Possible Head Gasket Leak

[99Venom]

I've noticed oil under the drivers side exhaust manifold near cylinders 6, 7, & 8. Nothing too crazy, but looks like a good steady leak. Everything above the manifold is bone dry, perfectly clean. I had the car at the dealer for an alignment recently so I asked them to take a look. They did an oil dye test with the UV light and confirmed it was coming from the head gasket. My question is, will a leakdown test give me any better information? I have not done a oil dye test before so I don't know how reliable they are. I would assume it all comes down to how good the UV light is and since I didn't see the results under the car, it's up to the tech's judgment.

I looked everywhere for other possible sources of a leak, but this oil is directly under the manifold, and the motor mount blocks pretty much anything else getting blown backwards onto the block. Just from a visual standpoint it would be hard to believe it's coming from anywhere else besides the head gasket.

 

[99Venom]

Ok, I'm changing the question. I have 2 options if the head gasket needs to be replaced, which one is best?

Replace the head gasket only, roughly $1300
Yank the motor and do a complete rebuild, roughly $3000

I just bought a house last year, and my second child was born in September, so if I fix the head gasket only, I'm effed if something else goes wrong in the next couple of years, like the passenger side head gasket for example.

A complete rebuild is better long term, but convincing my wife to dump 3 grand into a car worth 5 grand will not be easy. Car has 196k on it and the motor has 100k.

 

[01yellercobra]

Is this the forged motor in your sig?

 

[99Venom]

Yes, those components have 100k on them.

 

[Tabres]

I'd pull both heads, install two new head gaskets and call it a day.

Do the work yourself and you can be back in business for maybe $200 - $250.

 

[Parts-is-Parts]

Does it have head studs? You can try tightening them first.....bolts too.

 

[01yellercobra]

Can you handle putting the motor together yourself or would you have to take it a shop? If you can handle the motor work I would pull the motor apart and have it checked out. Even with 100K on it you might get lucky and not need an overbore and new pistons. Then you can have the heads and block checked to make sure everything is still square. New rings, bearings, and gaskets and you're back in business.

 

[99Venom]

Does it have head studs? You can try tightening them first.....bolts too.

Nope, no head studs, I wish I had done that from the first rebuild.

Can you handle putting the motor together yourself or would you have to take it a shop? If you can handle the motor work I would pull the motor apart and have it checked out. Even with 100K on it you might get lucky and not need an overbore and new pistons. Then you can have the heads and block checked to make sure everything is still square. New rings, bearings, and gaskets and you're back in business.

I still have the cherry picker and engine stand from the first rebuild, so this winter I could pull the motor. I've never rebuilt a 4.6, so I wouldn't feel comfortable tearing it apart myself, plus my time is so limited these days. I know I could pull the motor pretty quickly because I've done it before.

 

[01yellercobra]

It's not as difficult as most believe. There are more torque steps then the push rod motors. Just take your time and double check things. I built my big bore motor myself. I've done a few push rod motors, but this was my first mod motor. It has about 12k on it and hasn't blown up yet.

 

[BTSMUSTANG]

Sounds like the same thing thats going on with my 99 cobra w/137K on the motor.

Passenger side of the engine just below exhaust manifold oil is seaping out,

Are you burning oil? Mine has been smoking on and off for the past several months, smokes a little after high revs on the highway. I think the valve seals are leaking to but maybe its just the head gasket......my thinking if its seaping out on the outside, could be seaping into the combustion chamber too.

 

[Brutal Metal]

There's a guy in the Terminator section that has a way to fix head gaskets without pulling the heads, i've seen the thread pop up a few times in the last couple years, can't remember the details though sorry..

 

[swt99svt]

I'm in the same boat and in the middle of pulling my motor now. However, I have the stock rotating assembly with an Eaton swap. I'm almost ready to pull the motor... One last starter bolt (ya the top one) and the motor mounts and out she comes.

I can do one of two things: 1. replace the head gasket and drive it till it pops or 2. go with a rebuild now.

I've been picking up the rebuild parts so it can go either way... Guess I'll find out what I want to do once I pop the heads.