Burning smell and sizzling noise after turning car off

[kkg1280fl]

I've noticed for the last few months after I turn off my 91 Explorer that there's a burning oil smell so I took it in to a mechanic who told me there are "massive oil leaks". I had my mechanic friend check it over and he said there was nothing was leaking on the bottom. I used GUNK degreaser on Thursday and got rid of most of the build up around the engine and near the valve cover where I thought the leak was coming from and washed it off thoroughly. After driving it around the last two days, I've noticed the smell has been less noticeable.

Today after I got home from running around town, I popped the hood and noticed a sizzling noise and smoke coming from the spark plug area. I also noticed what looked like a little bit of oil between the spark plugs. Could there be oil leaking in that area? I replaced the spark plugs and wires in May 2012 and replaced the alternator in June 2012. The transmission was rebuilt in Feb 2012. That's all the work that's been done to the car since I've had it.

 

[wood1]

Leaky valve cover gasket. Very easy to replace.

Welcome to the site!

 

[kkg1280fl]

Ahh thank you! I thought so! Where exactly is the valve cover gasket located on a 91 Explorer?

 

[wood1]

They are under the valve covers. If you are just starting out doing things on your own get yourself a Chilton's or Hayne's manual. They describe in detail how to fix things, pics help as well.

If memory serves you have to pull the upper intake manifold to get to the driver's side valve cover.

Good luck

 

[R&T Babich]

...If memory serves you have to pull the upper intake manifold to get to the driver's side valve cover...

That explains it, I was wondering why the FelPro PermaDryPlus VS50368T valve cover set included an upper intake manifold gasket.
I have the same issue, but it's not real bad, yet.
I was thinking if I'm going that far might as well get the whole set, MS98005T, and replace the lower intake gasket, too.
Any thoughts on changing the rocker arms as well, the car has 102k?

 

[wood1]

Ah, it's not that much more work to do the LIM if you are doing the valve covers really. I left the LIM connected to the fuel lines (leave the fuel rail attached), just flipped it over to the driver's side upside down. Cleaned everything up and substituted RTV for the cork at the ends that seal the LIM to the block. Just have to make sure that you let the silicone cure up before you start the engine. Probably wouldn't cause any problems but doesn't hurt to leave it overnight. Your rockers making noise with 100K? I replaced mine when I did the heads at 320,000 kms.

 

[R&T Babich]

...Your rockers making noise with 100K?...

Thanks for the tip on changing the LIM.
The rockers aren't making any noise, I was just wondering.
Our parts '92 had 219k when it died and the rockers didn't make any noise.
The engine never needed any work so I'm not familiar with the 4.0L.
Most of my wrenching years ago was with 351Ws, 351Cs and 460s.
The PO of our new '92 took very good care of this car.
I change oil often so it may not have a problem with the rockers until it needs a valve job.

 

[wood1]

These 4.0L original heads are not worth doing a valve job to. The aftermarket replacement heads are a much better quality and are so cheap it just isn't worth rebuilding the factory ones.

If you don't have any noise, I would switch to synthetic and you may not ever have a problem.

Sorry for the hijackeness to the OP.

If you haven't done anything before, valve covers are a great first project. The passenger side one is a little of a PITA as the coil bracket bolts to the exhaust manifold and needs to come off. Don't be afraid to crank on that bolt. Even if it breaks off (shouldn't) it's not totally necessary. Just do one side at a time and if you get into problems ask for help.

Just do it.

 

[R&T Babich]

These 4.0L original heads are not worth doing a valve job to. The aftermarket replacement heads are a much better quality and are so cheap it just isn't worth rebuilding the factory ones...

I see King CylinderHeads sells new heads with springs & valves for $300 a head.
Is that reasonable and are there any other places?
Are there any rocker arms better than others?
Just collecting info for future reference.

 

[kkg1280fl]

Thanks for the tips!! No probs, Wood!!! I don't mind the hijack! lol The info is valuable. Now if I could find the valve covers, I'll be all set. I'm going to poke around in there this week on my days off. This should be interesting. I'm going to make a video if I can get someone to be my cameraman.

 

[wood1]

Cool, just didn't want you to feel left out in your own thread. That's how you learn, but do get a maintenance manual. Makes your life so much easier.

I bought heads from Clearwater? in FLA, I believe it was around 250ish fully dressed. Literally unwrap, clean the mating surfaces and bolt on.

 

[R&T Babich]

...
I bought heads from Clearwater? in FLA, I believe it was around 250ish fully dressed. Literally unwrap, clean the mating surfaces and bolt on.

Just talked to Tim at Clearwater Cylinder Head and they sell new heads w/springs & valves for $210 ea plus $30 shipping, 5 year warranty. They pay shipping to return your old head. He says the new castings are thicker where they normally crack on the factory head and the deck is thicker. Certainly not worth rebuilding the factory heads.

 

[wood1]

Yeah, you just can't beat that.

I replaced my rockers and push rods with Delta. There are a few guys that have had issues with them breaking but I have not had any problems. I cleaned up my lifters and reused them. I have zero noise now. My original rockers were worn a fair bit, when you unbolt one and look at where the push rod mates to it the wear is obvious.

 

[kkg1280fl]

Turns out the job was wayyyy too complicated for me AND my mechanic buddy to figure out. (too many hoses and stuff in the way) I got a quote from my local shop for $225 for both sides, parts and labor included. Can't beat that!