Valve cover gasket — Oil Leak from top of engine

[spacecruisers]

could you provide part numbers by chance?

[fuquan]

Greetings, TV fans:

The time has come for me to ask for advice from the community.

Let me boil it down:

• Engine in my '88 TV was rebuilt about 25K ago.
• Engine looses oil - more than normal.
• There is no evidence of oil dripping on the ground.
• Very rarely, I have blue smoke on startup.
• No visible smoke coming out the tailpipe while driving, but I know this is difficult to assess. Must find a 2nd party to help answer this question.
• Oil residue creeps up the valve cover from the vc gasket, and down from the vc gasket
• Valve cover is on tight enough, in my opinion.
• Oil residue is visible at the junction of the pcv valve and the valve cover.
• Oil residue is visible at the junction of the pcv tube where it meets the intake manifold
  
  • Or this could be from the other hose ?, the one that comes from the front of the valve cover and enters the intake manifold above the nipple for the pcv hose.
  
  
• I have a recollection of replacing both my valve cover gasket and pcv in this van, but this is my 3rd van so I could be mistaken.

Is this likely to be a simple pcv issue?
What steps can I take to diagnose/solve the problem?
I am about to buy a new pcv, pcv grommet, vc-gasket, and hoses to go from the valve cover to the intake.
Any input would be appreciated.
See attached pics.

[Ace MM]

I'd replace the valve cover too.
Easier to spot a leak after its cleaned up.

How do the plugs look?
Valve guide seals could be leaking.

[fuquan]

I'd replace the valve cover too.
Easier to spot a leak after its cleaned up.

How do the plugs look?
Valve guide seals could be leaking.

I think I'll just clean the valve cover with mineral spirits and paint the outside with high heat Rustoleum. I can't imagine anything being wrong with the cover, unless it's warped. I'll check for warpage.

Here are the plugs. I believe they have 20-25K miles on them. Could somebody with experience please read these plugs?

[Burntboot]

I imagine Ace meant the valve cover gasket, the leak portrayed in the pic is a classic example.

The cover should survive but if you're going to paint it, better to have it off so you can do a decent job.
Besides, its easier to extract the bits of PCV grommet that fall into the baffle plate, with the cover off.
Just as important as the gasket, the washers that go under the nuts, when they're hard they'll unscrew like a nut (making cover removal much easier)
But they'll also let the nut bottom out without providing sufficient pressure to seal.
Change the tube gaskets and toss in a fresh set of plugs while you're there and hopefully call it done.

[fuquan]

I imagine Ace meant the valve cover gasket, the leak portrayed in the pic is a classic example.

The cover should survive but if you're going to paint it, better to have it off so you can do a decent job.
Besides, its easier to extract the bits of PCV grommet that fall into the baffle plate, with the cover off.
Just as important as the gasket, the washers that go under the nuts, when they're hard they'll unscrew like a nut (making cover removal much easier)
But they'll also let the nut bottom out without providing sufficient pressure to seal.
Change the tube gaskets and toss in a fresh set of plugs while you're there and hopefully call it done.

Thanks, BB & Ace:

This time around, I ordered a genuine Toyota gasket, pcv, grommet, washers, and hoses. I was using fuel line for my pvc-to-intake hose, which I have since learned is a no-no. Also I was using a non-OEM hose from the front-hole in the valve cover to the intake. Will also replace plugs and tube gaskets.

[Ace MM]

So those are the plugs from the rebuild?
They don't look all that bad. Not fouled with oil deposits.
Definitely replace them.

I imagine Ace meant the valve cover gasket, the leak portrayed in the pic is a classic example.

[fuquan]

So those are the plugs from the rebuild?
They don't look all that bad. Not fouled with oil deposits.
Definitely replace them.

Yeah those plugs should be from the rebuild. Glad to hear they don't look bad. I'll replace them.

[blakebecker37130]

FYI,

My 89 had a loose/ cracked PCV hose. I would consume a quart of oil in less than 500 miles. After new hose was installed there was no more oil consumption issues. This is one of those issues that costs very little to fix and returns the desired results.

Best regards,

Blake

[fuquan]

FYI,

My 89 had a loose/ cracked PCV hose. I would consume a quart of oil in less than 500 miles. After new hose was installed there was no more oil consumption issues. This is one of those issues that costs very little to fix and returns the desired results.

Best regards,

Blake

That's reassuring. Here's hoping that's all there is to the oil loss, so that I can have a fun summer in the van . I will report back after I receive and install parts.

[fuquan]

Part replacement complete.
A few notes:

1. After comparing the new Toyota PCV (12204-15022), it became obvious that the old one was clogged, even though the old PCV did rattle to some degree.
1a. The Toyota PCV and grommet (90480-18001) fit into the valve cover much more securely than I recall with aftermarket PCV and grommet.
2. The Toyota valve cover gasket (11213-71020) fits SOOO much better than the aftermarket gasket. I remember struggling to keep the aftermarket gasket seated while I positioned the valve cover on the cylinder head. However, the Toyota gasket seats in the valve cover perfectly and it stays put.
3. The new Toyota hoses (12261-73021 & 12262-73010) that go from the valve cover to the intake are FAAAR superior to the auto-parts store tubing I was using. The fit is amazingly snug.
Next step is to take it out for a weekend (next ) and monitor the oil level .

A lingering question I have, and have always had, is: How tight should the valve cover be? I did my best to tighten the three acorn nuts slowly and evenly, getting them "firm" (beyond "snug"), while taking care not to get them "overly tight".

[Burntboot]

My factory manual makes it very clear.
"Install head cover"
No torque specs are listed anywhere.

Its always been my practice, to go just a little better than snug, keep an eye on it for a few days and if you notice any seepage, snug a little more.
You're description sounds about right.
OE parts are indeed the way to go, whenever the budget allows.

[Ace MM]

No torque specs are listed anywhere.

Its always been my practice, to go just a little better than snug, keep an eye on it for a few days and if you notice any seepage, snug a little more.

Spec is: goodNtite
Only needs a few ft/lbs, but the practice above is solid advice

[Mojoworkin]

I googled, searched, looked and looked. Then I bought the part so I would know exactly what I was looking for. No can find. Where is the PCV?

Reason I'm replacing: Van seems to be burning a lot of oil, so I'm going after the cheap possible causes first.
(Engine purrs, no obvious smoke,It's not in the coolant plugs looked OK, compression was 170, 170, 170, 150)

Thanks in advance!

[originalkwyjibo]

Pcv valve is in the top of the valve cover under the rear most hose. The design of the hose pretty much completely shrouds the valve. Be prepared for the hose and the grommet to disintegrate upon removal.

[blakebecker37130]

I had a similar issue. The hose to my PCV was cracked. From what I understand there needs to be vacuum pressure present inside the valve cover or the van will use a ton of oil. I was seeing a loss of a quart every 500 miles, with no burning symptoms. Once I replaced the hose and valve, the issue was resolved. Less than 15.00 if I remember correctly.

[Mojoworkin]

Thanks for the replies! I could not see the rear-most hose from the vantage of the seat-hatch.

I'll find out soon enough by myself, but do I have to pull the seats, etc, or is it reachable from one of those hatches on the rear? Regardless of answer, I may just take the time and cut myself a Hose of Death hatch anyway.

Blake: Did the PCV failure cause any issues other than oil? I have read that a bad PCV can cause rough idle, and this engine purrs pretty nicely.

Thanks again, friends.

[Mojoworkin]

UPDATE:

PCV is fine. It's an OEM and all metal. Makes the Beck-Arnley thing look like a piece of junk. Also, a quick test showed the new one did not hold vacuum, so... Yeah.

The interesting thing to note is that both the hose connected to the PCV to the intake(?) (throttle body? dunno what to call it) was cracked, as was another hose that connected the throttle body or whatever to a hard vacuum line. I am assuming the latter supplies vacuum to the "throttle body" and the former carries the vacuum to the valve cover.

In any case, both of these lines are pre-formed and rigid. LAPS says they can't find/get those parts and suggested straight hose. As long as there are no kinks and I can get a good seal, any downsides to this?


Thanks!

[blakebecker37130]

My van was running fine. I only discovered the issue after I kept getting bugged by the oil light on the dash. I used straight vacuum line to make the repair. The way I routed it as not to kink it was to take a piece of coat hanger, cut it and bend it to match the profile of the molded hose, overlay it on the straight replacement hose and apply halflap electrical tape to make the new hose assembly. It worked out great. I just sold that van, but I have no doubt the shade tree engineered hose will last a long time. Very similar process to wrapping brake and shifter cables under road bike handlebars, if you can visualize that?

Best regards,
Blake

[Mojoworkin]

Dig. I am still laughing at myself for totally not seeing the PCV. Turns out I could get to it no prob after pulling a few other hoses. Straight hose seems to be working fine.