Oil leaking through plenum

I've been having hard starts and need to sometimes floor the pedal to get the truck to start up. I've been thinking it was the injectors but potentially it's something else. And on further inspection it seems like I have a problem with oil in the air intake system. I have hoses that are looking a little oily at the connections from the air intake. It's looking like I'll be needing to replace the PCV valve seeing that I've never done that and the truck is almost at 300,000 mi. Has anyone dealt with something similar?

 

Kinda normal especially after 300k

here’s mine at 212k



After

 

Thanks for the reply I'm looking to potentially replace the injectors but I'm thinking this oil issue is what's causing the hard starts plus all that oil in the air intake is kind of crazy

 

Hard start issue has at least a dozen causes…..some simple like coolant temp sensor…..some more involved like leaky injectors
Start Down your Rabbit Hole searching
I always found a few threads here that matched my exact symptoms and then went from there

 

PCV valve might help, yes. Dirt cheap to start with

 

Starting here, I'll report back

 

What did you do or use to clean the intake plenum. I'd like to know, sandblasted or something else.

 

If, while replacing the PVC valve, you find that the rubber grommet that's on the valve cover is hard and you choose to replace it (and I certainly would), use extreme caution when pulling it out. You don't want it to break (and it probably will have hardened and thus be brittle). That would be a real "Aw shit" moment.

You might consider using an exacto-knife or a very fine coping saw blade and carefully cutting/sawing a few slits in the grommet and then working it out.

But if it does break and part of it falls onto the top of the head, you might be able to fish out the broken part without removing the valve cover if you're real careful.

Been there, done that.

 

Thanks for that tip. I do have valve covers on the mind since mine is always getting loose and I'm always retorqing the cover where I can. however I'm looking to avoid that currently. So I'll take your advice to heart

 

As someone who replaced their nearly 30 year old PCV valve grommet; if its on your mind now I'd just do them together. Or at least have the gaskets on hand just in case. Otherwise, if it falls apart you're screwed and the trucks parked until you get a replacement valve cover gasket for when you pull the covers to remove the pieces.
My grommet had turned to plastic and it shattered into 20 pieces that all fell down into the valves

I was not smart enough to use an exacto knife or fine blade to cut it before pulling it out though, so you'll probably have better luck if you are. I was admittedly brutal on that grommet trying to yank it out til it blew up on me.

 

That picture just looks like a normal 5VZE with 300,000 miles on it to me. As far as hard starts go, I'd start with a compression test and new NGK plugs and Denso wires. If that checks out good move on to testing fuel pressure and having injectors cleaned and serviced. Motorwest sells and cleans injectors and gets five star reviews. That's pretty good advice to change the PCV valve together with your valve gaskets. There is a boxed in piece of sheet metal on the inside of the valve covers underneath the PCV valve but it is open to the valves. Not sure I'd risk it and I doubt that's whats causing your hard start.

 

Thanks for the advice on the valve covers. They've been losing torque regularly over the past couple years, and I wouldn't be surprised if the pcv valve has been closed and allowing all that oil into the plenum. It's oiled up over the past six months, used to be spotless.

There's upper and lower plenum gaskets, correct? If I'm taking it off those will be required. Is there anything else that needs attention at this point?

thanks!

 

Yeah there should be plenum gaskets and intake manifold gaskets iirc, might want to throw a new throttle body gasket too.
Good time to clean the Tb and maybe the maf while you’re at it if it’s been a while, and of course clean up the plenums inside and out.
Probably want 10 cans of brake clean to get the oil off everything in the engine bay

 

Because its old, If your digging in for valve cover gasket repair and such replace rubber hoses large and small while your in there.
You can clip ends on cracked ones and save a little cash or get new by the ft is best.
Also prepare for broken wire loom replacement, fix/repair or fashion something. Its most likely going to need it. They are old and brittle they Crack up during VC repair. People on TW have done different things to remedy the need. Search posting for VC gasket replacement wire loom Yada Yada, you'll get good ideas.
Replacing vacuum hoses save you headaches down the road and maybe help or fix your original complaint. Have fun I hear a 20 yr old + 3.4l screaming fix me as I type. Lol

 

Yes, there are upper and lower gaskets and they are identical. Personally I would be addressing the hard start issue before the leaking valve covers. Of course you could do the valve cover gaskets while your doing injectors if it gets to that point. You could also test your PCV valve with a long piece of clean vacuum hose without pulling it out. Is your PCV valve hose full of oil? How do you know that there's oil inside the plenum? I can only see the one pic of the exterior. If your thinking the plenum gasket is leaking oil you would have a massive vacuum leak. Not to mention it would be sucking air, oil and dirt in and not blowing out.

 

Great advice. Once they harden up they like to push into to the valve cover. Then it's a different job...not a huge job but it certainly sucks when you didn't plan on pulling the valve cover.

 

like 12 cans brake clean (multiple trips to store) and lots of rags
Speedytech said(I wish I knew then) said you can buy same chemical (liquid/not pressurized) way cheaper than $4 a can
think it’s in my thread about the plenum cleaning

 

I've attached a couple of PDFs I've been saving regarding wiring loom repair. Hope they help someone here.

 

I'm not sure who I copied this from. But I wrapped both of my wire looms in Tessa Tape. worked really good.

 

thanks for this. I have parts coming.