Loose Valve Cover Bolts

02 V6 4WD w 190k miles.
I have had the truck for about 10 years, do almost all maintenance work myself.
I noticed a fair amount of oil around the engine yesterday, and decided to check the valve cover bolts. I was shocked to find them remarkably loose, like so loose that I could turn them without the wrench attached to the socket extension. 4/5 of the bolts were loose like this. The oil is completely new - I have never seen oil on it before and check it frequently.
Any idea why these bolts would be so loose all of a sudden after 190k miles? Has anyone else seen this before?

 

I’ve had those bolts loosen up and the covers seep.

I just chalked it up to expanding/contracting over the course of 20 years and 200,000 miles.

 

When I did my valve cover gaskets I don't think I needed a ratchet on any of them. The washers under them have a rubber plate on them that eventually dries up and shrinks.

 

Everyone has had this or will soon.

 

thanks for the reply. Has anyone replaced those washers with the rubber plates? Anyone know the part number?

 

You can snug them a bit and buy time but if you're keeping the truck it's time to do the valve cover gaskets. Cheap and easy. Lots of info. if you'll search. There's a sticky, there's a video. There's probably a website and a support group.

 

https://youtu.be/N5fAXAuGozI

 

About to do mine. Kinda dreading it

 

Mine also need doing, but I've been putting it off. so many small jobs that need done. All I need is time and money. Time I have, money I don't.

 

I don't have a part number for you but you definitely want to replace them when you do the valve cover. They will break very easily, and then you have to remove everything and start over. The torque on them is very low, something like 54 in/lb.

 

I just did mine last month,

If you have a 3.4 v6 timing belt and valve cover gaskets are something that have to been done
sooner or later.

It’s not that hard of a job, just time consuming, if you can use a dremel with a brass wire wheel
that will cut down your time removing all the old gasket material on the covers and heads and in those
tight places, cam seals and half moons.

Let the gasket material setup for 24 hours before running it too,

If you have the time painting the covers is pretty easy at this time.

 

Not sure how this will format

Part Number Part Name Price Quantity Total
11213-62020 Valve Cover Gasket $24.09 2 $48.18
11193-70010 Spark Plug Tube Seal $2.66 6 $15.96
17176-62040 Plenum Gasket $9.63 2 $19.26
90210-05007 Engine Valve Cover Grommet $1.08 16 $17.28
11188-62010 Plug $9.09 2 $18.18
11183-62010 Engine Camshaft Plug $6.63 4 $26.52
90480-18001 PCV Valve Grommet $4.28 1 $4.28

$21 00295-00103 Formed-in-Place Oil Pan Gasket - 3 oz. Tube

00295-00103 Oil Pan Sealer $11.62 1 $11.62

 

I have the same issue...loose valve cover bolts that caused leaking oil. I keep tightening them down to spec (53 in lb), but they keep loosening up. So I'm wondering if replacing the valve cover gasket is even going to solve the problem of continuously loosening bolts. Is it a result of oil in the threads that causes them to loosen? What part of the valve cover gasket replacement job fixes this issue, specifically? I've searched around, watched videos, but nobody talks about this exact part of it.

With that said, I should point out that half of the valve cover bolts are out of reach (covered up by other parts on the top of the engine). So I'm only able to tighten down the outer rows of bolts on each valve cover. It's occurred to me that maybe the loose bolts which are out of reach, cause the valve cover to vibrate and shake the other (recently tightened) bolts loose. That's my best guess.

I'm gathering the parts and tools to do the valve cover gasket replacement. So hopefully that will resolve the issue completely. But even still, I'd like to know the reasoning here, so I can be a better DIY home-mechanic. My Tacoma has ruined my mechanic skills, because I hardly ever get to practice!

 

^^^ This. It's because the gasket and rubber under the bolt washer have dried up and contracted. I just tightened my VC bolts to buy a little time on my 4.7 L.

I know I need a gasket kit.

Look at the bright side. You could have had a V8. I think the V6s are easier.

 

Yes, it’s common.
And it’s not hard to strip the threads if you “crank them down”.
Lubricated threads (from the leak) and over over torque can get you in trouble quick.
I like to use 1/4” drive ratchet on them.
Snug them up, and do the gasket when you get a chance.

Keep an eye on it from time time, you’ll be ok.

 

hopefully!! this thing does not come around but maybe every 20 years or so time-elapsed on the rubber washer things drying out... unless its mileage dependent
it was not the 'cheapest' of fixes at all , a bit north of $500 with a $50 coupin

 

if u do the cover gasket might as well do new tube seals & plugs too

 

THIS

Had mine done by a shop in Chamblee and they cranked mine down because my gaskets were still leaking (because they didn't do a good job) and they actually cracked my driver side valve cover. Then got mad and defensive when I told them they did it. They did replace it (with a beautiful new one stamped MADE IN CHINA after telling me it would be an OEM one) and redo the job again (even though they are still leaking).

Long story short, you will DEFINITELY get yourself in trouble by overtightening. I'm about to try and get my money or at least half back and redo the job again myself because I don't trust them.

Looking at this kit. Any ideas? It's a good bit cheaper than the Toyota way of buying it all individually and it's made in Japan.

https://www.ebay.com/itm/Stone-Valv...an/323598485954?fits=Model:Tacoma|Make:Toyota

 

Changed my valve cover gaskets last year, changed grommets in the valve covers, sealed the half moons, everything went OK. Yesterday I noticed leaks on both sides of the VC, bolts are loose. As stated above, it is a common problem. I am thinking of installing studs where the bolts are and tighten them with a nut, so I do not break the threads in the head, and have to take things apart (time consuming job). Does anyone have a part number for correct thread? I prefer allen head to tighten them , but can use 2 nuts as well. Thanks

 

What about using some loc tite in the threads?