I don't have any valve cover leaks, but I did this about 1,500 miles ago.

 

Most people, by an overwhelming majority, don't have reoccurring issues with the valve cover gasket job within the lifespan of the gaskets. Either the job was done improperly, or there is something wrong with the materials used (aka non-oem gaskets or FIPG).

 

Thank you for the feedback. I am fairly certain the last person to do the job used OEM gaskets but not sure if they also added FIPG at the time of replacement. It is not the worse leak just more of a nuisance due to the location and smell.

Per your advice I did hand tight then about a quarter turn on each starting on inside and moving out and repeating until good and snug. I will clean everything off and see how it does but will likely pull it all apart and do it again the correct way.

Thanks again!

 

If your having issues with the bolts coming loose put a bit of blue threadlocker on them when you do the gaskets, that should prevent them from vibrating loose.

I've done that many times on low torque bolts that are prone to coming loose.

 

Blue thread locker, not red!

 

Well I guess you could use red but they will never be loose ever again

 

Torch baby. And fingers crossed!

 

Hah! I was just thinking the same thing. Definitely dont want to make the mistake of red vs blue. That said, I am not sure how these bolts even stay tight from the factory with the rubber grommets and only 53 lb-in torque. I can easily go past that by hand with a nut driver.

 

The rubber grommets design seems terrible given that these bolts always loosen. What do newer vehicles use?

 

Be real careful tightening those bolts without a torque wrench.

I'm sure it can be down safely if you have a lot of experience turning wrenches, and know your strength. However, if you aren't the one even doing these gasket replacements I don't think its a good idea that you start blindly tightening these bolts past their torque spec.

Its very easy to crack a valve cover when you don't use a torque wrench, I can say that from personal experience.

They often do need to be re-torqued back to 53-in lbs, but not past it.

53-in lb is very low, but everything was designed around that very low spec. You should not have to surpass it to avoid leaks. If you have to tighten it more to get it to stop seeping, you have another issue to address.

 

I would avoid over-torque. Torque spec is there for a reason, to maximize the effectiveness of the bolt without breaking it. Beyond the torque spec you're playing a guessing game: how far can I go before it snaps? Bolts break, threads in the head can get stripped, as mentioned the cover itself can get cracked and it will always leak if it does. As Andy mentioned, it's something else, possibly the cover is already cracked or warped. You can check this with dye penetrant but the cover should be removed and clean.

 

UGH
Having an episode of PTSD reading about snapping VC bolt

after dropping engine on subframe (no engine mounts)
Couldn’t get drill (with bit/bolt extractor) at 90degree angle

 

Trimming subframe and destroying a 90 angle drill gave me JUST ENOUGH room
(And no, I didn’t have engine hoist/nor garage space)

I literally cried when cracked bolt came out

 

I know the feeling. Mine (most recent one anyway) was a simple spark plug change on a Cabrio, it had been neglected so long the threads came out with one of the plugs. Wound up rebuilding the top end over that one. "Every 5 minute project is one broken bolt away from a 3 day ordeal."

 

I've never had a VC leak after doing the job, but I recommend you use new rubber-washer things every time so they're nice and elastic and that you tighten the bolts with a nut driver by hand nice and snug, can always snug them up more but usually you won't have to if all your rubber is new.

 

Ugh VW Cabrio
Had the MISFORTUNE of wrenching on one of those Nazi sleds. Trying to impress a new GF bc alternator took a crap.
Freakin 5hr ordeal.
I finally figured out that was a combo of metric and standard size FTL.

live and learn and curse.

 

I did this last year. I used only Toyota Parts and Toyota FPG. I used an inch/lb torque wrench and tightened everything to spec. I've had no issues or leaks since. No burning oil smell for me when I come to a stop. Good Luck!!

 

Dumb question - What if you put a spring washer on the bolt, on top of the rubber grommet? Is that going to stay torqued better or is it the rubber that compresses and relieves the bolt torque?

Or else if the VC gasket is setting after some heat and vibration, what if I tapped the cover on with a rubber mallet to set better to start with?