1984 FJ60 Intake/Exhaust Manifold Gasket (1 Viewer)

[Spears41]

I had the rear heater hose bust on me a few weeks back, and spray hot coolant all over the driver's side of the engine. The motor did not over heat.

Shortly after that I developed an exhaust leak that was getting pretty loud, so I decided to replace the gasket. I pulled everything off, put a new remflex gasket on, and torqued to 25 ftlbs as recommended on the remflex packaging. I then cranked her up, only to still have a persistent leak. Due to this, I took everything back down to expose the manifold and retorqued the bolts to about 35 ft lbs. When I reassembled and cranked this time, I had an intake leak. I grabbed my spray bottle and hit the manifold with water. As expected, it idled down every time I sprayed the underside of the manifold.

My best guess is that the manifold is warped some and needs to be milled. I've taken everything back off again and think my suspicion is confirmed. No cracks anywhere. I'm planning drop it off for milling on Monday, and going back to doubled Toyota OEM gaskets on the next attempt. Anybody have any other ideas, critiques or comments?

 

[tmxmotorsports]

Why 2 oem gaskets? I Did this job about a year ago for a customer had the manifolds resurfaced used one oem gasket with no leaks its back here for front axle service and still no leaks.
Tommy

 

[Spears41]

Why 2 oem gaskets? I Did this job about a year ago for a customer had the manifolds resurfaced used one oem gasket with no leaks its back here for front axle service and still no leaks.
Tommy

I've read a few folks say that two gaskets will help if there's still some difference/the manifold still isn't flush, but to your point, if I'm having it milled, shouldn't be an issue.

 

[John McVicker]

See if you can get a smoke test done.
Engine off, pump smoke up thru the tail pipe. The best way to determine where your leak is. Then you can address the issue instead of guessing.

 

[OSS]

If it gets machined properly, you'll get it back as flat as a sheet of glass. Two gaskets are unnecessary and won't accomplish anything on a flat manifold - except drain your wallet

 

[Spike Strip]

Check the flatness of the head-side of the mating surface - If good, only one gasket necessary.

Be aware, after milling, the surface of the Intake/Exhaust combo where the fasteners go may be unequal, so you'll either have to use cut washers or have the machinist do an additional step and 'Spot Face' the surfaces. It's important so the 'ears' of the difference sides get torqued down evenly and in extreme cases, can crack an ear.

(pic courtesy of @HemiAlex )

 

[HemiAlex]

That’s a lovely picture of my crack.

 

[Spears41]

Just to close the loop, I got the manifold milled and replaced with a single remflex gasket. I also replaced the EGR block off gasket since I'm desmogged and I had the manifold off. No more vacuum/exhaust leak and we're all happy now. Thank you guys for the help and advice.

 

[Paullus]

Congrats on making progress. I've just about got mine off. I can't get the exhaust pipe flange to drop off the exhaust manifold stud without removing the pipe from the bracket down below. That bolt is so rusted I'm having to saw through it. I found in the process that my main exhaust leak was from the j pipe that runs from exhaust manifold to the EGR cooler. It was loose and slid out of the EGR cooler fitting. I think I will desmog since all the air inject air bypass valve(s) are rusted and fubar too - pretty pricey reconditioned part.

 

[SteveH]

@Spears41 - recheck your bolt torque every couple of months. My FJ40 bolts worked loose at times (with a FelPro gasket) and it got so annoying that I used threadlocker on the bolts. Given the misery of replacing manifold gaskets, the effort of checking the torque is minimal.

 

[FirstFJ60]

question for you guys and gals. I did the spray test but my rpms increased instead of decrease. what does this mean

 

[Seth S]

question for you guys and gals. I did the spray test but my rpms increased instead of decrease. what does this mean

if you spray a flammable gas or liquid on a manifold and the rpm increases it usually means you have a crack, missing hose, or bad gasket and the stuff you are spraying is getting sucked into the intake manifold and burned as fuel.