Oil Leak 3.4 2003 Tacoma

Hey guys so I have an issue. I just found out my 2003 Tacoma 3.4 has an oil leak.

Only issue is that I can't find the source of the leak.

The only thing I can stipulate is that it's somewhere in the back from the top of engine and running down the driver side headers.

If I can guess it's probably the valve cover gaskets. But I'm hoping you guys with more expirience can chime in.

If so where can I find a good OEM valve cover gasket kit, and good half moons.

Thanks.

Here are some images of the leak.

 

How's the oil level?

Bad valve cover at the rear half moon or the oil cooler could be spraying.

 

Have not checked the oil level. Last time I did about two weeks ago seemed normal levels. Tomorrow after I drive it I'll check the level out. Seems like a very slow leak.

I noticed it because I was changing a power steering leak and also earlier in the day I smelled oil burning.

 

Wow
IMO that has been seeping for long period of time to be that thick on the headers
Buy $20 of engine degreaser cans
Power wash(car wash or your own)
Make sure you spray from top and bottom
I actually took jack stands/Jack to the car wash to make sure
Wear shitty clothes

Once lil cleaner, see where fresh oil seeps

 

Try tightening the valve covers the gasket and the bolt gaskets shrink with age. Mine was leaking and someone here said to check tightness. Bolts were pretty loose and after getting them snug leak went away. Valve cover gaskets are a somewhat involved job on these trucks. Not simple like an old Chevy 350

 

I don't know how long it's been seeping oil. All I know is that I bought the truck in late 2021 and the Honda dealership I bought it from had done a valve cover gasket replacement.

But I found origin of the leak. It's in the real driver side valve cover I'll take some pictures tomorrow in the morning.

 

I will give this a try. Do you know the torque specs?

It is either that or the mechanics at the Honda dealership where I purchased my Tacoma must've not done a good job. A valve cover gasket replacement was done in 2021 in November.

 

So I've come to the conclusion that the whole valve cover needs to be done. I see that the leak is coming from either the half moon plug or the cam plug.

Other than that I've noticed that the valve cover is being sealed by some sort of silicone sealant and possibly not a gasket.

In all the job done by the Honda dealership I purchased my truck from did a real bad job.

FYI: I did not pay anything extra when they sealed the valve cover. This came as part of their service when selling the Truck.

 

So did you try tightening the valve covers? Don’t worry about torq spec they will either be super loose or not. After 20 years mine were super loose I did prob about 1 or 3/4 turn each easily

 

Not yet today I will and then I will let you know. I out some leak detection dye and it's leaking from the back close to where the half moon plugs and cam plug is at on the left valve cover.

 

The factory torque spec on the valve cover bolts is 53 in lbf. TBH this felt a little light when I did mine but with all new gaskets I've been leak free.
I used the kit from Aircabinman on ebay. Great seller. I ended up getting the kit that came with all the other things you'll need while you're there- camshaft plugs, intake plenum gaskets, etc.

I just ended up cleaning and resealing my half moons but I think replacements are cheap if you want to go that route.

And like the others have said, its a decently involved job... made me miss my little 22re!

 

Just checked my brothers 4cyl taco he has been having oil leak too the bolts were pretty much finger tight when we checked.

 

Today I got to tightening them. They felt very very loose. They went about what you said.

 

They probably did a decent job, it's common for those gaskets to shrink and allow the bolts to loosen. Really common on the 4.7 v8 too