Javelin
Javelin MegaDork
3/26/13 11:47 a.m.

I've done dozens of head gaskets, but never a 4.0 Exploder. Any tricks or pretty straightforward?

Javelin
Javelin MegaDork
3/26/13 1:51 p.m.

Anyone?

Ranger50
Ranger50 PowerDork
3/26/13 2:00 p.m.

OHC or OHV?

Knurled
Knurled UltraDork
3/26/13 2:07 p.m.

OHC, we just put a reman engine in.

The head gasket procedure says that you must loosen/remove the main caps before loosening the head bolts, or you risk warping the block. We figure that if the head gaskets failed, and the block is apparently that scary-edge flimsy, we don't know that the block isn't what caused the gasket(s) to fail in the first place. It then becomes best practice to just replace the whole engine.

Plus, the labor is actually lower, since either way, you're pulling the engine out and stripping all tinwork off, but doing a reman engine means you're not pulling the heads...

Streetwiseguy
Streetwiseguy UltraDork
3/26/13 5:38 p.m.

Those motors are scary stupid, and you need a bunch of tools to time the cams. They tear up the timing chain cassettes, too. If you got a reman and it failed, I'd scream like a bitch until I got another motor.

ultraclyde
ultraclyde Dork
3/26/13 6:45 p.m.

Swap in a 302 from the same year. It will be easier than the gaskets and possibly cheaper.

curtis73
curtis73 UltraDork
3/29/13 12:39 a.m.

The timing chains are an absolute nightmare on those. They don't even have timing marks. I had one that I was careful with when I replaced the chain guides (which are also a nightmare and frequent failure point) and it was horrific. I ended up calling the dealer to see if there was some special tool and they basically told me I was berkeleyed.

psychic_mechanic
psychic_mechanic Dork
3/29/13 8:28 a.m.
curtis73 wrote: The timing chains are an absolute nightmare on those. They don't even have timing marks. I had one that I was careful with when I replaced the chain guides (which are also a nightmare and frequent failure point) and it was horrific. I ended up calling the dealer to see if there was some special tool and they basically told me I was berkeleyed.

Oh, there's a special tool kit for setting the timing. IIRC the set is a few thousand dollars.

If it's a newer reman I'd try the whining method mentioned above.

duetto_67
duetto_67 New Reader
3/29/13 8:48 a.m.

have done the timing chains on my 4.0 SOHC, i don't think it can be done with the engine in the car. The right side chain has a bolt that needs to be loosened/tightened that is covered by the bellhousing when in the car.

i made my own tool for timing the cams with some alum angle. there is a slot on the cam opposite the chain that has to be parallel with the valve cover surface. 2 pieces of 1" alum angle bolted together at the right distance makes a fine tool for holding the cam. Worked ok, no code.

HappyAndy
HappyAndy Dork
3/29/13 9:14 a.m.

As much as I like FoMoCo, I hate, no I mean HATE engine work on exploders. Andy's underground economy back ally auto repair service usually refuses to work on them...even for family members

Javelin
Javelin MegaDork
3/29/13 9:14 a.m.

Thanks everyone, I talked them into a replacement/reman engine swap instead. It's a really nice truck, so it looks worth fixing up.

ransom
ransom UltraDork
3/29/13 10:28 a.m.
duetto_67 wrote: The right side chain has a bolt that needs to be loosened/tightened that is covered by the bellhousing when in the car.

Cam chain related bolt? Covered by bellhousing?

Knurled
Knurled UltraDork
3/29/13 12:59 p.m.
ransom wrote: Cam chain related bolt? Covered by bellhousing?

All chain VWAG engines have the chain in the back. Makes packaging easier since they car get the accessories in closer to the engine, the hoodline can be lower (on longitudinal models), and the chain noise is lost in the bellhousing so they don't need 1/4" thick aluminum timing covers for NVH reasons, so the engine can be smaller and lighter.

Ford's 4.0 SOHC has the same head on both sides of the engine. Left bank has the chain in the front, right bank has the chain in the back.

ransom
ransom UltraDork
3/29/13 1:01 p.m.

In reply to Knurled:

Wow. I had no idea...

HappyJack
HappyJack Reader
3/29/13 4:40 p.m.

I got an 02 Exploder with the 4.0 in it. Runs fine, but now I'm scared.

Knurled
Knurled UltraDork
3/29/13 4:54 p.m.
HappyJack wrote: I got an 02 Exploder with the 4.0 in it. Runs fine, but now I'm scared.

Don't be. I've only ever seen two fail. If you keep up with the maintenance, they outlast the rest of the truck.

Just like just about everything else made in the last 20-30 years.

It's easy to remember the ones that fail, hard to remember the 99% that last a couple hundred thousand miles and then the body's too rotten to be worth putting $50 of fuel into it...

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