geomcnasty

Hello Guys,


I have been a tried and true small block Chevy guy my entire life. But when it comes to trucks I have a soft spot for FORD. I just recently bought a 1997 F150 Supercab 4X4 with a 4.6 in it. It is a fixer upper but ran strong and sounded good. So after working on it for the last few months off and on I put it on the road this week. I just did a lot of work. New cats and dual exhaust. New exhaust manifold studs. Rebuilt entire front end, hubs brakes tires,etc. etc.


So, on my way to work the other day and bam started missing at highway speed. CEL started flashing. Got to work and ran a scan. Multiple misfires cylinder 4 & 7. Checked coil packs and wires seemed OK. Pulled the plugs and Cylinder 4 plug gap was closed completely and fouled. Cylinder 7 plug looked good. So I put a new plug in Cylinder 4 and as soon as I started it up it started tapping and then quieted down. Still missed. So I decided to do a compression test. All Cylinders were around 140 lbs except cylinder 4 had ZERO compression. Did a wet test and still had ZERO. So I stuck a inspection camera down into the plug hole and there is something in there blocking 1/2 the hole. I can see the piston and it looks good but cant see what the hell is in there. Pulled valve cover and everything looks OK. Valves are moving springs look good. I tried to pressurize the cylinder but its leaking out. How do I make sure I am at top dead center for that cylinder. Seems its either a piece of head gasket? A Piece of Valve? or Carbon? Never saw anything like this. If I need to swap out the heads do you guys recommend any company in particular? I saw CHI has a set shipped for 600 with return shipping for the cores. Any suggestions?


Thanks
Sorry for the long post.


Geo

Krack499

iTrader: (1)

If you need a head swap just swap to some pi (power improved) heads from I think the 99 + 4.6

jprevat

iTrader: (1)

So were you able to get the foreign object out?

geomcnasty

No I cant get it out. The heads are coming off today. We shall see what is wrong. For sure.

Cmanjr

I subscribed to this thread because I'm curious of your outcome. Best of luck. And yes if you do swap out heads, get some pi heads from a 99-03 4.6

geomcnasty

Any suggestions as to what else should be replaced while its torn apart? I'm guessing timing chains, water pump maybe fuel injectors just because. I did notice 4 things that concerned me after pulling the intake off. There is a sensor in the driver side head under the intake manifold. There is a metal pipe that connects the water pump to the heater core there is that flapper thing in the lower intake anD there is a sensor that is in the center of the block. All need the intake off to be changed. Should I at least swap the electrical stuff out while I'm at it? Not sure about the pipe connected to the back of the water pump. I did hear a drip and sizzle every time I would shut off the engine. I know it was coolant but couldn't find it.

Suggestions? Thanks in advance guys.

Geo

jstockert

I would replace knock sensor, located in the center of the top of block under manifold.
The hct-head coolant temp sensor, its located under the intake manifold on the front driver side. It can be replaced without removing the intake but for 20.00 i did mine with intake off.
Also inspect the heater hose tube which connects to the back of water pump housing. It will have a 3" heater hose crimped to a tube which runs to the back pass side of motor and connects to a heater hose.

geomcnasty

My heater hose tube is a pipe. It connects to the back of the water pump then straight under the plenum and out the back. It seems ok. But like I said before not sure where that sizzle was coming from when I would shut down the engine. Every post I read about that says its a hose but mine is a steel pipe. Was this a factory thing or was this added afterwards.

geomcnasty

Also what is that round electrical thing in the front of the lower intake called? IMRC? Mine has 2 screws holding it in. I removed it and there is a small flap on the back that looks like it opens and closes to allow air to flow through the lower intake? What is that called.

jstockert

The heater hose tube does not connect to the back of the water pump. It connects to the housing of the block. Like I said mine is a hose that crimps to the tube.
I dont know what it is called.