SOLVED: Valve Cover Gasket Fail

Feeling extremely humbled as I write this. Did the Valve Cover Gasket job today. Took about 7 hours in my driveway. Replaced spark plugs as well. Everything went pretty smooth aside from the expected PITA issues (cracked the fragile plastic wire harnesses sitting above each valve cover, dropped a nut behind plenum during reinstall and had to backtrack a few steps). Had some waves of frustration throughout but ended up feeling pretty good as everything seemed to go back together as it was supposed to and I had no leftover nuts or bolts when I was done (always a concern of mine). I closed the hood and prepared for the final step: starting the truck. Holding my breath, I cranked it over and it started perfectly. Sitting there in the drivers seat, I felt so proud of myself. This was the biggest job I have tried to do myself, and I had done it correctly . . . or so I thought. After about 30 seconds , the idle started to level out -- then did something I've never experienced before. The truck sputtered and died within about 3 seconds, leaving nothing but a strange whining (sounds sort of electrical). I turned the ignition off and waited a minute then engaged the ignition again without cranking. Same high pitched whine coming from somewhere directly in front of the drivers seat in the engine bay. At this point, and I'm not too proud to say this, I wanted to cry. So I did what anyone would do. I walked somberly into my house and told my girlfriend I f*cked my truck, then cracked a beer.

My plan now is to have the truck towed to the neighborhood mechanic to have someone who actually knows what they're doing figure out where I messed up and how they can fix it. I like working on my Tacoma, but sometimes I wonder what the hell I'm doing under the hood. Writing this post now for two reasons: 1) to get my sorrows on paper and out of my head and 2) to find out just how fudged the TW peanut gallery thinks I am.

So, if you're so inclined, feel free to take a guess as to where I went wrong and how much it's going to cost to get fixed. Closest guestimate to the actual mechanic bill wins a 6 pack from yours truly.

 

Ouch. Sorry to hear ya had a setback and seriously, I think we've all felt this way before... have faith man, it's all good.

 

I call DIBS on the frame

 

All vacuum hoses were put back in place correctly?

 

Could be anything. While I like doing stuff myself, sometimes you are better off going to a local mechanic. I have done a valve cover gasket on another car that worked well with no problems.

I didn't read the whole thing, but did you use a torque wrench?

Anyway, the real mechanic will probably be at least an hour. Hopefully no parts. I have had to do the same thing, and the mechanics will get a chuckle out of it, but they wont rub it in. It is how they make money after all.

 

Did you clean the idle control valve when you had it off? It’s possible to run gunk in there when you clean the throttle body if you don’t clean it separately. I would double check all vacuum lines are connected to the right spot. Someone with more knowledge and experience than me can chime in here, but what you described doesn’t sound to me like something wrong under the valve cover. I would recheck everything you took off to get to that point. It could be simple. If it ran fine before you did this, and you didn’t drop a tool in the valves, I would say to look at some diagrams or watch timmys video to ensure everything went back on correctly. I did mine a few months ago, so I can understand how frustrating it would be if something went wrong. I wouldn’t give up yet.

 

Also did you open the hood back up yet? There’s no oil blowing everywhere or anything right?

 

I would surprised if this is anything too serious. Go out tomorrow after your caffeine levels are fused in, and recheck everything. A buck says you sort it out. CEL on?

 

The 3.4 valve covers are a bastard, dont worry,

We actually found one leaking today on a 4runner, you kind of hope they decline the work on jobs like that.

 

My money is on the EVAP pump vacuum lines; you have one of the tiny lines disconnected they can kind of sit on or next to themselves and look hooked up but not be, there's also a tiny stir straw sized tube connecting some of it that can snap off flush and look fine but cause a vacuum leak.

As for the shut off the engine computer may have been used to accommodating for a small leak and with the new valve cover gaskets and such there is none so when it was adjusting the idle it went too low and stuttered.

I have a number of non-standard things on my truck and anytime I reset the battery it has to relearn it'll start up Rev really high and then flat out die have a little difficulty restarting and when it does it will have a high idle for about 5 minutes before it finally slowly creeps down and realizes it's okay. This is normal.

Something else I would try is disconnecting the battery for an hour, if you didn't already, if you did disconnect the battery while working (as you should) then that may be an explanation.

A valve cover job is pretty difficult to screw up, I wouldn't admit defeat quite yet nor would I take it to a mechanic and spend the money for the tow diag and work, I think you and TW can figure it out.

 

Thank you all for chiming in. After dinner went back out for another look and here are my updates:

Electrical whining noise is gone when key is turned. Now it just won't start. Best way to describe is that it's trying to fire but not catching. I've replaced a bad starter before and this sound is not that. It's more like the sound the engine makes when it's starting to start up but never does.

@eon_blue As far as I can tell, all hoses are where they are supposed to be. I'm going to take another solid run through tomorrow in the daylight to confirm.

@GreenYoda shamefully, no. I tightened to 'common sense' tightness. I know this was a mistake. In my defense, the valve cover bolts were so loose when I was removing -- I'm talking barely hand tight -- no wonder it was leaking.

@Davesbruh no visible oil blowing out. Didn't drop anything into the engine either. I did not clean the TB or IAC because I did that job a few months ago. That's actually what got me to finally do this one. After the TB/IAC cleaning, I have been running a high idle (1100RPM) so I figured doing the valve cover job might uncover that issue or at least eliminate potential sources, having replaced PCV and touched most hoses. Unfortunately, instead of potentially fixing the minor high idle, truck just doesn't run now -- which in a way means no high idle haha

@Key-Rei Good idea. I'll disconnect the battery tomorrow morning and try a computer reset. I had the battery disconnected while doing the job, and there was definitely something the computer had been compensating for prior as I was dealing with a high idle issue for a few months. As for those small lines (EVAP?) I was worried about forgetting those as I was going through the job, but I don't think I missed any when putting back together. I'll double check those in daylight tomorrow as well.

Here are two more points to consider: could it be the spark plugs? I had never gap checked a two prong style before today, although they all seemed to be factory set at the .043 that's suggested. I also didn't use any of the spark plug grease stuff that I bought when I got the plugs. Wasn't sure what it was for and to be totally honest, forgot I had it. Also, the coil pack came with three coils plus wires (drivers side). I had expected to replace the three on the passengers side as well but realized I didn't order those. Would the resuing of the old passenger side coils with the new drivers side coils and wires cause an issue?

Thanks all for the support. I'm feeling better now (beers helping too).

 

Another thing to check along the lines of vacuum leaks is check the bottom side of the plated elbows of the intake from the air filter box, they tend to crack out on the bottom and can stay more or less sealed until they're disturbed such as taking them off to perform maintenance.

But yeah my bet is on a simple vacuum leak.

Pictures will help.

And I totally relate to the tears and defeat.

Been there more than once with my truck.

 

Do you have the grounds hooked up to the intake plenum? Right above the front of the left valve cover. Probably not the issue since it started once but something to check. You sound better since your first post and were all pulling for ya, I highly doubt it’s something serious. Oh and in the future any time you work on a motor leave the hood open and fire it, let it warm up, flashlight around checking for leaks etc. good luck.

 

Uhhhh please don't tell me this. I literally just bought everything to do mine because a mechanic actually did a bad job and caused a leak.

However, I've been working on cars my whole life and it didn't look that hard. Now I'm wondering what you did wrong.

Did you use new gaskets? Is something not plugged back in correctly?

 

@SLAPS 65 the grounds are in place. I'll take a second look at those as well when I run through the whole deal tomorrow, just in case.

@Nessal if you have a lifetime of experience, you'll be fine. I am an amateur. I used new OEM parts from McGeorge Toyota. Aside from whatever I did wrong, the job wasn't all that hard, just time consuming. New parts were easy to install. My best advice is to group and label the bolts as you take them off. Once completely disassembled, there is a lot of hardware to keep track of. The more organized you can be, the less likely you'll have any issues.

 

Is there any chance the MAF connector is not making good contact,
Maybe but some dielectric grease on that connector and all the other wire connectors,
Coils, plugs, MAF, plug wires.

We have all been in your shoes before

 

If it ran and you didn't hear any horrible noises, my money is on an electrical connection. I'd go back and give every one a good squeeze and make sure they're fully connected. Seems like one could have been done partially and then popped out.

 

I trust you can figure it out if you were able to do the job. Good luck!

 

Sometimes these problems are as simple as an incorrect hose or connector and a simple fix

 

When I did the 4R, it was idling like crap. My brother in law (no mechanical prowess) was at my place the next day when I was starting to go over everything drinking a beer and said “is that hose supposed to be disconnected?”. Facepalm.