Timing Cover Leak

Yep, it's another one of those posts!

Got a 07 sitting in the driveway currently with a nasty oil leak and all signs are pointing to the infamous timing chain cover as the culprit.

Poking around here and other forums i've seen some brief mentions the plant may have changed the cover to a better (or fixed) design to prevent the leaks. Looking it up (good lord is it expensive, even with discounts) It has had part number changes. Coming from the Ford camp, a part number revision usually means something has been fixed and/or a change in who made the part. Not sure which is at play here.

Is this true, or just resealing fixes the problem for good?

I'd rather see it fixed once, then just rip it all apart for a band aid fix that causes leaks again if it's a poor design to begin with and it was fixed with a newer revision of the cover.

2007 Toyota Tacoma Prerunner extended cab 4.0 V6 automatic.

Thanks!

 

I've never dug into what if any replacement parts or new/improved FIPG might be used. I did poke thru the Factory Service Manual(FSM) and it'll keep you busy for awhile. Should you decide to tackle it yourself - this may help. Ignore the year.

http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

Timing or valve cover? Post pics man

 

I have an 07 as well that had a timing cover leak when I purchased the truck at 98k miles. The entire engine was covered in dried oil and at operating temp it could be smelled. I ended up using Gunk engine degreaser and a brush to clean off the majority of the caked on oil. I then monitored what I thought was a massive leak coming from the timing chain cover. I ended up switching my oil over to Valvoline High Mileage Synthetic Blend in the red jug/bottle. Ever since then, the leak has become minimal/non-existent. Many others have also stated that the synthetic blend has decreased their oil leak(s) as well. Before sinking hundreds of dollars into the replacement parts, I’d give it a shot. My truck now has 146k miles.

 

I sealed mine using minute gasket grey stuff from the outside.

Take off PS pump, clean well, let dry,smear on liberally where the block, head and timing cover meet, then wait at least 24 hours before starting engine. Not a drop since.

 

Here's a picture. It's real nasty on the passenger side. Oil got slung all over the engine compartment pretty much and it looks "rust proof" underneath with it's coating. Heh

 

Thanks for the help everyone so far. I'll see what the owner says when he arrives

 

Interesting. It's always had mobil oil put into it, full synthetic

 

Also, a odd question for folks. It's not uncommon with some vehicles (say a 1990 jaguar) to switch from the factory recommended oil to 5w40 (a diesel oil) in the desert. Think this is a good idea, or horrific? Don't know much about the oil galleys in a 4.0